Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research...Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research used chemical co-precipitation within an automated experimental device to synthesize RETaO_(4)(RE=Nd,Sm,Gd,Ho,Er)powders.The device automatically monitored and controlled the solutions'pH,improving the chemical co-precipitation efficiency.The crystal structure and microstructure of the RETaO_(4)powders can be controlled by changing the annealing temperature,and the materials undergo an m'-m phase transition.The m'-RETaO_(4)powders exhibit nano-size grains,while m-RETaO_(4)powders evince micron-size grains,altered by the annealing temperatures.A simultaneous thermal analysis es-timates the reversive ferroelastic tetragonal-monoclinic phase transition temperatures.Overall,this research focuses on the synthesis,crystal structures,microstructures,and phase transition of the fabricated RETaO_(4)powders.展开更多
Conventional hydrometallurgy recycling process for treating wasted lithium-ion batteries(LIBs)typically results in the consumption of large amounts of corrosive leachates.Recent research on reusable leachate is expect...Conventional hydrometallurgy recycling process for treating wasted lithium-ion batteries(LIBs)typically results in the consumption of large amounts of corrosive leachates.Recent research on reusable leachate is expected to significantly improve the economic and environmental benefits,but is usually limited to specific and unique chemical reactions which could only apply to one type of metal elements.Herein,we report the co-extraction of multiple metal elements can be extracted without adding precipitates by mixed crystal co-precipitation,which enables the reusability of the leachate.We show that an oxalic acid(OA):choline chloride(ChCl):ethylene glycol(EG)type DES leachate system can leach transition metals from wasted LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathode materials with satisfactory efficiency(The time required for complete leaching at 120℃ is 1.5 h).The transition metals were then efficiently extracted(with a recovery efficiency of over 96%for all elements)by directly adding water without precipitants.Noteworthy,the leachate can be efficiently recovered by directly evaporating the added water.The successful realization of reusability of leachate for the synergistic extraction of multiple elements relies on the regulation of the mixed crystal co-precipitation coefficient,which is realized by rationally design the reaction condition(composition of leachate,temperature and time)and induces the extraction of originally soluble manganese element.Our strategy is expected to be generally applicable and highly competent for industrial applications.展开更多
The LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathode materials have emerged as critical components in lithium-ion batteries due to their high energy and power densities.The co-precipitation method is widely used in laborator...The LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathode materials have emerged as critical components in lithium-ion batteries due to their high energy and power densities.The co-precipitation method is widely used in laboratory and industry settings to optimize the crystallinity,grain morphology,particle size,and sphericity of precursor materials,directly affecting NCM battery performance.This review addresses the nucleation mechanism and the thermodynamic and kinetic reaction processes of co-precipitation.The comprehensive effects of key parameters on precursor physicochemical properties are also systematically interpreted.展开更多
Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the s...Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied.It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7：1,uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy.The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm,and the tap-density was measured to be approximately 2.37 g/cm3,which is comparable with that of commercialized LiCoO2.XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure.The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA·h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8-4.5 V.The discharge capacity at the 50th cycle at 0.5C is 170.6 mA·h/g.展开更多
Magnetite concentrate was recovered from ferrous sulphate by co-precipitation and magnetic separation. In co-precipitation process, the effects of reaction conditions on iron recovery were studied, and the optimal rea...Magnetite concentrate was recovered from ferrous sulphate by co-precipitation and magnetic separation. In co-precipitation process, the effects of reaction conditions on iron recovery were studied, and the optimal reaction parameters are proposed as follows： n（CaO）/n（Fe2＋） 1.4：1, reaction temperature 80 ℃, ferrous ion concentration 0.4 mol/L, and the final mole ratio of Fe3＋ to FJ＋ in the reaction solution 1.9-2.1. In magnetic separation process, the effects of milling time and magnetic induction intensity on iron recovery were investigated. Wet milling played an important part in breaking the encapsulated magnetic phases. The results showed that the mixed product was wet-milled for 20 min before magnetic separation, the grade and recovery rate of iron in magnetite concentrate were increased from 51.41% and 84.15% to 62.05% and 85.35%, respectively.展开更多
MnxNi0.5-xZn0.5Fe2O4 nanorods were successfully synthesized by the thermal treatment of rod-like precursors that were fabricated by the co-precipitation of Mn2＋, Ni2＋, and Fe2＋ in the lye. The phase, morphology, an...MnxNi0.5-xZn0.5Fe2O4 nanorods were successfully synthesized by the thermal treatment of rod-like precursors that were fabricated by the co-precipitation of Mn2＋, Ni2＋, and Fe2＋ in the lye. The phase, morphology, and particle diameter were examined by the X-ray diffraction and transmission electron microscopy. The magnetic properties of the samples were studied using a vibrating sample magnetometer. nanorods with a diameter of 35 nm and an The results indicated that pure Ni0.5-xZn0.5Fe2O4 aspect ratio of 15 were prepared. It was found that the diametei of the MnxNi0.5-xZn0.5Fe2O4（0≤x≤0.5） samples increased, the length and the aspect .ratio decreased, with an increase in x value. When x=0.5, the diameter and the aspect ratio of the sample reached up to 50 nm and 7-8, respectively. The coercivity of the samples first increased and then decreased with the increase in the x value. The coercivity of the samples again increased when the x value was higher than 0.4. When x=0.5, the coercivity of the MnxNi0.5-xZn0.5Fe2O4 sample reached the maximal value （134.3 Oe） at the calcination temperature of 600 ℃. The saturation magnetization of the samples first increased and then. decreased with the increase in the x value. When x=0.2, the saturation magnetizat：ion of the sample reached the maximal value （68.5 emu/g） at the calcination temperature of 800 ℃.展开更多
A series of Ni-CeO2 catalysts were prepared by co-precipitation method with Na2CO3, NaOH, and mixed precipitant （Na2CO3：NaOH; 1：1 ratio） as precipitant, respectively. The effect of the precipitants on the catalyti...A series of Ni-CeO2 catalysts were prepared by co-precipitation method with Na2CO3, NaOH, and mixed precipitant （Na2CO3：NaOH; 1：1 ratio） as precipitant, respectively. The effect of the precipitants on the catalytic performance, physical and chemical properties of Ni-CeO2 catalysts was investigated with the aid of X-ray diffraction （XRD）, Bmmaner-Emmett-Teller method （BET）, Fou- rier-transform infrared spectroscopy （FT-IR）, thermogravimetry （TG）, and H2-TPR characterizations. The Ni-CeO2 catalysts were exam- ined with respect to their catalytic performance for the reverse water-gas shift reaction, and their catalytic activities were ranked as： Ni-CeO2-CP （Na2CO3：NaOH=I：I）〉Ni-CeO2-CP（Na2CO3）〉Ni-CeO2-CP（NaOH）- Correlating to the characteristic results, it was found that the catalyst prepared by co-precipitation with mixed precipitant （Na2CO3：NaOH; 1：1 ratio） as precipitant hadthe most amount of oxygen vacancies accompanied with highly dispersed Ni particles, which made the corresponding Ni-CeO2-CP（Na2CO3：NaOH=I： 1） catalyst exhibit the highest catalytic activity. While the precipitant of Na2CO3 or NaOH resulted in less or no oxygen vacancies in Ni-CeO2 catalysts. As a result, Ni-CeO2-CP（Na2CO3） and Ni-CeO2-CP（NaOH） catalysts presented poor catalytic performance.展开更多
Ti4+-mixed FePO4·xH2O precursor was prepared by co-precipitation method,with which Ti4+ cations were added in the process of preparing FePO4·xH2O to pursue an effective and homogenous doping way.Ti4+-doped L...Ti4+-mixed FePO4·xH2O precursor was prepared by co-precipitation method,with which Ti4+ cations were added in the process of preparing FePO4·xH2O to pursue an effective and homogenous doping way.Ti4+-doped LiFePO4 was prepared by an ambient-reduction and post-sintering method using the as-prepared precursor,Li2CO3 and oxalic acid as raw materials.The samples were characterized by scanning electron microscopy (SEM),X-ray diffractometry (XRD),electrochemical impedance spectroscopy (EIS),and electrochemical charge/discharge test.Effects of Ti4+-doping and sintering temperature on the physical and electrochemical performance of LiFePO4 powders were investigated.It is noted that Ti4+-doping can improve the electrochemical performance of LiFePO4 remarkably.The Ti4+-doped sample sintered at 600 ℃ delivers an initial discharge capacity of 150,130 and 125 mA·h/g with 0.1C,1C and 2C rates,respectively,without fading after 40 cycles.展开更多
Oxidative coupling of methane(OCM) was conducted over LaAlO3X catalysts that were prepared by a coprecipitation method using different co-precipitation pH values(X = 6–10). The aim is to investigate the effect of p H...Oxidative coupling of methane(OCM) was conducted over LaAlO3X catalysts that were prepared by a coprecipitation method using different co-precipitation pH values(X = 6–10). The aim is to investigate the effect of p H values on the catalytic activity of La AlO3 catalysts in this reaction. The results showed that the co-precipitation pH value affected greatly on the formation of chemical species of precipitate precursors in the co-precipitation step, leading to different phases of the finally obtained LaAlO3 catalysts.When the co-precipitation pH value increased up to 8, the lanthanum-related phases such as La2 O3 and La(OH)3 were gradually formed as by-products, preventing the formation of LaAlO3 perovskite crystalline structure and facilitating the formation of oxygen vacancies on catalyst surface. However, at pH value of9 or higher, the lanthanum content in the precipitate precursor was increased greatly. Not LaAlO3 perovskite but lanthanum-related phases were developed as main phases, reducing their catalytic activities in this reaction. Among LaAlO3 catalysts, the one prepared at pH = 8 showed the highest C2 yield due to its well-developed oxygen vacancies and electrophilic lattice oxygen. Therefore, the co-precipitation pH value strongly affected the LaAlO3 catalyst activity in OCM reaction. A precious pH control should be required to prepare various perovskite catalysts for the OCM.展开更多
The micron-sized Sr2（P2OT）：Ce,Tb green phosphors were prepared by being annealed at different temperatures with its precursors synthesized by co-pre-cipitates of （NH4）2HPO4 at ambient temperature. The phase struc...The micron-sized Sr2（P2OT）：Ce,Tb green phosphors were prepared by being annealed at different temperatures with its precursors synthesized by co-pre-cipitates of （NH4）2HPO4 at ambient temperature. The phase structure, grain size, surface morphology, and luminescent properties of phosphors were investigated by X-ray diffraction, scanning electron microscope, trans-mission electron microscope, and fluorescence spectrum. The results show that the product of precursor annealed at 1,100 ℃ is Sr2（P2O7）：Ce,Tb, which belongs to ortho-rhombic phase. The powder is spherical and the size dis-tribution is in micron grade. The sample with the molar ratio of Sr/Tb/Ce of 100.0：0.4：0.6 shows the best fluores-cence effect annealed at 1,100 ℃ for 3 h. The phosphors produce green fluorescence by being excitated with ultra-violet radiation of 254 nm wavelength, and the main emission peak is at 547 nm. The Sr2（P2O7）：Ce,Tb phos-phors synthesized by co-precipitation method of precursors at ambient temperature is a kind of efficient green-emitting phosphors.展开更多
A precursor of the Y3Al5O12:Ce (YAG:Ce) phosphor was obtained by co-precipitation of the solution of high purity nitrates with ammonium bicarbonate solution. The precipitation process of the precursor was studied in t...A precursor of the Y3Al5O12:Ce (YAG:Ce) phosphor was obtained by co-precipitation of the solution of high purity nitrates with ammonium bicarbonate solution. The precipitation process of the precursor was studied in this work. YAG:Ce yellow phosphors with fine morphology was synthesized by annealing the precursor at a reducing atmosphere. The crystal phase, microstructure of the phosphors and their photoluminescence were investigated. The results indicated that the pure phase of YAG:Ce could be obtained at ...展开更多
The uniform layered LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries was prepared by using （Ni1/3Co1/3Mn1/3）C2O4 as precursor synthesized via oxalate co-precipitation method in air. The effects of calc...The uniform layered LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries was prepared by using （Ni1/3Co1/3Mn1/3）C2O4 as precursor synthesized via oxalate co-precipitation method in air. The effects of calcination temperature and time on the structure and electrochemical properties of the LiNi1/3Co1/3Mn1/3O2 were systemically studied. XRD results revealed that the optimal calcination conditions to prepare the layered LiNi1/3Co1/3Mn1/302 were 950℃ for 15 h. Electrochemical measurement showed that the sample prepared under the such conditions has the highest initial discharge capacity of 160.8 mAh/g and the smallest irreversible capacity loss of 13.5% as well as stable cycling performance at a constant current density of 30 mA/g between 2.5 and 4.3 V versus Li at room temperature.展开更多
This paper studied the effect of ferric chloride on waste sludge digestion,dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process.The experimental results showed that the...This paper studied the effect of ferric chloride on waste sludge digestion,dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process.The experimental results showed that the concentration of mixed liquid suspended solid(MLSS) was 2436 mg.L-1 and 2385 mg.L-1 in co-precipitation phosphorus removal process(CPR) and biological phosphorous removal process(BPR),respectively.The sludge reduction ratio for each process was 22.6% and 24.6% in aerobic digestion,and 27.6% and 29.9% in anaerobic digestion,respectively.Due to the addition of chemical to the end of aeration tank,the sludge content of CPR was slightly higher than that of BPR,but the sludge reduction rate for both processes had no distinct difference.The sludge volume index(SVI) and sludge specific resistance of BPR were 126 ml.g-1 and 11.7×1012 m.kg-1,respectively,while those of CPR were only 98 ml.g-1 and 7.1×1012 m.kg-1,indicating that CPR chemical could improve sludge settling and dewatering.展开更多
Spherical cathode material LiNi_0.5Mn_1.5O_4 for lithium-ion batteries was synthesized by hydroxide co- precipitation method. X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical mea- su...Spherical cathode material LiNi_0.5Mn_1.5O_4 for lithium-ion batteries was synthesized by hydroxide co- precipitation method. X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical mea- surements were carried out to characterize prepared LiNi_0.5Mn_1.5O_4 cathode material. SEM images show that the LiNi_0.5Mn_1.5O_4 cathode material is constituted by micro-sized spherical particles （with a diameter of around 8 μm）. XRD patterns reveal that the structure of prepared LiNi_0.5Mn_1.5O_4 cathode material belongs to Fd3m space group. Electrochemical tests at 25℃show that the LiNi_0.5Mn_1.5O_4 cathode material prepared after annealing at 600 ℃ has the best electrochemical performances. The initial discharge capacity of prepared cathode material delivers 113.5 mAh·g-1 at 1C rate in the range of 3.50-4.95 V, and the sample retains 96.2% （1.0C） of the initial capacity after 50 cycles. Under different rates with a cutoff voltage range of 3.50-4.95 V at 25℃, the dis- charge capacities of obtained cathode material can be kept at about 145.0 （0.1C）, 126.8 （0.5C）, 113.5 （1.0C） and 112.4mAh·g-1 （2.0C）, the corresponding initial coulomb efficiencies retain above 95.2% （0.1C）, 95.0% （0.5C）, 92.5% （1.0C） and 94.8% （2.0C）, respectively.展开更多
Eu3＋ doped Gd2WO6 and Gd2（WO4）3 nanophosphors with different concentrations were prepared via a co-precipitation method. The structure and morphology of the nanocrystal samples were characterized by using X-ray dif...Eu3＋ doped Gd2WO6 and Gd2（WO4）3 nanophosphors with different concentrations were prepared via a co-precipitation method. The structure and morphology of the nanocrystal samples were characterized by using X-ray diffraction （XRD） and field emission scanning electron microscopy （FE-SEM）, respectively. The emission spectra and excitation spectra of samples were measured. J-O parameters and quantum efficiencies of Eu3＋ 5D0 energy level were calculated, and the concentration quenching of Eu3＋ luminescence in different matrixes were studied. The results indicated that effective Eu3＋：5D0-7F2 red luminescence could be achieved while excited by 395 nm near-UV light and 465 nm blue light in Gd2WO6 host, which was similar to the familiar Gd2（WO4）3：Eu. Therefore, the Gd2WO6：Eu red phosphors might have a potential application for white LED.展开更多
A new co-precipitation route was proposed to synthesize LiNi0.8A10.2-xTixO2 （x=0.0-0.20） cathode materials for lithium ion batteries, with Ni（NO3）2, Al（NO3）3, LiOH·H2O, and TiO2 as the starting materials. U...A new co-precipitation route was proposed to synthesize LiNi0.8A10.2-xTixO2 （x=0.0-0.20） cathode materials for lithium ion batteries, with Ni（NO3）2, Al（NO3）3, LiOH·H2O, and TiO2 as the starting materials. Ultrasonic vibration was used during preparing the precursors, and the precursors were protected by absolute ethanol before calcination in the air. The influences of doped-Ti content, calcination temperature and time, additional Li content, and ultrasonic vibration on the structure and properties of LiNi0.8A10.2-xTixO2 were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and charge-discharge tests, respectively. The results show that the optimal molar fraction of Ti, calcination temperature and time, and additional molar fraction of Li for LiNi0.8A10.2-xTixO2 cathode materials are 0.1,700℃, 20 h, and 0.05, respectively. Ti doping facilitates the formation of the α-NaFeO2 layered structure, and ultrasonic vibration improves the electrochemical performance of LiNi0.8A10.2-xTixO2.展开更多
LiNi0.8Co0.1Mn0.1O2 was prepared by a chloride co-precipitation method and characterized by thermogravimetric analysis, X-ray diffractometry with Rietveld refinement,electron scanning microscopy and electrochemical me...LiNi0.8Co0.1Mn0.1O2 was prepared by a chloride co-precipitation method and characterized by thermogravimetric analysis, X-ray diffractometry with Rietveld refinement,electron scanning microscopy and electrochemical measurements.Effects of lithium ion content and sintering temperature on physical and electrochemical performance of LiNi0.8Co0.1Mn0.1O2 were also investigated. The results show that the sample synthesized at 750℃with 105%lithium content has fine particle sizes around 200 nm and homogenous sizes distribution.The initial discharge capacity for the powder is 184 mA·h/g between 2.7 and 4.3 V at 0.1C and room temperature.展开更多
YAG:Ce3+(Yttrium aluminum garnet) fluorescence powders were successfully prepared by co-precipitation method using aluminum nitrate,yttrium nitrate,cerous nitrate as the starting materials and ammonium carbonate as pr...YAG:Ce3+(Yttrium aluminum garnet) fluorescence powders were successfully prepared by co-precipitation method using aluminum nitrate,yttrium nitrate,cerous nitrate as the starting materials and ammonium carbonate as precipitant.The products were characterized by X-ray powder diffraction,luminescence spectrometer,transmission electron microscope(TEM).The XRD results showed that the obtained YAG:Ce3+ fluorescence powders had the crystalline structures of YAG at calcinations temperature of 900 oC and the TEM results showed that the grain diameters were about 100 nm.The YAG:Ce3+ fluorescence powders,synthesized by co-precipitation method,had the best luminescence property when the Ce doping amount was x=0.06 in the molecular formula of Y3-xCexAl5O12,the calcinations time was 2 h and the calcinations temperature was 1000 °C.展开更多
Abstract： Monophasic Ce3＋ and Pr3＋ co-doped yttrium aluminum garnet （YAG：Ce3＋,pr3＋） nanoparticles with good dispersity and uniform grain sizes in the range of 50-80 nm were prepared by a two-step route, which ...Abstract： Monophasic Ce3＋ and Pr3＋ co-doped yttrium aluminum garnet （YAG：Ce3＋,pr3＋） nanoparticles with good dispersity and uniform grain sizes in the range of 50-80 nm were prepared by a two-step route, which consisted of a modified co-precipitation preparation of mixed metal hydroxide hydrate intermediates at low temperature of about 40℃ and a subsequent calcination conversion of the synthesized intermediates to crystalline nanoparticle products at about 1000℃. The influences of both the lanthanide ion （Ce3＋ and Pr3＋） doping concentration and different doping （Ce3＋/pr3＋） ratio on the photoluminescence intensity were systematically investigated. The synthesized （Ce0.6Pr0.4）0.04Y2.96Al5O12 nanoparticles were near spherical nanoclusters with good dispersity and uniform sizes in the range of 50-80 nm for about 85% of the particles. The strongest photoluminescence intensity was observed for the （Ce0.6Pr0.4）0.04Y2.96Al5O12 nanoparticle products.展开更多
A facile co-precipitation route for the synthesis of well-dispersed LaCoO3 nanocrystals was developed. The asprepared products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）,...A facile co-precipitation route for the synthesis of well-dispersed LaCoO3 nanocrystals was developed. The asprepared products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, energy dispersive X-ray spectrometer （EDX）, and laser Raman spectroscopy （LRS）. The resuks showed that modulating the growth parameters, such as the addition of surfactants as well as the adding manner of the precipitator had a significant effect on the overall shape and size of the obtained nanocrystals. The nanorods with the diameter of 20 nm and spherical LaCoO3 nanocrystals with the size of about 25 nm could be obtained at a relatively low calcining temperature of 600℃. Furthermore, the Raman properties of LaCoO3 products obtained at different calcining temperatures were investigated.展开更多
基金the Rare and Precious Metals Material Genetic Engineering Project of Yunnan Province(202102AB080019-1)National Key Research and Development Program of China(2022YFB3708600)the National Natural Science Foundation of China(91960103).
文摘Ferroelastic rare earth tantalates(RETaO_(4))are widely researched as the next-generation thermal barrier coatings(TBCs),and RETaO_(4)powders are hugely significant for synthesizing their coatings.The current research used chemical co-precipitation within an automated experimental device to synthesize RETaO_(4)(RE=Nd,Sm,Gd,Ho,Er)powders.The device automatically monitored and controlled the solutions'pH,improving the chemical co-precipitation efficiency.The crystal structure and microstructure of the RETaO_(4)powders can be controlled by changing the annealing temperature,and the materials undergo an m'-m phase transition.The m'-RETaO_(4)powders exhibit nano-size grains,while m-RETaO_(4)powders evince micron-size grains,altered by the annealing temperatures.A simultaneous thermal analysis es-timates the reversive ferroelastic tetragonal-monoclinic phase transition temperatures.Overall,this research focuses on the synthesis,crystal structures,microstructures,and phase transition of the fabricated RETaO_(4)powders.
基金supported by The National Natural Science Foundation of China(No.52262030)Natural Science Research Project of Guizhou Provincial Department of Education(No.[2022]041).
文摘Conventional hydrometallurgy recycling process for treating wasted lithium-ion batteries(LIBs)typically results in the consumption of large amounts of corrosive leachates.Recent research on reusable leachate is expected to significantly improve the economic and environmental benefits,but is usually limited to specific and unique chemical reactions which could only apply to one type of metal elements.Herein,we report the co-extraction of multiple metal elements can be extracted without adding precipitates by mixed crystal co-precipitation,which enables the reusability of the leachate.We show that an oxalic acid(OA):choline chloride(ChCl):ethylene glycol(EG)type DES leachate system can leach transition metals from wasted LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathode materials with satisfactory efficiency(The time required for complete leaching at 120℃ is 1.5 h).The transition metals were then efficiently extracted(with a recovery efficiency of over 96%for all elements)by directly adding water without precipitants.Noteworthy,the leachate can be efficiently recovered by directly evaporating the added water.The successful realization of reusability of leachate for the synergistic extraction of multiple elements relies on the regulation of the mixed crystal co-precipitation coefficient,which is realized by rationally design the reaction condition(composition of leachate,temperature and time)and induces the extraction of originally soluble manganese element.Our strategy is expected to be generally applicable and highly competent for industrial applications.
基金supported by the Major Science and Technology Project of Shenzhen’s Innovation and Entrepreneurship Program(Grant No.KJZD20231023100301004)Foshan Science and Technology Innovation Team Project(1920001004098)the Hydrometal urgy and Battery Materials Laboratory at PT.QMB New Energy Materials(Indonesia)under GEM Co.,Ltd.(China)as a company group。
文摘The LiNi_(x)Co_(y)Mn_(1-x-y)O_(2)(NCM)cathode materials have emerged as critical components in lithium-ion batteries due to their high energy and power densities.The co-precipitation method is widely used in laboratory and industry settings to optimize the crystallinity,grain morphology,particle size,and sphericity of precursor materials,directly affecting NCM battery performance.This review addresses the nucleation mechanism and the thermodynamic and kinetic reaction processes of co-precipitation.The comprehensive effects of key parameters on precursor physicochemical properties are also systematically interpreted.
基金Project(50721003)supported by the National Natural Science Foundation of ChinaProject(07JJ6082)supported by the Natural Science Foundation of Hunan Province,ChinaProject supported by the Open Project of State Key Laboratory of Powder Metallurgy in Central South University,China
文摘Layered Li[Ni1/3Co1/3Mn1/3]O2 was synthesized with complex metal hydroxide precursors that were prepared by a co-precipitation method.The influence of coordination between ammonia and transition-metal cations on the structural and electrochemical properties of the Li[Ni1/3Co1/3Mn1/3]O2 materials was studied.It is found that when the molar ratio of ammonia to total transition-metal cations is 2.7：1,uniform particle size distribution of the complex metal hydroxide is observed via scanning electron microscopy.The average particle size of Li[Ni1/3Co1/3Mn1/3]O2 materials was measured to be about 500 nm,and the tap-density was measured to be approximately 2.37 g/cm3,which is comparable with that of commercialized LiCoO2.XRD analysis indicates that the presently synthesized Li[Ni1/3Co1/3Mn1/3]O2 has a hexagonal layered-structure.The initial discharge capacity of the Li[Ni1/3Co1/3Mn1/3]O2 positive-electrode material is determined to be 181.5 mA·h/g using a Li/Li[Ni1/3Co1/3Mn1/3]O2 cell operated at 0.1C in the voltage range of 2.8-4.5 V.The discharge capacity at the 50th cycle at 0.5C is 170.6 mA·h/g.
基金Project(2013A090100013)supported by the Special Project on the Integration of Industry,Education and Research of Guangdong Province,ChinaProject(201407300993)supported by the High Technology Research and Development Program of Xinjiang Uygur Autonomous Region,China
文摘Magnetite concentrate was recovered from ferrous sulphate by co-precipitation and magnetic separation. In co-precipitation process, the effects of reaction conditions on iron recovery were studied, and the optimal reaction parameters are proposed as follows： n（CaO）/n（Fe2＋） 1.4：1, reaction temperature 80 ℃, ferrous ion concentration 0.4 mol/L, and the final mole ratio of Fe3＋ to FJ＋ in the reaction solution 1.9-2.1. In magnetic separation process, the effects of milling time and magnetic induction intensity on iron recovery were investigated. Wet milling played an important part in breaking the encapsulated magnetic phases. The results showed that the mixed product was wet-milled for 20 min before magnetic separation, the grade and recovery rate of iron in magnetite concentrate were increased from 51.41% and 84.15% to 62.05% and 85.35%, respectively.
文摘MnxNi0.5-xZn0.5Fe2O4 nanorods were successfully synthesized by the thermal treatment of rod-like precursors that were fabricated by the co-precipitation of Mn2＋, Ni2＋, and Fe2＋ in the lye. The phase, morphology, and particle diameter were examined by the X-ray diffraction and transmission electron microscopy. The magnetic properties of the samples were studied using a vibrating sample magnetometer. nanorods with a diameter of 35 nm and an The results indicated that pure Ni0.5-xZn0.5Fe2O4 aspect ratio of 15 were prepared. It was found that the diametei of the MnxNi0.5-xZn0.5Fe2O4（0≤x≤0.5） samples increased, the length and the aspect .ratio decreased, with an increase in x value. When x=0.5, the diameter and the aspect ratio of the sample reached up to 50 nm and 7-8, respectively. The coercivity of the samples first increased and then decreased with the increase in the x value. The coercivity of the samples again increased when the x value was higher than 0.4. When x=0.5, the coercivity of the MnxNi0.5-xZn0.5Fe2O4 sample reached the maximal value （134.3 Oe） at the calcination temperature of 600 ℃. The saturation magnetization of the samples first increased and then. decreased with the increase in the x value. When x=0.2, the saturation magnetizat：ion of the sample reached the maximal value （68.5 emu/g） at the calcination temperature of 800 ℃.
基金Project supported by Natural Science Foundation of Zhejiang Province(Y4110220)Foundation of the Zhejiang Provincial Department of Education(Y200908245)Foundation of the Dinghai Academy of Science and Technology(201006)
文摘A series of Ni-CeO2 catalysts were prepared by co-precipitation method with Na2CO3, NaOH, and mixed precipitant （Na2CO3：NaOH; 1：1 ratio） as precipitant, respectively. The effect of the precipitants on the catalytic performance, physical and chemical properties of Ni-CeO2 catalysts was investigated with the aid of X-ray diffraction （XRD）, Bmmaner-Emmett-Teller method （BET）, Fou- rier-transform infrared spectroscopy （FT-IR）, thermogravimetry （TG）, and H2-TPR characterizations. The Ni-CeO2 catalysts were exam- ined with respect to their catalytic performance for the reverse water-gas shift reaction, and their catalytic activities were ranked as： Ni-CeO2-CP （Na2CO3：NaOH=I：I）〉Ni-CeO2-CP（Na2CO3）〉Ni-CeO2-CP（NaOH）- Correlating to the characteristic results, it was found that the catalyst prepared by co-precipitation with mixed precipitant （Na2CO3：NaOH; 1：1 ratio） as precipitant hadthe most amount of oxygen vacancies accompanied with highly dispersed Ni particles, which made the corresponding Ni-CeO2-CP（Na2CO3：NaOH=I： 1） catalyst exhibit the highest catalytic activity. While the precipitant of Na2CO3 or NaOH resulted in less or no oxygen vacancies in Ni-CeO2 catalysts. As a result, Ni-CeO2-CP（Na2CO3） and Ni-CeO2-CP（NaOH） catalysts presented poor catalytic performance.
基金Project(2007CB613607) supported by the National Basic Research Program of China
文摘Ti4+-mixed FePO4·xH2O precursor was prepared by co-precipitation method,with which Ti4+ cations were added in the process of preparing FePO4·xH2O to pursue an effective and homogenous doping way.Ti4+-doped LiFePO4 was prepared by an ambient-reduction and post-sintering method using the as-prepared precursor,Li2CO3 and oxalic acid as raw materials.The samples were characterized by scanning electron microscopy (SEM),X-ray diffractometry (XRD),electrochemical impedance spectroscopy (EIS),and electrochemical charge/discharge test.Effects of Ti4+-doping and sintering temperature on the physical and electrochemical performance of LiFePO4 powders were investigated.It is noted that Ti4+-doping can improve the electrochemical performance of LiFePO4 remarkably.The Ti4+-doped sample sintered at 600 ℃ delivers an initial discharge capacity of 150,130 and 125 mA·h/g with 0.1C,1C and 2C rates,respectively,without fading after 40 cycles.
基金supported by C1 Gas Refinery Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT&Future Planning(2015M3D3A1A01064908)
文摘Oxidative coupling of methane(OCM) was conducted over LaAlO3X catalysts that were prepared by a coprecipitation method using different co-precipitation pH values(X = 6–10). The aim is to investigate the effect of p H values on the catalytic activity of La AlO3 catalysts in this reaction. The results showed that the co-precipitation pH value affected greatly on the formation of chemical species of precipitate precursors in the co-precipitation step, leading to different phases of the finally obtained LaAlO3 catalysts.When the co-precipitation pH value increased up to 8, the lanthanum-related phases such as La2 O3 and La(OH)3 were gradually formed as by-products, preventing the formation of LaAlO3 perovskite crystalline structure and facilitating the formation of oxygen vacancies on catalyst surface. However, at pH value of9 or higher, the lanthanum content in the precipitate precursor was increased greatly. Not LaAlO3 perovskite but lanthanum-related phases were developed as main phases, reducing their catalytic activities in this reaction. Among LaAlO3 catalysts, the one prepared at pH = 8 showed the highest C2 yield due to its well-developed oxygen vacancies and electrophilic lattice oxygen. Therefore, the co-precipitation pH value strongly affected the LaAlO3 catalyst activity in OCM reaction. A precious pH control should be required to prepare various perovskite catalysts for the OCM.
基金financially supported by the National Natural Science Foundation of China(No.21273060)the Program for New Century Excellent Talents in Heilongjiang Provincial University(No.1251-NCET-014)
文摘The micron-sized Sr2（P2OT）：Ce,Tb green phosphors were prepared by being annealed at different temperatures with its precursors synthesized by co-pre-cipitates of （NH4）2HPO4 at ambient temperature. The phase structure, grain size, surface morphology, and luminescent properties of phosphors were investigated by X-ray diffraction, scanning electron microscope, trans-mission electron microscope, and fluorescence spectrum. The results show that the product of precursor annealed at 1,100 ℃ is Sr2（P2O7）：Ce,Tb, which belongs to ortho-rhombic phase. The powder is spherical and the size dis-tribution is in micron grade. The sample with the molar ratio of Sr/Tb/Ce of 100.0：0.4：0.6 shows the best fluores-cence effect annealed at 1,100 ℃ for 3 h. The phosphors produce green fluorescence by being excitated with ultra-violet radiation of 254 nm wavelength, and the main emission peak is at 547 nm. The Sr2（P2O7）：Ce,Tb phos-phors synthesized by co-precipitation method of precursors at ambient temperature is a kind of efficient green-emitting phosphors.
基金Project supported by the Ministry of Science and Technology of China (2006CB601104)the Ministry of Industry and Information Technology of China (Electronics Development Foundation)
文摘A precursor of the Y3Al5O12:Ce (YAG:Ce) phosphor was obtained by co-precipitation of the solution of high purity nitrates with ammonium bicarbonate solution. The precipitation process of the precursor was studied in this work. YAG:Ce yellow phosphors with fine morphology was synthesized by annealing the precursor at a reducing atmosphere. The crystal phase, microstructure of the phosphors and their photoluminescence were investigated. The results indicated that the pure phase of YAG:Ce could be obtained at ...
基金financially supported by the Natural Science Foundation of Guangxi Province, China (No. GKZ0832256)
文摘The uniform layered LiNi1/3Co1/3Mn1/3O2 cathode material for lithium ion batteries was prepared by using （Ni1/3Co1/3Mn1/3）C2O4 as precursor synthesized via oxalate co-precipitation method in air. The effects of calcination temperature and time on the structure and electrochemical properties of the LiNi1/3Co1/3Mn1/3O2 were systemically studied. XRD results revealed that the optimal calcination conditions to prepare the layered LiNi1/3Co1/3Mn1/302 were 950℃ for 15 h. Electrochemical measurement showed that the sample prepared under the such conditions has the highest initial discharge capacity of 160.8 mAh/g and the smallest irreversible capacity loss of 13.5% as well as stable cycling performance at a constant current density of 30 mA/g between 2.5 and 4.3 V versus Li at room temperature.
基金Supported by the Major National Water Sci-Tech Projects of China(2009ZX07210-009)the Department of Environmental Protection of Shandong Province(2006032,2060403)
文摘This paper studied the effect of ferric chloride on waste sludge digestion,dewatering and sedimentation under the optimized doses in co-precipitation phosphorus removal process.The experimental results showed that the concentration of mixed liquid suspended solid(MLSS) was 2436 mg.L-1 and 2385 mg.L-1 in co-precipitation phosphorus removal process(CPR) and biological phosphorous removal process(BPR),respectively.The sludge reduction ratio for each process was 22.6% and 24.6% in aerobic digestion,and 27.6% and 29.9% in anaerobic digestion,respectively.Due to the addition of chemical to the end of aeration tank,the sludge content of CPR was slightly higher than that of BPR,but the sludge reduction rate for both processes had no distinct difference.The sludge volume index(SVI) and sludge specific resistance of BPR were 126 ml.g-1 and 11.7×1012 m.kg-1,respectively,while those of CPR were only 98 ml.g-1 and 7.1×1012 m.kg-1,indicating that CPR chemical could improve sludge settling and dewatering.
基金financially supported by the funding from the State Key Laboratory of Advanced Technologies for Comprehensive Utilization of Platinum Metals (No. SKL-SPM201211)the Program for Changjiang Scholars and Innovative Research Team in University (No. IRT13026)
文摘Spherical cathode material LiNi_0.5Mn_1.5O_4 for lithium-ion batteries was synthesized by hydroxide co- precipitation method. X-ray diffraction （XRD）, scanning electron microscopy （SEM） and electrochemical mea- surements were carried out to characterize prepared LiNi_0.5Mn_1.5O_4 cathode material. SEM images show that the LiNi_0.5Mn_1.5O_4 cathode material is constituted by micro-sized spherical particles （with a diameter of around 8 μm）. XRD patterns reveal that the structure of prepared LiNi_0.5Mn_1.5O_4 cathode material belongs to Fd3m space group. Electrochemical tests at 25℃show that the LiNi_0.5Mn_1.5O_4 cathode material prepared after annealing at 600 ℃ has the best electrochemical performances. The initial discharge capacity of prepared cathode material delivers 113.5 mAh·g-1 at 1C rate in the range of 3.50-4.95 V, and the sample retains 96.2% （1.0C） of the initial capacity after 50 cycles. Under different rates with a cutoff voltage range of 3.50-4.95 V at 25℃, the dis- charge capacities of obtained cathode material can be kept at about 145.0 （0.1C）, 126.8 （0.5C）, 113.5 （1.0C） and 112.4mAh·g-1 （2.0C）, the corresponding initial coulomb efficiencies retain above 95.2% （0.1C）, 95.0% （0.5C）, 92.5% （1.0C） and 94.8% （2.0C）, respectively.
基金Project supported by the National Natural Science Foundation of China (51002041)High and New Technique Project of Heilongjiang Province, China (GZ09A405)Science and Technology Research Project of Education Bureau of Heilongjiang Province, China (12511139)
文摘Eu3＋ doped Gd2WO6 and Gd2（WO4）3 nanophosphors with different concentrations were prepared via a co-precipitation method. The structure and morphology of the nanocrystal samples were characterized by using X-ray diffraction （XRD） and field emission scanning electron microscopy （FE-SEM）, respectively. The emission spectra and excitation spectra of samples were measured. J-O parameters and quantum efficiencies of Eu3＋ 5D0 energy level were calculated, and the concentration quenching of Eu3＋ luminescence in different matrixes were studied. The results indicated that effective Eu3＋：5D0-7F2 red luminescence could be achieved while excited by 395 nm near-UV light and 465 nm blue light in Gd2WO6 host, which was similar to the familiar Gd2（WO4）3：Eu. Therefore, the Gd2WO6：Eu red phosphors might have a potential application for white LED.
文摘A new co-precipitation route was proposed to synthesize LiNi0.8A10.2-xTixO2 （x=0.0-0.20） cathode materials for lithium ion batteries, with Ni（NO3）2, Al（NO3）3, LiOH·H2O, and TiO2 as the starting materials. Ultrasonic vibration was used during preparing the precursors, and the precursors were protected by absolute ethanol before calcination in the air. The influences of doped-Ti content, calcination temperature and time, additional Li content, and ultrasonic vibration on the structure and properties of LiNi0.8A10.2-xTixO2 were investigated by X-ray diffraction （XRD）, scanning electron microscopy （SEM）, and charge-discharge tests, respectively. The results show that the optimal molar fraction of Ti, calcination temperature and time, and additional molar fraction of Li for LiNi0.8A10.2-xTixO2 cathode materials are 0.1,700℃, 20 h, and 0.05, respectively. Ti doping facilitates the formation of the α-NaFeO2 layered structure, and ultrasonic vibration improves the electrochemical performance of LiNi0.8A10.2-xTixO2.
基金Project(2007CB613607)supported by National Basic Research Program of China
文摘LiNi0.8Co0.1Mn0.1O2 was prepared by a chloride co-precipitation method and characterized by thermogravimetric analysis, X-ray diffractometry with Rietveld refinement,electron scanning microscopy and electrochemical measurements.Effects of lithium ion content and sintering temperature on physical and electrochemical performance of LiNi0.8Co0.1Mn0.1O2 were also investigated. The results show that the sample synthesized at 750℃with 105%lithium content has fine particle sizes around 200 nm and homogenous sizes distribution.The initial discharge capacity for the powder is 184 mA·h/g between 2.7 and 4.3 V at 0.1C and room temperature.
基金Project supported by China Postdoctoral Science Foundation (20100471663)Science and Technology Program of Yantai Citiy (2008151)+1 种基金Natural Science Foundation of Shandong Province (ZR2009BL013)Innovation Group Foundation Plan of Ludong University
文摘YAG:Ce3+(Yttrium aluminum garnet) fluorescence powders were successfully prepared by co-precipitation method using aluminum nitrate,yttrium nitrate,cerous nitrate as the starting materials and ammonium carbonate as precipitant.The products were characterized by X-ray powder diffraction,luminescence spectrometer,transmission electron microscope(TEM).The XRD results showed that the obtained YAG:Ce3+ fluorescence powders had the crystalline structures of YAG at calcinations temperature of 900 oC and the TEM results showed that the grain diameters were about 100 nm.The YAG:Ce3+ fluorescence powders,synthesized by co-precipitation method,had the best luminescence property when the Ce doping amount was x=0.06 in the molecular formula of Y3-xCexAl5O12,the calcinations time was 2 h and the calcinations temperature was 1000 °C.
基金Project supported by the National High Technology Research and Development Program of China(863 Program)(2013AA031901)the National Natural Science Foundation of China(51425202)+1 种基金the Natural Science Foundation of Jiangsu Province(BK20160093)Topnotch Academic Programs Project of Jiangsu Higher Education Institutions(TAPP)
文摘Abstract： Monophasic Ce3＋ and Pr3＋ co-doped yttrium aluminum garnet （YAG：Ce3＋,pr3＋） nanoparticles with good dispersity and uniform grain sizes in the range of 50-80 nm were prepared by a two-step route, which consisted of a modified co-precipitation preparation of mixed metal hydroxide hydrate intermediates at low temperature of about 40℃ and a subsequent calcination conversion of the synthesized intermediates to crystalline nanoparticle products at about 1000℃. The influences of both the lanthanide ion （Ce3＋ and Pr3＋） doping concentration and different doping （Ce3＋/pr3＋） ratio on the photoluminescence intensity were systematically investigated. The synthesized （Ce0.6Pr0.4）0.04Y2.96Al5O12 nanoparticles were near spherical nanoclusters with good dispersity and uniform sizes in the range of 50-80 nm for about 85% of the particles. The strongest photoluminescence intensity was observed for the （Ce0.6Pr0.4）0.04Y2.96Al5O12 nanoparticle products.
基金Project supported by the Postdoctoral Foundation of China (20060390284)Jiangsu Planned Projects for Postdoctoral Research Funds
文摘A facile co-precipitation route for the synthesis of well-dispersed LaCoO3 nanocrystals was developed. The asprepared products were characterized by X-ray diffraction （XRD）, transmission electron microscopy （TEM）, energy dispersive X-ray spectrometer （EDX）, and laser Raman spectroscopy （LRS）. The resuks showed that modulating the growth parameters, such as the addition of surfactants as well as the adding manner of the precipitator had a significant effect on the overall shape and size of the obtained nanocrystals. The nanorods with the diameter of 20 nm and spherical LaCoO3 nanocrystals with the size of about 25 nm could be obtained at a relatively low calcining temperature of 600℃. Furthermore, the Raman properties of LaCoO3 products obtained at different calcining temperatures were investigated.
