304 capillary chubu Nanocomposites Kutengera Tungsten Oxide/Fullerene monga Electrocatalysts ndi Inhibitors of Parasitic VO2+/VO2+ Reactions mu Mixed Acids

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Chitsulo Chosapanga 304 Coil Tube Chemical Mapangidwe

304 Stainless Steel Coil Tube ndi mtundu wa austenitic chromium-nickel alloy.Malinga ndi Stainless Steel 304 Coil Tube Manufacturer, chigawo chachikulu mmenemo ndi Cr (17% -19%), ndi Ni (8% -10.5%).Pofuna kupititsa patsogolo kukana kwake ku dzimbiri, pali zochepa za Mn (2%) ndi Si (0.75%).

Zitsulo Zosapanga dzimbiri 304 Coil Tube Mechanical Properties

Makina amakina a chubu 304 chitsulo chosapanga dzimbiri ndi awa:

• Kulimba kwamphamvu: ≥515MPa
• Mphamvu zokolola: ≥205MPa
• Elongation: ≥30%

Kugwiritsa Ntchito ndi Kugwiritsa Ntchito Stainless Steel 304 Coil Tube

Kutsika mtengo kwa mabatire a vanadium redox flow (VRFBs) kumalepheretsa kufalikira kwawo.Ma kinetics a electrochemical reaction ayenera kusinthidwa kuti awonjezere kuchuluka kwa mphamvu ndi mphamvu ya VRFB, potero kuchepetsa mtengo wa kWh wa VRFB.Mu ntchitoyi, hydrothermally synthesized hydrated tungsten oxide (HWO) nanoparticles, C76 ndi C76 / HWO, adayikidwa pamagetsi a nsalu ya carbon ndi kuyesedwa ngati electrocatalysts kwa VO2 +/VO2+ redox reaction.Field emission scanning electron microscopy (FESEM), energy dispersive X-ray spectroscopy (EDX), high-resolution transmission electron microscopy (HR-TEM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), infrared Fourier sinthani Spectroscopy (FTIR) ndi miyeso yolumikizirana.Zapezeka kuti kuwonjezera kwa C76 fullerene ku HWO kungapangitse kinetics ya electrode pokhudzana ndi VO2 +/VO2 + redox reaction powonjezera ma conductivity ndi kupereka magulu ogwira ntchito okhala ndi mpweya pamwamba pake.The HWO/C76 composite (50 wt% C76) yakhala yoyenera kwambiri pakuchita kwa VO2 +/VO2+ ndi ΔEp ya 176 mV poyerekeza ndi 365 mV ya nsalu yopanda mpweya (UCC).Kuphatikiza apo, gulu la HWO / C76 linawonetsa kuletsa kwakukulu kwa parasitic chlorine evolution reaction chifukwa chamagulu ogwira ntchito a W-OH.
Zochita zamphamvu za anthu komanso kusintha kwachangu kwa mafakitale kwadzetsa kufunikira kwakukulu kwa magetsi, komwe kukukula pafupifupi 3% pachaka1.Kwa zaka zambiri, kufalikira kwa mafuta oyaka mafuta monga gwero lamphamvu kwadzetsa mpweya wowonjezera kutentha kwa dziko, kuchititsa kutentha kwa dziko, kuipitsidwa kwa madzi ndi mpweya, kuwopseza chilengedwe chonse.Zotsatira zake, pofika chaka cha 2050 gawo la mphamvu zongowonjezwdwanso zoyera komanso mphamvu zadzuwa likuyembekezeka kufika 75% yamagetsi onse.Komabe, pamene kupanga mphamvu zowonjezereka kupitirira 20% ya mphamvu zonse zamagetsi, gululi limakhala losakhazikika 1. Kupanga machitidwe osungiramo mphamvu zogwirira ntchito ndizofunikira kwambiri pa kusinthaku, chifukwa ayenera kusunga magetsi ochulukirapo ndi kulinganiza kupereka ndi kufunikira.
Pakati pa machitidwe onse osungira mphamvu monga ma hybrid vanadium redox flow batteries2, mabatire onse a vanadium redox flow (VRFBs) ndi apamwamba kwambiri chifukwa cha ubwino wawo wambiri3 ndipo amaonedwa kuti ndi njira yabwino yothetsera mphamvu zosungirako nthawi yaitali (~ zaka 30).Kugwiritsa ntchito mphamvu zongowonjezwdwa4.Izi ndi chifukwa cha kulekanitsa mphamvu ndi kachulukidwe ka mphamvu, kuyankha mofulumira, moyo wautali komanso ndalama zochepa zapachaka za $ 65 / kWh poyerekeza ndi $ 93-140 / kWh kwa Li-ion ndi mabatire a lead-acid ndi 279-420 USD / kWh./kWh mabatire motsatana 4.
Komabe, kugulitsa kwawo komwe kukufalikira kukupitilirabe kusokonezedwa ndi ndalama zotsika mtengo zamakina, makamaka chifukwa cha batri packs4,5.Chifukwa chake, kuwongolera magwiridwe antchito a batri powonjezera ma kinetics amitundu iwiri yama cell amatha kuchepetsa kukula kwa batri ndikuchepetsa mtengo.Chifukwa chake, kutengerapo kwa ma elekitironi mwachangu kumtunda wa electrode kumafunika, kutengera kapangidwe kake, kapangidwe kake ndi kapangidwe ka electrode, yomwe iyenera kukonzedwa bwino.Ngakhale kuti ma electrode a carbon-based electrodes ali ndi kukhazikika kwa mankhwala ndi electrochemical komanso kuyendetsa bwino kwa magetsi, ngati atasiyidwa, ma kinetics awo amatha pang'onopang'ono chifukwa cha kusowa kwa magulu ogwiritsira ntchito mpweya ndi hydrophilicity7,8.Chifukwa chake, ma electrocatalyst osiyanasiyana amaphatikizidwa ndi ma electrode a kaboni, makamaka ma carbon nanostructures ndi oxides zitsulo, kuti apititse patsogolo ma kinetics a maelekitirodi onse, potero akuwonjezera ma kinetics a ma elekitirodi a VRFB.
Zinthu zambiri za carbon zagwiritsidwa ntchito, monga carbon paper9, carbon nanotubes10,11,12,13, graphene-based nanostructures14,15,16,17, carbon nanofibers18 ndi ena19,20,21,22,23, kupatula banja la fullerene. .Mu phunziro lathu lapitalo pa C76, tinanena kwa nthawi yoyamba ntchito yabwino kwambiri ya electrocatalytic ya fullerene iyi yopita ku VO2 +/VO2+, poyerekeza ndi nsalu yotenthetsera komanso yosagwiritsidwa ntchito ya carbon, kukana kwa kutumiza ndalama kunachepetsedwa ndi 99.5% ndi 97% 24.Kuchita kwamphamvu kwa zida za kaboni pakuchita kwa VO2+/VO2+ poyerekeza ndi C76 kukuwonetsedwa mu Table S1.Kumbali ina, ma oxides ambiri achitsulo monga CeO225, ZrO226, MoO327, NiO28, SnO229, Cr2O330 ndi WO331, 32, 33, 34, 35, 36, 37, 38 amagwiritsidwa ntchito chifukwa chakuchulukira kwawo komanso kuchuluka kwa okosijeni.magulu.Table S2 ikuwonetsa magwiridwe antchito azitsulo izi mumayendedwe a VO2+/VO2+.WO3 yakhala ikugwiritsidwa ntchito pazinthu zambiri chifukwa cha mtengo wake wotsika mtengo, kukhazikika kwapamwamba muzofalitsa za acidic, ndi ntchito yothandiza kwambiri31,32,33,34,35,36,37,38.Komabe, WO3 idawonetsa kusintha pang'ono kwa cathode kinetics.Kupititsa patsogolo kayendedwe ka WO3, zotsatira zogwiritsira ntchito kuchepetsedwa kwa tungsten oxide (W18O49) pa ntchito yabwino ya electrode inayesedwa38.Hydrated tungsten oxide (HWO) sichinayambe yayesedwapo mu ntchito za VRFB, ngakhale kuti yawonetsa ntchito zapamwamba mu ntchito za supercapacitor chifukwa cha kufalikira kwa cation mofulumira poyerekeza ndi anhydrous WOx39,40.Batire ya m'badwo wachitatu wa all-vanadium redox flow flow imagwiritsa ntchito electrolyte ya asidi yosakanikirana yopangidwa ndi HCl ndi H2SO4 kuti ipititse patsogolo magwiridwe antchito a batri ndikuwongolera kusungunuka ndi kukhazikika kwa ma ion vanadium mu electrolyte.Komabe, kusinthika kwa chlorine kusinthika kwakhala chimodzi mwazovuta za m'badwo wachitatu, kotero kupeza njira zopondereza kuwunika kwa chlorine kwakhala ntchito yamagulu angapo ofufuza.
Apa, kuyesa kwa VO2+/VO2+ kunachitika pamitundu ya HWO/C76 yoyikidwa pa maelekitilodi ansalu ya kaboni kuti apeze bwino pakati pa madulidwe amagetsi a ma kompositi ndi redox reaction kinetics pamtunda wa elekitirodi ndikupondereza ma parasitic chlorine deposition.zochita (KVR).Hydrated tungsten okusayidi (HWO) nanoparticles anali apanga ndi losavuta hydrothermal njira.Kuyesera kunachitika mu osakaniza asidi electrolyte (H2SO4/HCl) kuti yesezera m'badwo wachitatu VRFB (G3) kuti zikhale zosavuta ndi kufufuza zotsatira za HWO pa parasitic klorini chisinthiko reaction42.
Vanadium (IV) sulfate oxide hydrate (VOSO4, 99.9%, Alfa-Aeser), sulfuric acid (H2SO4), hydrochloric acid (HCl), dimethylformamide (DMF, Sigma-Aldrich), polyvinylidene fluoride (PVDF, Sigma-Aldrich), sodium Tungsten oxide dihydrate (Na2WO4, 99%, Sigma-Aldrich) ndi hydrophilic carbon cloth ELAT (Fuel Cell Store) anagwiritsidwa ntchito mu phunziroli.
Hydrated tungsten oxide (HWO) idakonzedwa ndi hydrothermal reaction momwe 2 g ya mchere wa Na2WO4 idasungunuka mu 12 ml ya HO mpaka yankho lopanda mtundu litapezeka, ndiyeno 12 ml ya 2 M HCl idawonjezedwa mpaka kuyimitsidwa kwachikasu kopepuka. anapezedwa.kuyimitsidwa.Kutentha kwa hydrothermal kunachitika mu Teflon yokutidwa ndi chitsulo chosapanga dzimbiri autoclave mu uvuni pa 180 ºC kwa maola 3.Chotsaliracho chinasonkhanitsidwa ndi kusefera, kutsukidwa katatu ndi ethanol ndi madzi, zouma mu uvuni pa 70 ° C kwa ~ 3 h, ndiyeno pansi kuti mupeze ufa wa HWO wa buluu-imvi.
Ma electrodes (osagwiritsidwa ntchito) a carbon cloth electrodes (CCTs) anagwiritsidwa ntchito mu mawonekedwe omwe anapezedwa kapena kutenthedwa ndi kutentha mu ng'anjo ya chubu pa 450 ° C kwa 10 h pa kutentha kwa 15 ° C / min mu mpweya mpaka kupeza chithandizo UCC (TCC), s Mofanana ndi ntchito yapita 24. UCC ndi TCC anadulidwa mu maelekitirodi pafupifupi 1.5 cm mulifupi ndi 7 cm utali.Kuyimitsidwa kwa C76, HWO, HWO-10% C76, HWO-30% C76 ndi HWO-50% C76 kunakonzedwa powonjezera 20 mg ya ufa wakuthupi ndi 10 wt% (~ 2.22 mg) wa PVDF binder ku ~ 1 ml ya DMF anakonza ndi sonicated kwa 1 ora kusintha chifanane.Kenako 2 mg ya C76, HWO ndi HWO-C76 zophatikizika zinagwiritsidwa ntchito pafupifupi 1.5 cm2 ya UCC yogwira electrode area.Zothandizira zonse zidanyamulidwa pa ma electrode a UCC ndipo TCC idagwiritsidwa ntchito pofananiza zokha, monga momwe ntchito yathu yapitayi idawonetsa kuti chithandizo cha kutentha sichifunikira 24.Kukhazikika kwamalingaliro kunapezedwa ndikutsuka 100 µl ya kuyimitsidwa (katundu 2 mg) kuti mufanane kwambiri.Kenako maelekitirodi onse amawumitsidwa mu uvuni usiku wonse pa 60 ° C.Ma elekitirodi amayezedwa isanachitike komanso pambuyo pake kuti atsimikizire kutsitsa kolondola kwa masheya.Kuti mukhale ndi malo enaake a geometric (~ 1.5 cm2) ndikuletsa kukwera kwa vanadium electrolyte ku ma electrode chifukwa cha mphamvu ya capillary, parafini yopyapyala inayikidwa pazitsulo zogwira ntchito.
Makina ojambulira ma electron maikulosikopu (FESEM, Zeiss SEM Ultra 60.5 kV) adagwiritsidwa ntchito kuyang'ana kapangidwe ka HWO.Zowonera zamagetsi za X-ray zokhala ndi Feii8SEM (EDX, Zeiss AG) zidagwiritsidwa ntchito kupanga mapu azinthu za HWO-50% C76 pamagetsi a UCC.Ma electron microscope (HR-TEM, JOEL JEM-2100) omwe amagwira ntchito pamagetsi othamanga a 200 kV adagwiritsidwa ntchito kupeza zithunzi zowoneka bwino komanso mphete zosokoneza za tinthu tating'ono ta HWO.Gwiritsani ntchito pulogalamu ya Crystallographic Tool Box (CrysTBox) kuti mufufuze mphete za HWO diffraction pogwiritsa ntchito ringGUI ndikuyerekeza zotsatira ndi zitsanzo za XRD.Mapangidwe ndi graphitization ya UCC ndi TCC inatsimikiziridwa ndi X-ray diffraction (XRD) pa mlingo wa 2.4 ° / min kuchokera 5 ° mpaka 70 ° ndi Cu Kα (λ = 1.54060 Å) pogwiritsa ntchito Panalytical X-ray diffractometer.(Model 3600).XRD ikuwonetsa mawonekedwe a kristalo ndi magawo a HWO.Pulogalamu ya PANalytical X'Pert HighScore idagwiritsidwa ntchito kufananitsa nsonga za HWO ndi mamapu a tungsten oxide omwe amapezeka mu database45.Fananizani zotsatira za HWO ndi zotsatira za TEM.Kapangidwe ka mankhwala ndi mawonekedwe a HWO zitsanzo adatsimikiziridwa ndi X-ray photoelectron spectroscopy (XPS, ESCALAB 250Xi, ThermoScientific).Pulogalamu ya CASA-XPS (v 2.3.15) idagwiritsidwa ntchito pakuchepetsa kwambiri komanso kusanthula deta.Fourier transform infrared spectroscopy (FTIR, pogwiritsa ntchito miyeso ya Perkin Elmer class KBr FTIR spectrometer) idachitidwa kuti adziwe magulu ogwira ntchito a HWO ndi HWO-50% C76.Fananizani zotsatira ndi zotsatira za XPS.Miyezo yolumikizirana (KRUSS DSA25) idagwiritsidwanso ntchito kuwonetsa kunyowa kwa ma elekitirodi.
Pamiyezo yonse yama electrochemical, malo ogwirira ntchito a Biologic SP 300 adagwiritsidwa ntchito.Cyclic voltammetry (CV) ndi electrochemical impedance spectroscopy (EIS) anagwiritsidwa ntchito pophunzira ma elekitirodi kinetics a VO2+/VO2+ redox reaction ndi zotsatira za reagent diffusion (VOSO4 (VO2+)) pa mlingo anachita.Matekinoloje onsewa amagwiritsa ntchito selo la elekitirodi lachitatu lomwe lili ndi mphamvu ya electrolyte ya 0.1 M VOSO4 (V4+) yosungunuka mu 1 M H2SO4 + 1 M HCl (acid yosakanikirana).Deta yonse ya electrochemical yoperekedwa ndi IR yokonzedwa.Ma electrode a calomel electrode (SCE) ndi platinamu (Pt) adagwiritsidwa ntchito ngati cholumikizira ndi chowerengera, motsatana.Kwa CV, mitengo ya scan (ν) ya 5, 20, ndi 50 mV/s idayikidwa pawindo lomwe lingathe kuchitika (0-1) V poyerekeza ndi SCE ya VO2+/VO2+, kenako ndikuwongolera pa sikelo ya SHE kuti ipange chiwembu (VSCE = 0.242 V wachibale ndi HSE).Kuti mufufuze kasungidwe ka ma elekitirodi, kubwereza kwa CV kunachitika pa UCC, TCC, UCC-C76, UCC-HWO ndi UCC-HWO-50% C76 pa ν yofanana ndi 5 mV/s.Pamiyezo ya EIS ya VO2+/VO2+ redox reaction, ma frequency osiyanasiyana a 0.01-105 Hz ndi kusokonezeka kwamagetsi otseguka (OCV) a 10 mV adagwiritsidwa ntchito.Kuyesera kulikonse kunabwerezedwa nthawi 2-3 kuti zitsimikizire kuti zotsatira zake zikugwirizana.Zosintha zosasinthika (k0) zidapezedwa ndi njira ya Nicholson46,47.
Hydrated tungsten oxide (HVO) yapangidwa bwino ndi njira ya hydrothermal.Chithunzi cha SEM mu mkuyu.1a ikuwonetsa kuti HWO yoyikidwa ili ndi magulu a nanoparticles okhala ndi kukula kwa tinthu mumitundu ya 25-50 nm.
Mawonekedwe a X-ray diffraction a HWO amasonyeza nsonga (001) ndi (002) pa ~ 23.5 ° ndi ~ 47.5 °, motero, zomwe zimakhala ndi mawonekedwe a nonstoichiometric WO2.63 (W32O84) (PDF 077-0810, a = 21.4 Å, b = 17.8 Å, c = 3.8 Å, α = β = γ = 90 °), yomwe imagwirizana ndi maonekedwe ake a buluu (mkuyu 1b) 48,49.Mapiri ena pafupifupi 20.5°, 27.1°, 28.1°, 30.8°, 35.7°, 36.7° ndi 52.7° ali pa (140), (620), (350), (720), (740), (560).ndi (970) ndege zosokoneza, motero, 49 orthorhombic WO2.63.Songara et al.43 idagwiritsa ntchito njira yopangira yomweyi kuti ipeze chopangidwa choyera, chomwe chidachitika chifukwa cha kukhalapo kwa WO3(H2O) 0.333.Komabe, mu ntchitoyi, chifukwa cha zikhalidwe zosiyanasiyana, chopangidwa ndi buluu-imvi chinapezedwa, kusonyeza kukhalapo kwa WO3 (H2O) 0.333 (PDF 087-1203, a = 7.3 Å, b = 12.5 Å, c = 7.7 ) mu Å , α = β = γ = 90 °) ndi mawonekedwe ochepetsedwa a tungsten oxide.Kusanthula kwa semiquantitative ndi pulogalamu ya X'Pert HighScore kunawonetsa 26% WO3 (H2O) 0.333: 74% W32O84.Popeza W32O84 ili ndi W6+ ndi W4+ (1.67:1 W6+:W4+), zomwe zikuyerekezeredwa za W6+ ndi W4+ ndi pafupifupi 72% W6+ ndi 28% W4+, motsatana.Zithunzi za SEM, mawonekedwe a 1-sekondi a XPS pamlingo wapakati, zithunzi za TEM, mawonekedwe a FTIR ndi mawonekedwe a Raman a tinthu tating'ono ta C76 adawonetsedwa mu pepala lathu lapitalo24.Malingana ndi Kawada et al.50,51, X-ray diffraction chitsanzo cha C76 chimasonyeza mawonekedwe a monoclinic a FCC pambuyo pochotsa toluene.
Zithunzi za SEM mu mkuyu.2a ndi b akuwonetsa kuyika bwino kwa HWO ndi HWO-50% C76 pakati ndi pakati pa ma fiber a carbon a UCC electrode.Mapu oyambira a tungsten, kaboni ndi okosijeni mu chithunzi cha SEM mumkuyu 2c akuwonetsedwa mkuyu.2d-f kusonyeza kuti tungsten ndi kaboni zimasakanikirana mofanana (kusonyeza kugawa kofanana) pamwamba pa electrode pamwamba ndipo chophatikizikacho sichimayikidwa mofanana.chifukwa cha chikhalidwe cha mvula.
Zithunzi za SEM za tinthu tating'ono ta HWO (a) ndi HWO-C76 (b).Mapu a EDX adakwezedwa ku HWO-C76 ku UCC pogwiritsa ntchito malo omwe ali pachithunzi (c) akuwonetsa kugawidwa kwa tungsten (d), carbon (e), ndi mpweya (f) mu chitsanzo.
HR-TEM idagwiritsidwa ntchito pojambula kukweza kwakukulu ndi chidziwitso cha crystallographic (Chithunzi 3).HWO ikuwonetsa morphology ya nanocube monga momwe tawonetsera pa Chithunzi 3a komanso momveka bwino mu Chithunzi 3b.Mwa kukulitsa nanocube chifukwa cha diffraction ya malo osankhidwa, kapangidwe ka grating ndi ndege zosokoneza zokhutiritsa lamulo la Bragg zitha kuwonetsedwa monga momwe tawonetsera pa Chithunzi 3c, kutsimikizira crystallinity ya zinthuzo.Muzolemba za mkuyu 3c zikuwonetsa mtunda wa d 3.3 Å wofanana ndi (022) ndi (620) ndege zowonongeka mu WO3 (H2O) 0.333 ndi W32O84, 43, 44, 49 magawo, motsatira.Izi zikugwirizana ndi kusanthula pamwamba XRD (mkuyu. 1b) popeza anaona grating ndege mtunda d (mkuyu. 3c) likufanana ndi wamphamvu XRD pachimake mu HWO chitsanzo.Zitsanzo mphete zikuwonetsedwanso mkuyu.3d, pomwe mphete iliyonse imagwirizana ndi ndege yosiyana.Ndege za WO3 (H2O) 0.333 ndi W32O84 zimakhala zoyera ndi zabuluu, motero, nsonga zawo za XRD zogwirizana nazo zikuwonetsedwanso mkuyu 1b.Mphete yoyamba yomwe ikuwonetsedwa mu mpheteyo imafanana ndi nsonga yoyamba yodziwika bwino mu mawonekedwe a x-ray a (022) kapena (620) ndege yosokoneza.Kuchokera ku (022) mpaka (402) mphete, d-matali a 3.30, 3.17, 2.38, 1.93, ndi 1.69 Å adapezeka, omwe amagwirizana ndi ma XRD a 3.30, 3.17, 2 .45, 1.63 ndi 1.63.Å, 44, 45, motsatana.
(a) Chithunzi cha HR-TEM cha HWO, (b) chikuwonetsa chithunzi chokulitsa.Zithunzi za ndege zowonongeka zikuwonetsedwa mu (c), ndi chithunzi (c) chimasonyeza chithunzi chokulirapo cha ndege ndi nthawi ya d 0.33 nm yofanana ndi (002) ndi (620) ndege.(d) Chitsanzo cha mphete cha HWO chosonyeza ndege zomwe zimagwirizana ndi magawo a WO3 (H2O) 0.333 (woyera) ndi W32O84 (buluu).
Kusanthula kwa XPS kudachitika kuti adziwe momwe chemistry ndi oxidation state of tungsten (Zithunzi S1 ndi 4).Chiwonetsero cha XPS chojambula chojambula cha HWO chopangidwa chikuwonetsedwa mu Mkuyu.S1, kusonyeza kukhalapo kwa tungsten.Mawonekedwe a XPS ang'onoang'ono a magulu akuluakulu a W 4f ndi O 1s akuwonetsedwa muzithunzi.4a ndi b, motsatana.Sipekitiramu ya W 4f imagawidwa kukhala magawo awiri ozungulira-ozungulira ofanana ndi mphamvu yomangirira ya dziko la okosijeni W. Nsonga za W 4f5/2 ndi W 4f7/2 pa mphamvu zomangirira za 37.8 ndi 35.6 eV ndi za W6+, ndipo nsonga zake W6+. 4f5/2 ndi W 4f7/2 pa 36.6 ndi 34.9 eV ndi khalidwe la W4+ boma, motero.Kukhalapo kwa oxidation state (W4 +) kumatsimikiziranso kupangidwa kwa non-stoichiometric WO2.63, pamene kukhalapo kwa W6 + kumasonyeza stoichiometric WO3 chifukwa cha WO3 (H2O) 0.333.Zomwe zidaphatikizidwa zidawonetsa kuti maperesenti a atomiki a W6+ ndi W4+ anali 85% ndi 15%, motsatana, omwe anali pafupi ndi zomwe amayerekezedwa kuchokera ku data ya XRD, kutengera kusiyana pakati pa matekinoloje awiriwa.Njira zonsezi zimapereka chidziwitso chochepa kwambiri, makamaka XRD.Kuphatikiza apo, njira ziwirizi zimasanthula magawo osiyanasiyana azinthuzo chifukwa XRD ndi njira yochulukirapo pomwe XPS ndi njira yapamtunda yomwe imayandikira ma nanometer ochepa.Sipekitiramu ya O 1s imagawanika kukhala nsonga ziwiri pa 533 (22.2%) ndi 530.4 eV (77.8%).Yoyamba ikufanana ndi OH, ndipo yachiwiri ndi zomangira za okosijeni mu lattice mu WO.Kukhalapo kwa magulu ogwira ntchito a OH kumagwirizana ndi mphamvu za hydration za HWO.
Kusanthula kwa FTIR kudachitikanso pamiyeso iwiriyi kuti awone kukhalapo kwa magulu ogwira ntchito ndi mamolekyu olumikizana amadzi mumpangidwe wa HWO wa hydrated.Zotsatira zikuwonetsa kuti chitsanzo cha HWO-50% C76 ndi zotsatira za FT-IR HWO zimawoneka zofanana chifukwa cha kukhalapo kwa HWO, koma kukula kwa nsonga kumasiyana chifukwa cha kuchuluka kwa zitsanzo zomwe zimagwiritsidwa ntchito pokonzekera kusanthula (Mkuyu 5a). ).HWO-50% C76 Nsonga zonse za fullerene 24 zikuwonetsedwa kupatula nsonga ya tungsten oxide.Tsatanetsatane mkuyu.5a ikuwonetsa kuti zitsanzo zonsezi zikuwonetsa gulu lolimba kwambiri lokhala ndi ~ 710/cm, lotchedwa OWO kutambasula kugwedezeka mu kapangidwe ka HWO lattice, ndi phewa lolimba pa ~ 840/cm, lotchedwa WO.gulu lakuthwa ku ~ 1610/cm limagwirizana ndi kugwedezeka kopindika kwa OH, ndipo gulu lalikulu loyamwa pa ~ 3400/cm limagwirizana ndi kugwedezeka kwa OH mu gulu la hydroxyl43.Zotsatirazi zimagwirizana ndi mawonekedwe a XPS mumkuyu 4b, kumene gulu logwira ntchito la WO lingapereke malo ogwira ntchito pa VO2 +/VO2 + reaction.
Kusanthula kwa FTIR kwa HWO ndi HWO-50% C76 (a) kuwonetsa magulu ogwira ntchito ndi miyeso yolumikizirana (b, c).
Gulu la OH lingathenso kuchititsa kuti VO2 +/VO2+ ichitike, potero ikuwonjezera hydrophilicity ya electrode, potero kulimbikitsa kufalikira ndi kusinthasintha kwa ma elekitironi.Chitsanzo cha HWO-50% C76 chikuwonetsa nsonga yowonjezera ya C76 monga momwe tawonetsera pachithunzichi.Pamwamba pa ~ 2905, 2375, 1705, 1607, ndi 1445 cm3 akhoza kuperekedwa ku CH, O=C=O, C=O, C=C, ndi CO kutambasula kugwedezeka, motero.Ndizodziwika bwino kuti magulu ogwiritsira ntchito okosijeni C=O ndi CO amatha kukhala malo ogwirira ntchito a redox ya vanadium.Kuti ayese ndi kuyerekezera kunyowa kwa ma electrode awiri, miyeso ya angle yolumikizana inagwiritsidwa ntchito monga momwe tawonetsera mkuyu 5b, c.Electrode ya HWO nthawi yomweyo imatenga madontho amadzi, kusonyeza superhydrophilicity chifukwa cha magulu ogwira ntchito a OH omwe alipo.HWO-50% C76 imakhala ya hydrophobic kwambiri, yokhala ndi ngodya yolumikizana pafupifupi 135 ° pakadutsa masekondi 10.Komabe, mumiyezo ya electrochemical, electrode ya HWO-50% C76 idanyowa kwathunthu pasanathe mphindi imodzi.Miyezo ya kunyowa imagwirizana ndi zotsatira za XPS ndi FTIR, zomwe zikuwonetsa kuti magulu ambiri a OH pamtunda wa HWO amapangitsa kuti ikhale ya hydrophilic.
Zochita za VO2+/VO2+ za HWO ndi HWO-C76 nanocomposites zidayesedwa ndipo zinkayembekezeredwa kuti HWO idzapondereza kusintha kwa mpweya wa chlorine womwe umapezeka panthawi ya VO2+/VO2+ mu ma acid osakanikirana, pamene C76 idzawonjezera VO2 +/ VO2 + yomwe ikufunika.Kuyimitsidwa kwa HWO komwe kuli 10%, 30% ndi 50% C76 kunagwiritsidwa ntchito ku ma elekitirodi a UCC okhala ndi pafupifupi 2 mg/cm2.
Monga zikuwonetsedwa mkuyu.6, ma kinetics a VO2 +/VO2+ reaction pa electrode pamwamba adawunikidwa pogwiritsa ntchito CV mu osakaniza ma electrolyte acidic.Currents akuwonetsedwa ngati I/Ipa kuti athe kufananiza ΔEp ndi Ipa/Ipc.Zothandizira zosiyanasiyana zimapezedwa mwachindunji kuchokera pazithunzizo.Zomwe zilipo panopa zikuwonetsedwa mu Chithunzi 2S.Pa mkuyu.Chithunzi 6a chikuwonetsa kuti HWO imawonjezera pang'ono kuchuluka kwa ma elekitironi kutengerapo kwa VO2+/VO2+ redox reaction pamtunda wa elekitirodi ndikupondereza momwe chisinthiko cha parasitic chlorine.Komabe, C76 imakulitsa kwambiri kuchuluka kwa ma elekitironi kutengerapo ndipo imathandizira kusintha kwa chlorine.Chifukwa chake, chovuta chokhala ndi mawonekedwe olondola a HWO ndi C76 chiyenera kukhala ndi ntchito yabwino kwambiri komanso luso lapamwamba kwambiri loletsa kuyankha kwa chlorine.Zinapezeka kuti atatha kuonjezera chiwerengero cha C76, ntchito ya electrochemical ya electrode yakula bwino, monga momwe zikuwonetsedwera ndi kuchepa kwa ΔEp ndi kuwonjezeka kwa chiwerengero cha Ipa / Ipc (Table S3).Izi zinatsimikiziridwanso ndi ma RCT values ​​​​otengedwa kuchokera ku chiwembu cha Nyquist mu Chithunzi 6d (tebulo S3), pomwe zidapezeka kuti ma RCT adatsika ndi kuchuluka kwa C76.Zotsatira izi zimagwirizananso ndi kafukufuku wa Lee pomwe kuwonjezera kwa kaboni wa mesoporous ku mesoporous WO3 kunawongolera njira zosinthira malipoti pa VO2+/VO2+35.Izi zikusonyeza kuti kuyankhidwa kwabwino kungadalire kwambiri pamayendedwe a electrode (C = C bond) 18,24,35,36,37.Chifukwa cha kusintha kwa geometry yogwirizanitsa pakati pa [VO (H2O) 5] 2+ ndi [VO2 (H2O) 4]+, C76 ingachepetsenso kuyankha mopitirira muyeso mwa kuchepetsa mphamvu ya minofu.Komabe, izi sizingakhale zotheka ndi ma elekitirodi a HWO.
(a) Makhalidwe a cyclic voltammetric a UCC ndi HWO-C76 zophatikizika ndi HWO:C76 ma ratios osiyanasiyana mu VO2+/VO2+ reactions mu 0.1 M VOSO4/1 M H2SO4 + 1 M HCl electrolyte (pa ν = 5 mV/s).(b) Randles-Sevchik ndi (c) Njira ya Nicholson ya VO2+/VO2+ yoyezera kusagwira bwino ntchito komanso kupeza ma k0 values ​​​​(d).
Sikuti HWO-50% C76 imangowonetsa pafupifupi ntchito ya electrocatalytic yofanana ndi C76 ya VO2+/VO2+ reaction, koma chochititsa chidwi kwambiri, idaponderezanso kusinthika kwa mpweya wa chlorine poyerekeza ndi C76, monga momwe tawonetsera pachithunzichi.6a, kuwonjezera pakuwonetsa semicircle yaying'ono mumkuyu.6g (otsika RCT).C76 inawonetsa Ipa / Ipc yapamwamba kuposa HWO-50% C76 (Table S3), osati chifukwa cha kusintha kwa machitidwe, koma chifukwa cha kuphatikizika ndi nsonga yochepetsera klorini pa 1.2 V poyerekeza ndi SHE.Kuchita bwino kwambiri kwa HWO-50% C76 kumachitika chifukwa cha mgwirizano pakati pa C76 yoyendetsedwa molakwika komanso kunyowa kwambiri komanso magwiridwe antchito a W-OH pa HWO.Ngakhale kutulutsa kwa klorini pang'ono kumapangitsa kuti ma cell azilipiritsa bwino, ma kinetics owongolera amawonjezera mphamvu yamagetsi athunthu.
Malinga ndi equation S1, pa quasi-reversible (monga pang'onopang'ono electron transfer) imayendetsedwa ndi kufalikira, peak current (IP) imadalira chiwerengero cha ma elekitironi (n), electrode area (A), diffusion coefficient (D), nambala. ma elekitironi kusamutsa koyefiyenti (α) ndi liwiro la sikani (ν).Pofuna kuphunzira kufalikira kwa machitidwe oyendetsedwa ndi zida zoyesedwa, ubale pakati pa IP ndi ν1/2 udakonzedwa ndikuwonetseredwa mumkuyu 6b.Popeza zida zonse zikuwonetsa ubale wofananira, zomwe zimayendetsedwa ndi kufalikira.Popeza kuti VO2 +/VO2+ reaction ndi quasi-reversible, kutsetsereka kwa mzere kumadalira kufalikira kwa coefficient ndi mtengo wa α (equation S1).Chifukwa cha kufalikira kwanthawi zonse (≈ 4 × 10-6 cm2 / s) 52, kusiyana kwa mzere wotsetsereka kumawonetsa molunjika pamitundu yosiyanasiyana ya α motero milingo yosiyana ya kusamutsidwa kwa ma elekitirodi kumtunda, ndi C76 ndi HWO -50 % C76, yowonetsa malo otsetsereka kwambiri (kuchuluka kwambiri kwa ma elekitironi).
Malo otsetsereka a Warburg ocheperako (W) owonetsedwa mu Table S3 (mkuyu 6d) ali ndi miyeso pafupi ndi 1 pazinthu zonse, kuwonetsa kufalikira kwa tinthu ta redox ndikutsimikizira machitidwe amzere a IP motsutsana ndi ν1/2 pa CV.miyeso .Kwa HWO-50% C76, otsetsereka a Warburg amapatuka kuchoka ku umodzi kupita ku 1.32, kutanthauza chopereka osati kuchokera ku kufalikira kopanda malire kwa ma reactants (VO2+), komanso kukhala ndi khalidwe laling'ono mu khalidwe la kufalikira chifukwa cha electrode porosity.
Kuti muwunikenso kusinthika (kuchuluka kwa ma elekitironi) kwa VO2+/VO2+ redox reaction, njira ya Nicholson quasi-reversible reaction idagwiritsidwanso ntchito kudziwa mulingo wokhazikika wa k041.42.Izi zimachitika pokonza parameter ya kinetic yopanda dimensionless Ψ monga ntchito ya ΔEp ngati ntchito ya ν−1/2 pogwiritsa ntchito equation ya S2.Table S4 ikuwonetsa zotsatira za Ψ pamtundu uliwonse wa electrode.Konzani zotsatira (Chithunzi 6c) kuti mupeze k0 × 104 cm/s (zolembedwa pafupi ndi mzere uliwonse ndi kuperekedwa mu Table S4) pogwiritsa ntchito equation S3 pa malo otsetsereka a chiwembu chilichonse.HWO-50% C76 inapezeka kuti ili ndi malo otsetsereka kwambiri (mkuyu 6c) ndipo motero mtengo wapamwamba wa k0 wa 2.47 × 10-4 cm / s.Izi zikutanthauza kuti electrode iyi imapereka kinetics yothamanga kwambiri yogwirizana ndi CV ndi zotsatira za EIS mu Zithunzi 6a ndi d ndi Table S3.Kuphatikiza apo, mitengo ya k0 idapezedwanso kuchokera ku ziwembu za Nyquist (Mkuyu 6d) wa Equation S4 pogwiritsa ntchito ma RCT values ​​​​(Table S3).Zotsatira za k0 izi kuchokera ku EIS ndizofupikitsidwa mu Table S4 komanso zikuwonetsa kuti HWO-50% C76 ikuwonetsa kuchuluka kwa ma elekitironi apamwamba kwambiri chifukwa cha synergistic effect.Ngakhale mtengo wa k0 umasiyana chifukwa cha chiyambi chosiyana cha njira iliyonse, umasonyezabe dongosolo lofanana la kukula ndikuwonetsa kusasinthasintha.
Kuti mumvetsetse bwino ma kinetics omwe angakwaniritsidwe, ndikofunikira kufananiza ma elekitirodi abwino kwambiri ndi ma elekitirodi osasunthika a UCC ndi TCC.Pamachitidwe a VO2 +/VO2+, HWO-C76 sanangowonetsa otsika kwambiri ΔEp komanso kusinthika bwino, komanso kupondereza kwambiri kusintha kwa parasitic chlorine poyerekeza ndi TCC, monga zikuwonetseredwa ndi kutsika kwakukulu kwapano pa 1.45 V poyerekeza ndi kuwona OHA (Chith. 7a).Pankhani ya kukhazikika, tinkaganiza kuti HWO-50% C76 imakhala yokhazikika mwakuthupi chifukwa chothandiziracho chinasakanizidwa ndi PVDF binder ndipo kenako chimagwiritsidwa ntchito pamagetsi a carbon cloth.Poyerekeza ndi 50 mV ya UCC, HWO-50% C76 inawonetsa kusintha kwakukulu kwa 44 mV pambuyo pa 150 cycles (degradation rate 0.29 mV / cycle) (Chithunzi 7b).Sizingakhale kusiyana kwakukulu, koma ma kinetics a maelekitirodi a UCC ndi ochedwa kwambiri ndipo amawononga ndi njinga, makamaka chifukwa cha kubwerera kumbuyo.Ngakhale kusinthika kwa TCC kuli bwino kwambiri kuposa kwa UCC, TCC idapezeka kuti ili ndi kusintha kwakukulu kwa 73 mV pambuyo pa 150 cycle, zomwe zingakhale chifukwa cha kuchuluka kwa klorini yotulutsidwa kuchokera pamwamba pake.Kuonetsetsa kuti chothandizira amamatira bwino ndi electrode pamwamba.Monga momwe tingawonere pa maelekitirodi onse oyesedwa, ngakhale omwe alibe zida zothandizira amawonetsa kusakhazikika kwapang'onopang'ono mosiyanasiyana, kutanthauza kuti kusintha kwa kupatukana kwakukulu panthawi yoyendetsa njinga kumachitika chifukwa cha kutsekedwa kwa zinthu chifukwa cha kusintha kwa mankhwala kusiyana ndi kupatukana koyambitsa.Komanso, ngati kuchuluka kwa particles chothandizira akanati anasiyanitsidwa ndi elekitirodi pamwamba, izi zingachititse kuti kuwonjezeka kwambiri pachimake kulekana (osati 44 mV), popeza gawo lapansi (UCC) ndi wosagwira ntchito kwa VO2 +/VO2 + + redox reaction.
Kuyerekeza kwa CV (a) ndi kukhazikika kwa redox reaction VO2+/VO2+ (b) ya zinthu zabwino kwambiri zama elekitirodi pokhudzana ndi CCC.Mu electrolyte 0.1 M VOSO4/1 M H2SO4 + 1 M HCl, ma CV onse ndi ofanana ndi ν = 5 mV/s.
Kuti muwonjezere kukopa kwachuma kwaukadaulo wa VRFB, kukonza ndikumvetsetsa ma kinetics a vanadium redox reaction ndikofunikira kuti mukwaniritse bwino mphamvu zamagetsi.Ma Composites HWO-C76 adakonzedwa ndipo mphamvu yawo ya electrocatalytic pa VO2 +/VO2+ reaction idaphunziridwa.HWO idawonetsa kukulitsa pang'ono kwa kinetic koma idapondereza kwambiri kusinthika kwa chlorine mu ma electrolyte osakanikirana a acidic.Magawo osiyanasiyana a HWO: C76 adagwiritsidwa ntchito kuti apititse patsogolo ma kinetics a ma elekitirodi a HWO.Kuchulukitsa zomwe zili mu C76 kupita ku HWO kumatha kusintha ma kinetics otengera ma elekitironi a VO2+/VO2+ pa ma elekitirodi osinthidwa, omwe HWO-50% C76 ndiye chinthu chabwino kwambiri chifukwa amachepetsa kukana kutengerapo ndalama komanso kupondereza kusinthika kwa mpweya wa chlorine poyerekeza ndi C76.ndipo TCC imatulutsidwa.Izi zidachitika chifukwa cha mgwirizano pakati pa C=C sp2 hybridization, OH ndi W-OH magulu ogwira ntchito.Kuwonongeka kwa HWO-50% C76 kunapezeka kuti ndi 0.29mV / cycle pansi pa njinga zambiri pamene UCC ndi TCC ndi 0.33mV / cycle ndi 0.49mV / cycle motsatira, zomwe zimapangitsa kuti zikhale zokhazikika kwambiri mu electrolyte yosakanikirana ya asidi.Zotsatira zomwe zaperekedwa zimazindikira bwino zida zama elekitirodi pamachitidwe a VO2+/VO2+ okhala ndi kinetics mwachangu komanso kukhazikika kwakukulu.Izi ziwonjezera mphamvu yamagetsi, potero kuwongolera mphamvu ya VRFB, potero kuchepetsa mtengo wamalonda ake amtsogolo.
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