A na-ekewa graphite ka ọ bụrụ graphite wuruwuru na graphite eke, ihe nchekwa graphite eke egosipụtara n'ụwa n'ihe dị ka ijeri ijeri abụọ.
A na-enweta graphite artificial site na nbibi na ọgwụgwọ okpomọkụ nke ihe ndị nwere carbon n'okpuru nrụgide nkịtị.Ngbanwe a na-achọ oke okpomọkụ na ume dị elu dị ka ike na-anya ụgbọ ala, a ga-agbanwe usoro ahụ mebiri emebi ka ọ bụrụ nhazi kristal graphite nyere iwu.
Graphitization bụ n'ụzọ sara mbara nke carbonaceous ihe site n'elu 2000 ℃ okpomọkụ okpomọkụ ọgwụgwọ carbon atom rearrangement, Otú ọ dị ụfọdụ carbon ihe na elu okpomọkụ n'elu 3000 ℃ graphitization, ụdị carbon ihe a maara dị ka "ike unyi", maka Ihe dị mfe carbon graphitized, usoro eserese ọdịnala gụnyere oke okpomọkụ na usoro nrụgide dị elu, eserese catalytic, usoro ntinye ikuku kemịkalụ, wdg.
Graphitization bụ ụzọ dị irè nke itinye uru dị elu nke ihe carbonaceous.Ka ndị ọkà mmụta nyochachara nke ọma na nke miri emi, o tozuru oke ugbu a.Otú ọ dị, ụfọdụ ihe na-adịghị mma na-ejedebe ngwa nke graphitization omenala na ụlọ ọrụ, ya mere ọ bụ ihe a na-apụghị izere ezere iji nyochaa ụzọ graphitization ọhụrụ.
Usoro nnu a wụrụ awụ electrolysis ebe ọ bụ na narị afọ nke 19 bụ ihe karịrị otu narị afọ nke mmepe, ya bụ isi tiori na ụzọ ọhụrụ na-mgbe niile ọhụrụ na mmepe, ugbu a abụghịzi nanị na omenala metallurgical ụlọ ọrụ, na mmalite nke 21st narị afọ, metal na usoro nnu gbazere agbaze siri ike oxide electrolytic Mbelata nkwadebe nke elemental ọla aghọwo ihe na-elekwasị anya na-arụsi ọrụ ike karị,
N'oge na-adịbeghị anya, usoro ọhụrụ maka ịkwadebe ihe graphite site na electrolysis nnu a wụrụ awụ adọtala mmasị dị ukwuu.
Site na polarization cathodic na electrodeposition, ụdị abụọ dị iche iche nke akụrụngwa carbon na-agbanwe ka ọ bụrụ ihe nano-graphite nwere uru agbakwunyere.E jiri ya tụnyere teknụzụ graphitization ọdịnala, usoro eserese ọhụrụ ahụ nwere uru nke okpomọkụ graphitization dị ala na morphology na-achịkwa.
Akwụkwọ a na-enyocha ọganihu nke graphitization site na usoro electrochemical, na-ewebata nkà na ụzụ ọhụrụ a, nyochaa uru na ọghọm ya, ma na-atụ anya usoro mmepe ya n'ọdịnihu.
Nke mbụ, nnu gbazere agbaze electrolytic cathode polarization usoro
1.1 ihe eji eme ihe
Ka ọ dị ugbu a, isi akụrụngwa nke graphite wuru bụ agịga coke na pitch coke nke ogo graphitization dị elu, ya bụ site na mmanụ foduru na coal tar dị ka akụrụngwa iji mepụta ihe dị elu nke carbon, yana obere porosity, sọlfọ dị ala, obere uyi. ọdịnaya na uru nke graphitization, mgbe nkwadebe ya n'ime graphite nwere ezigbo nguzogide mmetụta, ike igwe dị elu, obere resistivity,
Agbanyeghị, oke nchekwa mmanụ na ọnụ ahịa mmanụ na-agbanwe agbanwe egbochila mmepe ya, yabụ ịchọ akụrụngwa ọhụrụ aghọwo nsogbu dị ngwa a ga-edozi.
Ụzọ eserese nke ọdịnala nwere oke, na ụzọ eserese dị iche iche na-eji akụrụngwa dị iche iche.Maka carbon na-abụghị graphitized, usoro ọdịnala enweghị ike ịdepụta ya, ebe usoro elektrọnịkị nke nnu a wụrụ awụ na-agbaji site na mmachi nke akụrụngwa, yana dabara maka ihe niile carbon ọdịnala.
Ihe carbon carbon ọdịnala gụnyere carbon ojii, carbon arụ ọrụ, coal, wdg, n'ime nke coal bụ nke kacha ekwe nkwa.Ink dabeere na coal na-ewere coal dị ka ihe mbụ ma kwadebere ya na ngwaahịa graphite na okpomọkụ dị elu mgbe emechara ya.
Na nso nso a, akwụkwọ a na-atụ aro a ọhụrụ electrochemical ụzọ, dị ka Peng, site a wụrụ awụ electrolysis bụ eleghi anya graphitized carbon ojii n'ime elu crystallinity nke graphite, na electrolysis nke graphite samples nwere petal udi graphite nanometer ibe, nwere elu kpọmkwem elu ebe, mgbe eji lithium batrị cathode gosiri magburu onwe electrochemical arụmọrụ karịa eke graphite.
Zhu et al.tinye deashing mesoro coal dị ala n'ime usoro nnu a wụrụ awụ nke CaCl2 maka electrolysis na 950 ℃, wee gbanwee nke ọma coal dị ala ka ọ bụrụ graphite nwere nnukwu crystallinity, nke gosipụtara arụmọrụ ọnụego dị mma na ogologo ndụ okirikiri mgbe ejiri ya dị ka anode nke batrị lithium ion batrị. .
Nnwale ahụ na-egosi na ọ ga-ekwe omume ịtụgharị ụdị carbon ọdịnala dị iche iche ka ọ bụrụ graphite site na nnu a wụrụ awụ nke na-emepe ụzọ ọhụrụ maka graphite sịntetik n'ọdịnihu.
1.2 usoro nke
Usoro nnu a wụrụ awụ na-eji ihe carbon dị ka cathode wee tụgharịa ya ka ọ bụrụ graphite nwere nnukwu crystallinity site na polarization cathodic.Ka ọ dị ugbu a, akwụkwọ ndị dị ugbu a na-ekwu maka iwepụ oxygen na nhazigharị anya nke atom carbon na usoro ntụgharị nke cathodic polarization nwere ike ime.
Ọnụnọ nke oxygen na ihe carbon ga-egbochi graphitization ruo n'ókè ụfọdụ.Na usoro eserese nke ọdịnala, oxygen ga-eji nwayọọ nwayọọ wepụ ya mgbe okpomọkụ dị elu karịa 1600K.Agbanyeghị, ọ dị oke mma iji deoxidize site na polarization cathodic.
Peng, wdg na nnwale maka oge mbụ tinye n'ihu nnu a wụrụ awụ electrolysis cathodic polarization usoro nwere ike, ya bụ graphitization kasị ebe na-amalite bụ na-emi odude ke siri ike carbon microspheres / electrolyte interface, mbụ carbon microsphere na-etolite gburugburu a isi otu dayameta. graphite shei, na mgbe ahụ agaghị eguzosi ike na carbon carbon carbon anhydrous na-agbasa ka kwụsie ike elu graphite flake, ruo mgbe kpamkpam graphitized,
Usoro graphitization na-esonyere na mwepụ nke oxygen, nke a na-akwadokwa site na nyocha.
Jin et al.gosikwara echiche a site na nnwale.Mgbe carbonization nke glucose gasịrị, a na-eme grafitization (17% oxygen ọdịnaya).Mgbe graphitization, mbụ siri ike carbon spheres (Fig. 1a na 1c) kpụrụ a porous shei mejupụtara graphite nanosheets (Fig. 1b na 1d).
Site na electrolysis nke carbon fibers (16% oxygen), enwere ike ịtụgharị eriri carbon ka ọ bụrụ tubes graphite mgbe graphitization dị ka usoro ngbanwe nke akọwara n'akwụkwọ.
Kwere na, ogologo anya ije bụ n'okpuru cathodic polarization nke carbon atom na elu crystal graphite ka amorphous carbon rearrange ga hazie, sịntetik graphite pụrụ iche petals na-akpụ nanostructures uru site oxygen atọm si, ma kpọmkwem otú e si emetụta graphite nanometer Ọdịdị bụ doro anya. dị ka oxygen si carbon skeleton mgbe otú na cathode mmeghachi omume, wdg.
Ka ọ dị ugbu a, nyocha nke usoro ahụ ka dị na mmalite mmalite, a chọkwara nyocha ọzọ.
1.3 Nkọwapụta gbasara mmụọ nke graphite sịntetik
A na-eji SEM na-ekiri ihe ndị dị n'elu graphite, a na-eji TEM na-ahụ nhazi nhazi nke ihe na-erughị 0.2 μm, XRD na Raman spectroscopy bụ ụzọ a na-ejikarị eme ihe iji mara microstructure nke graphite, XRD na-eji mara kristal. ozi nke graphite, na Raman spectroscopy na-eji iji mara ntụpọ na ịtụ ogo graphite.
Enwere ọtụtụ pores na graphite nke a kwadebere site na cathode polarization nke nnu a wụrụ awụ electrolysis.Maka akụrụngwa dị iche iche, dị ka carbon black electrolysis, petal-dị ka porous nanostructures na-enwetara.A na-eme nyocha ụdịdị dị iche iche nke XRD na Raman na carbon ojii mgbe electrolysis gasịrị.
Na 827 ℃, mgbe ejiri 2.6V voltaji agwọ ya maka 1h, ihe ngosi Raman nke carbon ojii fọrọ nke nta ka ọ bụrụ otu ihe ahụ nke graphite azụmahịa.Mgbe ejiri okpomoku dị iche iche mesoo oji carbon ahụ, a na-atụ ọnụ ọgụgụ kacha elu njirimara graphite dị nkọ (002).Ọnụ ọgụgụ kachasị elu (002) na-anọchi anya ogo nghazi nke oyi akwa carbon aromatic na graphite.
Ka carbon oyi akwa na-adị nkọ karị, ka ọ na-agbado anya karị.
Zhu jiri kol dị obere dị ọcha dị ka cathode na nnwale ahụ, a gbanwere microstructure nke ngwaahịa graphitized site na granular gaa na nnukwu eserese graphite, a na-ahụkwa oyi akwa graphite siri ike n'okpuru microscope elektrọn dị elu.
Na spectra Raman, na mgbanwe nke ọnọdụ nnwale, uru ID/Ig agbanwekwara.Mgbe electrolytic okpomọkụ bụ 950 ℃, electrolytic oge bụ 6h, na electrolytic voltaji bụ 2.6V, kasị ala ID / Ig uru bụ 0.3, na ọnụ ọnụ D dị nnọọ ala karịa G elu.N'otu oge ahụ, mpụta nke ọnụ ọgụgụ kasị elu 2D nọchikwara anya nguzobe nke usoro eserese graphite nke ukwuu.
Ọnụ ọgụgụ kasị elu dị nkọ (002) dị na foto XRD na-akwadokwa ntụgharị nke ọma nke coal dị ala n'ime graphite nwere nnukwu crystallinity.
Na usoro graphitization, mmụba nke okpomọkụ na voltaji ga-arụ ọrụ na-akwalite, ma oke voltaji ga-ebelata mkpụrụ nke graphite, na oke okpomọkụ ma ọ bụ ogologo oge graphitization ga-eduga n'iyi nke ihe onwunwe, ya mere maka ihe dị iche iche carbon. , ọ dị mkpa karịsịa ịchọpụta ọnọdụ electrolytic kasị mma, bụkwa ihe na-elekwasị anya na ihe isi ike.
Nke a petal-dị ka flake nanostructure nwere magburu onwe electrochemical Njirimara.Ọnụ ọgụgụ dị ukwuu nke pores na-ekwe ka ions tinye ngwa ngwa / tinye ya, na-enye ihe ndị dị elu nke cathode maka batrị, wdg. Ya mere, usoro electrochemical graphitization bụ usoro nhazi nke nwere ike ime.
Usoro electrodeposition nnu gbazere
2.1 Electrodeposition nke carbon dioxide
Dị ka gas griin haus kacha mkpa, CO2 bụkwa ihe na-adịghị egbu egbu, nke na-adịghị emerụ ahụ, dị ọnụ ala ma dị mfe ịnweta.Otú ọ dị, carbon dị na CO2 dị na steeti oxidation kasị elu, ya mere CO2 nwere nkwụsi ike nke thermodynamic dị elu, nke na-eme ka o sie ike ijikwa ya ọzọ.
Enwere ike ịchọta nyocha izizi na CO2 electrodeposition na 1960s.Ingram et al.kwadebere nke ọma carbon na electrode ọla edo na sistemu nnu gbazere nke Li2CO3-Na2CO3-K2CO3.
Van et al.rụtụrụ aka na ntụ ntụ carbon enwetara na ikike mbelata dị iche iche nwere usoro dị iche iche, gụnyere graphite, carbon amorphous na carbon nanofibers.
Site na nnu a wụrụ awụ iji weghara CO2 na usoro nkwadebe nke ihe ịga nke ọma nke ihe onwunwe carbon, mgbe ogologo oge nke ndị ọkà mmụta nyocha gasịrị, lekwasịrị anya na usoro nhazi nke carbon deposition na mmetụta nke ọnọdụ electrolysis na ngwaahịa ikpeazụ, nke gụnyere okpomọkụ electrolytic, voltaji electrolytic na ihe mejupụtara ya. Nnu a wụrụ awụ na electrodes, wdg, nkwadebe nke arụmọrụ dị elu nke ihe graphite maka electrodeposition nke CO2 tọrọ ntọala siri ike.
Site n'ịgbanwe electrolyte na iji usoro nnu a wụrụ awụ nke CaCl2 nwere arụmọrụ CO2 dị elu, Hu et al.kwadebere nke ọma graphene nwere ogo graphitization dị elu na carbon nanotubes na ihe ndị ọzọ nanographite site n'ịmụ ọnọdụ electrolytic dị ka okpomọkụ electrolysis, ihe mejupụtara electrode na ngwakọta nnu gbazere.
N'iji ya tụnyere usoro carbonate, CaCl2 nwere uru dị ọnụ ala ma dị mfe ịnweta, elu conductivity, dị mfe igbari na mmiri, na elu solubility nke oxygen ion, nke na-enye usoro usoro maka ntughari nke CO2 n'ime graphite ngwaahịa na elu gbakwunyere uru.
2.2 Usoro mgbanwe
Nkwadebe nke ihe carbon bara uru dị elu site na electrodeposition nke CO2 sitere na nnu a wụrụ awụ na-agụnye njide CO2 na mbelata na-apụtaghị ìhè.Emechara ijide CO2 site na O2- na nnu gbazere n'efu, dị ka egosiri na nha (1):
CO2+O2-→CO3 2- (1)
Ka ọ dị ugbu a, a tụpụtala usoro mmeghachi omume mbelata atọ na-apụtachaghị ìhè: mmeghachi omume otu nzọụkwụ, mmeghachi omume nzọụkwụ abụọ na usoro mmeghachi omume mbelata ígwè.
Ingram tụpụtara usoro mmeghachi omume otu nzọụkwụ mbụ, dịka egosiri na nha (2):
CO3 2-+ 4E – →C+3O2- (2)
Borucka et al tụpụtara usoro mmeghachi omume nzọụkwụ abụọ, dịka egosiri na nha nha (3-4):
CO3 2-+ 2E – →CO2 2-+O2- (3)
CO2 2-+ 2E – →C+2O2- (4)
Usoro mmeghachi omume mbelata ígwè bụ nke Deanhardt et al tụpụtara ya.Ha kwenyere na ion metal na-ebu ụzọ belata ka ọ bụrụ metal na cathode, wee belata metal ahụ ka ọ bụrụ ion carbonate, dị ka egosiri na Equation (5 ~ 6):
M- + E – →M (5)
4 m + M2CO3 – > C + 3 m2o (6)
Ka ọ dị ugbu a, a na-anabata usoro mmeghachi omume nke otu nzọụkwụ n'akwụkwọ ndị dị ugbu a.
Yin et al.mụọ usoro Li-Na-K carbonate na nickel dị ka cathode, tin dioxide dị ka anode na waya ọlaọcha dị ka electrode ntụaka, wee nweta ọnụ ọgụgụ ule cyclic voltammetry na Figure 2 (ọnụego nyocha nke 100 mV / s) na nickel cathode, wee chọta ya. na enwere naanị otu mbelata elu (na -2.0V) na nyocha adịghị mma.
Ya mere, enwere ike ikwubi na ọ bụ naanị otu mmeghachi omume mere n'oge mbelata carbonate.
Gao et al.nwetara otu voltammetry cyclic n'otu sistemu carbonate.
Ge et al.eji inert anode na tungsten cathode weghara CO2 na sistemu LiCl-Li2CO3 wee nweta onyonyo ndị yiri ya, na naanị mbelata elu nke ntinye carbon pụtara na nyocha na-adịghị mma.
N'ime usoro nnu gbazere nke alkaline, a ga-emepụta ọla alkali na CO ka cathode na-echekwa carbon.Otú ọ dị, n'ihi na ọnọdụ thermodynamic nke mmeghachi omume ntinye carbon dị ala na obere okpomọkụ, naanị mbelata carbonate na carbon ka enwere ike ịhụ na nnwale ahụ.
2.3 CO2 ijide nnu gbazere iji kwadebe ngwaahịa graphite
Enwere ike ịkwadebe nanomaterial graphite dị elu dị elu dị ka graphene na carbon nanotubes site na electrodeposition nke CO2 sitere na nnu gbazere site na ịchịkwa ọnọdụ nnwale.Hu et al.eji igwe anaghị agba nchara dị ka cathode na usoro nnu a wụrụ awụ nke CaCl2-NaCl-CaO na electrolyzed maka 4h n'okpuru ọnọdụ nke voltaji 2.6V mgbe niile na okpomọkụ dị iche iche.
N'ihi catalysis nke ígwè na mmetụta mgbawa nke CO n'etiti graphite layers, a chọtara graphene n'elu cathode.E gosipụtara usoro nkwadebe nke graphene na Fig 3.
Foto a
Mgbe e mesịrị ọmụmụ gbakwunyere Li2SO4 na ndabere nke CaCl2-NaClCaO gbazere nnu usoro, electrolysis okpomọkụ bụ 625 ℃, mgbe 4h nke electrolysis, n'otu oge ahụ na cathodic ntinye nke carbon hụrụ graphene na carbon nanotubes, ọmụmụ chọpụtara na Li + na SO4 2. - iji weta mmetụta dị mma na graphitization.
A na-ejikọta sọlfọ nke ọma n'ime ahụ carbon, na enwere ike nweta mpempe akwụkwọ graphite dị oke mkpa na carbon filamentous site na ịchịkwa ọnọdụ electrolytic.
Ihe dị ka electrolytic okpomọkụ nke elu na ala maka nhazi nke graphene dị oké egwu, mgbe okpomọkụ dị elu karịa 800 ℃ dị mfe ịmepụta CO kama carbon, ọ fọrọ nke nta ka ọ bụrụ enweghị ntinye carbon mgbe ọ dị elu karịa 950 ℃, ya mere njikwa okpomọkụ dị oke mkpa. iji mepụta graphene na carbon nanotubes, ma weghachi mkpa carbon deposition mmeghachi omume CO mmeghachi omume synergy iji hụ na cathode na-emepụta graphene kwụsiri ike.
Ọrụ ndị a na-enye usoro ọhụrụ maka nkwadebe ngwaahịa nano-graphite site na CO2, nke dị oke mkpa maka ngwọta nke gas griin haus na nkwadebe nke graphene.
3. Nchịkọta na Outlook
Site na mmepe ngwa ngwa nke ụlọ ọrụ ume ọhụrụ, graphite eke enweghị ike imezu ihe a na-achọ ugbu a, na graphite artificial nwere akụrụngwa anụ ahụ na kemịkalụ ka mma graphite eke, yabụ ọnụ ala, ịrụ ọrụ nke ọma na graphitization na gburugburu ebe obibi bụ ebumnuche ogologo oge.
Electrochemical ụzọ graphitization na siri ike na gaseous akụrụngwa na usoro nke cathodic polarization na electrochemical deposition bụ nke ọma nke graphite ihe na elu kwukwara uru, ma e jiri ya tụnyere omenala ụzọ graphitization, na electrochemical usoro bụ nke elu arụmọrụ, ala ike oriri. Green gburugburu ebe obibi nchebe, maka obere mmachi site nhọrọ ihe n'otu oge, dị ka electrolysis ọnọdụ dị iche iche nwere ike kwadebere na dị iche iche morphology nke graphite Ọdịdị,
Ọ na-enye ụzọ dị irè maka ụdị carbon amorphous na ikuku griin ha ga-agbanwe ka ọ bụrụ ihe graphite arụnyere nano bara uru ma nwee atụmanya ngwa dị mma.
Ka ọ dị ugbu a, teknụzụ a ka dị ọhụrụ.Enwere ọmụmụ ole na ole gbasara graphitization site na usoro electrochemical, ma a ka nwere ọtụtụ usoro a na-amaghị.Ya mere, ọ dị mkpa ịmalite site na akụrụngwa ma na-eduzi ọmụmụ ihe zuru oke na nhazi nke carbon amorphous dị iche iche, ma n'otu oge ahụ nyochaa thermodynamics na ike nke ntụgharị graphite na ọkwa dị omimi.
Ndị a nwere uru dị ukwuu maka mmepe nke ụlọ ọrụ graphite n'ọdịnihu.
Oge nzipu: Mee-10-2021