Implementation of non-precious electrocatalysts is key-enabling for water electrolysis to relieve challenges in energy and environmental sustainability. Self-supporting Ni-V2O3 electrodes consisting of nanostrip-like ...Implementation of non-precious electrocatalysts is key-enabling for water electrolysis to relieve challenges in energy and environmental sustainability. Self-supporting Ni-V2O3 electrodes consisting of nanostrip-like V2O3 perpendicularly anchored on Ni meshes are herein constructed via the electrochemical reduction of soluble NaVO3 in molten salts for enhanced electrocatalytic hydrogen evolution. Such a special configuration in morphology and composition creates a well confined interface between Ni and V2O3. Experimental and Density-Functional-Theory results confirm that the synergy between Ni and V2O3 accelerates the dissociation of H2O for forming hydrogen intermediates and enhances the combination of H*for generating H2.展开更多
The Y-Eu oxalate precursor was prepared with a homogeneous precipitation method. And the additives, Na2CO3, S, NaCl or their combination, were introduced into the precursor to prepare Y2O3 ：Eu^3＋ red phosphors at 10...The Y-Eu oxalate precursor was prepared with a homogeneous precipitation method. And the additives, Na2CO3, S, NaCl or their combination, were introduced into the precursor to prepare Y2O3 ：Eu^3＋ red phosphors at 1000 1300 ℃ for 2 h. The effect of molten salts on particle size and luminescent intensity was studied. The experimental results showed that the complex molten salt （Na：CO3 ＋ S ＋ NaCl） was conductive to enhance the luminescent intensity of Y2O3 ：Eu^3＋. The emission intensity of the phosphor prepared with these additives at 1300 ℃ was about 45% higher than that of the one prepared without molten salt, and about 11% higher than that of the corresponding commercial phosphor. Meanwhile, the particle size of Y2O3 ：Eu^3＋ phosphor was controlled effectively with the molten salt.展开更多
Bismuth titanate （Bi4Ti3O12） platelets were prepared by molten salt method in a new salt system of CaCl2·NaCl at 650-750℃, using bismuth nitrate pentahydrate （Bi （NO3）3·H2O） and titanium butoxide （Ti...Bismuth titanate （Bi4Ti3O12） platelets were prepared by molten salt method in a new salt system of CaCl2·NaCl at 650-750℃, using bismuth nitrate pentahydrate （Bi （NO3）3·H2O） and titanium butoxide （Ti （OC4H9）4） as raw materials. The synthesis temperature of Bi4Ti3O12 platelets was decreased to 650℃ from 900-1100℃. The phase compositions and crystalline morphology of Bi4Ti3O12 platelets were investigated by XRD and SEM. The experimental results indicate that Bi4Ti3O12 platelets containing tetragonal and orthorhombic phase with the size of 1-3μm can be synthesized at 650℃ for 2 h, and the orthorhombic phase becomes the dominant phase at 750℃ for 5 h. The size and proportion of Bi4Ti3O12 platelets increase with the increment of the calcining temperature and holding time. The proportion of platelets increases to about ninety percent, and the platelets grow up to about 3-10μm at 750℃ for 5 h from 1-2μm at 650℃ for 2 h. This technical route provides a new low-temperature molten salt system for preparing platelets by molten salt methods.展开更多
Vanadium trioxide（V2O3） was directly prepared by NaVO3 electrolysis in Na Cl molten salts. Electrolysis products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and energy dispers...Vanadium trioxide（V2O3） was directly prepared by NaVO3 electrolysis in Na Cl molten salts. Electrolysis products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and energy dispersive spectroscopy（EDS）. The existing state and electrochemical behavior of NaVO3 were also studied. The results indicated that V2O3 can be obtained from NaVO3. VC and C were also formed at high cell voltage, high temperature, and long electrolysis time. During electrolysis, NaVO3 was dissociated to Na＋ and VO3-in Na Cl molten salt. NaVO3 was initially electro-reduced to V2O3 on cathode and Na2O was released simultaneously. Na2CO3 was formed due to the reaction between Na2O and CO2. The production of C was ascribed to the electro-reduction of CO3（2-）. VC was produced due to the reaction between C and V2O3.展开更多
The chemical reaction and dissolution processes of RE2 O3 in REF3-LiF（RE = La and Nd） molten salts were studied by X-ray diffraction, differential thermal analysis and chemical analysis. Firstly, RE2 O3 disperses in...The chemical reaction and dissolution processes of RE2 O3 in REF3-LiF（RE = La and Nd） molten salts were studied by X-ray diffraction, differential thermal analysis and chemical analysis. Firstly, RE2 O3 disperses in molten salts and reacts with REF3 and LiF, which lead to the generation of a new phase REOF, resulting in the dissociation or formation of complex ions by part of REOF, and the sedimentation of excessive REOF at the bottom. The RE contents in molten salts were used to determine the solubility of RE2 O3. The results show that with 20 mol%-40 mol% of REF3, the solubility ranges from 1.79 to 3.05 g RE2 O3 per100 g electrolyte and the corresponding mole concentration is 0.33%-0.87%. RE2 O3 solubility increases with increasing temperature and REF3 concentration. The natural logarithm of the RE2 O3 solubility is plotted against 1/T and can be interpreted by linear relationship. The fitting parameters can be used to estimate the solubility of RE2 O3 with minimized experimental efforts and difficult experiment conditions.展开更多
Samarium（Sm） has been widely used in making aluminum（Al）-Sm magnet alloy materials. The research team for this study developed a molten salt electrolyte system which directly produces AI-Sm alloy to replace the en...Samarium（Sm） has been widely used in making aluminum（Al）-Sm magnet alloy materials. The research team for this study developed a molten salt electrolyte system which directly produces AI-Sm alloy to replace the energy intensive conventional distillation technology. In this study, molten melt density was measured and operation conditions were optimized to separate AI-Sm alloy product from the fluoride molten melt electrolysis media based on density differences, Archimedes＇ principle was applied to measure density for the basic molten fluoride system（BMFS： Na_3 AlF_6-AlF_3-LiF-MgF_2）electrolysis media in the temperature range from 905 to 1055 ℃.The impact of temperature（t） and the Al_2O_3 and Sm_2O_3 addition ratio（w_（（Al2O3））,w_（（Sm2O3）） in the basic fluoride system on molten melt density was examined. The fluoride molten melt density relationship was determined to be：ρ=3.11701-0.00802 w_（（Al2O3））＋0.027825 w_（（Sm2O3））-0.00117 t. The test results showed that molten density decreases with increase in temperature and Al_2O_3 addition ratio, and increases with the addition of Sm_2O_3, and/or Al_2O_3＋Sm_2O_3. The separation of Al-Sm（density 2.3 g/cm^3） product melt from the BMFS melt is achieved by controlling the BMFS density to less than 2.0 g/cm3. It is concluded that the optimal operation conditions to control the BMFS molten salt density to less than 2.0 g/cm^3 are：maintain addition of Al_2O_3＋Sm_2 O_3（w_（（Al2O3））＋w_（（Sm2O3））〈9% of Na_3AlF_6,Al_2O_3/Sm_2O_3 ratio（w_（（Al2O3））：w_（（Sm2O3）））〉 7：3, and temperature between 965 and 995 ℃.展开更多
The development of a highly efficient and durable electrocatalyst for nitrate reduction reaction(NO_(3)RR)wastewater valorization to ammonia(NH_(3))is a promising strategy.However,it is challenging to design scalable ...The development of a highly efficient and durable electrocatalyst for nitrate reduction reaction(NO_(3)RR)wastewater valorization to ammonia(NH_(3))is a promising strategy.However,it is challenging to design scalable low-cost electrocatalysts with high activity,high selectivity,and long-term stability by a facile and simple method.Herein,we construct this scalable Cu-based nanoarray with muti-oxidation states grown directly on nickel foam(NF)substrate(Cu_(2+1)O@Cu/NF)using a facile molten salt method combined in-situ electrochemical reduction.The as-prepared Cu_(2+1)O@Cu/NF nanoarrays reveal a high NH_(3) yield of 20.14 mg h^(−1) cm^(−2) at−0.95 V vs.a reversible hydrogen electrode(vs.RHE),Faradaic efficiency of 99.38%at−0.55 V vs.RHE in the neutral potassium phosphate(PBS)buffer solution with 50 mM NaNO_(3),which is ascribed to its electron redistribution with abundant oxygen vacancies and favorable charge/mass transfer.展开更多
基金the funding support from the National Natural Science Foundation of China(51722404,51674177,51804221 and 91845113)the National Key R&D Program of China(2018YFE0201703)+2 种基金the China Postdoctoral Science Foundation(2018M642906 and 2019T120684)the Fundamental Research Funds for the Central Universities(2042017kf0200)the Hubei Provincial Natural Science Foundation of China(2019CFA065)。
文摘Implementation of non-precious electrocatalysts is key-enabling for water electrolysis to relieve challenges in energy and environmental sustainability. Self-supporting Ni-V2O3 electrodes consisting of nanostrip-like V2O3 perpendicularly anchored on Ni meshes are herein constructed via the electrochemical reduction of soluble NaVO3 in molten salts for enhanced electrocatalytic hydrogen evolution. Such a special configuration in morphology and composition creates a well confined interface between Ni and V2O3. Experimental and Density-Functional-Theory results confirm that the synergy between Ni and V2O3 accelerates the dissociation of H2O for forming hydrogen intermediates and enhances the combination of H*for generating H2.
基金Project supported by the National Natural Science Foundation of China (50372086)the Ministry of Science and Technology of Chi-na (2006CB601104)
文摘The Y-Eu oxalate precursor was prepared with a homogeneous precipitation method. And the additives, Na2CO3, S, NaCl or their combination, were introduced into the precursor to prepare Y2O3 ：Eu^3＋ red phosphors at 1000 1300 ℃ for 2 h. The effect of molten salts on particle size and luminescent intensity was studied. The experimental results showed that the complex molten salt （Na：CO3 ＋ S ＋ NaCl） was conductive to enhance the luminescent intensity of Y2O3 ：Eu^3＋. The emission intensity of the phosphor prepared with these additives at 1300 ℃ was about 45% higher than that of the one prepared without molten salt, and about 11% higher than that of the corresponding commercial phosphor. Meanwhile, the particle size of Y2O3 ：Eu^3＋ phosphor was controlled effectively with the molten salt.
文摘Bismuth titanate （Bi4Ti3O12） platelets were prepared by molten salt method in a new salt system of CaCl2·NaCl at 650-750℃, using bismuth nitrate pentahydrate （Bi （NO3）3·H2O） and titanium butoxide （Ti （OC4H9）4） as raw materials. The synthesis temperature of Bi4Ti3O12 platelets was decreased to 650℃ from 900-1100℃. The phase compositions and crystalline morphology of Bi4Ti3O12 platelets were investigated by XRD and SEM. The experimental results indicate that Bi4Ti3O12 platelets containing tetragonal and orthorhombic phase with the size of 1-3μm can be synthesized at 650℃ for 2 h, and the orthorhombic phase becomes the dominant phase at 750℃ for 5 h. The size and proportion of Bi4Ti3O12 platelets increase with the increment of the calcining temperature and holding time. The proportion of platelets increases to about ninety percent, and the platelets grow up to about 3-10μm at 750℃ for 5 h from 1-2μm at 650℃ for 2 h. This technical route provides a new low-temperature molten salt system for preparing platelets by molten salt methods.
基金supported by the National Basic Research Program of China(973 Program)(No.2013CB632606)National Natural Science Foundation of China(Nos.51474200,51422405)Youth Innovation Promotion Association,CAS(No.2015036)
文摘Vanadium trioxide（V2O3） was directly prepared by NaVO3 electrolysis in Na Cl molten salts. Electrolysis products were characterized by X-ray diffraction（XRD）, scanning electron microscopy（SEM） and energy dispersive spectroscopy（EDS）. The existing state and electrochemical behavior of NaVO3 were also studied. The results indicated that V2O3 can be obtained from NaVO3. VC and C were also formed at high cell voltage, high temperature, and long electrolysis time. During electrolysis, NaVO3 was dissociated to Na＋ and VO3-in Na Cl molten salt. NaVO3 was initially electro-reduced to V2O3 on cathode and Na2O was released simultaneously. Na2CO3 was formed due to the reaction between Na2O and CO2. The production of C was ascribed to the electro-reduction of CO3（2-）. VC was produced due to the reaction between C and V2O3.
基金supported by the National High Technology Research and Development Program(2011AA03A409)Fundamental Research Funds for the Central Universities(N110202002)
文摘The chemical reaction and dissolution processes of RE2 O3 in REF3-LiF（RE = La and Nd） molten salts were studied by X-ray diffraction, differential thermal analysis and chemical analysis. Firstly, RE2 O3 disperses in molten salts and reacts with REF3 and LiF, which lead to the generation of a new phase REOF, resulting in the dissociation or formation of complex ions by part of REOF, and the sedimentation of excessive REOF at the bottom. The RE contents in molten salts were used to determine the solubility of RE2 O3. The results show that with 20 mol%-40 mol% of REF3, the solubility ranges from 1.79 to 3.05 g RE2 O3 per100 g electrolyte and the corresponding mole concentration is 0.33%-0.87%. RE2 O3 solubility increases with increasing temperature and REF3 concentration. The natural logarithm of the RE2 O3 solubility is plotted against 1/T and can be interpreted by linear relationship. The fitting parameters can be used to estimate the solubility of RE2 O3 with minimized experimental efforts and difficult experiment conditions.
基金Project supported by the National Natural Science Foundation of China(51564015,51674126)Graduate Student Innovation Special Fund of Jiangxi Province(YC2015-B064)+2 种基金Science and Technology Research Project of Jiangxi Department of Education(GJJ150664)Outstanding doctoral dissertation project fund of JXUST(YB2016007)Scientific Research Fund of JXUST(NSFJ2014-G09)
文摘Samarium（Sm） has been widely used in making aluminum（Al）-Sm magnet alloy materials. The research team for this study developed a molten salt electrolyte system which directly produces AI-Sm alloy to replace the energy intensive conventional distillation technology. In this study, molten melt density was measured and operation conditions were optimized to separate AI-Sm alloy product from the fluoride molten melt electrolysis media based on density differences, Archimedes＇ principle was applied to measure density for the basic molten fluoride system（BMFS： Na_3 AlF_6-AlF_3-LiF-MgF_2）electrolysis media in the temperature range from 905 to 1055 ℃.The impact of temperature（t） and the Al_2O_3 and Sm_2O_3 addition ratio（w_（（Al2O3））,w_（（Sm2O3）） in the basic fluoride system on molten melt density was examined. The fluoride molten melt density relationship was determined to be：ρ=3.11701-0.00802 w_（（Al2O3））＋0.027825 w_（（Sm2O3））-0.00117 t. The test results showed that molten density decreases with increase in temperature and Al_2O_3 addition ratio, and increases with the addition of Sm_2O_3, and/or Al_2O_3＋Sm_2O_3. The separation of Al-Sm（density 2.3 g/cm^3） product melt from the BMFS melt is achieved by controlling the BMFS density to less than 2.0 g/cm3. It is concluded that the optimal operation conditions to control the BMFS molten salt density to less than 2.0 g/cm^3 are：maintain addition of Al_2O_3＋Sm_2 O_3（w_（（Al2O3））＋w_（（Sm2O3））〈9% of Na_3AlF_6,Al_2O_3/Sm_2O_3 ratio（w_（（Al2O3））：w_（（Sm2O3）））〉 7：3, and temperature between 965 and 995 ℃.
基金the National Natural Science Foundation of China(Nos.21975106 and 21403232)MOE&SAFEA,111 Project(B13025)for financial support.
文摘The development of a highly efficient and durable electrocatalyst for nitrate reduction reaction(NO_(3)RR)wastewater valorization to ammonia(NH_(3))is a promising strategy.However,it is challenging to design scalable low-cost electrocatalysts with high activity,high selectivity,and long-term stability by a facile and simple method.Herein,we construct this scalable Cu-based nanoarray with muti-oxidation states grown directly on nickel foam(NF)substrate(Cu_(2+1)O@Cu/NF)using a facile molten salt method combined in-situ electrochemical reduction.The as-prepared Cu_(2+1)O@Cu/NF nanoarrays reveal a high NH_(3) yield of 20.14 mg h^(−1) cm^(−2) at−0.95 V vs.a reversible hydrogen electrode(vs.RHE),Faradaic efficiency of 99.38%at−0.55 V vs.RHE in the neutral potassium phosphate(PBS)buffer solution with 50 mM NaNO_(3),which is ascribed to its electron redistribution with abundant oxygen vacancies and favorable charge/mass transfer.
