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Chidzidzo ichi chinoongorora mhedzisiro yeNH4+ tsvina uye chiyero chembeu pakukura uye mashandiro enickel sulfate hexahydrate pasi pe discontinuous cooling crystallization, uye inoongorora mhedzisiro yeNH4+ tsvina pakukura, hunhu hwekupisa, uye mapoka anoshanda enickel sulfate hexahydrate. Pahuwandu hwakaderera hwekusvibiswa, maion eNi2+ neNH4+ anokwikwidzana neSO42− pakusungana, zvichikonzera kudzikira kwekristaro uye chiyero chekukura uye kuwedzera simba rekuita kuti crystallization ishande. Pahuwandu hwakanyanya hwekusvibiswa, maion eNH4+ anosanganiswa muchimiro chekristaro kuti agadzire complex salt (NH4)2Ni(SO4)2 6H2O. Kuumbwa kwe complex salt kunoguma nekuwedzera kwekristaro uye chiyero chekukura uye kudzikira kwesimba rekuita kuti crystallization ishande. Kuvapo kwehuwandu hweNH4+ ion hwakakwira uye hwakaderera kunokonzera kukanganiswa kwelattice, uye makristaro anogadzikana pakupisa kusvika ku80 °C. Pamusoro pezvo, pesvedzero yeNH4+ tsvina pakukura kwekristaro yakakura kupfuura yehuwandu hwembeu. Kana huwandu hwekusvibiswa hwakaderera, kusvibiswa kuri nyore kubatanidza nekristaro; Kana huwandu hwacho hwakwira, kusachena kwacho kuri nyore kuisa mukristaro. Chiyero chembeu chinogona kuwedzera goho rekristaro zvakanyanya uye kuwedzera kuchena kwekristaro zvishoma.
Nickel sulfate hexahydrate (NiSO4 6H2O) ikozvino chinhu chakakosha chinoshandiswa mumaindasitiri akasiyana-siyana, anosanganisira kugadzira mabhatiri, electroplating, catalysts, uye kunyange mukugadzira chikafu, mafuta, uye zvinonhuwira. 1,2,3 Kukosha kwayo kuri kukura nekukurumidza nekuvandudzwa kwemotokari dzemagetsi, dzinovimba zvakanyanya nemabhatiri e lithium-ion (LiB) ane nickel. Kushandiswa kwemhando yepamusoro ye nickel alloys dzakadai seNCM 811 kunotarisirwa kukunda panosvika 2030, zvichiwedzera kudiwa kwe nickel sulfate hexahydrate. Zvisinei, nekuda kwekushaikwa kwezviwanikwa, kugadzirwa kunogona kusaenderana nekudiwa kuri kukura, zvichigadzira musiyano pakati pekuwanikwa nekudiwa. Kushomeka uku kwakamutsa kunetseka nezvekuwanikwa kwezviwanikwa uye kugadzikana kwemitengo, zvichiratidza kudiwa kwekugadzirwa kwakanaka kwe nickel sulfate ine bhatiri rakasimba. 1,4
Kugadzirwa kwe nickel sulfate hexahydrate kunowanzoitwa ne crystallization. Pakati penzira dzakasiyana-siyana, nzira yekutonhodza inzira inoshandiswa zvakanyanya, ine zvakanakira zvekushandisa simba shoma uye kugona kugadzira zvinhu zvakachena zvakanyanya. 5,6 Tsvagiridzo pamusoro pe crystallization ye nickel sulfate hexahydrate uchishandisa discontinuous cooling crystallization yakaita kufambira mberi kukuru. Parizvino, tsvakiridzo zhinji dzinotarisa pakuvandudza maitiro e crystallization nekuvandudza ma parameter akadai sekupisa, mwero wekutonhodza, saizi yembeu uye pH. 7,8,9 Chinangwa ndechekuwedzera goho re crystal uye kuchena kwema crystals akawanikwa. Zvisinei, pasinei nekudzidza kwakazara kwema parameters aya, kuchine mukaha mukuru mukutarisisa kwakapihwa kune simba rekusvibiswa, kunyanya ammonium (NH4+), pamhedzisiro ye crystallization.
Kusvibiswa kweammonium kunogona kunge kuripo mumushonga we nickel unoshandiswa pakugadzira nickel nekuda kwekuvapo kwetsvina yeammonium panguva yekubviswa kwayo. Amonia inowanzo shandiswa semushonga we saponifying, unosiya huwandu hushoma hweNH4+ mumushonga we nickel. 10,11,12 Pasinei nekuwanda kwetsvina yeammonium, mhedzisiro yayo pahunhu hwekristaro senge chimiro chekristaro, nzira yekukura, hunhu hwekupisa, kuchena, nezvimwewo hazvisati zvanyatsonzwisiswa. Tsvagiridzo shoma pamhedzisiro yavo yakakosha nekuti kusvibiswa kunogona kukanganisa kana kushandura kukura kwekristaro uye, mune dzimwe nguva, kunoita sezvidziviriro, zvichikanganisa kuchinja pakati pemafomu ekristaro akagadzikana uye akagadzikana. 13,14 Kunzwisisa mhedzisiro iyi kwakakosha kubva pamaonero emaindasitiri nekuti kusvibiswa kunogona kukanganisa kunaka kwechigadzirwa.
Zvichibva pamubvunzo chaiwo, chidzidzo ichi chaive nechinangwa chekuongorora mhedzisiro yetsvina yeammonium pahunhu hwekristaro yenickel. Nekunzwisisa mhedzisiro yetsvina, nzira itsva dzinogona kugadzirwa kudzora nekuderedza mhedzisiro yadzo yakaipa. Chidzidzo ichi chakaongororawo hukama huripo pakati pekuwanda kwetsvina uye shanduko muhuwandu hwembeu. Sezvo mbeu ichishandiswa zvakanyanya mukugadzirwa, zviyero zvembeu zvakashandiswa muchidzidzo ichi, uye zvakakosha kunzwisisa hukama huripo pakati pezvinhu zviviri izvi. 15 Mhedzisiro yezvikamu zviviri izvi yakashandiswa kudzidza goho rekristaro, mashandiro ekukura kwekristaro, chimiro chekristaro, chimiro, uye kuchena. Pamusoro pezvo, maitiro ekinetic, hunhu hwekupisa, uye mapoka anoshanda emakristaro pasi pesimba retsvina yeNH4+ chete zvakaongororwazve.
Zvinhu zvakashandiswa muchidzidzo ichi zvaive nickel sulfate hexahydrate (NiSO 6H2O, ≥ 99.8%) yakapihwa neGEM; ammonium sulfate ((NH)SO, ≥ 99%) yakatengwa kubva kuTianjin Huasheng Co., Ltd.; mvura yakasanganiswa. Kristaro yembeu yakashandiswa yaive NiSO 6H2O, yakapwanywa uye yakasefewa kuti pave nehukuru hwakaenzana hwe 0.154 mm. Hunhu hweNiSO 6H2O hunoratidzwa muTafura 1 neMufananidzo 1.
Kukanganiswa kweNH4+ tsvina uye chiyero chembeu pakuumbwa kwenickel sulfate hexahydrate yakaongororwa uchishandisa kutonhora kwepakati nepakati. Kuedza kwese kwakaitwa patembiricha yekutanga ye25 °C. 25 °C yakasarudzwa setembiricha yekuumbwa kwekristaro tichifunga nezvemiganho yekudzora tembiricha panguva yekusefa. Kuumbwa kwekristaro kunogona kukonzerwa nekuchinja-chinja kwetembiricha kamwe kamwe panguva yekusefa kwemvura inopisa uchishandisa funnel yeBuchner ine tembiricha yakaderera. Maitiro aya anogona kukanganisa zvakanyanya kinetics, kutorwa kwetsvina, uye hunhu hwakasiyana-siyana hwekristaro.
Mhinduro ye nickel yakatanga kugadzirwa nekunyungudutsa 224 g NiSO4 6H2O mumvura yakasanganiswa ye200 ml. Kuwanda kwakasarudzwa kunoenderana ne supersaturation (S) = 1.109. Supersaturation yakaongororwa nekuenzanisa kunyunguduka kwemakristaro e nickel sulfate akanyungudutswa nekunyunguduka kwe nickel sulfate hexahydrate pa25 °C. Supersaturation yakaderera yakasarudzwa kudzivirira crystallization inongoerekana yaitika kana tembiricha yadzikiswa kusvika kune yekutanga.
Mhedzisiro yehuwandu hweNH4+ ion pakuita kwekristaro yakaongororwa nekuwedzera (NH4)2SO4 kumhinduro ye nickel. Huwandu hweNH4+ ion hwakashandiswa muchidzidzo ichi hwaive 0, 1.25, 2.5, 3.75, uye 5 g/L. Mhinduro yacho yakapiswa pa60 °C kwemaminitsi makumi matatu ichikurunga pa300 rpm kuti ive nechokwadi chekusanganiswa kwakafanana. Mhinduro yacho yakazotonhodzwa kusvika patembiricha yaidiwa. Kana tembiricha yasvika pa25 °C, huwandu hwakasiyana hwemakristaro embeu (huwandu hwembeu hwe0.5%, 1%, 1.5%, uye 2%) hwakawedzerwa kumhinduro. Huwandu hwembeu hwakaonekwa nekuenzanisa huremu hwembeu nehuremu hweNiSO4 6H2O mumhinduro.
Mushure mekuwedzera makristaro embeu mumushonga, maitiro ekristaro akaitika zvega. Maitiro ekristaro akatora maminetsi makumi matatu. Mushonga wacho wakaseferwa uchishandisa firita kuti uparadzanise makristaro akaunganidzwa nemushonga. Munguva yekuseferwa, makristaro aishambidzwa nguva dzose neethanol kuderedza mukana wekuti adzokororwe uye kuderedza kunamira kwetsvina mumushonga pamusoro pemakristaro. Ethanol yakasarudzwa kuti isukure makristaro nekuti makristaro haanyungudike muethanol. Makristaro akaseferwa akaiswa murabhoritari incubator pa50 °C. Mitemo yakadzama yekuedza yakashandiswa muchidzidzo ichi inoratidzwa muTafura 2.
Maumbirwo ekristaro akaongororwa pachishandiswa XRD instrument (SmartLab SE—HyPix-400) uye kuvapo kweNH4+ compounds kwakaonekwa. SEM characterization (Apreo 2 HiVac) yakaitwa kuongorora crystal morphology. Hunhu hwekupisa hwekristaro hwakaongororwa pachishandiswa TGA instrument (TG-209-F1 Libra). Mapoka anoshanda akaongororwa neFTIR (JASCO-FT/IR-4X). Kuchena kwemuenzaniso kwakaongororwa pachishandiswa ICP-MS instrument (Prodigy DC Arc). Sampuro yakagadzirwa nekunyungudutsa 0.5 g yemakristaro mu 100 mL yemvura yakasanganiswa. Kubudirira kwekristaro (x) kwakaverengwa nekuparadzanisa huremu hwekristaro inobuda nehuremu hwekristaro inopinzwa zvichienderana nefomula (1).
apo x iri kristaro, inosiyana kubva pa0 kusvika pa1, mout huremu hwekristaro dzinobuda (g), min huremu hwekristaro dzinopinda (g), msol huremu hwekristaro dziri mumushonga, uye mseed huremu hwekristaro dzembeu.
Kubudirira kwekristaro kwakaongororwazve kuti kuonekwe kwekristaro kukura uye kufungidzira kukosha kwesimba rekuita kuti zvinhu zvishande. Chidzidzo ichi chakaitwa nechiyero chekubereka che2% uye maitiro akafanana neakare. Maparamita ekristaro ekristaro eisothermal akaonekwa nekuongorora kukosha kwekristaro panguva dzakasiyana dzekristaro (10, 20, 30, uye 40 min) uye tembiricha yekutanga (25, 30, 35, uye 40 °C). Kuwanda kwakasarudzwa patembiricha yekutanga kwaienderana nehukuru hwesupersaturation (S) hwe1.109, 1.052, 1, uye 0.953, zvichiteerana. Kuwanda kwesupersaturation kwakaonekwa nekuenzanisa kunyungudika kwemakristaro enickel sulfate akanyungudika nekunyungudika kwenickel sulfate hexahydrate patembiricha yekutanga. Muchidzidzo ichi, kunyungudika kweNiSO4 6H2O mu200 mL yemvura patembiricha dzakasiyana dzisina tsvina kunoratidzwa muMufananidzo 2.
Johnson-Mail-Avrami (dzidziso yeJMA) inoshandiswa kuongorora maitiro e-isothermal crystallization. Dzidziso yeJMA inosarudzwa nekuti maitiro e-crystallization haaitike kusvika makristaro embeu awedzerwa mumushonga. Dzidziso yeJMA inotsanangurwa seinotevera:
Apo x(t) inomiririra shanduko panguva t, k inomiririra shanduko yenguva dzose, t inomiririra nguva yekuchinja, uye n inomiririra Avrami index. Fomura 3 inotorwa kubva pafomura (2). Simba rekuita kuti crystallization ivepo rinoonekwa uchishandisa Arrhenius equation:
Apo kg iri reaction rate constant, k0 iri constant, Eg i activation energy yekukura kwekristaro, R iri molar gas constant (R=8.314 J/mol K), uye T iri isothermal crystallization temperature (K).
Mufananidzo 3a unoratidza kuti chiyero chekubereka mbeu uye huwandu hwedopant zvine chekuita nekukohwa kwekristaro yenickel. Kana huwandu hwedopant mumushonga hwakawedzera kusvika pa2.5 g/L, goho rekristaro rakaderera kubva pa7.77% kusvika pa6.48% (chiyero chembeu che0.5%) uye kubva pa10.89% kusvika pa10.32% (chiyero chembeu che2%). Kuwedzera kwakawedzerwa kwehuwandu hwedopant kwakaita kuti goho rekristaro riwedzere zvakaenzana. Goho repamusoro rakasvika pa17.98% apo chiyero chekubereka chaive 2% uye huwandu hwedopant hwaive 5 g/L. Kuchinja kwemaitiro ekristaro nekuwedzera kwehuwandu hwedopant kunogona kunge kwakabatana nekuchinja kwemaitiro ekukura kwekristaro. Kana huwandu hwedopant hwakaderera, maion eNi2+ neNH4+ anokwikwidzana kubatana neSO42−, izvo zvinotungamira mukuwedzera kwekunyungudika kwenickel mumushonga uye kudzikira kwegoho rekristaro. 14 Kana huwandu hwetsvina hwakwira, maitiro ekukwikwidzana achiri kuitika, asi mamwe maNH4+ ions anosangana nemaion nickel nesulfate kuti vagadzire munyu wakapetwa we nickel ammonium sulfate. 16 Kuumbwa kwemunyu wakapetwa kunotungamira kudzikira kwekunyungudika kwe solute, nokudaro zvichiwedzera goho rekristaro. Kuwedzera chiyero chekubereka kunogona kuramba kuchivandudza goho rekristaro. Mbeu dzinogona kutanga maitiro e nucleation uye kukura kwekristaro kwega kwega nekupa nzvimbo yekutanga yesolute ions kuronga nekugadzira makristaro. Sezvo chiyero chekubereka chichiwedzera, nzvimbo yekutanga yesolute ions kuronga inowedzera, saka makristaro akawanda anogona kuumbwa. Naizvozvo, kuwedzera chiyero chekubereka kune mhedzisiro yakananga pakukura kwekristaro uye goho rekristaro. 17
Zviyero zveNiSO4 6H2O: (a) kristaro uye (b) pH ye nickel solution isati yaiswa mushonga uye mushure mekuiswa mushonga.
Mufananidzo 3b unoratidza kuti chiyero chembeu uye huwandu hwedopant zvinokanganisa pH yemushonga wenickel usati wawedzerwa mbeu uye mushure mekuwedzerwa. Chinangwa chekutarisa pH yemushonga ndechekunzwisisa shanduko mukuenzanisa kwemakemikari mumushonga. Usati wawedzera makristaro embeu, pH yemushonga inowanzo kudzikira nekuda kwekuvapo kwemaion eNH4+ anoburitsa mapurotoni eH+. Kuwedzera huwandu hwedopant kunoita kuti mapurotoni eH+ akawanda aburitswe, nokudaro zvichideredza pH yemushonga. Mushure mekuwedzera makristaro embeu, pH yemhinduro dzese inowedzera. Maitiro epH anoenderana zvakanaka nemaitiro ekristaro. pH yakaderera yakawanikwa pahuwandu hwedopant hwe2.5 g/L uye chiyero chembeu che0.5%. Sezvo huwandu hwedopant huchiwedzera kusvika 5 g/L, pH yemushonga inowedzera. Chiitiko ichi chinonzwisisika, sezvo kuwanikwa kwemaion eNH4+ mumushonga kuchiderera nekuda kwekutorwa, kana nekuda kwekuiswa, kana nekuda kwekutorwa uye kuiswa kwemaion eNH4+ nemakristaro.
Kuedza nekuongorora kwekristaro kwakaenderera mberi kuti vaone maitiro ekukura kwekristaro uye kuverenga simba rekuita kuti kukura kwekristaro kushande. Maparamita ekiristaro yeisothermal akatsanangurwa muchikamu cheMethods. Mufananidzo 4 unoratidza Johnson-Mehl-Avrami (JMA) plot inoratidza maitiro ekukura kwekristaro yenickel sulfate. Plot yakagadzirwa nekuronga kukosha kweln[− ln(1− x(t))] zvichienderana ne ln t value (Equation 3). Ma gradient values ​​​​akawanikwa kubva paplot anoenderana neJMA index (n) values ​​​​inoratidza saizi yekristaro inokura uye nzira yekukura. Nepo cutoff value ichiratidza mwero wekukura unomiririrwa ne constant ln k. Ma JMA index (n) values ​​​​anotangira pa 0.35 kusvika 0.75. Iyi n value inoratidza kuti makristaro ane kukura kwechikamu chimwe chete uye anotevera nzira yekukura inodzorwa nekupararira; 0 < n < 1 inoratidza kukura kwechikamu chimwe chete, nepo n < 1 ichiratidza nzira yekukura inodzorwa nekupararira. 18 Kukura kwehuwandu hwek hunogara huripo kunoderera nekupisa kuri kuwedzera, zvichiratidza kuti maitiro ekristaro anoitika nekukurumidza pakupisa kwakaderera. Izvi zvine chekuita nekuwedzera kwe supersaturation yemushonga pakupisa kwakaderera.
Johnson-Mehl-Avrami (JMA) mapoinzi e nickel sulfate hexahydrate pakupisa kwakasiyana kwekristaro: (a) 25 °C, (b) 30 °C, (c) 35 °C uye (d) 40 °C.
Kuwedzerwa kwedopants kwakaratidza maitiro akafanana ekukura kwemazinga patembiricha dzese. Kana huwandu hwedopant hwaive 2.5 g/L, chiyero chekukura kwekristaro chakadzikira, uye kana huwandu hwedopant hwaive hwakakwira kupfuura 2.5 g/L, chiyero chekukura kwekristaro chakawedzera. Sezvambotaurwa, shanduko muchimiro chekukura kwekristaro inokonzerwa nekuchinja kwemaitiro ekudyidzana pakati peiyoni mumushonga. Kana huwandu hwedopant hwakaderera, maitiro emakwikwi pakati peiyoni mumushonga anowedzera kunyungudika kwemusanganiswa, nokudaro zvichideredza chiyero chekukura kwekristaro. 14 Uyezve, kuwedzerwa kwehuwandu hwakawanda hwedopants kunoita kuti maitiro ekukura achinje zvakanyanya. Kana huwandu hwedopant hwapfuura 3.75 g/L, mamwe manuclei matsva ekristaro anoumbwa, izvo zvinotungamira kudzikira kwekunyungudika kwemusanganiswa, nokudaro zvichiwedzera chiyero chekukura kwekristaro. Kuumbwa kwenuclei itsva dzekristaro kunogona kuratidzwa nekuumbwa kwemunyu wakapetwa kaviri (NH4)2Ni(SO4)2 6H2O. 16 Pakukurukura nezvenzira yekukura kwekristaro, mhedzisiro yeX-ray diffraction inosimbisa kuumbwa kwemunyu wakapetwa kaviri.
Basa reJMA plot rakaongororwazve kuti rione simba rekuita kuti crystallization ishande. Simba rekuita kuti crystallization iverengwe uchishandisa Arrhenius equation (inoratidzwa muEquation (4)). Mufananidzo 5a unoratidza hukama huripo pakati pe ln(kg) kukosha uye 1/T kukosha. Zvadaro, simba rekuita kuti crystallization iverengwe uchishandisa gradient value yakawanikwa kubva mu plot. Mufananidzo 5b unoratidza simba rekuita kuti crystallization iverengwe pasi pemazinga akasiyana ekusvibiswa. Mhedzisiro yacho inoratidza kuti shanduko muhuwandu hwekusvibiswa inokanganisa simba rekuita kuti crystallization iverengwe. Simba rekuita kuti crystallization iverengwe yemakristaro enickel sulfate asina tsvina i215.79 kJ/mol. Kana huwandu hwekusvibiswa hukasvika pa2.5 g/L, simba rekuita kuti crystallization iverengwe rinokwira ne3.99% kusvika pa224.42 kJ/mol. Kuwedzera kwesimba rekuita kuti crystallization iverengwe kunoratidza kuti simba rekudzivirira crystallization rinowedzera, izvo zvinotungamira kudzikira kwekukura kwekristaro uye goho rekristaro. Kana huwandu hwekusvibiswa hwapfuura 2.5 g/L, simba rekuita kuti crystallization iverengwe rinoderera zvakanyanya. Pahuwandu hwekusvibiswa hwe5 g/l, simba rekuita kuti chinhu chishande riri 205.85 kJ/mol, iro riri pasi ne8.27% pane simba rekuita kuti chinhu chishande pahuwandu hwekusvibiswa hwe2.5 g/l. Kuderera kwesimba rekuita kuti chinhu chishande kunoratidza kuti maitiro ekuita kuti chinhu chishande zvakanaka, izvo zvinoita kuti pave nekuwedzera kwekukura kwekristaro uye goho rekristaro.
(a) Kuiswa kwemufananidzo we ln(kg) zvichienzaniswa ne 1/T uye (b) simba rekuita kuti zvinhu zviite sekristaro pahuwandu hwakasiyana hwekusachena.
Maitiro ekukura kwekristaro akaongororwa neXRD neFTIR spectroscopy, uye kinetics yekukura kwekristaro uye simba rekuita kuti zvinhu zvishande zvakaongororwa. Mufananidzo 6 unoratidza mhedzisiro yeXRD. Data iri rinoenderana nePDF #08–0470, iyo inoratidza kuti iα-NiSO4 6H2O (red silica). Kristaro iri ndeye tetragonal system, boka renzvimbo iP41212, ma parameter eyuniti cell ndea = b = 6.782 Å, c = 18.28 Å, α = β = γ = 90°, uye vhoriyamu i840.8 Å3. Mhedzisiro iyi inoenderana nemhedzisiro yakamboburitswa naManomenova et al. 19 Kuunzwa kweNH4+ ions kunotungamirawo pakuumbwa kwe (NH4)2Ni(SO4)2 6H2O. Data iri nderePDF Nhamba 31–0062. Kiristaro iri mu monoclinic system, space group P21/a, ma unit cell parameters ari a = 9.186 Å, b = 12.468 Å, c = 6.242 Å, α = γ = 90°, β = 106.93°, uye vhoriyamu yacho i684 Å3. Mhedzisiro iyi inoenderana neongororo yapfuura yakataurwa naSu et al.20.
Maitiro ekupatsanurwa kweX-ray emakristaro enickel sulfate: (a–b) 0.5%, (c–d) 1%, (e–f) 1.5%, uye (g–h) 2% mbeu. Mufananidzo wekurudyi ndiwo mufananidzo wakakura wekuruboshwe.
Sezvakaratidzwa muMifananidzo 6b, d, f uye h, 2.5 g/L ndiyo muganho wepamusoro wehuwandu hweammonium mumusanganiswa usina kugadzira munyu wakawedzerwa. Kana huwandu hwetsvina huri 3.75 uye 5 g/L, maNH4+ ions anosanganiswa muchimiro chekristaro kuti agadzire munyu wakaoma (NH4)2Ni(SO4)2 6H2O. Zvichienderana nedata, simba repamusoro remunyu wakaoma rinowedzera sezvo huwandu hwetsvina huchiwedzera kubva pa3.75 kusvika pa5 g/L, kunyanya pa2θ 16.47° uye 17.44°. Kuwedzera kwenhamba yepamusoro yemunyu wakaoma kunokonzerwa chete nepfungwa yekuenzanisa kwemakemikari. Zvisinei, mamwe matunhu asina kujairika anoonekwa pa2θ 16.47°, izvo zvinogona kukonzerwa nekushanduka kwekristaro. 21 Mhedzisiro yehunhu inoratidzawo kuti chiyero chepamusoro chembeu chinoguma nekuderera kwesimba repamusoro remunyu wakaoma. Chiyero chepamusoro chembeu chinokurumidza maitiro ekristaro, izvo zvinotungamira kudzikira kukuru kwe solute. Muchiitiko ichi, maitiro ekukura kwekristaro anonyanya kutariswa pambeu, uye kuumbwa kwezvikamu zvitsva kunokanganiswa nekudzikira kwe supersaturation yemushonga. Kusiyana neizvi, kana chiyero chembeu chiri chidiki, maitiro e crystallization anononoka, uye supersaturation yemushonga inoramba iri padanho rakakwirira. Mamiriro aya anowedzera mukana wekuti munyu mudiki unonyungudika kaviri (NH4)2Ni(SO4)2 6H2O upfuure. Data repamusoro-soro remunyu muviri rinopiwa muTafura 3.
Kutsanangurwa kweFTIR kwakaitwa kuti kuongorore chero kusagadzikana kana shanduko dzechimiro mu lattice yemugadziri nekuda kwekuvapo kwema ions eNH4+. Samples dzine chiyero chembeu chinogara chiripo che2% dzakaratidzwa. Mufananidzo 7 unoratidza mhedzisiro yekushandurwa kweFTIR. Ma peaks akafara akaonekwa pa3444, 3257 uye 1647 cm−1 anokonzerwa nemaitiro ekutambanudza eO–H emamorekuru. Ma peaks pa2370 uye 2078 cm−1 anomiririra ma hydrogen bonds pakati pemamorekuru emvura. Bhandi pa412 cm−1 rinokonzerwa nekudengenyeka kwekutambanudza kweNi–O. Pamusoro pezvo, ma free SO4− ions anoratidza maitiro mana makuru ekuzunza pa450 (υ2), 630 (υ4), 986 (υ1) uye 1143 uye 1100 cm−1 (υ3). Zviratidzo υ1-υ4 zvinomiririra hunhu hwema "vibrational modes", apo υ1 inomiririra "non-degenerate mode" (symmetric stretching), υ2 inomiririra "doubly degenerate mode" (symmetric bending), uye υ3 na υ4 zvinomiririra "triply degenerate modes" (asymmetric stretching uye asymmetric bending, zvichiteerana). 22,23,24 Mhedzisiro yehunhu inoratidza kuti kuvapo kwe "ammonium impurity" kunopa "peak" yakawedzerwa pa "wavenumber" ye1143 cm-1 (yakanyorwa nedenderedzwa dzvuku mumufananidzo). "Other peak" pa1143 cm-1 inoratidza kuti kuvapo kwe "NH4+ ions", zvisinei nehuwandu, kunokonzera kukanganisa kwechimiro che "lattice", izvo zvinotungamira kuchinjo mukutenderera kwe "vibration frequency" yema "sulfate ion molecules" mukati mekristaro.
Zvichibva pamhedzisiro yeXRD neFTIR ine chekuita nemafambiro ekukura kwekristaro uye simba rekuita kuti zvinhu zvishande, Mufananidzo 8 unoratidza hunyanzvi hwekuita kuti zvinhu zvishande nemakristaro enickel sulfate hexahydrate nekuwedzera tsvina yeNH4+. Kana pasina tsvina, maion eNi2+ achaita neH2O kuumba nickel hydrate [Ni(6H2O)]2−. Zvadaro, nickel hydrate inosangana nemaion eSO42− kuumba manuclei eNi(SO4)2 6H2O uye inokura kuita makristaro enickel sulfate hexahydrate. Kana huwandu hwakaderera hwetsvina yeammonium (2.5 g/L kana pasi) hukawedzerwa kumhinduro, [Ni(6H2O)]2− zvinonetsa kusanganisa zvizere nemaion eSO42− nekuti maion eNi(6H2O)]2− neNH4+ anokwikwidzana kusanganiswa nemaion eSO42−, kunyangwe paine maion esulfate akakwana ekuita nemaion ese ari maviri. Mamiriro aya anotungamira mukuwedzera kwesimba rekuita kuti zvinhu zvishande nemakristaro uye kudzikira kwekukura kwekristaro. 14,25 Mushure mekunge nickel sulfate hexahydrate nuclei dzaumbwa uye dzakura kuita makristaro, maNH4+ akawanda uye (NH4)2SO4 ions anonyudzwa pamusoro pekristaro. Izvi zvinotsanangura kuti nei boka rinoshanda reSO4− ion (wavenumber 1143 cm−1) muNSH-8 neNSH-12 samples richiramba richiumbwa pasina doping process. Kana huwandu hwekusvibiswa hwakwira, maNH4+ ions anotanga kuiswa muchimiro chekristaro, zvichigadzira double salts. 16 Chiitiko ichi chinoitika nekuda kwekushaikwa kweSO42− ions mumushonga, uye maSO42− ions anosunga ku nickel hydrates nekukurumidza kupfuura maammonium ions. Iyi nzira inokurudzira nucleation nekukura kwedouble salts. Munguva ye alloying process, maNi(SO4)2 6H2O uye (NH4)2Ni(SO4)2 6H2O nuclei dzinoumbwa panguva imwe chete, izvo zvinotungamira mukuwedzera kwenhamba yemanuclei anowanikwa. Kuwedzera kwenhamba yemanuclei kunokurudzira kukurumidza kwekukura kwekristaro uye kudzikira kwesimba rekuita kuti zvinhu zvishande.
Maitiro emakemikari ekunyungudutsa nickel sulfate hexahydrate mumvura, kuwedzera huwandu hushoma nehuwandu hwakawanda hweammonium sulfate, uye kuita maitiro ekristaro kunogona kuratidzwa seizvi:
Mhedzisiro yeSEM ​​inoratidzwa muMufananidzo 9. Mhedzisiro yehunhu inoratidza kuti huwandu hwemunyu weammonium hwakawedzerwa uye chiyero chembeu hazvikanganisi zvakanyanya chimiro chekristaro. Saizi yemakristaro akaumbwa inoramba yakafanana, kunyangwe makristaro makuru achionekwa pane dzimwe nguva. Zvisinei, kutsanangurwa kwakawedzerwa kuchiri kudiwa kuti uone mhedzisiro yehuwandu hwemunyu weammonium uye chiyero chembeu paavhareji yehukuru hwemakristaro akaumbwa.
Maumbirwo ekristaro eNiSO4 6H2O: (a–e) 0.5%, (f–j) 1%, (h–o) 1.5% uye (p–u) 2% chiyero chembeu chinoratidza shanduko yehuwandu hweNH4+ kubva kumusoro kuenda pasi, inova 0, 1.25, 2.5, 3.75 uye 5 g/L, zvichiteerana.
Mufananidzo 10a unoratidza makomba eTGA emakristaro ane huwandu hwakasiyana hwekusvibiswa. Ongororo yeTGA yakaitwa pamasampuli ane chiyero chekubereka che2%. Ongororo yeXRD yakaitwawo pasampuli yeNSH-20 kuti ione makomponi akaumbwa. Mhedzisiro yeXRD inoratidzwa muMufananidzo 10b inosimbisa shanduko muchimiro chekristaro. Kuyerwa kweThermogravimetric kunoratidza kuti makristaro ese akagadzirwa anoratidza kugadzikana kwekupisa kusvika ku80°C. Mushure mezvo, huremu hwekristaro hwakaderera ne35% apo tembiricha yakawedzera kusvika 200°C. Kurasikirwa nehuremu kwemakristaro kunokonzerwa nemaitiro ekuora, ayo anosanganisira kurasikirwa kwemamorekuru mashanu emvura kuti aumbe NiSO4 H2O. Tembiricha payakawedzera kusvika 300–400°C, huremu hwekristaro hwakaderera zvakare. Kurasikirwa nehuremu kwemakristaro kwaive ne6.5%, nepo kurasikirwa nehuremu kwesampuli yekristaro yeNSH-20 kwakakwira zvishoma, 6.65%. Kuora kwemaion eNH4+ kuita gasi reNH3 mumuenzaniso weNSH-20 kwakaita kuti pave nekuderera zvishoma. Sezvo tembiricha yakawedzera kubva pa300 kusvika pa400°C, huremu hwemakristaro hwakaderera, zvichiita kuti makristaro ese ave nechimiro cheNiSO4. Kuwedzera tembiricha kubva pa700°C kusvika pa800°C kwakaita kuti chimiro chekristaro chishanduke kuita NiO, zvichikonzera kuburitswa kwemagasi eSO2 neO2.25,26
Kuchena kwemakristaro e nickel sulfate hexahydrate kwakaonekwa nekuongorora huwandu hweNH4+ uchishandisa DC-Arc ICP-MS instrument. Kuchena kwemakristaro e nickel sulfate kwakaonekwa uchishandisa formula (5).
Apo Ma iri huwandu hwetsvina mukristaro (mg), Mo iri huwandu hwekristaro (mg), Ca iri huwandu hwetsvina mumhinduro (mg/l), V iri huwandu hwemhinduro (l).
Mufananidzo 11 unoratidza kuchena kwemakristaro e nickel sulfate hexahydrate. Kukosha kwekuchena ndiko kukosha kweavhareji yehunhu hutatu. Mhedzisiro inoratidza kuti chiyero chekucheneswa kwembeu uye huwandu hwekusvibiswa zvinokanganisa zvakananga kuchena kwemakristaro e nickel sulfate akagadzirwa. Kana huwandu hwekusvibiswa hwakakwira, kunyudzwa kwetsvina kwakanyanya, zvichikonzera kuchena kwakaderera kwemakristaro akagadzirwa. Zvisinei, maitiro ekunyudzwa kwetsvina anogona kuchinja zvichienderana nehuwandu hwekusvibiswa, uye girafu yemhedzisiro inoratidza kuti kunyudzwa kwetsvina nemakristaro hakuchinji zvakanyanya. Pamusoro pezvo, mhedzisiro iyi inoratidzawo kuti chiyero chepamusoro chekucheneswa kwembeu chinogona kuvandudza kuchena kwemakristaro. Chiitiko ichi chinogoneka nekuti kana akawanda emakristaro akagadzirwa akanyanya pa nickel nuclei, mukana wekuti nickel ions iungane pa nickel wakakwira. 27
Chidzidzo chacho chakaratidza kuti maion eammonium (NH4+) anokanganisa zvakanyanya maitiro ekristaro uye hunhu hwekristaro hwemakristaro enickel sulfate hexahydrate, uye zvakare yakaratidza simba rehuwandu hwembeu pamaitiro ekristaro.
Kana huwandu hwemakristaro huri pamusoro pe2.5 g/l, goho remakristaro uye mwero wekukura kwekristaro zvinoderera. Kana huwandu hwemakristaro huri pamusoro pe2.5 g/l, goho remakristaro uye mwero wekukura kwekristaro zvinowedzera.
Kuwedzera tsvina mumushonga we nickel kunowedzera kukwikwidzana pakati peNH4+ ne [Ni(6H2O)]2− maion eSO42−, izvo zvinoita kuti simba rekuita kuti zvinhu zvisashande zvakanaka riwedzere. Kuderera kwesimba rekuita kuti zvinhu zvisashande zvakanaka mushure mekuwedzera huwandu hwakawanda hwetsvina kunokonzerwa nekupinda kwemaion eNH4+ muchimiro chekristaro, nokudaro zvichigadzira munyu wakapetwa kaviri (NH4)2Ni(SO4)2 6H2O.
Kushandisa chiyero chepamusoro chekubereka mbeu kunogona kuvandudza goho rekristaro, mwero wekukura kwekristaro uye kuchena kwekristaro kwenickel sulfate hexahydrate.
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Saguntala, P. naYasota, P. Kushandiswa kwemakristaro e nickel sulfate pakupisa kwakanyanya: Zvidzidzo zvehunhu neamino acids akawedzerwa semadopants. Mater. Today Proc. 9, 669–673. https://doi.org/10.1016/J.MATPR.2018.10.391 (2019).
Babaahmadi, V., nevamwe. Kuiswa kwema electrode kwe nickel pamativi emucheka ne polyol-mediated printing pa reduction graphene oxide. Journal of Physical and Chemical Engineering of Colloidal Surfaces 703, 135203. https://doi.org/10.1016/J.COLSURFA.2024.135203 (2024).
Fraser, J., Anderson, J., Lazuen, J., nevamwe. "Kudiwa kweramangwana uye kuchengetedzeka kwekuwanikwa kwe nickel yemabhatiri emotokari dzemagetsi." Hofisi yeMabhuku eEuropean Union; (2021). https://doi.org/10.2760/212807
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Hahn, B., Böckman, O., Wilson, BP, Lundström, M. naLouhi-Kultanen, M. Kucheneswa kwe nickel sulfate ne crystallization yakatonhorerwa ne batch. Chemical Engineering Technology 42(7), 1475–1480. https://doi.org/10.1002/ceat.201800695 (2019).