作为一种具有广泛应用前景的高效电合成技术,耦合电溶解的铪醇盐合成(EHS)基于铪溶解/乙醇脱氢的同时非均相反应以及溶液中Hf^(4+)阳离子和烷氧阴离子的自发结合反应。为了阐明EHS过程的机制和动力学,通过电化学测试、扫描电镜、气相色...作为一种具有广泛应用前景的高效电合成技术,耦合电溶解的铪醇盐合成(EHS)基于铪溶解/乙醇脱氢的同时非均相反应以及溶液中Hf^(4+)阳离子和烷氧阴离子的自发结合反应。为了阐明EHS过程的机制和动力学,通过电化学测试、扫描电镜、气相色谱和微观动力学模拟等手段,探究阳极铪溶解和阴极乙醇脱氢的电化学行为。结果表明,优选的支持电解质四乙基氯化铵(Et_(4)NCl)展现了钝化膜击穿与铪溶解协同的剧烈点蚀机制以及两段脱氢机制。为量化钝化膜击穿和铪点蚀的动力学参数,提取与钝化速率、钝化膜击穿敏感性和点蚀速率相关的3个指标,并通过建立微观动力学模型评估基于Et_(4)NCl体系的EHS工艺,其电能消耗为1.53~1.83 k W·h/kg Hf(OC_(2)H_(5))_(4)。展开更多
为了明确La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子的机理,利用XRD、SEM和EDX对吸附剂进行表征,研究吸附剂用量和吸附时间对吸附过程的影响,采用吸附等温线与吸附动力学对吸附过程进行探究。结果表明,Langmuir吸附等温线模型更适合吸...为了明确La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子的机理,利用XRD、SEM和EDX对吸附剂进行表征,研究吸附剂用量和吸附时间对吸附过程的影响,采用吸附等温线与吸附动力学对吸附过程进行探究。结果表明,Langmuir吸附等温线模型更适合吸附过程;在303和313 K条件下,吸附剂的最大理论吸附容量分别为20.83和23.04 mg/g;Temkin和D-R吸附等温线模型证明氟离子脱除过程为物理吸附,且吸附过程遵从准二级动力学模型;同时,热力学计算结果(?G~Θ<0 k J/mol,?H~Θ=8.28 k J/mol,?S~Θ=0.030 k J/(mol?K))说明La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子是自发、吸热的物理过程;将La(Ⅲ)改性沸石应用在工业硫酸锌溶液中,用量为15 g/L时,氟离子浓度从98.05 mg/L降低至44.09 mg/L。展开更多
Antimony sulfide(Sb_(2)S_(3))is a promising anode for lithium-ion batteries due to its high capacity and vast reserves.However,the low electronic conductivity and severe volume change during cycling hinder its commerc...Antimony sulfide(Sb_(2)S_(3))is a promising anode for lithium-ion batteries due to its high capacity and vast reserves.However,the low electronic conductivity and severe volume change during cycling hinder its commercialization.Herein our work,a three-dimensional(3D)Sb_(2)S_(3) thin film anode was fabricated via a simple vapor transport deposition system by using natural stibnite as raw material and stainless steel fiber-foil(SSF)as 3D current collector,and a carbon nanotube interphase was introduced onto the film surface by a simple dropping-heating process to promote the electrochemical performances.This 3D structure can greatly improve the initial coulombic efficiency to a record of 86.6% and high reversible rate capacity of 760.8 mAh·g^(-1) at 10 C.With carbon nanotubes interphase modified,the Sb_(2)S_(3) anode cycled extremely stable with high capacity retention of 94.7% after 160 cycles.This work sheds light on the economical preparation and performance optimization of Sb_(2)S_(3)-based anodes.展开更多
基金Science and Technology Innovation Program of Hunan Province,China(No.2021RC2002)Yangfan Plan,China(No.2017YT05C107)。
文摘作为一种具有广泛应用前景的高效电合成技术,耦合电溶解的铪醇盐合成(EHS)基于铪溶解/乙醇脱氢的同时非均相反应以及溶液中Hf^(4+)阳离子和烷氧阴离子的自发结合反应。为了阐明EHS过程的机制和动力学,通过电化学测试、扫描电镜、气相色谱和微观动力学模拟等手段,探究阳极铪溶解和阴极乙醇脱氢的电化学行为。结果表明,优选的支持电解质四乙基氯化铵(Et_(4)NCl)展现了钝化膜击穿与铪溶解协同的剧烈点蚀机制以及两段脱氢机制。为量化钝化膜击穿和铪点蚀的动力学参数,提取与钝化速率、钝化膜击穿敏感性和点蚀速率相关的3个指标,并通过建立微观动力学模型评估基于Et_(4)NCl体系的EHS工艺,其电能消耗为1.53~1.83 k W·h/kg Hf(OC_(2)H_(5))_(4)。
基金Projects(51474238,51674301)supported by the National Natural Science Foundation of China
文摘为了明确La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子的机理,利用XRD、SEM和EDX对吸附剂进行表征,研究吸附剂用量和吸附时间对吸附过程的影响,采用吸附等温线与吸附动力学对吸附过程进行探究。结果表明,Langmuir吸附等温线模型更适合吸附过程;在303和313 K条件下,吸附剂的最大理论吸附容量分别为20.83和23.04 mg/g;Temkin和D-R吸附等温线模型证明氟离子脱除过程为物理吸附,且吸附过程遵从准二级动力学模型;同时,热力学计算结果(?G~Θ<0 k J/mol,?H~Θ=8.28 k J/mol,?S~Θ=0.030 k J/(mol?K))说明La(Ⅲ)改性沸石脱除模拟硫酸锌溶液中氟离子是自发、吸热的物理过程;将La(Ⅲ)改性沸石应用在工业硫酸锌溶液中,用量为15 g/L时,氟离子浓度从98.05 mg/L降低至44.09 mg/L。
基金financially supported by the National Natural Science Foundation of China(No.51774343).
文摘Antimony sulfide(Sb_(2)S_(3))is a promising anode for lithium-ion batteries due to its high capacity and vast reserves.However,the low electronic conductivity and severe volume change during cycling hinder its commercialization.Herein our work,a three-dimensional(3D)Sb_(2)S_(3) thin film anode was fabricated via a simple vapor transport deposition system by using natural stibnite as raw material and stainless steel fiber-foil(SSF)as 3D current collector,and a carbon nanotube interphase was introduced onto the film surface by a simple dropping-heating process to promote the electrochemical performances.This 3D structure can greatly improve the initial coulombic efficiency to a record of 86.6% and high reversible rate capacity of 760.8 mAh·g^(-1) at 10 C.With carbon nanotubes interphase modified,the Sb_(2)S_(3) anode cycled extremely stable with high capacity retention of 94.7% after 160 cycles.This work sheds light on the economical preparation and performance optimization of Sb_(2)S_(3)-based anodes.
