Enkosi ngokundwendwela i-Nature.com.Usebenzisa uguqulelo lwebrawuza enenkxaso enyiniweyo yeCSS.Ngowona mava angcono, sicebisa ukuba usebenzise isikhangeli esihlaziyiweyo (okanye uvale iModi yokuThelela kwi-Internet Explorer).Okwangoku, ukuqinisekisa inkxaso eqhubekayo, siya kunika isayithi ngaphandle kwezitayela kunye neJavaScript.
Ubonisa ikharawusi yezilayidi ezithathu ngaxeshanye.Sebenzisa amaqhosha angaphambili nalandelayo ukutyhutyha izilayidi ezithathu ngexesha, okanye sebenzisa amaqhosha esilayidi ekupheleni ukuya kwizilayidi ezithathu ngexesha.
Ukuphuhliswa ngokukhawuleza kwe-nanotechnology kunye nokudibanisa kwayo kwizicelo zemihla ngemihla kunokusongela indalo.Ngelixa iindlela eziluhlaza zokonakaliswa kongcoliseko lwe-organic zisekwe kakuhle, ukubuyiswa kongcoliseko lwe-inorganic crystalline yeyona nto ixhalabisayo ngenxa yobuntununtunu obusezantsi kwi-biotransformation kunye nokungaqondi ukusebenzisana komphezulu wezinto kunye nezo zebhayoloji.Apha, sisebenzisa i-Nb-based based inorganic 2D MXenes imodeli edityaniswe nendlela yokuhlalutya iparameter yemilo elula ukulandelela indlela ye-bioremediation ye-2D ye-ceramic nanomaterials yi-microalgae eluhlaza i-Raphidocelis subcapitata.Sifumene ukuba i-microalgae ithoba i-Nb-based MXenes ngenxa yentsebenziswano enxulumene nomphezulu we-physico-chemical interactions.Ekuqaleni, i-MXene-layer kunye ne-multilayer nanoflakes ye-MXene yancanyathiselwa kumphezulu we-microalgae, eyanciphisa ukukhula kwe-algae.Nangona kunjalo, ekusebenzisaneni ixesha elide nomphezulu, i-microalgae oxidized MXene nanoflakes kwaye yaphinda yabola kwi-NbO kunye ne-Nb2O5.Ngenxa yokuba ezi oksidi zingenatyhefu kwiiseli ze-microalgae, zisebenzisa i-Nb oxide nanoparticles ngendlela yokufunxa ebuyisela ngakumbi i-microalgae emva kweeyure ezingama-72 zokunyanga kwamanzi.Imiphumo yezondlo ezihambelana nokufunxa nazo zibonakaliswe ekunyuseni umthamo weseli, ukumila kwazo okugudileyo kunye nokutshintsha kwezinga lokukhula.Ngokusekelwe kwezi ziphumo, sigqiba ekubeni ubukho bexesha elifutshane kunye nexesha elide le-MXenes esekelwe kwi-Nb kwi-ecosystems yamanzi ahlaziyekileyo kunokubangela iimpembelelo ezincinci zokusingqongileyo.Kuyaphawuleka ukuba, sisebenzisa ama-nanomaterials amabini njengeenkqubo zemodeli, sibonisa ukuba kunokwenzeka ukulandelela ukuguqulwa kwemilo nakwizinto ezicolekileyo.Ngokubanzi, olu pho nonongo luphendula umbuzo obalulekileyo obalulekileyo malunga neenkqubo ezinxulumene nokunxibelelana komphezulu oqhuba inkqubo ye-bioremediation ye-2D nanomaterials kwaye ibonelela ngesiseko sokuqhubela phambili kwexesha elifutshane kunye nezifundo zexesha elide zempembelelo yokusingqongileyo ye-inorganic crystalline nanomaterials.
I-Nanomaterials yenze umdla omkhulu ukusukela oko yafunyanwa, kwaye ii-nanotechnologies ezahlukeneyo zisandula ukungena kwisigaba sokuphucula i-1.Ngelishwa, ukuhlanganiswa kwama-nanomaterials kwizicelo zemihla ngemihla kunokukhokelela ekukhutshweni ngengozi ngenxa yokuchithwa okungafanelekanga, ukuphatha ngokungakhathali, okanye iziseko zokhuseleko ezinganeleyo.Ngoko ke, kunengqiqo ukucinga ukuba i-nanomaterials, kubandakanywa ne-nanomaterials ezimbini-dimensional (2D), inokukhutshwa kwindawo yendalo, ukuziphatha kunye nomsebenzi we-biological ongekaqondwa ngokupheleleyo.Ngoko ke, akumangalisi ukuba inkxalabo ye-ecotoxicity igxininise kwikhono le-2D nanomaterials ukungena kwiinkqubo zamanzi2,3,4,5,6.Kwezi zinto eziphilayo, ezinye i-nanomaterials ze-2D zinokusebenzisana nezinto ezahlukeneyo eziphilayo kumanqanaba ahlukeneyo etrophic, kubandakanywa ne-microalgae.
I-Microalgae zizidalwa zamandulo ezifumaneka ngokwemvelo emanzini ahlaziyekileyo kunye ne-ecosystems yaselwandle evelisa iindidi ngeendidi zeemveliso zemichiza nge-photosynthesis7.Ngaloo ndlela, zibalulekile kwi-ecosystems yasemanzini8,9,10,11,12 kodwa zikwanovakalelo, azibizi kwaye zisetyenziswa ngokubanzi izikhombisi ze-ecotoxicity13,14.Ekubeni iiseli ze-microalgae ziphindaphinda ngokukhawuleza kwaye ziphendule ngokukhawuleza ubukho bezinto ezahlukeneyo, zithembisa ukuphuhliswa kweendlela zokusingqongileyo zokunyanga amanzi angcolileyo ngezinto eziphilayo15,16.
Iiseli ze-algae zinokususa i-ion ze-inorganic emanzini ngokusebenzisa i-biosorption kunye ne-accumulation17,18.Ezinye iintlobo ze-algal ezifana ne-Chlorella, i-Anabaena invar, i-Westiellopsis prolifica, i-Stigeoclonium tenue kunye ne-Synechococcus sp.Ifunyaniswe ukuba ithwala kwaye yondle iiyoni zesinyithi ezinetyhefu ezifana ne-Fe2+, Cu2+, Zn2+ kunye ne-Mn2+19.Olunye uphando lubonise ukuba i-Cu2+, i-Cd2+, i-Ni2+, i-Zn2+ okanye i-Pb2+ i-ion iyanciphisa ukukhula kwe-Scenedesmus ngokuguqula i-cell morphology kunye nokutshabalalisa i-chloroplasts20,21 yabo.
Iindlela eziluhlaza zokubola kwezinto ezingcolisa indalo kunye nokususwa kwee-ion zentsimbi enzima ziye zatsala ingqalelo yezazinzulu kunye neenjineli kwihlabathi liphela.Oku kubangelwa ikakhulu kukuba ezi zingcolisi zicutshungulwa ngokulula kwisigaba solwelo.Nangona kunjalo, ukungcola kwe-crystalline ye-inorganic kubonakaliswe ukunyibilika kwamanzi aphantsi kunye nokuchaphazeleka okuphantsi kwezinto ezahlukeneyo ze-biotransformations, ezibangela ubunzima obukhulu ekulungiseni, kunye nenkqubela encinci yenziwe kule ndawo22,23,24,25,26.Ngaloo ndlela, ukukhangela izisombululo zokusingqongileyo zokulungiswa kwama-nanomaterials kuhlala kuyinkimbinkimbi kunye nommandla ongahlolisiswanga.Ngenxa yezinga eliphezulu lokungaqiniseki malunga nemiphumo ye-biotransformation ye-2D nanomaterials, akukho ndlela elula yokufumana iindlela ezinokwenzeka zokuthotywa kwazo ngexesha lokunciphisa.
Kolu phononongo, sisebenzise i-microalgae eluhlaza njenge-agent esebenzayo ye-aqueous bioremediation ye-inorganic ceramic materials, idityaniswe ne-situ esweni inkqubo yokuthotywa kwe-MXene njengommeli we-inorganic ceramic materials.Igama elithi "MXene" libonisa i-stoichiometry yezinto eziphathekayo ze-Mn + 1XnTx, apho i-M yintsimbi yokuqala yokuguquka, i-X yikhabhoni kunye / okanye i-nitrogen, i-Tx yi-terminator yomhlaba (umz, -OH, -F, -Cl), kunye n = 1, 2, 3 okanye 427.28.Ukususela ekufumaneni i-MXenes nguNaguib et al.I-Sensorics, unyango lomhlaza kunye ne-membrane filtration 27,29,30.Ukongeza, i-MXenes inokuthathwa njengenkqubo ye-2D yemodeli ngenxa yozinzo oluhle kakhulu lwe-colloidal kunye nokusebenzisana okunokwenzeka kwezinto eziphilayo31,32,33,34,35,36.
Ngoko ke, indlela ephuhliswe kweli nqaku kunye neengcamango zethu zophando ziboniswe kuMzobo 1. Ngokwale ngcamango, i-microalgae ithobisa i-Nb-based MXenes kwi-non-toxic compounds ngenxa yokusebenzisana kwe-surface-related physico-chemical interactions, evumela ukubuyiswa ngakumbi kwe-algae.Ukuvavanya le ngcamango, amalungu amabini entsapho ye-niobium-based transition metal carbides kunye / okanye i-nitrides (MXenes), okuyi-Nb2CTx kunye ne-Nb4C3TX, yakhethwa.
Indlela yophando kunye neengcamango ezisekelwe kubungqina bokubuyiselwa kwe-MXene nge-microalgae eluhlaza i-Raphidocelis subcapitata.Nceda uqaphele ukuba olu luyilo nje lokumelwa kweengqikelelo ezisekelwe kubungqina.Imeko-bume yechibi iyahluka kwindlela yezondlo ezisetyenziswayo kunye neemeko (umzekelo, umjikelo wemini kunye nezithintelo kwizondlo ezibalulekileyo ezikhoyo).Yenziwe ngeBioRender.com.
Ngoko ke, ngokusebenzisa i-MXene njengenkqubo yemodeli, siye savula umnyango wokufunda ngemiphumo eyahlukeneyo yezinto eziphilayo ezingenakubonwa kunye nezinye i-nanomaterials eziqhelekileyo.Ngokukodwa, sibonisa ukuba kunokwenzeka ukuba i-bioremediation ye-nanomaterials ezimbini-dimensional, ezifana ne-niobium-based MXenes, nge-microalgae Raphidocelis subcapitata.I-Microalgae iyakwazi ukuthobisa i-Nb-MXenes kwi-non-toxic oxides i-NbO kunye ne-Nb2O5, ekwabonelela ngezondlo ngokusebenzisa i-niobium uptake mechanism.Ngokubanzi, olu phononongo luphendula umbuzo obalulekileyo obalulekileyo malunga neenkqubo ezinxulumene nokusebenzisana komphezulu we-physicochemical olawula iindlela ze-bioremediation ze-nanomaterials ezimbini-dimensional.Ukongeza, siphuhlisa indlela elula-esekwe kwiparamitha yokulandelela utshintsho olufihlakeleyo kwimilo ye-nanomaterials ye-2D.Oku kukhuthaza uphando olongezelelekileyo lwexesha elifutshane kunye nexesha elide kwiimpembelelo ezahlukeneyo zokusingqongileyo ze-inorganic crystalline nanomaterials.Ke, isifundo sethu sonyusa ukuqonda konxibelelwano phakathi komphezulu wezinto kunye nezinto eziphilayo.Sikwabonelela ngesiseko sophononongo olwandisiweyo lwexesha elifutshane kunye nexesha elide malunga neempembelelo zabo ezinokuthi zibe khona kwi-ikhosistim yamanzi ahlaziyekileyo, ngoku enokuqinisekiswa lula.
I-MXenes imele iklasi enomdla yezinto eziphathekayo kunye neempawu ezikhethekileyo kunye ezikhangayo zomzimba kunye neekhemikhali kwaye ngoko ke ezininzi izicelo ezinokubakho.Ezi zakhiwo zixhomekeke kakhulu kwi-stoichiometry yazo kunye ne-surface chemistry.Ngoko ke, kwisifundo sethu, siye saphanda iindidi ezimbini ze-Nb-based hierarchical single-layer (SL) MXenes, Nb2CTx kunye ne-Nb4C3TX, ekubeni imiphumo eyahlukeneyo ye-biological yala ma-nanomaterials ingabonwa.I-MXenes iveliswa kwizinto zabo zokuqalisa ngokucofa okuphezulu-phantsi okukhethiweyo kwe-atomically encinci ye-MAX-isigaba A-amaleyi.Isigaba se-MAX yi-ternary ceramic eyenziwe ngeebhloko "ezibophekileyo" ze-transition metal carbides kunye neengqimba ezibhityileyo ze "A" ezifana ne-Al, Si, kunye ne-Sn kunye ne-MnAXn-1 stoichiometry.I-morphology yesigaba sokuqala se-MAX yabonwa ngokuskena i-electron microscopy (SEM) kwaye yayihambelana nezifundo zangaphambili (Jonga ulwazi oloNgezelelweyo, SI, uMfanekiso S1).I-Multilayer (ML) i-Nb-MXene ifunyenwe emva kokususa i-Al layer kunye ne-48% ye-HF (i-hydrofluoric acid).I-morphology ye-ML-Nb2CTx kunye ne-ML-Nb4C3TX yavavanywa ngokuskena i-electron microscopy (SEM) (Amanani e-S1c kunye ne-S1d ngokulandelanayo) kunye ne-MXene morphology enemigangatho eqhelekileyo yabonwa, efana ne-nanoflakes ene-dimensional-dimensional edlula kwi-slits emide efana ne-pore.Zombini i-Nb-MXenes inezinto ezininzi ezifanayo kunye nezigaba ze-MXene ezenziwe ngaphambili nge-acid etching27,38.Emva kokuqinisekisa isakhiwo se-MXene, sayibeka ngokudibanisa i-tetrabutylammonium hydroxide (TBAOH) elandelwa ngokuhlamba kunye ne-sonication, emva koko sifumene i-single-layer okanye i-low-layer (SL) 2D Nb-MXene nanoflakes.
Sisebenzise i-electron microscopy (HRTEM) kunye ne-X-ray diffraction (XRD) ukuvavanya ukusebenza kakuhle kwe-etching kunye nokuxobula ngakumbi.Iziphumo ze-HRTEM zicutshungulwe kusetyenziswa i-Inverse Fast Fourier Transform (IFFT) kunye ne-Fast Fourier Transform (FFT) ziboniswe kwi-Fig.Imifanekiso ye-HRTEM ye-MXene Nb2CTx kunye ne-Nb4C3TX i-nanoflakes ibonakalise i-atomically thin layered nature (jonga i-Fig. 2a1, a2), njengoko kuchazwe ngaphambili nguNaguib et al.27 kunye noJastrzębska et al.38.Kwii-monolayers ezimbini ezikufutshane ne-Nb2CTx kunye ne-Nb4C3Tx, sinqume imigama ye-interlayer ye-0.74 kunye ne-1.54 nm, ngokulandelanayo (Imifanekiso 2b1, b2), ekwavumelana neziphumo zethu zangaphambili38.Oku kwaqinisekiswa ngakumbi yinguqu ekhawulezayo yeFourier eguqukileyo (Umfanekiso 2c1, c2) kunye noguqulo olukhawulezayo lweFourier (Umfanekiso 2d1, d2) obonisa umgama phakathi kwe-Nb2CTx kunye ne-Nb4C3Tx ye-monolayers.Umfanekiso ubonisa ukutshintshwa kweebhanti ezikhanyayo kunye nezimnyama ezihambelana ne-niobium kunye ne-athomu ye-carbon, eqinisekisa ubume be-MXenes efundwayo.Kubalulekile ukuqaphela ukuba amandla e-dispersive X-ray spectroscopy (EDX) afunyenwe kwi-Nb2CTx kunye ne-Nb4C3Tx (Amanani S2a kunye ne-S2b) abonisa ukuba akukho ntsalela yesigaba sokuqala se-MAX, ekubeni akukho Al peak yafunyanwa.
Uphawu lwe-SL Nb2CTx kunye ne-Nb4C3Tx MXene nanoflakes, kubandakanywa (a) isisombululo esiphezulu se-electron microscopy (HRTEM) i-side-view ye-2D nanoflake imaging kunye ehambelanayo, (b) intensity mode, (c) inverse fast Fourier transform (IFFT), (d) fast Fourier transform (FFT-), (e) iipatheni ze-Xb ze-Xb.Kwi-SL 2D Nb2CTx, amanani achazwa njenge (a1, b1, c1, d1, e1).Kwi-SL 2D Nb4C3Tx, amanani achazwa njenge (a2, b2, c2, d2, e1).
Imilinganiselo ye-X-ray ye-diffraction ye-SL Nb2CTx kunye ne-Nb4C3Tx MXenes iboniswe kwiMifanekiso.2e1 kunye ne-e2, ngokulandelanayo.I-Peaks (002) kwi-4.31 kunye ne-4.32 ihambelana ne-MXenes Nb2CTx echazwe ngaphambili kunye ne-Nb4C3TX38,39,40,41 ngokulandelanayo.Iziphumo ze-XRD zikwabonisa ubukho bezinye izakhiwo ze-ML ezishiyekileyo kunye nezigaba ze-MAX, kodwa ubukhulu becala iipatheni ze-XRD ezinxulumene ne-SL Nb4C3Tx (Fig. 2e2).Ubukho bamasuntswana amancinci enqanaba le-MAX bunokuchaza eyona ncopho ye-MAX eyomeleleyo xa ithelekiswa neengqimba ezipakishwe ngokungakhethiyo ze-Nb4C3Tx.
Uphando olongezelelweyo lujolise kwi-microalgae eluhlaza yohlobo lwe-R. subcapitata.Sakhetha i-microalgae kuba ingabavelisi ababalulekileyo ababandakanyekayo kwi-webs yokutya enkulu42.Zikwazezinye zezona zalathisi zetyhefu ngenxa yokukwazi ukususa izinto eziyityhefu ezithwalwa kumanqanaba aphezulu ekhonkco lokutya43.Ukongeza, uphando kwi-R. subcapitata lunokukhanyisa kwi-toxicity engalindelekanga ye-SL Nb-MXenes kwii-microorganisms zamanzi eziqhelekileyo.Ukubonisa oku, abaphandi baqikelela ukuba intsholongwane nganye inovakalelo olwahlukileyo kwiikhompawundi eziyityhefu ezikhoyo kwimekobume.Kwizinto ezininzi eziphilayo, ukugxila okuphantsi kwezinto akuchaphazeli ukukhula kwazo, ngelixa ukugxila okungaphezulu komda othile kunokukuthintela okanye kubangele ukufa.Ke ngoko, kwizifundo zethu zokusebenzisana komphezulu phakathi kwe-microalgae kunye ne-MXenes kunye nokubuyiswa okuhambelanayo, sagqiba ekubeni sivavanye i-Nb-MXenes engenabungozi kunye netyhefu.Ukwenza oku, sivavanye ukugxilwa kwe-0 (njengesalathiso), i-0.01, i-0.1 kunye ne-10 mg l-1 MXene kunye ne-microalgae eyosulelekileyo ene-concentrations ephezulu kakhulu ye-MXene (100 mg l-1 MXene), enokuthi ibe yinto egqithiseleyo kwaye ibulale..kuyo nayiphi na imeko yebhayoloji.
Imiphumo ye-SL Nb-MXenes kwi-microalgae iboniswe kwi-Figure 3, echazwe njengepesenti yokunyuswa kokukhula (+) okanye inhibition (-) ilinganiswe kwiisampuli ze-0 mg l-1.Ukuthelekisa, isigaba se-Nb-MAX kunye ne-ML Nb-MXenes nazo zavavanywa kwaye iziphumo ziboniswa kwi-SI (jonga umfanekiso we-S3).Iziphumo ezifunyenweyo ziqinisekisile ukuba i-SL Nb-MXenes iphantse ingabikho ubuthi kuluhlu oluphantsi lwe-0.01 ukuya kwi-10 mg / l, njengoko kuboniswe kwi-Fig. 3a, b.Kwimeko ye-Nb2CTx, asibonanga ngaphezulu kwe-5% ye-ecotoxicity kuluhlu oluchaziweyo.
Ukuvuselela (+) okanye ukuvinjelwa (-) kokukhula kwe-microalgae phambi kobukho be-SL (a) Nb2CTx kunye (b) Nb4C3TX MXene.I-24, i-48 kunye ne-72 iiyure zokusebenzisana kwe-MXene-microalgae zahlaziywa. Idatha ebalulekileyo (t-test, p <0.05) yaphawulwa ngeenkwenkwezi (*). Idatha ebalulekileyo (t-test, p <0.05) yaphawulwa ngeenkwenkwezi (*). Значимые данные (t-критерий, p < 0,05) отмечены звездочкой (*). Idatha ebalulekileyo (t-test, p <0.05) imakishwe ngeenkwenkwezi (*).重要数据（t 检验，p <0.05）用星号(*) 标记。重要数据（t 检验，p <0.05）用星号(*) 标记。 Важные данные (t-test, p < 0,05) отмечены звездочкой (*). Idatha ebalulekileyo (t-test, p <0.05) imakishwe ngeenkwenkwezi (*).Iintolo ezibomvu zibonisa ukupheliswa kovuselelo lwe-inhibitory.
Ngakolunye uhlangothi, ugxininiso oluphantsi lwe-Nb4C3TX luye lwaba yityhefu ngakumbi, kodwa alukho ngaphezu kwe-7%.Njengoko bekulindelekile, siye sabona ukuba i-MXenes inetyhefu ephezulu kunye ne-microalgae inhibition ukukhula kwi-100mg L-1.Okubangel 'umdla kukuba, akukho nanye yezinto ezibonisa indlela efanayo kunye nokuxhomekeka kwexesha kwimiphumo enetyhefu / enetyhefu xa kuthelekiswa neesampuli ze-MAX okanye ze-ML (jonga i-SI ngeenkcukacha).Ngelixa kwisigaba se-MAX (jonga i-Fig. S3) ubuthi bufikelele malunga ne-15-25% kwaye yanda ngexesha, i-reverse trend yabonwa kwi-SL Nb2CTx kunye ne-Nb4C3TX MXene.Ukuthintelwa kokukhula kwe-microalgae kwehlile ngokuhamba kwexesha.Ifikelele malunga ne-17% emva kweeyure ze-24 kwaye yehla ukuya ngaphantsi kwe-5% emva kweeyure ze-72 (umzobo 3a, b, ngokulandelanayo).
Okubaluleke ngakumbi, kwi-SL Nb4C3TX, inhibition yokukhula kwe-microalgae yafikelela malunga ne-27% emva kweeyure ze-24, kodwa emva kweeyure ze-72 zehla malunga ne-1%.Ngoko ke, sibhale umphumo ojongiweyo njenge-inverse inhibition of stimulation, kwaye umphumo wawunamandla kwi-SL Nb4C3TX MXene.Ukukhuthazwa kokukhula kwe-microalgae kwaphawulwa ngaphambili kunye ne-Nb4C3TX (intsebenziswano kwi-10 mg L-1 ye-24 h) xa kuthelekiswa ne-SL Nb2CTx MXene.I-inhibition-stimulation reversal effect nayo ibonakaliswe kakuhle kwi-biomass yokuphindaphinda i-curve (jonga i-Fig. S4 ngeenkcukacha).Ukuza kuthi ga ngoku, kuphela i-ecotoxicity ye-Ti3C2TX MXene efundwe ngeendlela ezahlukeneyo.Ayiyotyhefu kwi-zebrafish embryos44 kodwa iphakathi kwi-ecotoxic kwi-microalgae iDesmodesmus quadricauda kunye nezityalo zeSorghum saccharatum45.Eminye imizekelo yeempembelelo ezithile ibandakanya ubuthi obuphezulu kwimigca yeeseli zomhlaza kunemizila yeeseli eziqhelekileyo46,47.Kungacingelwa ukuba iimeko zovavanyo ziya kuba nefuthe ekutshintsheni ukukhula kwe-microalgae ebonwe phambi kwe-Nb-MXenes.Ngokomzekelo, i-pH malunga ne-8 kwi-chloroplast stroma ilungile ekusebenzeni ngokufanelekileyo kwe-enzyme ye-RuBisCO.Ngoko ke, utshintsho lwe-pH luchaphazela kakubi izinga le-photosynthesis48,49.Nangona kunjalo, asizange sibone utshintsho oluphawulekayo kwi-pH ngexesha lovavanyo (jonga i-SI, i-Fig. S5 ngeenkcukacha).Ngokuqhelekileyo, iinkcubeko ze-microalgae kunye ne-Nb-MXenes zinciphisa kancinci i-pH yesisombululo ngokuhamba kwexesha.Nangona kunjalo, oku kuncipha kwakufana nokutshintsha kwe-pH ye-medium ecocekileyo.Ukongezelela, uluhlu lweenguqu ezifunyenweyo zifana nokulinganisa inkcubeko ecocekileyo ye-microalgae (isampuli yokulawula).Ngaloo ndlela, sigqiba ekubeni i-photosynthesis ayichatshazelwa lutshintsho kwi-pH ekuhambeni kwexesha.
Ukongeza, i-MXenes edibeneyo ineziphelo zomhlaba (ezichazwe njenge-Tx).Ezi ikakhulu ngamaqela asebenzayo -O, -F kunye -OH.Nangona kunjalo, ikhemistri yomphezulu inxulumene ngokuthe ngqo nendlela yokudibanisa.La maqela ayaziwa ukuba asasazwa ngokungaqhelekanga phezu komhlaba, okwenza kube nzima ukuqikelela umphumo wabo kwiipropati ze-MXene50.Kungaxoxwa ukuba i-Tx ingaba amandla okwenza i-oxidation ye-niobium ngokukhanya.Amaqela asebenza kumphezulu ngokwenene abonelela ngeendawo ezininzi zokubambelela kwiifotocatalysts zazo ezisezantsi ukuze zenze i-heterojunctions51.Nangona kunjalo, ukubunjwa okuphakathi kokukhula akuzange kunikeze i-photocatalyst esebenzayo (i-detailed medium composition ingafumaneka kwi-SI Table S6).Ukongezelela, naluphi na ukuguqulwa kwendawo kubaluleke kakhulu, njengoko umsebenzi we-biological we-MXenes unokutshintshwa ngenxa yoluhlu lwe-post-processing, i-oxidation, ukuguqulwa kwendawo yeekhemikhali ye-organic and inorganic compounds52,53,54,55,56 okanye i-surface charge engineering38.Ngoko ke, ukuvavanya ukuba i-niobium oxide inento yokwenza nokungazinzi kwezinto eziphakathi, senze izifundo ze-zeta (ζ) ezinokubakho kwi-microalgae yokukhula okuphakathi kunye namanzi adibeneyo (ukuthelekisa).Iziphumo zethu zibonisa ukuba i-SL Nb-MXenes izinzile ngokufanelekileyo (jonga i-SI Fig. S6 ye-MAX kunye neziphumo zeML).Ikhono le-zeta le-SL MXenes limalunga -10 mV.Kwimeko ye-SR Nb2CTx, ixabiso le-ζ lithe libi kakhulu kunelo le-Nb4C3Tx.Utshintsho olunjalo kwixabiso ζ lunokubonisa ukuba umphezulu we-MXene nanoflakes ochajiwe kakubi ufunxa iiyoni ezichajiwe kakuhle ukusuka kwisiphakathi senkcubeko.Imilinganiselo yesikhashana ye-zeta enokwenzeka kunye ne-conductivity ye-Nb-MXenes kwinkcubeko yenkcubeko (jonga iMifanekiso ye-S7 kunye ne-S8 kwi-SI ngeenkcukacha ezingaphezulu) ibonakala ixhasa i-hypothesis yethu.
Nangona kunjalo, zombini i-Nb-MXene SLs ibonise utshintsho oluncinci ukusuka kwi-zero.Oku kubonisa ngokucacileyo ukuzinza kwabo kwi-microalgae yokukhula.Ukongezelela, siye savavanya ukuba ubukho be-microalgae yethu eluhlaza buya kuchaphazela ukuzinza kwe-Nb-MXenes phakathi.Iziphumo ze-zeta ezinokwenzeka kunye ne-conductivity ye-MXenes emva kokusebenzisana ne-microalgae kwimidiya yezondlo kunye nenkcubeko ngexesha elide inokufumaneka kwi-SI (Amanani S9 kunye ne-S10).Okubangel 'umdla kukuba, siqaphele ukuba ubukho be-microalgae bubonakala buzinzisa ukusasazeka kwe-MXenes zombini.Kwimeko ye-Nb2CTx SL, amandla e-zeta ancipha kancinci ekuhambeni kwexesha ukuya kumaxabiso angalunganga (-15.8 ngokuchasene -19.1 mV emva kwe-72 h yokufukanyelwa).Ikhono le-zeta le-SL Nb4C3TX liye landa kancane, kodwa emva kwe-72 h isabonisa ukuzinza okuphezulu kune-nanoflakes ngaphandle kobukho be-microalgae (-18.1 vs. -9.1 mV).
Kwakhona sifumene i-conductivity ephantsi yezisombululo ze-Nb-MXene ezifakwe phambi kwe-microalgae, ebonisa inani eliphantsi le-ion kwi-nutrient medium.Ngokucacileyo, ukungazinzi kwee-MXenes emanzini kubangelwa ikakhulu yi-oxidation yomphezulu57.Ngoko ke, sikrokrela ukuba i-microalgae eluhlaza ngandlela-thile yasusa i-oxides eyenziwe phezu kwe-Nb-MXene kwaye yaze yathintela ukwenzeka kwabo (i-oxidation ye-MXene).Oku kunokubonwa ngokuphonononga iintlobo zezinto ezifunxwa yi-microalgae.
Nangona izifundo zethu ze-ecotoxicological zibonise ukuba i-microalgae ikwazi ukunqoba ubuthi be-Nb-MXenes ngokuhamba kwexesha kunye nokuvinjelwa okungaqhelekanga kokukhula okukhuthazwayo, injongo yophando lwethu yayikukuphanda iindlela ezinokwenzeka zokwenza.Xa izinto eziphilayo ezifana ne-algae zibonakaliswe kwiikhompawundi okanye izinto ezingaqhelekanga kwi-ecosystems yazo, zinokusabela ngeendlela ezahlukeneyo58,59.Ukungabikho kweeoksidi zetsimbi ezinetyhefu, i-microalgae inokuzondla, ivumela ukuba ikhule ngokuqhubekayo60.Emva kokungeniswa kwezinto ezinobuthi, iindlela zokukhusela zinokuthi zisebenze, ezifana nokutshintsha imilo okanye ifom.Ukuba nokwenzeka kokufunxa kufuneka kuqwalaselwe58,59.Ngokucacileyo, naluphi na uphawu lwendlela yokukhusela luphawu olucacileyo lwetyhefu yekhompawundi yovavanyo.Ngoko ke, kumsebenzi wethu oqhubekayo, siye saphanda ukusebenzisana okunokwenzeka komphezulu phakathi kwe-SL Nb-MXene nanoflakes kunye ne-microalgae yi-SEM kunye nokufunxa okunokwenzeka kwe-Nb-based MXene nge-X-ray fluorescence spectroscopy (XRF).Qaphela ukuba uhlalutyo lwe-SEM kunye ne-XRF lwenziwa kuphela kwindawo ephezulu ye-MXene ukujongana nemiba yetyhefu yomsebenzi.
Iziphumo ze-SEM ziboniswe kwi-Fig.4.Iiseli ze-microalgae ezingaphathwanga (jonga umfanekiso we-4a, isampuli yesalathiso) ibonise ngokucacileyo i-R. subcapitata morphology kunye ne-croissant-like cell shape.Iiseli zibonakala zicaba kwaye azilungelelananga noko.Ezinye iiseli ze-microalgae ziwela kwaye zibambene enye kwenye, kodwa oku mhlawumbi kubangelwa yinkqubo yokulungiselela isampuli.Ngokubanzi, iiseli ze-microalgae ezicocekileyo zinendawo egudileyo kwaye azizange zibonise naluphi na utshintsho lwe-morphological.
Imifanekiso ye-SEM ebonisa ukusebenzisana komhlaba phakathi kwe-microalgae eluhlaza kunye ne-MXene nanosheets emva kweeyure ze-72 zokusebenzisana ekugxininiseni okukhulu (100 mg L-1).(a) I-microalgae eluhlaza engaphathwanga emva kokusebenzisana ne-SL (b) Nb2CTx kunye (c) Nb4C3TX MXenes.Qaphela ukuba ii-nanoflakes ze-Nb-MXene ziphawulwe ngeentolo ezibomvu.Ukuthelekisa, iifoto ezivela kwi-microscope yamehlo nazo zongezwa.
Ngokwahlukileyo, iiseli ze-microalgae ezibhengezwe yi-SL Nb-MXene nanoflakes zonakaliswe (jonga umfanekiso we-4b, c, iintolo ezibomvu).Kwimeko ye-Nb2CTx MXene (umzobo 4b), i-microalgae ivame ukukhula kunye ne-nanoscales edibeneyo emibini, enokutshintsha i-morphology yabo.Ngokucacileyo, sikwalubonile olu tshintsho phantsi kwe-microscopy yokukhanya (jonga i-SI Figure S11 ngeenkcukacha).Olu tshintsho lwe-morphological lunesiseko esicacileyo kwi-physiology ye-microalgae kunye nokukwazi kwabo ukuzikhusela ngokuguqula i-cell morphology, njengokwandisa i-cell volume61.Ngoko ke, kubalulekile ukujonga inani leeseli ze-microalgae ngokwenene zidibanisa ne-Nb-MXenes.Izifundo ze-SEM zibonise ukuba malunga ne-52% yeeseli ze-microalgae zavezwa kwi-Nb-MXenes, ngelixa i-48% yala maseli e-microalgae agweme ukudibanisa.Kwi-SL Nb4C3Tx MXene, i-microalgae izama ukuphepha ukudibanisa ne-MXene, ngaloo ndlela ibeka indawo kwaye ikhule ukusuka kwii-nanoscales ezimbini-dimensional (Fig. 4c).Nangona kunjalo, asizange sibone ukungena kwe-nanoscales kwiiseli ze-microalgae kunye nomonakalo wabo.
Ukuzigcina kwakhona kukuziphatha okuxhomekeke kwixesha lokuphendula kwi-blockage ye-photosynthesis ngenxa ye-adsorption of particles on the cell surface and the called shading (shading) effect62.Kucacile ukuba into nganye (umzekelo, i-Nb-MXene nanoflakes) ephakathi kwe-microalgae kunye nomthombo wokukhanya unciphisa umlinganiselo wokukhanya othathwe yi-chloroplasts.Nangona kunjalo, asithandabuzi ukuba oku kunempembelelo ebalulekileyo kwiziphumo ezifunyenweyo.Njengoko kuboniswe kwimibono yethu ye-microscopic, i-nanoflakes ye-2D ayizange ihlanganiswe ngokupheleleyo okanye inamathele kumphezulu we-microalgae, nangona xa iiseli ze-microalgae zidibene ne-Nb-MXenes.Endaweni yoko, ii-nanoflakes ziye zajongwa kwiiseli ze-microalgae ngaphandle kokugubungela umphezulu wazo.Iseti enjalo ye-nanoflakes / microalgae ayinakukhawulela kakhulu umlinganiselo wokukhanya ofakwe kwiiseli ze-microalgae.Ngaphezu koko, ezinye iiphononongo ziye zabonisa ukuphuculwa kokuxutywa kokukhanya yi-photosynthetic organisms phambi kwee-nanomaterials ezimbini-dimensional63,64,65,66.
Ekubeni imifanekiso ye-SEM ayikwazanga ukuqinisekisa ngokuthe ngqo ukuthathwa kwe-niobium ngamaseli e-microalgae, uphononongo lwethu olongezelelweyo luguqukele kwi-X-ray fluorescence (XRF) kunye ne-X-ray photoelectron spectroscopy (XPS) ukucacisa lo mbandela.Ngoko ke, siqhathanise ubuninzi bee-Nb eziphakamileyo zeesampuli ze-microalgae ze-reference ezingazange zidibanise ne-MXenes, i-MXene nanoflakes ekhutshwe ebusweni beeseli ze-microalgae, kunye neeseli ze-microalgal emva kokususwa kwe-MXenes eqhotyoshelweyo.Kuyafaneleka ukuba uqaphele ukuba ukuba akukho kuthathwa kwe-Nb, ixabiso le-Nb elifunyenwe ngamaseli e-microalgae kufuneka libe yi-zero emva kokususwa kwe-nanoscales eqhotyoshelweyo.Ke ngoko, ukuba ukuthathwa kwe-Nb kwenzeka, zombini iziphumo ze-XRF kunye ne-XPS kufuneka zibonise incopho ye-Nb ecacileyo.
Kwimeko ye-spectra ye-XRF, iisampulu ze-microalgae zibonise iincopho ze-Nb ze-SL Nb2CTx kunye ne-Nb4C3Tx MXene emva kokusebenzisana ne-SL Nb2CTx kunye ne-Nb4C3Tx MXene (jonga umfanekiso we-5a, kwakhona uqaphele ukuba iziphumo ze-MAX kunye ne-ML MXenes ziboniswe kwi-SIC1-Figs 72).Kuyathakazelisa ukuba ubukhulu be-Nb peak bufanayo kwiimeko zombini (imivalo ebomvu kwi-Fig. 5a).Oku kubonise ukuba i-algae ayinakukwazi ukufumana i-Nb engaphezulu, kwaye umthamo omkhulu wokuqokelela i-Nb ufunyenwe kwiiseli, nangona amaxesha amabini amaninzi i-Nb4C3Tx MXene ifakwe kwiiseli ze-microalgae (imivalo eluhlaza okwesibhakabhaka kwi-Fig. 5a).Ngokucacileyo, ukukwazi kwe-microalgae ukufunxa isinyithi kuxhomekeke kugxininiso lwee-oxide zetsimbi kwindawo engqongileyo67,68.UShamshada et al.67 wafumanisa ukuba amandla okufunxa amanzi acocekileyo algae ayancipha ngokunyuka kwe-pH.URaize et al.68 waphawula ukuba amandla olwandle olwandle ukufunxa isinyithi ayemalunga ne-25% ephezulu kwi-Pb2 + kune-Ni2 +.
(a) Iziphumo ze-XRF ze-basal Nb ezithatha iiseli ze-microalgae eziluhlaza ezifakwe kwi-concentration egqithisileyo ye-SL Nb-MXenes (100 mg L-1) kwiiyure ze-72.Iziphumo zibonisa ubukho be-α kwiiseli ze-microalgae ezicocekileyo (isampuli yokulawula, iikholomu ezimpunga), i-nanoflakes ye-2D eyodwa kwiiseli ze-microalgae ezingaphezulu (iikholamu eziluhlaza okwesibhakabhaka), kunye neeseli ze-microalgae emva kokuhlukana kwe-nanoflakes ye-2D ukusuka phezulu (iikholamu ezibomvu).Isixa se-Nb ye-elemental, (b) ipesenti ye-chemical composition of microalgae organic components (C = O kunye ne-CHx / C-O) kunye ne-Nb oxides ekhoyo kwiiseli ze-microalgae emva kokufakwa kunye ne-SL Nb-MXenes, (c-e) Ukufakela i-peak yokwakheka kwe-XPS SL I-Nb2CTx ye-spectra yangaphakathi ye-XPS SL Nb2CTx SL kunye ne-microx Nb4Ce3 iiseli ze-microalgae (fh4C)
Ke ngoko, besilindele ukuba i-Nb inokufunxwa ziiseli ze-algal ngendlela yee-oxides.Ukuvavanya oku, senze izifundo ze-XPS kwi-MXenes Nb2CTx kunye ne-Nb4C3TX kunye neeseli ze-algae.Iziphumo zentsebenziswano ye-microalgae kunye ne-Nb-MXenes kunye ne-MXenes ehlukanisiwe kwiiseli ze-algae ziboniswe kwiMifanekiso.5b.Njengoko kulindelwe, sifumene iincopho ze-Nb 3d kwiisampuli ze-microalgae emva kokususwa kwe-MXene ebusweni be-microalgae.Ukunqunyulwa kobungakanani be-C = O, CHx / CO, kunye ne-Nb oxides kubalwa ngokusekelwe kwi-Nb 3d, O 1s, kunye ne-C 1s spectra efunyenwe nge-Nb2CTx SL (Umfanekiso 5c-e) kunye ne-Nb4C3Tx SL (Umfanekiso 5c-e).) efunyenwe kwi-microalgae eqanduselweyo.Umzobo 5f–h) Mxenes.Itheyibhile ye-S1-3 ibonisa iinkcukacha zeeparamitha zepeak kunye nekhemistry jikelele ephuma kwi-fit.Kuyaphawuleka ukuba imimandla ye-Nb 3d ye-Nb2CTx SL kunye ne-Nb4C3Tx SL (Umfanekiso 5c, f) ihambelana necandelo elinye le-Nb2O5.Apha, asifumananga iincopho ezinxulumene ne-MXene kwi-spectra, ebonisa ukuba iiseli ze-microalgae zithatha kuphela ifom ye-oxide ye-Nb.Ukongeza, silinganisele i-C 1 s spectrum kunye ne-C-C, CHx / C-O, C = O, kunye -COOH.Sabela iincopho ze-CHx/C-O kunye ne-C=O kwigalelo lezinto eziphilayo zeeseli ze-microalgae.Ezi zixhobo ze-organic zenza i-36% kunye ne-41% ye-C 1s iphakamileyo kwi-Nb2CTx SL kunye ne-Nb4C3TX SL, ngokulandelanayo.Emva koko sifake i-O 1s spectra ye-SL Nb2CTx kunye ne-SL Nb4C3TX kunye ne-Nb2O5, i-organic components of microalgae (CHx / CO), kunye namanzi adsorbed angaphezulu.
Ekugqibeleni, iziphumo ze-XPS zibonise ngokucacileyo uhlobo lwe-Nb, kungekhona nje ubukho bayo.Ngokwesikhundla somqondiso we-Nb 3d kunye neziphumo ze-deconvolution, siqinisekisa ukuba i-Nb ifakwe kuphela kwifom ye-oxides kwaye kungekhona i-ion okanye i-MXene ngokwayo.Ukongezelela, iziphumo ze-XPS zibonise ukuba iiseli ze-microalgae zinamandla amakhulu okuthatha i-Nb oxides ukusuka kwi-SL Nb2CTx xa kuthelekiswa ne-SL Nb4C3TX MXene.
Ngelixa iziphumo zethu zokuthatha i-Nb ziyamangalisa kwaye zisivumela ukuba sichonge ukuthotywa kwe-MXene, akukho ndlela ekhoyo yokulandelela utshintsho oluhambelanayo lwe-morphological kwi-2D nanoflakes.Ngoko ke, sagqiba ekubeni siphuhlise indlela efanelekileyo enokuthi iphendule ngokuthe ngqo naluphi na utshintsho olwenzeka kwi-2D Nb-MXene nanoflakes kunye neeseli ze-microalgae.Kubalulekile ukuqaphela ukuba sicinga ukuba ukuba iintlobo ezisebenzisanayo zifumana nayiphi na inguqu, ukubola okanye ukuchithwa, oku kufuneka kubonakale ngokukhawuleza njengotshintsho kwiiparamitha zemilo, ezifana nobubanzi bommandla olinganayo wesetyhula, ukungqukuva, ububanzi beFeret, okanye ubude beFeret.Ekubeni ezi parameters zifanelekile ukuchaza iinqununu ezide okanye i-nanoflakes ezimbini-dimensional, ukulandelela kwabo ngokuhlalutya kobume be-particle kuya kusinika ulwazi oluxabisekileyo malunga nokuguqulwa kwe-morphological ye-SL Nb-MXene nanoflakes ngexesha lokunciphisa.
Iziphumo ezifunyenweyo ziboniswa kuMfanekiso 6. Ukuthelekisa, siphinde savavanya isigaba sokuqala se-MAX kunye ne-ML-MXenes (jonga i-SI Figures S18 kunye ne-S19).Uhlalutyo olunamandla lwe-particle shape lubonise ukuba zonke iiparameters zemilo ezimbini ze-Nb-MXene SL zitshintshile kakhulu emva kokusebenzisana ne-microalgae.Njengoko kubonisiwe yiparameter yommandla olinganayo ojikelezayo wedayamitha (umzobo 6a, b), ukuncitshiswa kokuqina kwencapha ye-nanoflakes enkulu kubonisa ukuba zivame ukubola zibe ngamaqhekeza amancinci.Kwikhiwane.I-6c, d ibonisa ukuhla kweencopho ezihambelana nobukhulu obunqamlekileyo beeflakes (i-elongation ye-nanoflakes), ebonisa ukuguqulwa kwee-nanoflakes ze-2D kwi-particle-like shape.Umfanekiso 6e-h obonisa ububanzi nobude beFeret, ngokulandelelanayo.Ububanzi beFerethi kunye nobude ziiparamitha ezihambelanayo kwaye ke kufuneka ziqwalaselwe kunye.Emva kokufakwa kwe-2D Nb-MXene nanoflakes phambi kwe-microalgae, i-Feret correlation peaks yazo ishintshile kwaye ukuqina kwabo kuyancipha.Ngokusekelwe kwezi ziphumo ngokudibanisa ne-morphology, i-XRF kunye ne-XPS, sagqiba ekubeni utshintsho oluphawulweyo lunxulumene kakhulu ne-oxidation njengoko i-MXenes ene-oxidized iba yimibimbi kwaye iphule ibe ngamaqhekeza kunye ne-spherical oxide particles69,70.
Uhlalutyo lwenguqu yeMXene emva kokusebenzisana ne-microalgae eluhlaza.Uhlalutyo lwemilo yamasuntswana aguqukayo luthathela ingqalelo iiparamitha ezinje ngo (a, b) ubukhulu bommandla olinganayo wesetyhula, (c, d) ukungqukuva, (e, f) Ububanzi beFerethi kunye (g, h) nobude beFerethi.Ukuza kuthi ga ngoku, iisampuli ezimbini ze-microalgae ezibhekiselele zahlalutywa kunye ne-SL Nb2CTx ephambili kunye ne-SL Nb4C3Tx MXenes, i-SL Nb2CTx kunye ne-SL Nb4C3Tx MXenes, i-microalgae eyonakalisiwe, kunye ne-microalgae SL Nb2CTx kunye ne-SL Nb4C3Tx MXenes.Iintolo ezibomvu zibonisa utshintsho lweeparamitha zemilo yee-nanoflakes ezine-dimensional ezifundiweyo.
Ekubeni uhlalutyo lweparameter yemilo luthembeke kakhulu, lunokutyhila utshintsho lwe-morphological kwiiseli ze-microalgae.Ngoko ke, sihlalutye i-diameter yendawo yesetyhula elinganayo, ukujikeleza, kunye nobubanzi beFeret / ubude beeseli ze-microalgae ezicocekileyo kunye neeseli emva kokusebenzisana ne-2D Nb nanoflakes.Kwikhiwane.I-6a-h ibonisa utshintsho kwiiparameters zemilo yeeseli ze-algae, njengoko kubonakaliswe ukuhla kwesantya esiphezulu kunye nokutshintshwa kwe-maxima ukuya kumaxabiso aphezulu.Ngokukodwa, iiparamitha zokujikeleza kweeseli zibonise ukuhla kweeseli ezide kunye nokwanda kweeseli ze-spherical (Fig. 6a, b).Ukongezelela, ububanzi beeseli ze-Feret zanda ngama-micrometer amaninzi emva kokusebenzisana ne-SL Nb2CTx MXene (Umfanekiso 6e) xa kuthelekiswa ne-SL Nb4C3TX MXene (Umfanekiso 6f).Sikrokrela ukuba le nto inokuba ngenxa yokunyuka okunamandla kwe-Nb oxides nge-microalgae xa usebenzisana ne-Nb2CTx SR.Ukuqhotyoshelwa okuncinci kwee-Nb flakes kumphezulu wabo kunokubangela ukukhula kweeseli kunye nefuthe elincinci lomthunzi.
Ukuqwalasela kwethu utshintsho kwiiparameters zemilo kunye nobukhulu be-microalgae ihambelana nezinye izifundo.I-microalgae eluhlaza inokutshintsha i-morphology yabo ekuphenduleni uxinzelelo lwendalo ngokutshintsha ubungakanani beeseli, imilo okanye imetabolism61.Umzekelo, ukutshintsha ubungakanani beeseli kunceda ukufunxa izondlo71.Iiseli ezincinci ze-algae zibonisa ukuthathwa kwezondlo ezisezantsi kunye nezinga lokukhula eliphazamisekileyo.Ngakolunye uhlangothi, iiseli ezinkulu zidla ngokutya izondlo ezininzi, ezithi zifakwe kwi-intracellularly72,73.I-Machado kunye ne-Soares yafumanisa ukuba i-triclosan yokungunda inokunyusa ubungakanani beeseli.Bafumene utshintsho olunzulu kwimilo ye-algae74.Ukongezelela, i-Yin et al.9 iphinde ibonise utshintsho lwe-morphological kwi-algae emva kokuvezwa ekunciphiseni i-graphene oxide nanocomposites.Ngoko ke, kuyacaca ukuba ubungakanani obutshintshiweyo / iiparitha zemilo ye-microalgae zibangelwa ubukho be-MXene.Ekubeni olu tshintsho kubukhulu kunye nokuma lubonisa utshintsho ekuthathweni kwezondlo, sikholelwa ukuba uhlalutyo lobungakanani kunye neeparitha zemilo ngokuhamba kwexesha kunokubonisa ukufunyanwa kwe-niobium oxide nge-microalgae phambi kwe-Nb-MXenes.
Ngaphezu koko, i-MXenes inokuthi ifakwe i-oxidized phambi kwe-algae.U-Dalai et al.75 waqaphela ukuba i-morphology ye-algae eluhlaza evezwe kwi-nano-TiO2 kunye ne-Al2O376 yayingafani.Nangona uqwalaselo lwethu lufana nolu phando lwangoku, lufanelekile kuphela kwisifundo semiphumo ye-bioremediation ngokubhekiselele kwimveliso yokuthotywa kweMXene phambi kwee-nanoflakes ze-2D kwaye kungekhona i-nanoparticles.Ekubeni i-MXenes inokunciphisa ibe yi-oxides yensimbi, i-31,32,77,78 kunengqiqo ukucinga ukuba i-Nb nanoflakes yethu inokwenza i-Nb oxides emva kokusebenzisana neeseli ze-microalgae.
Ukuze uchaze ukunciphisa i-nanoflakes ye-2D-Nb ngokusebenzisa indlela yokubola esekelwe kwinkqubo ye-oxidation, senze izifundo zisebenzisa i-high-resolution transmission electron microscopy (HRTEM) (Fig. 7a,b) kunye ne-X-ray photoelectron spectroscopy (XPS) (Umfanekiso 7).7c-i kunye neetafile S4-5).Zombini iindlela zifanelekile ukufunda i-oxidation yezinto ze-2D kwaye ziyancedisana.I-HRTEM iyakwazi ukuhlalutya ukuthotywa kwezakhiwo ezinqamlekileyo ze-dimensional kunye nokubonakala okulandelayo kwe-metal oxide nanoparticles, ngelixa i-XPS inomdla kwiibhondi zomhlaba.Ngenxa yale njongo, sivavanye i-2D Nb-MXene nanoflakes ekhutshwe kwi-microalgae cell dispersions, oko kukuthi, imilo yabo emva kokusebenzisana neeseli ze-microalgae (jonga umfanekiso 7).
Imifanekiso ye-HRTEM ebonisa i-morphology ye-oxidized (a) SL Nb2CTx kunye (b) SL Nb4C3Tx MXenes, iziphumo zokuhlalutya kwe-XPS ezibonisa (c) ukubunjwa kweemveliso ze-oxide emva kokunciphisa, (d-f) i-peak ehambelanayo yamacandelo e-XPS spectra ye-SL Nb2CTx kunye (g- i-3) ne-green Nb4Ced ukulungiswa kwe-Nb4Ce.
Izifundo ze-HRTEM ziqinisekisile i-oxidation yeentlobo ezimbini ze-Nb-MXene nanoflakes.Nangona i-nanoflakes igcina i-morphology ye-dimensional morphology ukuya kwinqanaba elithile, i-oxidation ibangele ukubonakala kwee-nanoparticles ezininzi ezigubungela ubuso be-MXene nanoflakes (jonga umfanekiso 7a, b).Uhlalutyo lwe-XPS lwe-c Nb 3d kunye ne-O 1s izibonakaliso zibonise ukuba i-Nb oxides yenziwe kwiimeko zombini.Njengoko kuboniswe kwi-Figure 7c, i-2D MXene Nb2CTx kunye ne-Nb4C3TX inezibonakaliso ze-Nb ze-3d ezibonisa ubukho be-NbO kunye ne-Nb2O5 oxides, ngelixa iimpawu ze-O 1s zibonisa inani le-O-Nb ebhondi ehambelana nokusebenza kwendawo ye-nanoflake ye-2D.Siqaphele ukuba igalelo le-Nb oxide libalaseleyo xa kuthelekiswa ne-Nb-C kunye ne-Nb3 + -O.
Kwikhiwane.Amanani 7g-i bonisa i-XPS spectra ye-Nb 3d, i-C 1s, kunye ne-O 1s SL Nb2CTx (bona i-Figs. 7d-f) kunye ne-SL Nb4C3TX MXene eyedwa kwiiseli ze-microalgae.Iinkcukacha ze-Nb-MXenes peak parameters zinikezelwa kwiiThebhile S4-5, ngokulandelanayo.Siqale sahlalutya ukubunjwa kwe-Nb 3d.Ngokuchasene ne-Nb efunnwe ngamaseli e-microalgae, kwi-MXene eyodwa kwiiseli ze-microalgae, ngaphandle kwe-Nb2O5, ezinye izinto zafunyanwa.Kwi-Nb2CTx SL, siye sabona igalelo le-Nb3 + -O kwisixa se-15%, ngelixa yonke i-Nb 3d spectrum yayilawulwa yi-Nb2O5 (85%).Ukongezelela, isampuli ye-SL Nb4C3TX iqukethe i-Nb-C (9%) kunye ne-Nb2O5 (91%).Apha i-Nb-C ivela kwimigangatho emibini yangaphakathi ye-athomu ye-carbide yensimbi kwi-Nb4C3Tx SR.Emva koko senza imephu ye-C 1s spectra kumacandelo amane ahlukeneyo, njengoko senzile kwiisampuli zangaphakathi.Njengoko kulindelekile, i-spectrum ye-C 1s ilawulwa yikhabhoni ye-graphic, ilandelwa ngamagalelo avela kwi-organic particles (CHx / CO kunye ne-C = O) kwiiseli ze-microalgae.Ukongezelela, kwi-spectrum ye-O 1s, siye sabona igalelo leefom eziphilayo ze-microalgae cells, i-niobium oxide, kunye namanzi adsorbed.
Ukongezelela, siye saphanda ukuba i-Nb-MXenes cleavage ihambelana nobukho beentlobo ze-oksijini ezisebenzayo (ROS) kwindawo yezondlo kunye / okanye iiseli ze-microalgae.Ukuza kuthi ga ngoku, sivavanye amanqanaba e-singlett oxygen (1O2) kwinkcubeko yenkcubeko kunye ne-intracellular glutathione, i-thiol esebenza njenge-antioxidant kwi-microalgae.Iziphumo ziboniswa kwi-SI (Figures S20 kunye ne-S21).Iinkcubeko kunye ne-SL Nb2CTx kunye ne-Nb4C3TX MXenes zibonakaliswe ngokunciphisa inani le-1O2 (jonga umfanekiso we-S20).Kwimeko ye-SL Nb2CTx, i-MXene 1O2 iyancitshiswa ibe malunga ne-83%.Kwiinkcubeko ze-microalgae usebenzisa i-SL, i-Nb4C3TX 1O2 yehla nangakumbi, ukuya kwi-73%.Okubangel 'umdla kukuba, utshintsho kwi-1O2 lubonise umzila ofanayo kunye ne-inhibitory-stimulatory effect ebonwe ngaphambili (jonga umfanekiso we-3).Kungaxoxwa ukuba ukufukanyelwa ekukhanyeni okuqaqambileyo kunokutshintsha i-photooxidation.Nangona kunjalo, iziphumo zohlalutyo lolawulo zibonise amanqanaba aphantse ahlala e-1O2 ngexesha lovavanyo (Fig. S22).Kwimeko yamanqanaba e-ROS e-intracellular, siphinde saqaphela indlela efanayo yokuhla (jonga umfanekiso we-S21).Ekuqaleni, amanqanaba e-ROS kwiiseli ze-microalgae ezikhuliswe phambi kwe-Nb2CTx kunye ne-Nb4C3Tx SLs zigqithise amanqanaba afunyenwe kwiinkcubeko ezicocekileyo ze-microalgae.Ekugqibeleni, nangona kunjalo, kwabonakala ukuba i-microalgae iguqulelwe kubukho be-Nb-MXenes zombini, njengoko amanqanaba e-ROS ancipha ukuya kwi-85% kunye ne-91% yamanqanaba alinganiswa kwiinkcubeko ezicocekileyo ze-microalgae inoculated kunye ne-SL Nb2CTx kunye ne-Nb4C3TX, ngokulandelanayo.Oku kungabonisa ukuba i-microalgae iziva ikhululekile ngaphezu kwexesha phambi kwe-Nb-MXene kune-nutrition medium yodwa.
I-Microalgae liqela elihlukeneyo lezinto eziphilayo ze-photosynthetic.Ngexesha lephotosynthesis, baguqula i-atmospheric carbon dioxide (CO2) ibe yi-organic carbon.Iimveliso zephotosynthesis yiglucose kunye neoksijini79.Sikrokrela ukuba i-oksijini eyenziwe ngaloo ndlela idlala indima ebalulekileyo kwi-oxidation ye-Nb-MXenes.Enye inkcazo enokwenzeka yale nto kukuba i-parameter ye-aeration eyahlukileyo yenziwa kwiingcinezelo eziphantsi kunye eziphezulu ze-oksijini ngaphandle nangaphakathi kwe-Nb-MXene nanoflakes.Oku kuthetha ukuba naphi na apho kukho imimandla eyahlukeneyo yoxinzelelo lweoksijini, indawo enelona nqanaba lisezantsi liya kwenza i-anode 80, 81, 82. Apha, i-microalgae inegalelo ekudalweni kweeseli ezinomoya ohlukeneyo kumphezulu we-MXene flakes, ovelisa i-oksijini ngenxa yeempawu zabo ze-photosynthetic.Ngenxa yoko, iimveliso ze-biocorrosion (kule meko, i-niobium oxides) zenziwe.Enye inkalo kukuba i-microalgae inokuvelisa i-organic acids ekhutshwe emanzini83,84.Ngoko ke, indawo enobudlova yenziwa, ngaloo ndlela itshintsha i-Nb-MXenes.Ukongeza, i-microalgae inokutshintsha i-pH yendawo kwi-alkaline ngenxa yokufunxa i-carbon dioxide, enokubangela ukubola79.
Okona kubaluleke kakhulu, ifotoperiod emnyama/ekhanyayo esetyenziswa kuphononongo lwethu ibalulekile ekuqondeni iziphumo ezifunyenweyo.Lo mba uchazwe ngokweenkcukacha kwi-Djemai-Zoghlache et al.85 Basebenzisa ngabom i-12/12 iyure photoperiod ukubonisa i-biocorrosion ehambelana ne-biofouling yi-red microalgae Porphyridium purpureum.Babonisa ukuba i-photoperiod inxulunyaniswa ne-evolution yezinto ezinokubakho ngaphandle kwe-biocorrosion, ezibonakalisa njenge-pseudoperiodic oscillations malunga ne-24: 00.Olu qwalaselo lwaqinisekiswa nguDowling et al.86 Baye babonisa iphotosynthetic biofilms yecyanobacteria Anabaena.I-oksijeni echithweyo yenziwa phantsi kwesenzo sokukhanya, esihambelana nokutshintsha okanye ukuguquguquka kwi-biocorrosion yamahhala.Ukubaluleka kwefotoperiod kugxininiswe yinto yokuba amandla amahhala e-biocorrosion ayanda kwinqanaba lokukhanya kwaye ayancipha kwisigaba esimnyama.Oku kungenxa yeoksijini eveliswa yi-photosynthetic microalgae, echaphazela ukusabela kwe-cathodic ngoxinzelelo oluyinxenye oluveliswa kufuphi ne-electrodes87.
Ukongeza, i-Fourier iguqule i-infrared spectroscopy (FTIR) yenziwa ukufumanisa ukuba kukho naluphi na utshintsho olwenzekayo kukwakheka kweekhemikhali zeeseli ze-microalgae emva kokudibana ne-Nb-MXenes.Ezi ziphumo zifunyenwe zinzima kwaye sizibonisa kwi-SI (Amanani S23-S25, kubandakanywa neziphumo zesigaba se-MAX kunye ne-ML MXenes).Ngokufutshane, i-spectra yereferensi efunyenweyo ye-microalgae isinika ulwazi olubalulekileyo malunga neempawu zekhemikhali zezi zinto ziphilayo.Ezi ntshukumo zinokwenzeka zifumaneka kwii-frequencies ze-1060 cm-1 (CO), 1540 cm-1, 1640 cm-1 (C = C), 1730 cm-1 (C = O), 2850 cm-1, 2920 cm-1.Nye.I-1 1 (C-H) kunye ne-3280 cm-1 (O-H).Kwi-SL Nb-MXenes, sifumene i-CH-bond yokwelula isignesha ehambelana nesifundo sethu sangaphambili38.Nangona kunjalo, siye saqaphela ukuba ezinye iincopho ezongezelelweyo ezinxulumene ne-C = C kunye ne-CH bonds zanyamalala.Oku kubonisa ukuba ukubunjwa kweekhemikhali ze-microalgae kunokutshintsha utshintsho oluncinci ngenxa yokusebenzisana ne-SL Nb-MXenes.
Xa uqwalasela utshintsho olunokwenzeka kwi-biochemistry ye-microalgae, ukuqokelela kwe-inorganic oxides, njenge-niobium oxide, kufuneka kuqwalaselwe kwakhona59.Ibandakanyeka ekuthathweni kweentsimbi nge-cell surface, ukuthuthwa kwabo kwi-cytoplasm, ukudibanisa kwabo kunye namaqela e-intracellular carboxyl, kunye nokuqokelela kwi-microalgae polyphosphosomes20,88,89,90.Ukongezelela, ubudlelwane phakathi kwe-microalgae kunye neentsimbi zigcinwa ngamaqela asebenzayo eeseli.Ngesi sizathu, ukufunxa kukwaxhomekeke kwikhemikhali yomphezulu wealgae, entsokothileyo9,91.Ngokuqhelekileyo, njengoko kulindelwe, ukubunjwa kweekhemikhali ze-microalgae eluhlaza kwatshintsha kancinci ngenxa yokufunxa kwe-Nb oxide.
Okubangela umdla kukuba, ukuvinjwa kokuqala kwe-microalgae kwabuyiselwa umva ngokuhamba kwexesha.Njengoko sibonile, i-microalgae yoyisa utshintsho lokuqala lokusingqongileyo kwaye ekugqibeleni yabuyela kumazinga aqhelekileyo okukhula kwaye yanda.Izifundo ze-zeta ezinokubakho zibonisa ukuzinza okuphezulu xa zingeniswa kwimidiya yezondlo.Ngaloo ndlela, ukusebenzisana komhlaba phakathi kweeseli ze-microalgae kunye ne-Nb-MXene nanoflakes zigcinwe kulo lonke uvavanyo lokunciphisa.Kuhlalutyo lwethu olongezelelweyo, sishwankathela iindlela eziphambili zesenzo eziphantsi kokuziphatha okuphawulekayo kwe-microalgae.
Ukuqwalaselwa kwe-SEM kubonise ukuba i-microalgae ivame ukunamathela kwi-Nb-MXenes.Ukusebenzisa uhlalutyo lwemifanekiso eguquguqukayo, siqinisekisa ukuba esi siphumo sikhokelela ekuguqulweni kwee-nanoflakes ze-Nb-MXene ezine-dimensional zibe ngamaqhekeza amaninzi, ngaloo ndlela ebonisa ukuba ukubola kwe-nanoflakes kuhambelana ne-oxidation yabo.Ukuvavanya i-hypothesis yethu, senze uluhlu lwezinto eziphathekayo kunye nezifundo ze-biochemical.Emva kokuvavanya, i-nanoflakes i-oxidized ngokuthe ngcembe kwaye yachithwa kwi-NbO kunye ne-Nb2O5 yeemveliso, ezingazange zibe yingozi kwi-microalgae eluhlaza.Ukusebenzisa ukujonga kwe-FTIR, asifumananga utshintsho olubalulekileyo kwi-chemical composition of microalgae incubated phambi kwe-2D Nb-MXene nanoflakes.Ukuthathela ingqalelo ukuba kunokwenzeka ukufunxa i-niobium oxide nge-microalgae, senze uhlalutyo lwe-X-ray fluorescence.Ezi ziphumo zibonisa ngokucacileyo ukuba i-microalgae efundwayo idla i-niobium oxides (i-NbO kunye ne-Nb2O5), engeyona inetyhefu kwi-microalgae efundwayo.