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Saurin haɓaka nanotechnology da haɗin kai cikin aikace-aikacen yau da kullun na iya yin barazana ga yanayin.Duk da yake hanyoyin kore don lalata abubuwan gurɓataccen ƙwayoyin halitta suna da kyau, dawo da gurɓataccen ƙwayar ƙwayar cuta ta inorganic crystalline yana da babban damuwa saboda ƙarancin fahimtar su ga biotransformation da rashin fahimtar hulɗar saman kayan abu tare da masu ilimin halitta.Anan, muna amfani da ƙirar 2D MXenes na inorganic na Nb wanda aka haɗe tare da hanyar bincike mai sauƙi na siga don gano tsarin bioremediation na 2D yumbu nanomaterials ta koren microalgae Raphidocelis subcapitata.Mun gano cewa microalgae yana lalata MXenes na tushen Nb saboda hulɗar physico-chemical da ke da alaƙa.Da farko, Layer-Layer da Multilayer MXene nanoflakes an haɗa su zuwa saman microalgae, wanda ya ɗan rage haɓakar algae.Duk da haka, a kan dogon hulɗa tare da surface, microalgae oxidized MXene nanoflakes da kuma kara bazuwar su cikin NbO da Nb2O5.Saboda waɗannan oxides ba su da guba ga ƙwayoyin microalgae, suna cinye Nb oxide nanoparticles ta hanyar shayarwa wanda ke kara mayar da microalgae bayan sa'o'i 72 na maganin ruwa.Har ila yau, tasirin abubuwan gina jiki da ke hade da sha suna nunawa a cikin karuwa a cikin ƙwayar salula, siffar su mai laushi da canji a cikin girma.Dangane da waɗannan binciken, mun yanke shawarar cewa kasancewar MXenes na ɗan gajeren lokaci da na dogon lokaci na Nb a cikin yanayin muhallin ruwa na iya haifar da ƙananan tasirin muhalli kawai.Abin lura ne cewa, ta yin amfani da nanomaterials na nau'i biyu a matsayin tsarin ƙirar, muna nuna yiwuwar sa ido kan canjin siffar har ma a cikin kayan aiki mai kyau.Gabaɗaya, wannan binciken yana amsa wata muhimmiyar tambaya mai mahimmanci game da hanyoyin da ke da alaƙa da alaƙar da ke motsa tsarin bioremediation na nanomaterials na 2D kuma yana ba da tushe don ƙarin ɗan gajeren lokaci da nazarin dogon lokaci na tasirin muhalli na nanomaterials crystalline inorganic.
Nanomaterials sun haifar da sha'awa mai yawa tun lokacin da aka gano su, kuma fasahohin nano daban-daban kwanan nan sun shiga wani zamani na zamani.Abin takaici, haɗa kayan nanomaterials cikin aikace-aikacen yau da kullun na iya haifar da sakewa na bazata saboda zubar da bai dace ba, kulawar rashin kulawa, ko rashin isassun kayan aikin aminci.Saboda haka, yana da ma'ana a ɗauka cewa nanomaterials, gami da biyu-girma (2D) nanomaterials, za a iya smaracaterials biyu, ana iya smaractials, halayen da ayyukan ilimin halitta, ana iya sannu da ayyukan halittar halitta.Saboda haka, ba abin mamaki ba ne cewa abubuwan da suka shafi muhalli sun mayar da hankali kan ikon 2D nanomaterials don shiga cikin tsarin ruwa2,3,4,5,6.A cikin waɗannan halittun halittu, wasu nanomaterials na 2D na iya yin hulɗa tare da halittu daban-daban a matakan trophic daban-daban, gami da microalgae.
Microalgae kwayoyin halitta ne na farko da ake samun su ta dabi'a a cikin ruwa mai dadi da muhallin ruwa wadanda ke samar da nau'ikan sinadarai iri-iri ta hanyar photosynthesis7.Don haka, suna da mahimmanci ga tsarin halittu na ruwa8,9,10,11,12 amma kuma suna da hankali, marasa tsada da alamomin amfani da yawa na ecotoxicity13,14.Tun da ƙwayoyin microalgae suna haɓaka da sauri kuma suna amsawa da sauri ga kasancewar mahaɗan daban-daban, suna da alƙawarin haɓaka hanyoyin da ke da alaƙa da muhalli don magance ruwan da aka gurbata da abubuwan halitta15,16.
Kwayoyin algae na iya cire ions inorganic daga ruwa ta hanyar biosorption da tarawa17,18.Wasu nau'in algal irin su Chlorella, Anabaena invar, Westiellopsis prolifica, Stigeoclonium tenue da Synechococcus sp.An gano yana ɗauka har ma yana ciyar da ions ƙarfe masu guba kamar Fe2+, Cu2+, Zn2+ da Mn2+19.Sauran binciken sun nuna cewa Cu2+, Cd2+, Ni2+, Zn2+ ko Pb2+ ions suna iyakance haɓakar Scenedesmus ta hanyar canza yanayin halittar kwayar halitta da lalata chloroplasts20,21.
Hanyoyin kore don bazuwar gurɓataccen yanayi da kuma kawar da ions masu nauyi na ƙarfe sun ja hankalin masana kimiyya da injiniyoyi a duniya.Wannan ya samo asali ne saboda gaskiyar cewa ana iya sarrafa waɗannan gurɓatattun abubuwa a cikin yanayin ruwa.Duk da haka, gurɓataccen kristal na inorganic yana da ƙarancin narkewar ruwa da ƙarancin sauƙi ga canje-canje iri-iri, wanda ke haifar da matsaloli masu yawa a cikin gyara, kuma an sami ɗan ci gaba a wannan yanki22,23,24,25,26.Don haka, neman hanyoyin da ke da alaƙa da muhalli don gyara nanomaterials ya kasance yanki mai sarƙaƙƙiya kuma ba a bincika ba.Saboda babban matakin rashin tabbas game da tasirin biotransformation na 2D nanomaterials, babu wata hanya mai sauƙi don gano hanyoyin da za su iya lalata su yayin raguwa.
A cikin wannan binciken, mun yi amfani da koren microalgae a matsayin wakili mai aiki na ruwa na bioremediation don kayan yumbu na inorganic, haɗe tare da kula da yanayin lalacewa na MXene a matsayin wakilin kayan yumbu na inorganic.Kalmar "MXene" tana nuna stoichiometry na kayan Mn + 1XnTx, inda M shine ƙarfe na farko na canzawa, X shine carbon da / ko nitrogen, Tx shine mai ƙarewa (misali, -OH, -F, -Cl), da n = 1, 2, 3 ko 427.28.Tun lokacin da aka gano MXenes ta Naguib et al.Sensorics, ciwon daji da tacewa membrane 27,29,30.Bugu da ƙari, MXenes za a iya la'akari da tsarin 2D samfurin saboda kyakkyawan kwanciyar hankali na colloidal da yiwuwar hulɗar halittu31,32,33,34,35,36.
Sabili da haka, hanyoyin da aka haɓaka a cikin wannan labarin da kuma ra'ayoyin bincikenmu an nuna su a cikin Hoto 1. Bisa ga wannan hasashe, microalgae yana lalata MXenes na tushen Nb a cikin mahaɗan da ba su da guba saboda abubuwan da suka shafi physico-chemical interactions, wanda ke ba da damar sake dawo da algae.Don gwada wannan hasashe, an zaɓi mambobi biyu na dangin farko na tushen niobium na canjin ƙarfe da / ko nitrides (MXenes), wato Nb2CTx da Nb4C3TX.
Hanyar bincike da ra'ayoyin tushen shaida don dawo da MXene ta koren microalgae Raphidocelis subcapitata.Lura cewa wannan kawai wakilci ne na ƙirƙira na zato na tushen shaida.Yanayin tafkin ya bambanta da matsakaicin sinadirai da aka yi amfani da su da yanayin (misali, zagayowar rana da iyakoki a cikin abubuwan gina jiki masu mahimmanci).An ƙirƙira da BioRender.com.
Sabili da haka, ta amfani da MXene a matsayin tsarin ƙira, mun buɗe kofa don nazarin tasirin halittu daban-daban waɗanda ba za a iya lura da su tare da sauran nanomaterials na al'ada ba.Musamman, muna nuna yiwuwar bioremediation na nanomaterials masu girma biyu, irin su MXenes na tushen niobium, ta microalgae Raphidocelis subcapitata.Microalgae suna iya lalata Nb-MXenes a cikin oxides marasa guba NbO da Nb2O5, waɗanda kuma suna ba da kayan abinci mai gina jiki ta hanyar tsarin ɗaukar niobium.Gabaɗaya, wannan binciken yana amsa wata muhimmiyar tambaya ta asali game da hanyoyin da ke da alaƙa da hulɗar physicochemical na sama waɗanda ke tafiyar da hanyoyin haɓakar halittu na nanomaterials masu girma biyu.Bugu da kari, muna haɓaka hanya mai sauƙi-tushen siga don bin diddigin canje-canje na dabara a cikin sifar nanomaterials na 2D.Wannan yana ƙarfafa ƙarin bincike na ɗan gajeren lokaci da na dogon lokaci cikin tasirin muhalli iri-iri na nanomaterials crystalline inorganic.Don haka, bincikenmu yana ƙara fahimtar hulɗar da ke tsakanin saman abu da kayan halitta.Har ila yau, muna ba da tushe don faɗaɗa nazarin ɗan gajeren lokaci da na dogon lokaci game da tasirinsu akan yanayin muhallin ruwa, wanda yanzu ana iya tantancewa cikin sauƙi.
MXenes suna wakiltar nau'in kayan abu mai ban sha'awa tare da keɓaɓɓen kuma kyawawan kaddarorin jiki da sinadarai don haka yawancin aikace-aikace masu yuwuwa.Waɗannan kaddarorin sun fi dogara ga stoichiometry da kuma sinadarai na saman.Saboda haka, a cikin bincikenmu, mun bincika nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan nau'ikan Nb (SL) MXenes, Nb2CTx da Nb4C3TX, tunda ana iya lura da tasirin halittu daban-daban na waɗannan nanomaterials.Ana samar da MXenes daga kayan farawa ta hanyar zaɓin zaɓi na sama-ƙasa na siraran MAX-A-Layer.Matakin MAX shine yumbu na ternary wanda ya ƙunshi tubalan '' bonded'' na ɓangarorin ƙarfe na canji da siraran abubuwa na "A" kamar Al, Si, da Sn tare da stoichiometry na MnAXn-1.An lura da ilimin halittar ɗan adam na farkon lokacin MAX ta hanyar duban microscopy na lantarki (SEM) kuma ya yi daidai da binciken da ya gabata (Dubi Ƙarin Bayani, SI, Hoto S1).An samu Multilayer (ML) Nb-MXene bayan cire Al Layer tare da 48% HF (hydrofluoric acid).An yi nazarin ilimin halittar ɗan adam na ML-Nb2CTx da ML-Nb4C3TX ta hanyar bincikar microscopy na lantarki (SEM) (Figures S1c da S1d bi da bi) kuma an lura da yanayin yanayin halittar MXene na yau da kullun, kama da nanoflakes masu girma biyu da ke wucewa ta hanyar tsage-tsalle masu tsayi.Dukansu Nb-MXenes suna da alaƙa da yawa tare da matakan MXene da aka haɗa a baya ta hanyar etching27,38.Bayan tabbatar da tsarin MXene, mun sanya shi ta hanyar intercalation na tetrabutylammonium hydroxide (TBAOH) ta hanyar wankewa da sonication, bayan haka mun sami Layer-Layer ko low-Layer (SL) 2D Nb-MXene nanoflakes.
Mun yi amfani da babban ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙwayoyin lantarki (HRTEM) da rarrabuwar X-ray (XRD) don gwada ingancin etching da ƙara kwasfa.Sakamakon HRTEM da aka sarrafa ta amfani da Inverse Fast Fourier Transform (IFFT) da Saurin Canjin Saurin Saurin (FFT) an nuna su a cikin siffa 2. Nb-MXene nanoflakes sun daidaita gefen har zuwa duba tsarin tsarin atomic Layer kuma auna nisa tsakanin juna.Hotunan HRTEM na MXene Nb2CTx da Nb4C3TX nanoflakes sun bayyana yanayin su na atomically na bakin ciki (duba siffa 2a1, a2), kamar yadda Naguib et al.27 da Jastrzębska et al.38 suka ruwaito a baya.Don masu haɗin Nb2CTx guda biyu da Nb4C3Tx monolayers, mun ƙayyade nisa tsakanin 0.74 da 1.54 nm, bi da bi (Figs. 2b1,b2), wanda kuma ya yarda da sakamakonmu na baya38.An kara tabbatar da wannan ta hanyar juzu'in juzu'i mai sauri na Fourier (Fig. 2c1, c2) da kuma saurin Fourier canzawa (Fig. 2d1, d2) yana nuna nisa tsakanin Nb2CTx da Nb4C3Tx monolayers.Hoton yana nuna canjin haske da makada masu duhu daidai da niobium da carbon atom, wanda ke tabbatar da yanayin yanayin MXenes da aka yi nazari.Yana da mahimmanci a lura cewa hasken wutar lantarki mai watsawa na X-ray spectroscopy (EDX) wanda aka samo don Nb2CTx da Nb4C3Tx (Figures S2a da S2b) bai nuna ragowar lokacin MAX na ainihi ba, tun da ba a gano Al peak ba.
Halaye na SL Nb2CTx da Nb4C3Tx MXene nanoflakes, ciki har da (a) high ƙuduri na lantarki microscopy (HRTEM) gefen-view 2D nanoflake imaging da kuma m, (b) yanayin tsanani, (c) jujjuya sauri Fourier canza (IFFT), (d) sauri Fourier canza (FFT), (e) X-MX NbrayDon SL 2D Nb2CTx, an bayyana lambobin azaman (a1, b1, c1, d1, e1).Don SL 2D Nb4C3Tx, an bayyana lambobin azaman (a2, b2, c2, d2, e1).
Ana nuna ma'aunin rarrabawar X-ray na SL Nb2CTx da Nb4C3Tx MXenes a cikin Figs.2e1 da e2, bi da bi.Kololuwa (002) a 4.31 da 4.32 sun dace da abin da aka bayyana a baya Layered MXenes Nb2CTx da Nb4C3TX38,39,40,41 bi da bi.Sakamakon XRD kuma yana nuna kasancewar wasu sifofi na ML da suka rage da kuma matakan MAX, amma galibin tsarin XRD da ke da alaƙa da SL Nb4C3Tx (Fig. 2e2).Kasancewar ƙananan ɓangarorin lokaci na MAX na iya yin bayanin mafi girman kololuwar MAX idan aka kwatanta da yaduddukan Nb4C3Tx da aka tara bazuwar.
Ƙarin bincike ya mayar da hankali kan koren microalgae na nau'in R. subcapitata.Mun zaɓi microalgae saboda sune masu kera masu mahimmanci waɗanda ke da hannu cikin manyan gidajen yanar gizo na abinci42.Hakanan suna ɗaya daga cikin mafi kyawun alamun guba saboda ikon cire abubuwa masu guba waɗanda ake ɗauka zuwa manyan matakan sarkar abinci43.Bugu da ƙari, bincike a kan R. subcapitata na iya ba da haske game da rashin lafiyar SL Nb-MXenes zuwa kwayoyin halitta na ruwa na yau da kullum.Don kwatanta wannan, masu binciken sunyi tsammanin cewa kowane microbe yana da nau'i daban-daban ga mahadi masu guba da ke cikin yanayi.Ga mafi yawan kwayoyin halitta, ƙananan ƙwayoyin abubuwa ba sa tasiri ga ci gaban su, yayin da ƙididdiga sama da ƙayyadaddun iyaka na iya hana su ko ma haifar da mutuwa.Sabili da haka, don nazarin mu game da hulɗar da ke tsakanin microalgae da MXenes da kuma dawo da haɗin gwiwa, mun yanke shawarar gwada ƙananan ƙwayoyin cuta da masu guba na Nb-MXenes.Don yin wannan, mun gwada ƙididdiga na 0 (a matsayin tunani), 0.01, 0.1 da 10 mg l-1 MXene da kuma kamuwa da microalgae tare da babban adadin MXene (100 mg l-1 MXene), wanda zai iya zama matsananci kuma mai mutuwa..ga kowane yanayi na halitta.
Ana nuna tasirin SL Nb-MXenes akan microalgae a cikin Hoto 3, wanda aka bayyana azaman adadin haɓaka haɓaka (+) ko hanawa (-) wanda aka auna don samfuran 0 mg l-1.Don kwatantawa, an gwada lokaci na Nb-MAX da ML Nb-MXenes kuma an nuna sakamakon a SI (duba siffa S3).Sakamakon da aka samu ya tabbatar da cewa SL Nb-MXenes kusan ba shi da guba a cikin kewayon ƙananan ƙira daga 0.01 zuwa 10 mg / l, kamar yadda aka nuna a cikin Fig. 3a,b.A cikin yanayin Nb2CTx, mun lura ba fiye da 5% ecotoxicity a cikin kewayon da aka ƙayyade ba.
Ƙarfafawa (+) ko hanawa (-) ci gaban microalgae a gaban SL (a) Nb2CTx da (b) Nb4C3TX MXene.24, 48 da 72 hours na hulɗar MXene-microalgae an yi nazari. Bayanai masu mahimmanci (t-gwajin, p <0.05) an yi musu alama tare da alamar alama (*). Bayanai masu mahimmanci (t-gwajin, p <0.05) an yi musu alama tare da alamar alama (*). Значимые данные (t-критерий, p <0,05) отмечены звездочкой (*). Mahimman bayanai (t-gwajin, p <0.05) ana yiwa alama alama (*).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-gwajin, p <0,05) отмечены звездочкой (*). Bayanai masu mahimmanci (t-gwajin, p <0.05) ana yiwa alama alama (*).Jajayen kibau suna nuna kawar da kuzarin hanawa.
A gefe guda, ƙananan ƙididdiga na Nb4C3TX ya juya ya zama dan kadan mai guba, amma bai fi 7% ba.Kamar yadda aka zata, mun lura cewa MXenes yana da yawan guba da kuma hana ci gaban microalgae a 100mg L-1.Abin sha'awa, babu wani abu daga cikin kayan da ya nuna irin wannan yanayin da kuma dogara da lokaci na mai guba / mai guba idan aka kwatanta da samfurori na MAX ko ML (duba SI don cikakkun bayanai).Yayin da lokacin MAX (duba siffa S3) mai guba ya kai kusan 15-25% kuma ya karu tare da lokaci, an lura da yanayin da aka canza don SL Nb2CTx da Nb4C3TX MXene.Hana ci gaban microalgae ya ragu akan lokaci.Ya kai kusan 17% bayan sa'o'i 24 kuma ya ragu zuwa ƙasa da 5% bayan sa'o'i 72 (Fig. 3a, b, bi da bi).
Mafi mahimmanci, don SL Nb4C3TX, hana haɓakar microalgae ya kai kusan 27% bayan sa'o'i 24, amma bayan sa'o'i 72 ya ragu zuwa kusan 1%.Sabili da haka, mun lakafta tasirin da aka lura a matsayin ingantacciyar hana haɓakawa, kuma tasirin ya fi ƙarfi ga SL Nb4C3TX MXene.An lura da haɓakar haɓakar microalgae a baya tare da Nb4C3TX (ma'amala a 10 MG L-1 don 24 h) idan aka kwatanta da SL Nb2CTx MXene.Har ila yau, an nuna tasirin hanawa-ƙarfafawa da kyau a cikin biomass biomass rate curve (duba siffa S4 don cikakkun bayanai).Ya zuwa yanzu, kawai ecotoxicity na Ti3C2TX MXene an yi nazarin ta hanyoyi daban-daban.Ba mai guba bane ga embryos na zebrafish44 amma matsakaicin ecotoxic zuwa microalgae Desmodesmus quadricauda da sorghum saccharatum shuke-shuke45.Sauran misalan takamaiman tasirin sun haɗa da mafi girman guba ga layin ƙwayoyin cutar kansa fiye da layin salula na al'ada46,47.Ana iya ɗauka cewa yanayin gwajin zai tasiri canje-canje a cikin ci gaban microalgae da aka lura a gaban Nb-MXenes.Misali, pH na kusan 8 a cikin chloroplast stroma shine mafi kyawun aiki don ingantaccen aiki na enzyme RuBisCO.Saboda haka, pH canje-canje sun yi mummunan tasiri akan ƙimar photosynthesis48,49.Duk da haka, ba mu lura da canje-canje masu mahimmanci a cikin pH ba yayin gwajin (duba SI, Fig. S5 don cikakkun bayanai).Gabaɗaya, al'adun microalgae tare da Nb-MXenes kaɗan sun rage pH na maganin a kan lokaci.Koyaya, wannan raguwa yayi kama da canji a cikin pH na matsakaici mai tsafta.Bugu da ƙari, kewayon bambance-bambancen da aka samo sun kasance daidai da wanda aka auna don al'ada mai tsabta na microalgae (samfurin sarrafawa).Don haka, mun yanke shawarar cewa canje-canje a pH ba ya shafar photosynthesis.
Bugu da kari, MXenes da aka haɗa suna da ƙarshen saman (wanda aka nuna azaman Tx).Waɗannan su ne galibi ƙungiyoyin aiki -O, -F da -OH.Duk da haka, ilimin kimiyyar sararin samaniya yana da alaƙa kai tsaye da hanyar haɗin gwiwa.An san waɗannan ƙungiyoyin da za a rarraba su ba tare da izini ba a saman, yana da wuya a iya hango hasashen tasirin su akan kaddarorin MXene50.Ana iya jayayya cewa Tx na iya zama ƙarfin kuzari don iskar oxygenation na niobium ta haske.Ƙungiyoyin ayyuka na saman haƙiƙa suna ba da rukunoni masu yawa don ɗaukar hoto na asali don samar da heterojunctions51.Koyaya, matsakaicin matsakaicin haɓaka bai samar da ingantaccen photocatalyst (ana iya samun cikakken abun da ke cikin matsakaici a cikin SI Table S6).Bugu da kari, duk wani surface gyare-gyare yana da matukar muhimmanci, kamar yadda nazarin halittu aiki na MXenes za a iya canza saboda Layer post-processing, hadawan abu da iskar shaka, sinadaran surface gyara na Organic da inorganic mahadi52,53,54,55,56 ko surface cajin injiniya38.Sabili da haka, don gwada ko niobium oxide yana da wani abu da ya dace da rashin daidaituwa na kayan abu a cikin matsakaici, mun gudanar da nazarin yiwuwar zeta (ζ) a cikin ƙananan ci gaban microalgae da ruwa mai tsabta (don kwatanta).Sakamakonmu ya nuna cewa SL Nb-MXenes suna da kwanciyar hankali (duba SI Fig. S6 don sakamakon MAX da ML).Yiwuwar zeta na SL MXenes shine kusan -10 mV.A cikin yanayin SR Nb2CTx, ƙimar ζ yana da ɗan ƙaranci fiye da na Nb4C3Tx.Irin wannan canji a cikin ƙimar ζ na iya nuna cewa saman MXene nanoflakes mara kyau yana ɗaukar ions masu inganci daga matsakaicin al'ada.Ma'auni na wucin gadi na yuwuwar zeta da haɓakawa na Nb-MXenes a cikin matsakaicin al'adu (duba Figures S7 da S8 a SI don ƙarin cikakkun bayanai) suna neman tallafawa hasashen mu.
Koyaya, duka Nb-MXene SLs sun nuna ƙaramin canje-canje daga sifili.Wannan a fili yana nuna kwanciyar hankali a cikin matsakaicin ci gaban microalgae.Bugu da ƙari, mun tantance ko kasancewar koren microalgae ɗin mu zai shafi kwanciyar hankali na Nb-MXenes a cikin matsakaici.Sakamakon yuwuwar zeta da haɓakawa na MXenes bayan hulɗa tare da microalgae a cikin kafofin watsa labarai na abinci da al'adu a tsawon lokaci ana iya samun su a SI (Figures S9 da S10).Abin sha'awa, mun lura cewa kasancewar microalgae ya zama kamar ya daidaita tarwatsawar MXenes biyu.A cikin yanayin Nb2CTx SL, yuwuwar zeta ko da dan kadan ya ragu akan lokaci zuwa ƙarin ƙimar mara kyau (-15.8 da -19.1 mV bayan 72 h na shiryawa).Halin zeta na SL Nb4C3TX ya karu kadan, amma bayan 72 h har yanzu yana nuna kwanciyar hankali fiye da nanoflakes ba tare da kasancewar microalgae (-18.1 vs. -9.1 mV).
Mun kuma sami ƙananan ƙaddamarwa na Nb-MXene mafita wanda aka haɗa a gaban microalgae, yana nuna ƙananan adadin ions a cikin matsakaici na gina jiki.Musamman ma, rashin zaman lafiyar MXenes a cikin ruwa shine yafi saboda oxidation surface57.Saboda haka, muna zargin cewa koren microalgae ko ta yaya share oxides kafa a saman Nb-MXene kuma ko da hana su faru (oxidation na MXene).Ana iya ganin wannan ta hanyar nazarin nau'ikan abubuwan da microalgae ke sha.
Yayin da binciken mu na ecotoxicological ya nuna cewa microalgae sun iya shawo kan gubar Nb-MXenes a tsawon lokaci da kuma hanawa da ba a saba ba na haɓaka haɓaka, manufar binciken mu shine bincika hanyoyin da za a iya aiwatarwa.Lokacin da kwayoyin halitta irin su algae suka fallasa ga mahadi ko kayan da ba a saba da su ba, za su iya mayar da martani ta hanyoyi daban-daban58,59.Idan babu oxides karfe mai guba, microalgae na iya ciyar da kansu, ba su damar ci gaba da girma60.Bayan shan abubuwa masu guba, ana iya kunna hanyoyin kariya, kamar canza siffa ko tsari.Yiwuwar sha dole ne kuma a yi la'akari da58,59.Musamman ma, duk wata alama ta hanyar tsaro wata alama ce bayyananne na gubar wurin gwajin.Sabili da haka, a cikin aikinmu na gaba, mun bincika yuwuwar hulɗar da ke tsakanin SL Nb-MXene nanoflakes da microalgae ta SEM da kuma yiwuwar shayar da Nb-based MXene ta X-ray fluorescence spectroscopy (XRF).Lura cewa ƙididdigar SEM da XRF an yi su ne kawai a mafi girman ƙaddamar da MXene don magance matsalolin guba na ayyuka.
Ana nuna sakamakon SEM a cikin Fig.4.Kwayoyin microalgae da ba a kula da su ba (duba siffa 4a, samfurin tunani) a fili ya nuna yanayin R. subcapitata ilimin halittar jiki da siffar tantanin halitta kamar croissant.Kwayoyin suna bayyana baƙaƙe da ɗan rashin tsari.Wasu ƙwayoyin microalgae sun mamaye juna kuma sun haɗa juna, amma wannan ƙila ya faru ne ta hanyar tsarin shirya samfurin.Gabaɗaya, ƙwayoyin ƙwayoyin microalgae masu tsabta suna da ƙasa mai santsi kuma ba su nuna wani canje-canjen yanayin halitta ba.
Hotunan SEM suna nuna hulɗar ƙasa tsakanin koren microalgae da MXene nanosheets bayan 72 hours na hulɗar a matsananciyar hankali (100 MG L-1).(a) Koren microalgae mara magani bayan hulɗa tare da SL (b) Nb2CTx da (c) Nb4C3TX MXenes.Lura cewa Nb-MXene nanoflakes ana yiwa alama da kibiyoyi ja.Don kwatantawa, ana kuma ƙara hotuna daga na'urar gani da ido.
Sabanin haka, ƙwayoyin microalgae da SL Nb-MXene nanoflakes ke tallatawa sun lalace (duba siffa 4b, c, kibiyoyi ja).A cikin yanayin Nb2CTx MXene (Fig. 4b), microalgae suna girma tare da nanoscales masu girma biyu da aka haɗe, wanda zai iya canza yanayin su.Musamman ma, mun kuma lura da waɗannan sauye-sauye a ƙarƙashin ƙaramin haske (duba SI Figure S11 don cikakkun bayanai).Wannan sauye-sauyen yanayin halitta yana da tushe mai ma'ana a cikin ilimin halittar jiki na microalgae da ikon su na kare kansu ta hanyar canza yanayin halittar tantanin halitta, kamar haɓaka ƙarar tantanin halitta61.Sabili da haka, yana da mahimmanci don bincika adadin ƙwayoyin microalgae waɗanda ke da alaƙa da Nb-MXenes.Nazarin SEM ya nuna cewa kusan 52% na ƙwayoyin microalgae an fallasa su zuwa Nb-MXenes, yayin da 48% na waɗannan ƙwayoyin microalgae sun guje wa haɗuwa.Don SL Nb4C3Tx MXene, microalgae yayi ƙoƙari don guje wa hulɗa da MXene, ta haka ne ke ganowa da girma daga nanoscales mai girma biyu (Fig. 4c).Koyaya, ba mu lura da shigar nanoscales cikin ƙwayoyin microalgae da lalacewarsu ba.
Kiyaye kai kuma hali ne na dogaro da lokaci ga toshewar photosynthesis saboda tallan barbashi a saman tantanin halitta da abin da ake kira shading (shading) sakamako62.A bayyane yake cewa kowane abu (misali, Nb-MXene nanoflakes) wanda ke tsakanin microalgae da tushen haske yana iyakance adadin hasken da chloroplasts ke ɗauka.Duk da haka, ba mu da shakka cewa wannan yana da tasiri mai mahimmanci ga sakamakon da aka samu.Kamar yadda aka nuna ta hanyar binciken mu na ƙwanƙwasa, 2D nanoflakes ba a nannade gaba ɗaya ba ko manne da saman microalgae, ko da lokacin da ƙwayoyin microalgae ke hulɗa da Nb-MXenes.Madadin haka, nanoflakes ya juya ya zama daidaitacce zuwa ƙwayoyin microalgae ba tare da rufe saman su ba.Irin wannan saitin nanoflakes/microalgae ba zai iya iyakance adadin hasken da ƙwayoyin microalgae ke ɗauka ba.Bugu da ƙari, wasu nazarin sun ma nuna ci gaba a cikin shayar da haske ta hanyar kwayoyin photoynthetic a gaban nanomaterials masu girma biyu63,64,65,66.
Tun da hotunan SEM ba za su iya tabbatar da ɗaukar niobium ta hanyar ƙwayoyin microalgae kai tsaye ba, ƙarin bincikenmu ya juya zuwa X-ray fluorescence (XRF) da X-ray photoelectron spectroscopy (XPS) bincike don bayyana wannan batu.Sabili da haka, mun kwatanta girman kololuwar Nb na samfuran samfuran microalgae waɗanda ba su yi hulɗa da MXenes ba, MXene nanoflakes da aka ware daga saman sel microalgae, da ƙwayoyin microalgal bayan cirewar MXenes da aka haɗe.Yana da kyau a lura cewa idan babu karɓar Nb, ƙimar Nb da aka samu ta ƙwayoyin microalgae ya kamata ya zama sifili bayan cire nanoscales da aka haɗe.Don haka, idan ɗaukan Nb ya faru, duka sakamakon XRF da XPS yakamata su nuna cikakkiyar kololuwar Nb.
A cikin yanayin XRF spectra, samfurori na microalgae sun nuna Nb kololuwa na SL Nb2CTx da Nb4C3Tx MXene bayan hulɗa tare da SL Nb2CTx da Nb4C3Tx MXene (duba Fig. 5a, kuma lura cewa an nuna sakamakon MAX da ML MXenes a SI, Figs S12).Abin sha'awa shine, tsananin ƙarfin Nb ɗin daidai yake a cikin lokuta biyu (sanduna ja a cikin siffa 5a).Wannan ya nuna cewa algae ba zai iya ɗaukar fiye da Nb ba, kuma an sami iyakar ƙarfin don tarawa na Nb a cikin sel, kodayake sau biyu fiye da Nb4C3Tx MXene an haɗa shi zuwa ƙwayoyin microalgae (sanduna blue a cikin Fig. 5a).Musamman ma, ikon microalgae don ɗaukar karafa ya dogara ne akan yawan adadin oxides na ƙarfe a cikin muhalli67,68.Shamshada et al.67 ya gano cewa ƙarfin shayarwa na algae ruwan sha yana raguwa tare da karuwar pH.Raize et al.68 ya lura cewa iyawar ciyawa don ɗaukar karafa ya kasance kusan 25% mafi girma ga Pb2+ fiye da na Ni2+.
(a) Sakamakon XRF na basal Nb ta hanyar ƙwayoyin microalgae koren da aka haɗa a cikin matsanancin ƙwayar SL Nb-MXenes (100 mg L-1) na 72 hours.Sakamakon ya nuna kasancewar α a cikin ƙwayoyin microalgae mai tsabta (samfurin sarrafawa, ginshiƙan launin toka), 2D nanoflakes da aka ware daga sel microalgae (ginshiƙan shuɗi), da ƙwayoyin microalgae bayan rabuwa na 2D nanoflakes daga saman ( ginshiƙan ja).Adadin Nb na farko, (b) kashi na sinadarai na ƙwayoyin ƙwayoyin ƙwayoyin ƙwayoyin microalgae (C = O da CHx / C-O) da kuma Nb oxides da ke cikin ƙwayoyin microalgae bayan an haɗa su tare da SL Nb-MXenes, (c-e) Daidaitawa ga kololuwar ƙirar XPS SL Nb2CTx spectra da (fhene) SL NX SL NXXX microXXX.
Saboda haka, muna sa ran cewa Nb zai iya shayar da kwayoyin algal a cikin nau'i na oxides.Don gwada wannan, mun yi nazarin XPS akan MXenes Nb2CTx da Nb4C3TX da ƙwayoyin algae.Sakamakon hulɗar microalgae tare da Nb-MXenes da MXenes da aka ware daga kwayoyin algae an nuna su a cikin Figs.5b ku.Kamar yadda aka zata, mun gano kololuwar Nb 3d a cikin samfuran microalgae bayan cirewar MXene daga saman microalgae.An ƙididdige ƙayyadaddun ƙididdiga na C = O, CHx / CO, da Nb oxides bisa ga Nb 3d, O 1s, da C 1s da aka samu tare da Nb2CTx SL (Fig. 5c-e) da Nb4C3Tx SL (Fig. 5c-e).) samu daga incubated microalgae.Hoto na 5f–h) MXenes.Tebura S1-3 yana nuna cikakkun bayanai na ma'auni na kololuwa da gabaɗayan sinadarai waɗanda ke haifar da dacewa.Yana da mahimmanci cewa yankunan Nb 3d na Nb2CTx SL da Nb4C3Tx SL (Fig. 5c, f) sun dace da ɗayan Nb2O5.Anan, ba mu sami kololuwa masu alaƙa da MXene a cikin bakan, yana nuna cewa ƙwayoyin microalgae kawai suna ɗaukar nau'in oxide na Nb.Bugu da ƙari, mun ƙaddamar da bakan C 1 tare da abubuwan C-C, CHx/C–O, C = O, da -COOH.Mun sanya kololuwar CHx/C–O da C = O zuwa ga gudummawar kwayoyin halitta na ƙwayoyin microalgae.Waɗannan abubuwan ɓangarorin halitta suna lissafin 36% da 41% na kololuwar C 1s a cikin Nb2CTx SL da Nb4C3TX SL, bi da bi.Daga nan mun dace da sikelin O 1s na SL Nb2CTx da SL Nb4C3TX tare da Nb2O5, abubuwan da aka gyara na microalgae (CHx/CO), da ruwa mai tallata ruwa.
A ƙarshe, sakamakon XPS ya nuna a sarari nau'in Nb, ba kawai kasancewar sa ba.Dangane da matsayi na siginar Nb 3d da sakamakon deconvolution, mun tabbatar da cewa Nb yana tunawa ne kawai a cikin nau'i na oxides kuma ba ions ko MXene kanta ba.Bugu da ƙari, sakamakon XPS ya nuna cewa ƙwayoyin microalgae suna da ikon da za su iya ɗaukar Nb oxides daga SL Nb2CTx idan aka kwatanta da SL Nb4C3TX MXene.
Yayin da sakamakon karɓar Nb ɗin mu yana da ban sha'awa kuma yana ba mu damar gano lalacewar MXene, babu wata hanya da za a iya bi don bibiyar sauye-sauyen yanayi a cikin 2D nanoflakes.Sabili da haka, mun kuma yanke shawarar haɓaka hanyar da ta dace wacce za ta iya amsa kai tsaye ga kowane canje-canje da ke faruwa a cikin 2D Nb-MXene nanoflakes da ƙwayoyin microalgae.Yana da mahimmanci a lura cewa muna ɗauka cewa idan nau'in hulɗar ya sami wani canji, ɓarna ko ɓarna, wannan ya kamata ya bayyana da sauri a matsayin canje-canje a cikin sigogin sifofi, kamar diamita na daidai wurin madauwari, zagaye, nisa Feret, ko tsayin Feret.Tun da waɗannan sigogi sun dace don kwatanta ƙwayoyin elongated ko nanoflakes masu girma biyu, bin diddigin su ta hanyar bincike mai ƙarfi mai ƙarfi zai ba mu bayani mai mahimmanci game da canjin yanayin halittar SL Nb-MXene nanoflakes yayin raguwa.
Ana nuna sakamakon da aka samu a cikin Hoto 6. Don kwatanta, mun kuma gwada ainihin lokacin MAX da ML-MXenes (duba SI Figures S18 da S19).Binciken mai ƙarfi na sifar barbashi ya nuna cewa duk sigogin sifofi na Nb-MXene SLs guda biyu sun canza sosai bayan hulɗa tare da microalgae.Kamar yadda aka nuna ta wurin madaidaicin madauwari mai faɗin yanki (Hoto 6a, b), rage girman ƙarfin juzu'i na manyan nanoflakes yana nuna cewa suna ƙanƙantar da lalacewa zuwa ƙananan guntu.A kan fig.6c, d yana nuna raguwa a cikin kololuwar da ke da alaƙa da girman juzu'i na flakes (exlongation na nanoflakes), yana nuna canjin nanoflakes na 2D zuwa wani nau'i mai kama da barbashi.Hoto na 6e-h yana nuna nisa da tsayin Feret, bi da bi.Faɗin ƙafafu da tsayin su ne ma'auni masu dacewa don haka ya kamata a yi la'akari da su tare.Bayan shiryawa na 2D Nb-MXene nanoflakes a gaban microalgae, kololuwar alaƙar su ta Feret ta motsa kuma ƙarfinsu ya ragu.Dangane da waɗannan sakamakon a hade tare da ilimin halittar jiki, XRF da XPS, mun kammala cewa canje-canjen da aka lura suna da alaƙa da haɓakar iskar shaka yayin da MXenes oxidized ya zama mafi wrinkled kuma ya rushe cikin gutsuttsura da spherical oxide particles69,70.
Binciken canjin MXene bayan hulɗa tare da microalgae kore.Binciken siffar barbashi mai ƙarfi yana yin la'akari da sigogi kamar (a, b) diamita daidai wurin madauwari, (c, d) zagaye, (e, f) Faɗin ƙafa da (g, h) Tsawon ƙafar ƙafa.Don wannan karshen, an bincika samfuran microalgae guda biyu tare da SL Nb2CTx na farko da SL Nb4C3Tx MXenes, SL Nb2CTx da SL Nb4C3Tx MXenes, ƙananan microalgae, da kuma kula da microalgae SL Nb2CTx da SL Nb4C3Tx MXenes.Jajayen kiban suna nuna jujjuyawar sifofin siffa na nanoflakes masu girma biyu da aka yi nazari.
Tunda binciken siga na sigar abin dogaro ne sosai, kuma yana iya bayyana sauye-sauyen yanayi a cikin ƙwayoyin microalgae.Saboda haka, mun bincika daidai da diamita madauwari yanki, zagaye, da Feret nisa/tsawon tsantsar ƙwayoyin microalgae da sel bayan hulɗa tare da 2D Nb nanoflakes.A kan fig.6a-h yana nuna canje-canje a cikin sigogin sifofin algae, kamar yadda aka nuna ta hanyar raguwa a cikin ƙarfin kololuwa da kuma motsi na maxima zuwa mafi girma dabi'u.Musamman ma, sigogi na zagaye na tantanin halitta sun nuna raguwa a cikin ƙwayoyin elongated da karuwa a cikin kwayoyin halitta (Fig. 6a, b).Bugu da ƙari, faɗin tantanin halitta Feret ya karu da micrometers da yawa bayan hulɗa tare da SL Nb2CTx MXene (Fig. 6e) idan aka kwatanta da SL Nb4C3TX MXene (Fig. 6f).Muna zargin cewa wannan na iya kasancewa saboda ƙarfin ɗaukar Nb oxides ta microalgae akan hulɗa tare da Nb2CTx SR.Ƙananan haɗe-haɗe na Nb flakes zuwa samansu na iya haifar da haɓakar tantanin halitta tare da ƙarancin shading.
Abubuwan da muka lura na canje-canje a cikin sigogi na sifa da girman microalgae sun dace da wasu nazarin.Koren microalgae na iya canza yanayin halittar su don mayar da martani ga matsalolin muhalli ta hanyar canza girman tantanin halitta, siffar ko metabolism61.Misali, canza girman sel yana sauƙaƙe sha na abubuwan gina jiki71.Ƙananan ƙwayoyin algae suna nuna ƙarancin haɓakar abinci mai gina jiki da ƙarancin girma.Sabanin haka, sel masu girma suna son cin abinci mai gina jiki, wanda sai a ajiye su ta cikin salula72,73.Machado da Soares sun gano cewa triclosan fungicide na iya ƙara girman tantanin halitta.Sun kuma sami canje-canje masu zurfi a cikin siffar algae74.Bugu da ƙari, Yin et al.9 kuma ya bayyana sauye-sauyen ilimin halittar jiki a cikin algae bayan da aka fallasa zuwa rage yawan graphene oxide nanocomposites.Sabili da haka, a bayyane yake cewa canje-canjen girman / siffar sifofi na microalgae suna haifar da kasancewar MXene.Tun da wannan canji a girman da siffar yana nuna alamun canje-canje a cikin abubuwan da ake amfani da su na gina jiki, mun yi imanin cewa nazarin girman da sikelin sifofi a tsawon lokaci zai iya nuna nauyin niobium oxide ta microalgae a gaban Nb-MXenes.
Bugu da ƙari, MXenes na iya zama oxidized a gaban algae.Dalai et al.75 ya lura cewa ilimin halittar halitta na kore algae da aka fallasa zuwa nano-TiO2 da Al2O376 ba daidai ba ne.Kodayake abubuwan da muka lura sun yi kama da binciken na yanzu, yana da dacewa kawai don nazarin tasirin bioremediation dangane da samfuran lalata MXene a gaban 2D nanoflakes kuma ba nanoparticles ba.Tun da MXenes na iya raguwa zuwa karfe oxides,31,32,77,78 yana da kyau a ɗauka cewa Nb nanoflakes ɗinmu kuma na iya samar da Nb oxides bayan yin hulɗa tare da ƙwayoyin microalgae.
Don bayyana raguwar 2D-Nb nanoflakes ta hanyar tsarin bazuwa dangane da tsarin iskar oxygen, mun gudanar da nazarin ta yin amfani da microscope na lantarki mai mahimmanci (HRTEM) (Fig. 7a,b) da kuma X-ray photoelectron spectroscopy (XPS) (Fig. 7).7c-i da tebur S4-5).Dukansu hanyoyin sun dace don nazarin oxidation na kayan 2D kuma suna daidaita juna.Hrtem yana iya nazarin lalacewar yanayin da aka yi amfani da shi sau biyu da kuma bayyanar da XPS na gaba na ƙarfe na ƙarfe na ƙarfe, yayin da XPs yana kula da shaidu na ƙasa.Don wannan dalili, mun gwada 2D Nb-MXene nanoflakes da aka samo daga microalgae cell dispersions, wato, siffar su bayan hulɗa tare da kwayoyin microalgae (duba siffa 7).
Hotunan HRTEM da ke nuna ilimin halittar jiki na oxidized (a) SL Nb2CTx da (b) SL Nb4C3Tx MXenes, sakamakon bincike na XPS da ke nuna (c) abun da ke tattare da samfuran oxide bayan raguwa, (d-f) madaidaicin madaidaicin abubuwan da ke cikin sikelin XPS na SL Nb2CTx da (g-i) Nb4C3T da aka gyara tare da micro SLga.
Nazarin HRTEM sun tabbatar da iskar shaka na nau'ikan nau'ikan Nb-MXene nanoflakes guda biyu.Ko da yake nanoflakes sun ci gaba da riƙe nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i) nau'i-nau'i-nanoflakes.Binciken XPS na c Nb 3d da siginar O 1s sun nuna cewa an samar da Nb oxides a cikin duka biyun.Kamar yadda aka nuna a cikin Hoto 7c, 2D MXene Nb2CTx da Nb4C3TX suna da siginar Nb 3d da ke nuna kasancewar NbO da Nb2O5 oxides, yayin da siginar O 1s suna nuna adadin O-Nb bonds da ke hade da aikin aiki na 2D nanoflake surface.Mun lura cewa gudummawar Nb oxide ta mamaye idan aka kwatanta da Nb-C da Nb3+-O.
A kan fig.Figures 7g-i suna nuna nau'in XPS na Nb 3d, C 1s, da O 1s SL Nb2CTx (duba Fig. 7d-f) da SL Nb4C3TX MXene keɓe daga ƙwayoyin microalgae.Ana ba da cikakkun bayanai na ma'auni mafi girman Nb-MXenes a cikin Tables S4-5, bi da bi.Mun fara bincikar abubuwan da ke cikin Nb 3d.Ya bambanta da Nb da ƙwayoyin microalgae ke sha, a cikin MXene keɓe daga ƙwayoyin microalgae, ban da Nb2O5, an samo wasu abubuwan.A cikin Nb2CTx SL, mun lura da gudummawar Nb3+ -O a cikin adadin 15%, yayin da sauran Nb 3d spectrum ya mamaye Nb2O5 (85%).Bugu da ƙari, samfurin SL Nb4C3TX ya ƙunshi abubuwan Nb-C (9%) da Nb2O5 (91%).Anan Nb-C ya fito daga nau'ikan atomic guda biyu na karfen carbide a cikin Nb4C3Tx SR.Sa'an nan kuma mu yi taswirar bakan C 1s zuwa sassa huɗu daban-daban, kamar yadda muka yi a cikin samfuran ciki.Kamar yadda ake tsammani, bakan C 1s yana mamaye da carbon mai hoto, sannan gudummawar da aka samu daga kwayoyin halitta (CHx/CO da C = O) daga ƙwayoyin microalgae.Bugu da ƙari, a cikin bakan O 1s, mun lura da gudummawar nau'o'in kwayoyin halitta na ƙwayoyin microalgae, niobium oxide, da ruwa mai yalwaci.
Bugu da ƙari, mun bincika ko Nb-MXenes cleavage yana da alaƙa da kasancewar nau'in oxygen mai amsawa (ROS) a cikin ma'aunin abinci mai gina jiki da / ko ƙwayoyin microalgae.Don wannan karshen, mun tantance matakan iskar oxygen guda ɗaya (1O2) a cikin matsakaicin al'ada da kuma glutathione na intracellular, thiol wanda ke aiki azaman antioxidant a cikin microalgae.Ana nuna sakamakon a SI (Hoto S20 da S21).Al'adu tare da SL Nb2CTx da Nb4C3TX MXenes an kwatanta su da raguwar adadin 1O2 (duba Hoto S20).A cikin yanayin SL Nb2CTx, MXene 1O2 an rage shi zuwa kusan 83%.Don al'adun microalgae ta amfani da SL, Nb4C3TX 1O2 ya ragu har ma da ƙari, zuwa 73%.Abin sha'awa shine, canje-canje a cikin 1O2 sun nuna irin wannan yanayin kamar yadda aka gani a baya-bayanar tasirin hanawa-stimulatory (duba siffa 3).Ana iya jayayya cewa shiryawa a cikin haske mai haske na iya canza photooxidation.Duk da haka, sakamakon binciken bincike ya nuna kusan matakan 1O2 akai-akai a lokacin gwaji (Fig. S22).Dangane da matakan ROS na cikin salula, mun kuma lura da yanayin ƙasa iri ɗaya (duba Hoto S21).Da farko, matakan ROS a cikin ƙwayoyin microalgae da aka haɓaka a gaban Nb2CTx da Nb4C3Tx SLs sun wuce matakan da aka samo a cikin al'adu masu tsabta na microalgae.Daga ƙarshe, duk da haka, ya bayyana cewa microalgae ya dace da kasancewar duka Nb-MXenes, yayin da matakan ROS suka ragu zuwa 85% da 91% na matakan da aka auna a cikin al'adu masu tsabta na microalgae da aka yi tare da SL Nb2CTx da Nb4C3TX, bi da bi.Wannan na iya nuna cewa microalgae yana jin dadi a tsawon lokaci a gaban Nb-MXene fiye da matsakaicin abinci mai gina jiki kadai.
Microalgae rukuni ne daban-daban na kwayoyin photosynthesis.A lokacin photosynthesis, suna canza yanayin carbon dioxide (CO2) zuwa carbon carbon.Abubuwan photosynthesis sune glucose da oxygen79.Muna tsammanin cewa iskar oxygen ta haka aka kafa tana taka muhimmiyar rawa a cikin iskar oxygenation na Nb-MXenes.Ɗaya daga cikin bayanin da za a iya yi don wannan shine cewa an kafa ma'auni na aeration daban-daban a ƙananan ƙananan matsa lamba na oxygen a waje da cikin Nb-MXene nanoflakes.Wannan yana nufin cewa duk inda akwai wurare daban-daban na matsi na iskar oxygen, yankin da ke da mafi ƙanƙanci zai samar da anode 80, 81, 82. A nan, microalgae yana taimakawa wajen samar da kwayoyin halitta daban-daban a saman filayen MXene, wanda ke samar da iskar oxygen saboda halayen hotuna.A sakamakon haka, an kafa samfuran biocorrosion (a cikin wannan yanayin, niobium oxides).Wani al'amari shine cewa microalgae na iya samar da kwayoyin acid da aka saki a cikin ruwa83,84.Sabili da haka, an kafa yanayi mai ban tsoro, don haka canza Nb-MXenes.Bugu da ƙari, microalgae na iya canza pH na yanayi zuwa alkaline saboda shayar da carbon dioxide, wanda kuma zai iya haifar da lalata79.
Mafi mahimmanci, lokacin duhu / haske da aka yi amfani da shi a cikin bincikenmu yana da mahimmanci don fahimtar sakamakon da aka samu.An kwatanta wannan dalla-dalla a cikin Djemai-Zoglache et al.85 Da gangan sun yi amfani da lokacin daukar hoto na awa 12/12 don nuna biocorrosion mai alaƙa da biofouling ta microalgae Porphyridium purpureum.Suna nuna cewa lokacin daukar hoto yana da alaƙa da juyin halitta na yuwuwar ba tare da biocorrosion ba, yana bayyana kanta azaman oscillations pseudoperiodic a kusa da 24:00.Dowling et al ya tabbatar da waɗannan abubuwan lura.86 Sun nuna hotunan biofilms na cyanobacteria Anabaena.An narkar da iskar oxygen a ƙarƙashin aikin haske, wanda ke da alaƙa da canji ko sauye-sauye a cikin yuwuwar biocorrosion na kyauta.An jaddada mahimmancin lokaci na photoperiod ta gaskiyar cewa damar da za a iya samun kyauta don biocorrosion yana ƙaruwa a cikin lokacin haske kuma yana raguwa a cikin duhu.Wannan ya faru ne saboda iskar oxygen da microalgae na photosynthetic ke samarwa, wanda ke yin tasiri ga yanayin cathodic ta hanyar matsa lamba da aka samar kusa da electrodes87.
Bugu da ƙari, an yi Fourier transform infrared spectroscopy (FTIR) don gano ko wasu canje-canje sun faru a cikin sinadarai na ƙwayoyin microalgae bayan hulɗa tare da Nb-MXenes.Waɗannan sakamakon da aka samu suna da rikitarwa kuma muna gabatar da su a cikin SI (Figures S23-S25, gami da sakamakon matakin MAX da ML MXenes).A takaice, bayanan da aka samu na microalgae suna ba mu mahimman bayanai game da halayen sinadarai na waɗannan kwayoyin halitta.Wadannan firgita masu yuwuwa suna samuwa a mitoci na 1060 cm-1 (CO), 1540 cm-1, 1640 cm-1 (C=C), 1730 cm-1 (C=O), 2850 cm-1, 2920 cm-1.daya.1 1 (C-H) da 3280 cm-1 (O-H).Don SL Nb-MXenes, mun sami sa hannun miƙewa na CH-bond wanda ya yi daidai da bincikenmu na baya38.Koyaya, mun lura cewa wasu ƙarin kololuwa masu alaƙa da haɗin C=C da CH sun ɓace.Wannan yana nuna cewa sinadarai na microalgae na iya fuskantar ƙananan canje-canje saboda hulɗa tare da SL Nb-MXenes.
Idan aka yi la'akari da yuwuwar canje-canje a cikin biochemistry na microalgae, tarin inorganic oxides, kamar niobium oxide, yana buƙatar sake tunani59.Yana da hannu a cikin ɗaukar karafa ta fuskar tantanin halitta, jigilar su zuwa cikin cytoplasm, haɗin gwiwa tare da ƙungiyoyin carboxyl na ciki, da kuma tarin su a cikin microalgae polyphosphosomes20,88,89,90.Bugu da ƙari, dangantaka tsakanin microalgae da karafa suna kiyaye su ta hanyar ƙungiyoyi masu aiki na sel.A saboda wannan dalili, sha kuma ya dogara da microalgae surface chemistry, wanda yake shi ne quite hadaddun9,91.Gabaɗaya, kamar yadda aka zata, sinadari na koren microalgae ya ɗan canza kaɗan saboda ɗaukar Nb oxide.
Abin sha'awa, an lura da hanawar farko na microalgae a cikin lokaci.Kamar yadda muka lura, microalgae ya shawo kan canjin muhalli na farko kuma a ƙarshe ya koma yawan ci gaban al'ada har ma ya karu.Nazarin yiwuwar zeta yana nuna babban kwanciyar hankali lokacin da aka gabatar da shi a cikin kafofin watsa labarai na gina jiki.Don haka, an kiyaye hulɗar da ke tsakanin ƙwayoyin microalgae da Nb-MXene nanoflakes a cikin gwaje-gwajen raguwa.A cikin ƙarin bincikenmu, mun taƙaita manyan hanyoyin aiwatar da aiki waɗanda ke ƙarƙashin wannan kyakkyawan hali na microalgae.
Abubuwan lura na SEM sun nuna cewa microalgae suna da alaƙa da Nb-MXenes.Yin amfani da nazarin hoto mai tsauri, muna tabbatar da cewa wannan tasirin yana haifar da canji na Nb-MXene nanoflakes masu girma biyu zuwa mafi yawan nau'in nau'in nau'in nau'in nau'in nau'in nau'in nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i nau'i)) wanda ke nuna cewa bazuwar nanoflakes yana hade da oxidation.Don gwada hasashen mu, mun gudanar da jerin abubuwa da nazarin halittu.Bayan gwaje-gwaje, nanoflakes a hankali ya zama oxidized kuma ya bazu cikin samfuran NbO da Nb2O5, waɗanda ba su haifar da barazana ga koren microalgae ba.Yin amfani da lura da FTIR, ba mu sami wani gagarumin canje-canje a cikin sinadarai na microalgae da aka haɗa a gaban 2D Nb-MXene nanoflakes.Yin la'akari da yuwuwar ɗaukar niobium oxide ta microalgae, mun yi nazarin hasken hasken X-ray.Wadannan sakamakon sun nuna a fili cewa nazarin microalgae yana ciyarwa akan niobium oxides (NbO da Nb2O5), wadanda ba su da guba ga microalgae da aka yi nazari.