Graphite waxa loo qaybiyaa garaafka macmalka ah iyo garaafyada dabiiciga ah, kaydka la xaqiijiyay ee garaafiga dabiiciga ah ee aduunka oo ku dhaw 2 bilyan oo tan.
Garaafyada macmalka ah waxaa lagu helaa burburka iyo daaweynta kulaylka ee walxaha kaarboon-ku jira ee cadaadiska caadiga ah.Isbeddelkani wuxuu u baahan yahay heerkul sare oo ku filan iyo tamar sida xoogga wadista, iyo qaab dhismeedka khalkhalka leh ayaa loo beddeli doonaa qaab dhismeed garaafeed la dalbaday.
Graphitization waa in dareenka ugu ballaaran ee walxaha carbonaceous iyada oo kor ku xusan 2000 ℃ daaweynta kulaylka sare atamka kaarboon dib u habaynta, si kastaba ha ahaatee qaar ka mid ah walxaha carbon in heerkulka sare ee 3000 ℃ garaafiti, noocan oo kale ah qalabka carbon waxaa loo yaqaan "Dhuxu adag", waayo, Qalabka kaarboonka ee fudud ee garaafyada, habka garaafaynta dhaqameed waxaa ka mid ah heerkulka sare iyo habka cadaadiska sare, garaafyada catalytic, habka kaydinta uumiga kiimikada, iwm.
Graphitization waa hab wax ku ool ah oo qiimo sare leh oo ka faa'iidaysiga alaabta kaarboon-aceous.Baadhitaan qotodheer oo qotodheer oo ay culimadu sameeyeen ka dib, asal ahaan hadda way qaan gaadhay.Si kastaba ha ahaatee, qaar ka mid ah arrimaha aan fiicnayn ayaa xaddidaya adeegsiga garaafyada dhaqanka ee warshadaha, sidaas darteed waa isbeddel lama huraan ah in la sahamiyo hababka garaafaynta cusub.
Habka Electrolysis cusbo dhalaalay tan iyo qarnigii 19-aad ahaa in ka badan qarni horumarinta, ay aragti aasaasiga ah iyo hababka cusub si joogto ah hal-abuurnimo iyo horumarinta, hadda mar dambe kuma koobna warshadaha macdan dhaqameed, bilowgii qarnigii 21-aad, biraha in nidaamka milixda dhalaalay, diyaarinta yaraynta electrolytic adag ee biraha element ayaa noqday diiradda in ka badan firfircoon,
Dhawaan, hab cusub oo loogu talagalay diyaarinta walxaha graphite ee elektiroleejka cusbada dhalaalay ayaa soo jiidatay dareen badan.
Iyada oo la adeegsanayo polarization cathodic iyo electrodeposition, labada nooc ee kala duwan ee alaabta ceeriin ee kaarboon waxaa loo beddelaa agab nano-graphite oo leh qiime sare.Marka la barbar dhigo tignoolajiyada garaafka garaafka ee soo jireenka ah, habka garaafka cusubi wuxuu leeyahay faa'iidooyinka heerkulka garaafyada hoose iyo qaab-dhismeed la xakameyn karo.
Warqadani waxay dib u eegis ku samaynaysaa horumarka garaafaynta iyadoo la adeegsanayo habka elektiroonigga ah, waxay soo bandhigaysaa tignoolajiyadan cusub, waxay falanqaynaysaa faa'iidooyinka iyo faa'iido darrada, waxayna filaysaa isbeddelkeeda horumarinta mustaqbalka.
Marka hore, milix dhalaalaysa habka polarization cathode
1.1 alaabta ceeriin
Waqtigan xaadirka ah, alaabta ceeriin ee ugu weyn ee garaafyada macmalka ah waa coke coke iyo coke garoonka ee heerka garaafka sare, kuwaas oo ay ka mid yihiin hadhaaga saliidda iyo daamurka dhuxusha sida alaabta ceeriin si loo soo saaro qalab tayo sare leh oo kaarboon ah, oo leh porosity hooseeya, baaruud hoose, dambas hooseeya. content iyo faa'iidooyinka graphitization, ka dib markii ay diyaarinta galay graphite leeyahay iska caabin wanaagsan saamaynta, xoog farsamo sare, iska caabin hoose,
Si kastaba ha ahaatee, kaydka saliida ee xadidan iyo sicirka saliida ee isbedbedela ayaa xaddiday horumarkiisa, sidaas darteed raadinta alaabta ceeriin ee cusub waxay noqotay dhibaato degdeg ah oo la xalliyo.
Hababka garaafaynta dhaqameedku waxay leeyihiin xaddidaadyo, iyo hababka garaafyada kala duwan waxay isticmaalaan alaab cayriin oo kala duwan.Kaarboonka aan graphitized-ka ahayn, hababka dhaqameedku si dhib leh ayey u jaan-qaadi karaan, halka qaacidada korantada ee korantada milixda ee dhalaalaysa ay jebiso xaddidaadda alaabta ceeriin, waxayna ku habboon tahay ku dhawaad dhammaan agabka kaarboon-dhaqameedka.
Qalabka kaarboon dhaqameedka waxaa ka mid ah kaarboon madow, kaarboon firfircoon, dhuxul, iwm., kuwaas oo dhuxushu ay tahay tan ugu rajo-gelinta badan.Khadka dhuxusha ku salaysan wuxuu u qaataa dhuxusha horudhac ahaan waxaana loo diyaariyaa alaabada garaafka heerkul sare ka dib daawaynta ka hor.
Dhawaan, warqadani waxay soo jeedinaysaa habab koronto kiimikaad oo cusub, sida Peng, by electrolysis cusbo dhalaalaysa uma badna in graphitized carbon madow galay crystallinity sare ee graphite, electrolysis ee muunado graphite ka kooban yahay qaabka petal graphite nanometer chips, leeyahay meel sare oo gaar ah. marka loo isticmaalo cathode baytariga lithium waxay muujisay waxqabadka korantada ee aad u fiican marka loo eego garaafyada dabiiciga ah.
Zhu iyo al.dhig dhuxusha la daweeyay ee tayada hoose leh ee CaCl2 nidaamka cusbada dhalaalaysa ee electrolysis ee 950 ℃, oo si guul leh u beddeshay dhuxusha tayada hoose leh graphite leh crystallinity sare, taas oo muujisay waxqabadka heerka wanaagsan iyo nolosha wareegga dheer marka loo isticmaalo sida anode ee baytari lithium ion. .
Tijaabadu waxay muujinaysaa inay suurtogal tahay in noocyada kala duwan ee agabka kaarboonka ee dhaqameed loo rogo garaafiyada iyadoo la adeegsanayo electrolysis cusbo dhalaalaysa, taas oo u furaysa hab cusub oo mustaqbalka ah garaafyada synthetic.
1.2 habka
Habka milixda dhalaalaysa waxay u isticmaashaa walxo kaarboon sidii cathode oo waxay u beddeshaa graphite leh crystallinity sare iyadoo la adeegsanayo polarization cathodic.Waqtigan xaadirka ah, suugaanta hadda jirta waxay sheegaysaa ka-saarista ogsijiinta iyo dib-u-habaynta fogaanta fog ee atamka kaarboonka ee habka beddelka ee suurtagalka ah ee polarization cathodic.
Joogitaanka ogsajiinta ee alaabta kaarboon waxay caqabad ku noqon doontaa garaafaynta ilaa xad.Habka garaafaynta dhaqameed, ogsijiinta si tartiib ah ayaa looga saari doonaa marka heerkulku ka sarreeyo 1600K.Si kastaba ha ahaatee, aad bay ugu habboon tahay in lagu deoxidize iyada oo loo marayo polarization cathodic.
Peng, iwm ee tijaabooyinka markii ugu horeysay waxay soo bandhigeen habka suurtogalka ah ee suurtogalka ah ee electrolysis cathodic milixda, kuwaas oo ah graphitization inta badan meesha laga bilaabo waa in ay ku yaalaan microspheres carbon adag / electrolyte interface. qolof garaafeed, ka dibna waligiis waligiis xasilloonayn atamka kaarboonka kaarboonka ee anhydrous ku faafay flake garaafyada bannaanka oo deggan, ilaa si dhammaystiran loo garaafay,
Habka garaafyada waxaa weheliya ka saarista ogsijiinta, taas oo sidoo kale lagu xaqiijiyay tijaabooyin.
Jin iyo al.sidoo kale waxay cadeeyeen aragtidan iyada oo loo marayo tijaabooyin.Kaarboonaysiinta gulukoosta ka dib, garaafaynta (17% oksijiinta ka kooban) ayaa la sameeyay.Garaafaynta ka dib, qaybaha kaarboonka adag ee asalka ah (Jaantus. 1a iyo 1c) waxay sameeyeen qolof daloola oo ka kooban nanosheets graphite (Jaantus. 1b iyo 1d).
Electrolysis ee fiilooyinka kaarboonka (16% ogsijiin), fiilooyinka kaarboonka waxaa loo rogi karaa tuubooyinka garaafka ka dib garaafaynta iyadoo loo eegayo habka beddelka ee lagu qiyaasay suugaanta.
Waxaa la rumeysan yahay in, dhaqdhaqaaqa fogaan fog waa hoos polarization cathodic ee atamka carbon graphite crystal sare si aad u habayn kaarboon amorphous waa in la farsameeyo, graphite synthetic tufaax gaar ah u qaabeeya nanostructures ka faa'iidaysan atamka oxygen ka, laakiin sida gaarka ah sida loo saameeyo qaab dhismeedka nanometer graphite ma cadda. sida ogsijiinta ka soo qalfoofka carbon ka dib sida at falcelinta cathode, iwm.
Waqtigan xaadirka ah, cilmi-baarista farsamada ayaa weli ku jirta marxaladda hore, waxaana loo baahan yahay cilmi-baaris dheeraad ah.
1.3 Sifada maskaxeed ee garaafka synthetic
SEM waxaa loo isticmaalaa in lagu eego qaab-dhismeedka microscopic ee garaafyada, TEM waxaa loo isticmaalaa in lagu ilaaliyo qaabdhismeedka qaabdhismeedka ka yar 0.2 μm, XRD iyo Raman spectroscopy waa habka ugu badan ee loo isticmaalo in lagu garto garaafyada yar yar, XRD waxaa loo isticmaalaa in lagu garto crystal macluumaadka garaafka, iyo Raman spectroscopy waxaa loo isticmaalaa in lagu garto cilladaha iyo nidaamka heerka garaafka.
Waxa jira daloolo badan oo garaafka ku jira oo ay diyaarisay cathode polarization of electrolysis cusbo dhalaalay.Qalab cayriin oo kala duwan, sida kaarboonka elektiroonigga madow, nanostructures dalool oo kale ah ayaa la helay.XRD iyo falanqaynta spectrum Raman waxaa lagu sameeyaa kaarboonka madow ka dib korantada.
At 827 ℃, ka dib markii lagu daaweeyay koronto 2.6V ee 1h, Raman spectral image ee kaarboon madow ku dhawaad la mid ah sida garaafyada ganacsiga.Ka dib marka madowga kaarboonka lagu daweeyo heerkul kala duwan, garaafiga fiiqan ee sifada ugu sarreysa (002) ayaa la cabbiraa.Diffraction-ka ugu sarreeya (002) wuxuu matalaa heerka hanuuninta lakabka kaarboonka udgoonka ee garaafka.
Sida uu u fiiqan yahay lakabka kaarboonka, waa inta u jihaysan.
Zhu wuxuu u adeegsaday dhuxusha hoose ee la safeeyey sida cathode ee tijaabada, iyo qaab-dhismeedka yar-yar ee badeecada graphitized ayaa laga beddelay qaab-dhismeedka garaafiga weyn, lakabka garaafka dhagan ayaa sidoo kale lagu arkay hoos mikroskoob heer sare ah oo gudbinta elektarooniga ah.
Raman spectra, oo leh isbeddelka xaaladaha tijaabada, aqoonsiga aqoonsiga / Ig sidoo kale wuu isbedelay.Marka heerkulka korantada uu ahaa 950 ℃, waqtiga korantada wuxuu ahaa 6h, korantada korantadana waxay ahayd 2.6V, qiimaha aqoonsiga / Ig ugu hooseeya wuxuu ahaa 0.3, D ugu sarreysa ayaa aad uga hooseeya G ugu sarreysa.Isla mar ahaantaana, muuqaalka kore ee 2D wuxuu sidoo kale matalaa samaynta qaab dhismeedka garaafyada aadka loo dalbado.
Diffraction fiiqan (002) ee sawirka XRD sidoo kale wuxuu xaqiijinayaa beddelka guusha leh ee dhuxusha hoose ee garaafka leh crystallinity sare.
Habka garaafyada, kororka heerkulka iyo korantada ayaa door dhiirrigelin ah ka ciyaari doona, laakiin korantada aad u sarreysa waxay yareyn doontaa wax-soo-saarka graphite, heerkulka aad u sarreeya ama waqtiga garaafyada aad u dheer waxay horseedi doontaa qashinka kheyraadka, sidaas darteed agabyada kala duwan ee kaarboonka. , waxaa si gaar ah muhiim u ah in la sahamiyo xaaladaha korantada ee ugu habboon, sidoo kale waa diiradda iyo dhibka.
Nanostructure-ka tufaax u eg wuxuu leeyahay sifooyin kiimikaad oo aad u wanaagsan.Tiro badan oo daloolada ah ayaa u oggolaanaya ions in si dhakhso ah loo geliyo / loo dhejiyo, iyada oo la siinayo qalab tayo sare leh oo cathode ah oo loogu talagalay baytariyada, iwm. Sidaa darteed, habka korantada garaafyada ayaa ah habka garaafaynta.
Habka koronto-soo-saarka milixda dhalaalaysa
2.1 koronto-soo-baxa kaarboon laba ogsaydh
Sida gaaska aqalka dhirta lagu koriyo ee ugu muhiimsan, CO2 sidoo kale waa mid aan sun ahayn, dhib lahayn, raqiis ah oo si sahlan loo heli karo kheyraad dib loo cusboonaysiin karo.Si kastaba ha ahaatee, kaarboonka CO2 ayaa ku jira gobolka oksaydhka ugu sarreeya, markaa CO2 waxay leedahay xasillooni heerkul sare ah, taas oo adkeynaysa in dib loo isticmaalo.
Cilmi-baaristii ugu horreysay ee CO2 electrodeposition waxaa dib loo raadin karaa 1960-meeyadii.Ingram iyo al.si guul leh loogu diyaariyey kaarboon on electrode dahab ah ee nidaamka milixda dhalaalay ee Li2CO3-Na2CO3-K2CO3.
Van iyo al.ayaa tilmaamay in budada kaarboonka ee laga helay awoodo dhimis kala duwan ay lahaayeen qaabab kala duwan, oo ay ku jiraan graphite, carbon amorphous iyo carbon nanofibers.
By cusbo la dhalaalay si ay u qabtaan CO2 iyo habka diyaarinta ee guusha walxaha carbon, ka dib markii muddo dheer cilmi-baaris cilmi-baaris ah ayaa diiradda saaray habka formation dhigaalka carbon iyo saamaynta xaaladaha electrolysis on alaabta kama dambaysta ah, oo ay ku jiraan heerkulka electrolytic, danab electrolytic iyo ka kooban yahay. cusbo la dhalaaliyay iyo electrodes, iwm, diyaarinta waxqabadka sare ee qalabka graphite ee electrodeposition of CO2 ayaa dhigay aasaas adag.
Adiga oo bedelaya elektrolytka oo isticmaalaya nidaamka cusbada dhalaalaysa ee CaCl2 oo leh waxtarka sare ee CO2, Hu et al.si guul leh loo diyaariyey graphene oo leh shahaadada garaafyada sare iyo kaarboon nanotubes kaarboon iyo qaabab kale oo nanographite ah iyadoo la baranayo xaaladaha korantada sida heerkulka korantada, halabuurka korantada iyo halabuurka milixda dhalaalay.
Marka la barbardhigo nidaamka carbonate, CaCl2 waxay leedahay faa'iidooyinka raqiis ah oo sahlan in la helo, dhaqdhaqaaqa sare, sahlanaanta biyaha, iyo milanka sare ee ions oksijiinta, taas oo bixisa shuruudo aragti ah oo loogu talagalay beddelka CO2 ee alaabta graphite ee qiimaha sare leh.
2.2 Habka Isbeddelka
Diyaarinta alaabada kaarboonka ee qiimaha sare leh ee lagu daro korantada CO2 ee cusbada dhalaalaysa inta badan waxaa ka mid ah CO2 qabashada iyo dhimista dadban.Qabashada CO2 waxaa lagu dhameeyay O2- milix dhalaalaysa oo bilaash ah, sida lagu muujiyey isla'egta (1):
CO2+O2-→CO3 2- (1)
Hadda, saddex hab oo falcelinta dhimista tooska ah ayaa la soo jeediyay: falcelin hal-tallaabo ah, falcelin laba-tallaabo ah iyo habka falcelinta dhimista birta.
Habka falcelinta hal-tallaabo waxaa markii ugu horreysay soo jeediyay Ingram, sida lagu muujiyey isla'egta (2):
CO3 2-+ 4E – →C+3O2- (2)
Habka falcelinta laba-tallaabo waxaa soo jeediyay Borucka et al., sida lagu muujiyey isla'egta (3-4):
CO3 2-+ 2E – →CO2 2-+O2- (3)
CO2 2-+ 2E - →C+2O2- (4)
Habka falcelinta dhimista birta waxaa soo jeediyay Deanhardt et al.Waxay rumaysnaayeen in ions birta markii hore lagu yareeyay birta cathode, ka dibna birta ayaa la dhimay ion carbonate, sida lagu muujiyay isla'egta (5 ~ 6):
M- + E – →M (5)
4 m + M2CO3 – > C + 3 m2o (6)
Waqtigan xaadirka ah, habka falcelinta hal-tallaabo ayaa guud ahaan lagu aqbalay suugaanta jirta.
Yin iyo al.wuxuu bartay nidaamka carbonate ee Li-Na-K oo leh nikkel sida cathode, tin dioxide sida anode iyo silig qalin ah oo ah elektrode tixraac ah, waxayna heleen jaantuska tijaabada voltammetry wareegtada ee Jaantuska 2 (heerka sawirka 100 mV/s) ee nikkel cathode, oo la helay in ay jirto hal kaliya oo dhimis ah (at -2.0V) ee iskaanka xun.
Sidaa darteed, waxaa la soo gabagabeyn karaa in hal falcelin oo kaliya ay dhacday intii lagu jiray dhimista karbonat-ka.
Gao iyo al.la helay voltammetry wareeg ah oo isku mid ah oo ku jira nidaamka karbonti isku mid ah.
Ge iyo al.loo isticmaalo inert anode iyo tungsten cathode si ay u qabtaan CO2 ee nidaamka LiCl-Li2CO3 oo la helay sawiro la mid ah, oo kaliya hoos u dhigista ugu sarreysa ee kaydinta kaarboonka ayaa ka muuqday iskaanka xun.
Nidaamka milixda dhalaalay ee birta alkaline, biraha alkali iyo CO ayaa la soo saari doonaa halka kaarboonka lagu keydiyo cathode.Si kastaba ha ahaatee, sababtoo ah xaaladaha kulaylka ee falcelinta dhigidda kaarboonku way hooseeyaan heerkul hoose, kaliya dhimista kaarboonka ilaa kaarboonka ayaa lagu ogaan karaa tijaabada.
2.3 CO2 oo lagu qabto cusbo dhalaalay si loo diyaariyo alaabta garaafyada
Nanomaterials garaafyo-qiimo sare leh sida graphene iyo kaarboon nanotubes waxaa lagu diyaarin karaa by electrodeposition of CO2 ka milix dhalaalay iyadoo la xakameynayo xaaladaha tijaabada.Hu iyo al.loo isticmaalo birta aan la taaban karin sida cathode ee nidaamka cusbada dhalaalaysa ee CaCl2-NaCl-CaO oo koronto lagu shubay 4h iyadoo loo eegayo xaalada 2.6V danab joogto ah heerkul kala duwan.
Thanks to catalysis of birta iyo saamaynta qaraxa CO ee u dhexeeya lakabyada graphite, graphene ayaa laga helay dusha sare ee cathode.Habka diyaarinta ee graphene waxa lagu muujiyay sawirka 3.
Sawirka
Daraasadaha dambe ayaa ku daray Li2SO4 iyada oo ku saleysan nidaamka milixda ee CaCl2-NaClCaO, heerkulka elektiroonigga ah wuxuu ahaa 625 ℃, ka dib 4h ee electrolysis, isla mar ahaantaana ku dhejinta cathodic ee carbon laga helay graphene iyo carbon nanotubes, daraasaddu waxay ogaatay in Li + iyo SO4 2 - si ay u keenaan saamayn togan on graphitization.
Sulfur sidoo kale si guul leh ayaa loogu dhex milmay jirka kaarboonka, iyo xaashiyo garaafyo khafiif ah oo khafiif ah iyo kaarboon fiilo leh ayaa lagu heli karaa iyadoo la xakameynayo xaaladaha korantada.
Walxaha sida heerkulka electrolytic ee sare iyo hoose ee samaynta graphene waa muhiim, marka heerkulka ka sarreeya 800 ℃ ay fududahay in la dhaliyo CO halkii kaarboonka, ku dhawaad ma kaydin kaarboon marka ay ka sarreyso 950 ℃, sidaas darteed xakamaynta heerkulka ayaa aad muhiim u ah. si loo soo saaro graphene iyo nanotubes kaarboon, oo loo soo celiyo baahida dhigashada kaarboon isku-dhafka falcelinta CO si loo hubiyo in cathode uu dhaliyo graphene deggan.
Shaqooyinkani waxay bixiyaan hab cusub oo loogu talagalay diyaarinta alaabta nano-graphite ee CO2, taas oo muhiimad weyn u leh xallinta gaaska aqalka dhirta lagu koriyo iyo diyaarinta graphene.
3. Kooban iyo Muuqaal
Iyadoo horumarinta degdega ah ee warshadaha tamarta cusub, graphite dabiiciga ah ayaa awoodi waayay in uu daboolo baahida hadda jirta, iyo graphite macmal ah ayaa leh sifooyin jidheed iyo kiimiko oo ka wanaagsan garaafyada dabiiciga ah, sidaas darteed raqiis, hufan iyo garaafka deegaanka saaxiibtinimo ayaa ah hadaf wakhti dheer ah.
Hababka Electrochemical graphitization in alaabta ceeriin adag iyo gaseous la habka of polarization cathodic iyo dhigaalka electrochemical ahaa si guul leh ka soo baxay qalabka graphite qiimo sare ku daray, marka la barbar dhigo habka dhaqameed ee graphitization, habka electrochemical waa hufnaan sare, isticmaalka tamarta hoose. ilaalinta deegaanka cagaaran, waayo, yar oo xaddiday by alaabta xulashada isku mar, sida ay shuruudaha electrolysis kala duwan waxaa lagu diyaarin karaa qaab-dhismeedka kala duwan ee garaafyada,
Waxay siisaa hab wax ku ool ah oo loogu talagalay dhammaan noocyada kala duwan ee kaarboonka amorphous iyo gaaska aqalka dhirta lagu koriyo si loogu beddelo agab nano-qaabaysan oo garaaf ah oo qiimo leh waxayna leedahay rajo codsi oo wanaagsan.
Waqtigan xaadirka ah, farsamadani waxay ku jirtaa bilawgeeda.Waxaa jira daraasado yar oo ku saabsan garaafaynta habka elektiroonigga ah, waxaana weli jira habab badan oo aan la ogaan karin.Sidaa darteed, waa lagama maarmaan in laga bilaabo alaabta ceeriin iyo in la sameeyo daraasad dhamaystiran oo nidaamsan oo ku saabsan kaarboonka kala duwan ee amorphous, isla markaana sahaminta heerkulka iyo dhaqdhaqaaqa isbeddelka garaafka heer qoto dheer.
Kuwani waxay muhiimad fog u leeyihiin horumarka mustaqbalka ee warshadaha garaafyada.
Waqtiga boostada: Meey-10-2021