E kewara graphite ụzọ abụọ: graphite e ji aka rụọ na graphite eke, nke bụ ebe a na-echekwa graphite eke n'ụwa n'ihe dị ka tọn ijeri abụọ.
A na-enweta graphite arụrụ arụ site na ire ere na ọgwụgwọ okpomọkụ nke ihe ndị nwere carbon n'okpuru nrụgide nkịtị. Mgbanwe a chọrọ okpomọkụ na ike zuru oke dị ka ike na-akpali, a ga-agbanwekwa nhazi ahụ na-adịghị mma ka ọ bụrụ nhazi kristal graphite nke edobere.
N'echiche sara mbara nke ihe carbon site na nhazigharị atọm carbon n'elu okpomọkụ dị elu nke 2000 ℃, mana ụfọdụ ihe carbon na okpomọkụ dị elu karịa 3000 ℃ graphitization. A maara ụdị ihe carbon a dị ka "coal siri ike", maka ihe carbon graphitization dị mfe, usoro graphitization ọdịnala gụnyere usoro okpomọkụ dị elu na nrụgide dị elu, graphitization catalytic, usoro itinye vapor kemịkalụ, wdg.
Nhazi eserese bụ ụzọ dị irè isi jiri ihe ndị na-emepụta carbon eme ihe bara uru. Mgbe ndị ọkà mmụta nyochachara nke ọma ma mee nnyocha miri emi, ọ tozuola ugbu a. Agbanyeghị, ụfọdụ ihe ndị na-adịghị mma na-egbochi ojiji nke nhazi eserese ọdịnala n'ụlọ ọrụ, yabụ ọ bụ usoro a na-apụghị izere ezere ịchọpụta ụzọ nhazi eserese ọhụrụ.
Usoro electrolysis nnu a kpụrụ akpụ kemgbe narị afọ nke 19 karịrị otu narị afọ nke mmepe, ozizi ya bụ isi na ụzọ ọhụrụ ya bụ ihe ọhụrụ na mmepe mgbe niile, ugbu a ejedebeghị naanị na ụlọ ọrụ ọla ọdịnala, na mmalite nke narị afọ nke 21, ígwè dị na sistemụ nnu a gbazere agbaze siri ike nke oxide electrolytic nkwadebe nke metal elemental aghọwo ihe a na-elekwasị anya na ndị na-arụsi ọrụ ike karị,
N'oge na-adịbeghị anya, ụzọ ọhụrụ e si akwadebe ihe ndị e ji graphite mee site na iji electrolysis nnu agbaze agbaze adọtala ọtụtụ mmadụ.
Site na iji cathodic polarization na electrodeposition, a na-agbanwe ụdị ihe abụọ dị iche iche nke ihe ndị e ji carbon emepụta ka ọ bụrụ ihe nano-graphite nwere uru dị elu. Ma e jiri ya tụnyere teknụzụ graphitization ọdịnala, usoro graphitization ọhụrụ nwere uru nke obere okpomọkụ graphitization na ọdịdị a na-achịkwa.
Akwụkwọ a na-enyocha ọganihu nke nhazi eserese site na usoro electrochemical, na-ewebata teknụzụ ọhụrụ a, na-enyocha uru na ọghọm ya, ma na-atụ anya usoro mmepe ya n'ọdịnihu.
Nke mbụ, usoro polarization nke nnu electrolytic cathode nke gbazere agbaze
1.1 ihe eji eme ihe
Ugbu a, ihe kachasị mkpa nke graphite arụrụ arụ bụ agịga coke na pitch coke nke ogo graphitization dị elu, ya bụ site na ihe fọdụrụ na mmanụ na coal tar dị ka ihe eji emepụta ihe carbon dị elu, yana obere porosity, obere sọlfọ, obere ntụ ntụ na uru nke graphitization, mgbe nkwadebe ya na graphite nwere ezigbo iguzogide mmetụta, ike igwe dị elu, obere iguzogide,
Agbanyeghị, obere ebe nchekwa mmanụ na ọnụ ahịa mmanụ na-agbanwe agbanwe emeela ka mmepe ya ghara ịdị irè, yabụ ịchọ ihe ọhụrụ aghọọla nsogbu dị oke mkpa a ga-edozi.
Usoro nhazi eserese ọdịnala nwere oke mmachi, ụzọ nhazi eserese dị iche iche na-ejikwa ihe dị iche iche. Maka carbon na-abụghị graphitized, usoro ọdịnala enweghị ike ịmepụta ya graphitized, ebe usoro electrochemical nke electrolysis nnu agbaze agbaze na-agbaji oke nke ihe ndị e ji emepụta ihe, ọ dabara adaba maka ihe fọrọ nke nta ka ọ bụrụ ihe niile e ji emepụta carbon ọdịnala mee.
Ihe ndị e ji mee ka kabọn ọdịnala dịka kabọn ojii, kabọn a na-arụ ọrụ, kol, wdg, nke so na kol bụ nke kacha mma. Ink e ji kol mee na-ewere kol dị ka ihe na-ebute ụzọ ma na-akwadebe ya ka ọ bụrụ ngwaahịa graphite n'oge okpomọkụ dị elu mgbe e mechara ọgwụgwọ tupu e mee ya.
N'oge na-adịbeghị anya, akwụkwọ a na-atụ aro ụzọ electrochemical ọhụrụ, dịka Peng, site na nnu gbazere agbaze electrolysis agaghị graphitized carbon black n'ime nnukwu kristal nke graphite, electrolysis nke ihe nlele graphite nwere obere nanometer graphite, nwere oke elu dị elu, mgbe ejiri ya maka batrị lithium cathode gosiri arụmọrụ electrochemical dị mma karịa graphite eke.
Zhu na ndị otu ya tinyere kol dị ala nke a gwọrọ n'ime sistemu nnu CaCl2 maka electrolysis na 950 ℃, ma gbanwee kol dị ala ka ọ bụrụ graphite nwere nnukwu kristal, nke gosipụtara arụmọrụ dị mma na ndụ ogologo oge mgbe ejiri ya dị ka anode nke batrị ion lithium.
Nnwale ahụ na-egosi na ọ ga-ekwe omume ịtụgharị ụdị ihe carbon ọdịnala dị iche iche ka ọ bụrụ graphite site na iji electrolysis nnu gbazere agbaze, nke na-emepe ụzọ ọhụrụ maka graphite sịntetik n'ọdịnihu.
1.2 usoro nke
Usoro electrolysis nnu a kpụrụ akpụ na-eji ihe carbon dị ka kathode ma na-agbanwe ya ka ọ bụrụ graphite nwere nnukwu kristal site na iji cathodic polarization. Ugbu a, akwụkwọ ndị dị ugbu a na-ekwu maka iwepụ oxygen na nhazi ogologo oge nke atọm carbon na usoro mgbanwe nke cathodic polarization.
Ọnụnọ oxygen dị n'ime ihe ndị e ji carbon mee ga-egbochi nhazi graphitization ruo n'ókè ụfọdụ. N'usoro nhazi graphitization ọdịnala, a ga-ewepụ oxygen nwayọ nwayọ mgbe okpomọkụ dị elu karịa 1600K. Agbanyeghị, ọ dị oke mma iwepụ oxidation site na polarization cathodic.
Peng, wdg. na nnwale ndị a maka oge mbụ, tinyere usoro ikike polarization nke nnu gbazere agbaze, ya bụ, nhazi graphitization ebe kachasị mkpa ịmalite bụ ịnọ na microspheres carbon siri ike/njikọ electrolyte, mepụta microsphere carbon gburugburu shei graphite dị otu dayameta, wee ghara ịgbasa atọm carbon carbon anhydrous na-agbasa gaa na flake graphite mpụta kwụsiri ike karị, ruo mgbe graphitization zuru oke.
Usoro nhazi eserese na-esokwa mwepụ nke oxygen, nke a na-akwadokwa site na nnwale.
Jin na ndị otu ya gosikwara echiche a site na nnwale. Mgbe emechara ka glucose dị ka carbon, e mere graphitization (ọkwa oxygen 17%). Mgbe emechara graphitization, oghere carbon siri ike mbụ (Foto 1a na 1c) kpụrụ shei oghere nke ejiri nanosheets graphite mee (Foto 1b na 1d).
Site na electrolysis nke eriri carbon (16% oxygen), enwere ike ịgbanwe eriri carbon ka ọ bụrụ ọkpọkọ graphite mgbe graphitization gasịrị dịka usoro ntụgharị a tụrụ anya ya n'akwụkwọ.
Ekwenyere na mmegharị anya dị anya dị n'okpuru polarization nke atom carbon dị elu nke graphite kristal dị elu ruo na amorphous carbon rehabilitation ga-edozi, graphite pụrụ iche petals na-akpụzi nanostructures na-erite uru site na atọm oxygen site na ya, mana otu esi metụta nhazi nanometer graphite edoghị anya, dị ka oxygen sitere na ọkpụkpụ carbon mgbe otu esi emeghachi omume na cathode, wdg.
Ugbu a, nnyocha gbasara usoro ahụ ka dị na mbido, a chọkwara nnyocha ọzọ.
1.3 Nkọwapụta nke graphite sịntetik
A na-eji SEM elele ọdịdị elu nke graphite, a na-eji TEM elele ọdịdị nhazi nke ihe na-erughị 0.2 μm, XRD na Raman spectroscopy bụ ụzọ a na-ejikarị akọwapụta ọdịdị obere nke graphite, a na-eji XRD akọwapụta ozi kristal nke graphite, a na-ejikwa Raman spectroscopy akọwapụta ntụpọ na ọkwa nhazi nke graphite.
E nwere ọtụtụ oghere dị na graphite nke e ji cathode polarization nke nnu agbaze agbaze nke electrolysis kwadebere. Maka ihe dị iche iche e ji emepụta ihe, dị ka carbon black electrolysis, a na-enweta nanostructures dị ka petal. A na-eme nyocha XRD na Raman spectrum na carbon black mgbe electrolysis gasịrị.
Na 827 ℃, mgbe ejiri voltaji 2.6V gwọọ ya ruo otu awa, onyonyo Raman nke carbon ojii fọrọ nke nta ka ọ bụrụ otu ihe ahụ dị na graphite azụmaahịa. Mgbe ejiri okpomọkụ dị iche iche gwọọ carbon ojii ahụ, a na-atụ oke njirimara graphite dị nkọ (002). Oke diffraction (002) na-anọchite anya ogo nhazi nke oyi akwa carbon na-esi ísì ụtọ na graphite.
Ka oyi akwa carbon ahụ na-adị nkọ, otú ahụ ka ọ na-eme ka ọ na-eche echiche nke ọma.
Zhu jiri coal dị ala dị ka kathode na nnwale ahụ, a gbanwere obere nhazi nke ngwaahịa graphitized site na granular gaa na nnukwu nhazi graphite, a hụkwara oyi akwa graphite siri ike n'okpuru igwe elektrọn nnyefe dị elu.
N'ihe gbasara Raman, site na mgbanwe nke ọnọdụ nnwale, uru ID/Ig gbanweekwara. Mgbe okpomọkụ electrolytic dị 950 ℃, oge electrolytic bụ awa 6, voltaji electrolytic bụ 2.6V, uru ID/Ig kacha ala bụ 0.3, oke D dịkwa ala karịa oke G. N'otu oge ahụ, ọdịdị nke oke 2D na-anọchitekwa anya nhazi nke nhazi graphite dị oke mma.
Oke mgbasa ozi dị nkọ (002) dị na onyonyo XRD na-egosikwa mgbanwe nke coal dị ala ka ọ bụrụ graphite nwere nnukwu kristal.
N'ime usoro nhazi eserese, mmụba nke okpomọkụ na voltaji ga-arụ ọrụ nkwalite, mana oke voltaji ga-ebelata mmepụta nke graphite, oke okpomọkụ ma ọ bụ oge nhazi eserese ogologo ga-eduga na mkpofu akụrụngwa, yabụ maka ihe carbon dị iche iche, ọ dị mkpa karịsịa ịchọpụta ọnọdụ electrolytic kacha mma, ọ bụkwa ihe a na-elekwasị anya na ihe isi ike.
Nanostructure dị ka petal a nwere ezigbo ihe onwunwe electrochemical. Ọtụtụ pores na-enye ohere itinye/ịchọpụta ion ngwa ngwa, na-enye ihe dị elu maka batrị, wdg. Ya mere, usoro electrochemical graphitization bụ ụzọ graphitization nwere ike isi mee ya.
Usoro nhazi elektrọde nnu a kpụrụ akpụ
2.1 Ngụkọta elektrọniks nke carbon dioxide
Dịka gas kacha mkpa n'ime ụlọ okpomọkụ, CO2 bụkwa ihe na-adịghị egbu egbu, na-adịghị emerụ ahụ, dị ọnụ ala, ma dịkwa mfe ịnweta mmeghari ohuru. Agbanyeghị, carbon dị na CO2 dị n'ọnọdụ oxidation kachasị elu, yabụ CO2 nwere nnukwu nkwụsi ike thermodynamic, nke na-eme ka ọ sie ike iji ya ọzọ.
A pụrụ ịchọpụta nchọpụta mbụ gbasara ọnọdụ elektrọd CO2 na 1960. Ingram na ndị otu ya kwadebere carbon na elektrọd ọlaedo nke ọma na sistemụ nnu agbaze nke Li2CO3-Na2CO3-K2CO3.
Van na ndị otu ya kwuru na ntụ ntụ carbon e nwetara na ikike mbelata dị iche iche nwere usoro dị iche iche, gụnyere graphite, carbon amorphous na carbon nanofibers.
Site na nnu gbazere agbaze iji jide CO2 na usoro nkwadebe nke ihe ịga nke ọma nke ihe carbon, mgbe ogologo oge nke ndị ọkà mmụta nyocha lekwasị anya na usoro nhazi nke carbon deposition na mmetụta nke ọnọdụ electrolysis na ngwaahịa ikpeazụ, nke gụnyere okpomọkụ electrolytic, voltaji electrolytic na nhazi nke nnu agbazere agbaze na electrodes, wdg, nkwadebe nke arụmọrụ dị elu nke ihe graphite maka electrodeposition nke CO2 atọọla ntọala siri ike.
Site n'ịgbanwe electrolyte na iji sistemụ nnu agbaze nke dabeere na CaCl2 nke nwere arụmọrụ njide CO2 dị elu, Hu et al. mepụtara graphene nke nwere ogo graphitization dị elu na carbon nanotubes na nhazi nanographite ndị ọzọ nke ọma site n'ịmụ banyere ọnọdụ electrolytic dị ka okpomọkụ electrolysis, nhazi electrode na nhazi nnu agbaze.
Ma e jiri ya tụnyere sistemụ carbonate, CaCl2 nwere uru dị ka ọnụ ala na mfe inweta, ike dị elu, ike ịgbaze na mmiri, na ike ịgbaze nke ion oxygen dị elu, nke na-enye ọnọdụ echiche maka mgbanwe nke CO2 ka ọ bụrụ ngwaahịa graphite nwere uru dị elu.
2.2 Usoro Mgbanwe
Nkwadebe nke ihe carbon agbakwunyere dị elu site na elektrọd nke CO2 site na nnu gbazere agbaze gụnyere njide CO2 na mbelata na-apụtaghị ìhè. A na-emecha njide nke CO2 site na nnu gbazere agbaze O2 n'efu, dịka egosiri na Nha nhata (1):
CO2+O2-→CO3 2- (1)
Ugbu a, a tụpụtala usoro mmeghachi omume mbelata atọ na-apụtaghị ìhè: mmeghachi omume otu nzọụkwụ, mmeghachi omume nzọụkwụ abụọ na usoro mmeghachi omume mbelata ígwè.
Ingram bu ụzọ tụọ aro usoro mmeghachi omume otu nzọụkwụ, dịka egosiri na Nha nhata (2):
CO3 2-+ 4E – →C+3O2- (2)
Borucka et al. tụrụ aro usoro mmeghachi omume nke nzọụkwụ abụọ, dịka egosiri na Nha nhata (3-4):
CO3 2-+ 2E – →CO2 2-+O2- (3)
CO2 2-+ 2E – →C+2O2- (4)
Deanhardt na ndị otu ya tụrụ aro usoro nke mbelata mmeghachi omume ígwè. Ha kwenyere na a na-ebu ụzọ belata ion ígwè ka ọ bụrụ metal na kathode, e mesịa belata metal ahụ ka ọ bụrụ ion carbonate, dịka egosiri na Nha nhata (5~6):
M- + E – →M (5)
4 m + M2CO3 – > C + 3 m2o (6)
Ugbu a, a na-anabata usoro mmeghachi omume otu nzọụkwụ n'akwụkwọ ndị dị ugbu a.
Yin na ndị otu ya mụrụ usoro carbonate Li-Na-K na nickel dị ka kathode, tin dioxide dị ka anode na waya ọlaọcha dị ka elektrọd ntụaka, wee nweta ọnụọgụ ule voltammetry cyclic na Foto nke 2 (ọsọ nyocha nke 100 mV/s) na kathode nickel, wee chọpụta na enwere naanị otu oke mbelata (na -2.0V) na nyocha na-adịghị mma.
Ya mere, enwere ike ikwubi na naanị otu mmeghachi omume mere n'oge mbelata nke carbonate.
Gao na ndị otu ya nwetara otu voltammetry cyclic ahụ n'otu sistemụ carbonate ahụ.
Ge na ndị otu ya jiri anode inert na tungsten cathode jide CO2 na sistemụ LiCl-Li2CO3 wee nweta onyonyo ndị yiri ya, naanị mbelata nke ọkwa carbon pụtara na nyocha na-adịghị mma.
N'ime sistemu nnu a gbazere agbaze nke ígwè alkaline, a ga-emepụta ọla alkali na CO ebe katọde na-etinye carbon. Agbanyeghị, n'ihi na ọnọdụ thermodynamic nke mmeghachi omume itinye carbon dị ala na obere okpomọkụ, naanị mbelata nke carbon ka ọ bụrụ carbon ka a ga-achọpụta na nnwale ahụ.
2.3 Njide CO2 site na nnu gbazere agbaze iji kwadebe ngwaahịa graphite
Enwere ike ịkwadebe ihe ndị dị na graphite dị oke ọnụ ahịa dịka graphene na carbon nanotubes site na nhazi elektrọd nke CO2 sitere na nnu gbazere agbaze site na ijikwa ọnọdụ nnwale. Hu et al. jiri ígwè anaghị agba nchara dị ka kathode na sistemụ nnu agbazere CaCl2-NaCl-CaO ma gbanye ya na electrolyze ruo awa 4 n'okpuru ọnọdụ nke voltaji na-adịgide adịgide 2.6V na okpomọkụ dị iche iche.
N'ihi catalysis nke ígwè na mmetụta mgbawa nke CO n'etiti akwa graphite, a hụrụ graphene n'elu kathode. E gosiri usoro nkwadebe nke graphene na Fig. 3.
Foto ahụ
Nnyocha ndị e mechara gbakwunyere Li2SO4 dabere na sistemụ nnu agbazere agbaze nke CaCl2-NaClCaO, okpomọkụ electrolysis bụ 625 ℃, mgbe awa 4 nke electrolysis gasịrị, n'otu oge ahụ na ntinye cathodic nke carbon hụrụ graphene na carbon nanotubes, ọmụmụ ihe ahụ chọpụtara na Li+ na SO4 2- na-eweta mmetụta dị mma na graphitization.
A na-etinyekwa sọlfọ n'ime ahụ carbon nke ọma, a pụkwara inweta mpempe akwụkwọ graphite dị gịrịgịrị na carbon filamentous site n'ịchịkwa ọnọdụ electrolytic.
Ihe dị ka okpomọkụ electrolytic nke dị elu na ala maka imepụta graphene dị oke mkpa, mgbe okpomọkụ dị elu karịa 800 ℃ dị mfe ịmepụta CO kama carbon, ihe fọrọ nke nta ka ọ bụrụ enweghị nkwụnye carbon mgbe ọ dị elu karịa 950 ℃, yabụ njikwa okpomọkụ dị oke mkpa iji mepụta graphene na carbon nanotubes, ma weghachite mkpa mmeghachi omume carbon CO mmeghachi omume iji hụ na cathode ahụ na-emepụta graphene kwụsiri ike.
Ọrụ ndị a na-enye ụzọ ọhụrụ maka ịkwadebe ngwaahịa nano-graphite site na CO2, nke dị oke mkpa maka ngwọta nke gas griinhaus na nkwadebe nke graphene.
3. Nchịkọta na Echiche
Site na mmepe ngwa ngwa nke ụlọ ọrụ ike ọhụrụ, graphite eke enwebeghị ike imezu ihe achọrọ ugbu a, graphite arụrụ arụ nwekwara ihe onwunwe anụ ahụ na kemịkalụ ka mma karịa graphite eke, yabụ graphitization dị ọnụ ala, dị irè ma dịkwa mma maka gburugburu ebe obibi bụ ihe mgbaru ọsọ ogologo oge.
Usoro electrochemical graphitization na ihe siri ike na gasous raw materials na usoro nke cathodic polarization na electrochemical deposition e si na graphite ihe onwunwe pụta nke ọma na elu agbakwunyere uru, ma e jiri ya tụnyere ụzọ ọdịnala nke graphitization, usoro electrochemical bụ nke arụmọrụ dị elu, obere ike oriri, akwụkwọ ndụ akwụkwọ ndụ nchekwa gburugburu ebe obibi, maka obere oke site na ihe nhọrọ n'otu oge, dịka ọnọdụ electrolysis dị iche iche si dị, enwere ike ịkwadebe ya na ụdị dị iche iche nke nhazi graphite,
Ọ na-enye ụzọ dị irè iji gbanwee ụdị carbon amorphous na gas griinhaus niile ka ha bụrụ ihe ndị bara uru nke nwere nhazi nano ma nwee ezigbo ohere itinye ha n'ọrụ.
Ugbu a, teknụzụ a ka dị ọhụrụ. Ọ dị obere ọmụmụ gbasara nhazi graphitization site na usoro electrochemical, a ka nwekwara ọtụtụ usoro a na-amaghị ama. Ya mere, ọ dị mkpa ịmalite site na ihe ndị e ji emepụta ihe ma mee nnyocha zuru oke na usoro na carbon dị iche iche amorphous, ma n'otu oge ahụ nyochaa thermodynamics na dynamics nke ntụgharị graphite n'ọkwa dị omimi.
Ihe ndị a nwere nnukwu uru maka mmepe nke ụlọ ọrụ graphite n'ọdịnihu.
Oge ozi: Mee-10-2021