Magnesium hydride serves as a promising solid-state hydrogen storage material owing to its high potential.However,its practical applications are constrained by the high enthalpy of hydrogen absorption and slow kinetic...Magnesium hydride serves as a promising solid-state hydrogen storage material owing to its high potential.However,its practical applications are constrained by the high enthalpy of hydrogen absorption and slow kinetics.In this study,we prepared a Ni/Ti3O5@graphene oxide(GO)dual-heterojunction composite material via solvent heating,electrostatic adsorption,and calcination to improve the hydrogen storage capabilities of MgH2.Adding Ni/Ti3O5@GO to MgH2 lowered the initial dehydrogenation temperature of MgH2 to 183℃;at a dehydrogenation temperature of 275℃,6.4 wt.%of H2 escaped from the MgH2 bulk.In addition,the hydrogen storage material absorbed 1.8 wt.%H2 at 30℃ for 30 min.The calculated activation energy of dehydrogenation was 48.221±0.141 kJ·mol-1,which was significantly lower than that of the ball-milled MgH2(112.63±1.44 kJ·mol-1).Mechanistic analysis results revealed that the heterojunction constructed from the multiphase compound system provided a large number of active sites and hydrogen diffusion routes,resulting in a synergistic catalytic effect that enhanced the hydrogen storage capacity of MgH2.In this work,we clarified the compositions of fuzzy interfaces in heterostructured materials by conducting ultraviolet photoelectron spectroscopy tests and identified key composite materials for the formation of heterojunctions.展开更多
Methodology for the electrochemical decomposition of imazethapyr using Ti/SnO2-Sb2O5/PbO2 anode in Na2SO4 medium is suggested in this paper. The electrolysis reaction conditions were optimized. The process of electroc...Methodology for the electrochemical decomposition of imazethapyr using Ti/SnO2-Sb2O5/PbO2 anode in Na2SO4 medium is suggested in this paper. The electrolysis reaction conditions were optimized. The process of electrochemical decomposition was monitored by ultra-violet spectrophotometry and CODCr method. The electrochemical decomposition mechanism of imazethapyr was studied primarily by UV-VIS spectrophotometry. The effectiveness of the electrochemical pretreatment was proved by the comparative aerobic biological treatment test based on the activated sludge process.展开更多
The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solu...The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solution of sodium sulfate and chlorimuron-ethyl was studied. The experimental results of cyclic voltammetry show that the acidic medium was suitable for the efficient electrochemical oxidation of chlorimuron-ethyl. Some electro-generated reagent was formed in the electrolysis process and chlorimuron-ethyl could be oxidized by the electro-generated reagent. A Ti/SnO2-Sb2O5/PbO2 electrode was used as the anode and the electrolysis experiment was carried out under the optimized conditions. The electrolysis process was monitored by UV-Vis spectrometry and high performance liquid chromatography(HPLC), and the chemical oxygen demand(COD) was determined by the potassium dichromate method. The mechanism of chlorimuron-ethyl to be oxided was studied primarily by the cyclic voltammetry and UV-Vis spectrometry. The results of electrolysis experiment demonstrate the possibility of the electrode to be used as an anode for the electrochemical treatment of chlorimuron-ethyl contained in waste water.展开更多
目前在电化学氧化处理法降解苯酚废水的研究过程中,研究者多将重心放在活性电极的探索及制备上,而对于反应器的开发鲜有报道。就这一问题,本文研究了新型微流控反应器中苯酚的电化学降解效果。电化学氧化实验在装有Ti/SnO2-Sb2O5阳极的...目前在电化学氧化处理法降解苯酚废水的研究过程中,研究者多将重心放在活性电极的探索及制备上,而对于反应器的开发鲜有报道。就这一问题,本文研究了新型微流控反应器中苯酚的电化学降解效果。电化学氧化实验在装有Ti/SnO2-Sb2O5阳极的微型流通池中操作进行,实验对循环体系的体积流率ΦV、电极间距h的影响进行了考察。结果表明,当流通电解槽中的阴阳极间距采用微米级尺寸时,苯酚的阳极氧化反应取得了较快的氧化速度。在i=20 m A/cm2、ΦV=0.54 m L/min的电解条件下,电解2~3h苯酚去除率即可达到90%以上,相同流速下电极间距h越小降解速率越快。且由数据回归得到了苯酚的一系列随h的减小而增大的准一级反应的反应速率常数。这一结论表明微流控电解槽内的苯酚降解过程主要传质控制过程。展开更多
PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction method.These electrocatalysts were characterized by EDX,X-ray diffracti...PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction method.These electrocatalysts were characterized by EDX,X-ray diffraction,transmission electron microscopy and the catalytic activity toward formic acid electro-oxidation in acid medium investigated by cyclic voltammetry(CV),chroamperometry(CA)and tests on direct formic acid fuel cell(DFAFC)at 100℃.X-ray diffractograms of PdAuIr/C-Sb2O5·SnO2electrocatalysts showed the presence of Pd fcc phase,Pd-Au fcc alloys,carbon and ATO phases,while Ir phases were not observed.TEM micrographs and histograms indicated that the nanoparticles were not well dispersed on the support and some agglomerates.The cyclic voltammetry and chroamperometry studies showed that PdAuIr/C-Sb2O5·SnO2(50∶45∶5)had superior performance toward formic acid electro-oxidation at 25℃compared to PdAuIr/C-Sb2O5·SnO2(70∶20∶10),PdAuIr/C-Sb2O5·SnO2(90∶5∶5)and Pd/C-Sb2O5·SnO2electrocatalysts.The experiments in a single DFAFC also showed that all PdAuIr/C-Sb2O5·SnO2electrocatalysts exhibited higher performance for formic acid oxidation in comparison with Pd/C-Sb2O5·SnO2electrocatalysts,however PdAuIr/C-Sb2O5·SnO2(90∶5∶5)had superior performance.These results indicated that the addition of Au and Ir to Pd favor the electro-oxidation of formic acid,which could be attributed to the bifunctional mechanism(the presence of ATO,Au and Ir oxides species)associated to the electronic effect(Pd-Au fcc alloys).展开更多
The Ti/SnO2-Sb2O5/PbO2 electrode was prepared by electrodeposition method onto Ti substrate with SnO2-Sb2O5 interlayer. Microstructure information of SnO2-Sb2O5 interlayer and PbO2 coating was characterized by scannin...The Ti/SnO2-Sb2O5/PbO2 electrode was prepared by electrodeposition method onto Ti substrate with SnO2-Sb2O5 interlayer. Microstructure information of SnO2-Sb2O5 interlayer and PbO2 coating was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Our study shows that the titanium substrate is completely covered by the SnO2-Sb2O5 solid solution interlayer and the interlayer combines the Ti substrate closely with the PbO2 coating. The electrochemical performance of the Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltammogram (CV), electrochemical impedance spectros-copy (EIS) and accelerated life test. The results show the electrochemical activity, electrical conductivity and stabil- ity of Ti-substrate lead dioxide electrode are increased. The deactivation process of the Ti/SnOe-Sb2O5/PbO2 elec- trode was also studied by the EIS. The SnO2-Sb2O5 interlayer can effectively prevent the growth of a TiO2 insulating layer between the substrate and the PbO2 coating during the lifetime tests, thus maintain high activity of Ti/SnO2-Sb2O5/PbO2 electrode for 10 times longer than Ti/PbO2 electrode without interlayer.展开更多
构建准确可靠的热力学数据库对提钒过程优化以及钒酸盐材料的制备具有重要的应用价值和指导意义。采用封闭铂金坩埚,结合X射线衍射(XRD)与差热分析(DTA)技术,证实了K2O-V2O5体系中K3V5O14为稳定存在的化合物,并试验...构建准确可靠的热力学数据库对提钒过程优化以及钒酸盐材料的制备具有重要的应用价值和指导意义。采用封闭铂金坩埚,结合X射线衍射(XRD)与差热分析(DTA)技术,证实了K2O-V2O5体系中K3V5O14为稳定存在的化合物,并试验测定了K2V8O21和KVO3的熔化温度分别为532.4℃和516.5℃。随后采用修正的准化学模型(MQM),引入溶液中第二相邻阳离子短程有序对描述吉布斯自由能的变化。基于CALPHAD框架(CALculation of PHAse Diagram,相图计算),构建了Na2O-K2O-V2O5体系的热力学模型,重现了Na2O-K2O-V2O5体系全组分范围的实验数据和热力学性质,获得了该体系中所有物相一系列自洽的热力学模型参数,最终构建了可靠的热力学数据库。进一步探讨了当前数据库在钒渣钠化焙烧提钒中的应用,明确了含钒物相的迁移规律,确定了最佳的操作温度窗口。展开更多
Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making th...Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making them a highly promising technology for low-grade heat recovery and utilization.However,the low output power density and energy conversion efficiency resulted by the slow diffusion kinetics of Zn2+hinder their development.Herein,we present a highperformance thermal charging cell design using Zn2+/NH4+hybrid ion electrolyte,which not only maintains the high output voltage of the Zn-based thermoelectric system,but also significantly enhances the output power density due to the fast diffusion kinetics of NH4+.Based on this strategy,the thermal charging cell displays a high thermopower of 12.5 mV K-1and an excellent normalized power density of 19.6 mW m-2K-2at a temperature difference of 35 K.The Carnot-relative efficiency is as high as 12.74%.Moreover,it can operate continuously for over 72 h when the temperature difference persists,achieving a balance between thermoelectric conversion and output.This work provides a simple and effective strategy for the design of high-performance thermal charging cells for low-grade heat conversion and utilization.展开更多
基金supported by the National Natural Science Foundation of China[grant number U24A2044]Science and Technology Major Program of Guangxi Province[grant number GUIKEAA24206007].
摘要Magnesium hydride serves as a promising solid-state hydrogen storage material owing to its high potential.However,its practical applications are constrained by the high enthalpy of hydrogen absorption and slow kinetics.In this study,we prepared a Ni/Ti3O5@graphene oxide(GO)dual-heterojunction composite material via solvent heating,electrostatic adsorption,and calcination to improve the hydrogen storage capabilities of MgH2.Adding Ni/Ti3O5@GO to MgH2 lowered the initial dehydrogenation temperature of MgH2 to 183℃;at a dehydrogenation temperature of 275℃,6.4 wt.%of H2 escaped from the MgH2 bulk.In addition,the hydrogen storage material absorbed 1.8 wt.%H2 at 30℃ for 30 min.The calculated activation energy of dehydrogenation was 48.221±0.141 kJ·mol-1,which was significantly lower than that of the ball-milled MgH2(112.63±1.44 kJ·mol-1).Mechanistic analysis results revealed that the heterojunction constructed from the multiphase compound system provided a large number of active sites and hydrogen diffusion routes,resulting in a synergistic catalytic effect that enhanced the hydrogen storage capacity of MgH2.In this work,we clarified the compositions of fuzzy interfaces in heterostructured materials by conducting ultraviolet photoelectron spectroscopy tests and identified key composite materials for the formation of heterojunctions.
摘要Methodology for the electrochemical decomposition of imazethapyr using Ti/SnO2-Sb2O5/PbO2 anode in Na2SO4 medium is suggested in this paper. The electrolysis reaction conditions were optimized. The process of electrochemical decomposition was monitored by ultra-violet spectrophotometry and CODCr method. The electrochemical decomposition mechanism of imazethapyr was studied primarily by UV-VIS spectrophotometry. The effectiveness of the electrochemical pretreatment was proved by the comparative aerobic biological treatment test based on the activated sludge process.
基金Supported by the Science and Technology Foundation of the Education Department of Liaoning Province,China (No.2009A557)
摘要The electrochemical oxidation of chlorimuron-ethyl on metry. The electrochemical behaviour of the electrode in a sodium Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltamsulfate solution and in the mixture solution of sodium sulfate and chlorimuron-ethyl was studied. The experimental results of cyclic voltammetry show that the acidic medium was suitable for the efficient electrochemical oxidation of chlorimuron-ethyl. Some electro-generated reagent was formed in the electrolysis process and chlorimuron-ethyl could be oxidized by the electro-generated reagent. A Ti/SnO2-Sb2O5/PbO2 electrode was used as the anode and the electrolysis experiment was carried out under the optimized conditions. The electrolysis process was monitored by UV-Vis spectrometry and high performance liquid chromatography(HPLC), and the chemical oxygen demand(COD) was determined by the potassium dichromate method. The mechanism of chlorimuron-ethyl to be oxided was studied primarily by the cyclic voltammetry and UV-Vis spectrometry. The results of electrolysis experiment demonstrate the possibility of the electrode to be used as an anode for the electrochemical treatment of chlorimuron-ethyl contained in waste water.
摘要目前在电化学氧化处理法降解苯酚废水的研究过程中,研究者多将重心放在活性电极的探索及制备上,而对于反应器的开发鲜有报道。就这一问题,本文研究了新型微流控反应器中苯酚的电化学降解效果。电化学氧化实验在装有Ti/SnO2-Sb2O5阳极的微型流通池中操作进行,实验对循环体系的体积流率ΦV、电极间距h的影响进行了考察。结果表明,当流通电解槽中的阴阳极间距采用微米级尺寸时,苯酚的阳极氧化反应取得了较快的氧化速度。在i=20 m A/cm2、ΦV=0.54 m L/min的电解条件下,电解2~3h苯酚去除率即可达到90%以上,相同流速下电极间距h越小降解速率越快。且由数据回归得到了苯酚的一系列随h的减小而增大的准一级反应的反应速率常数。这一结论表明微流控电解槽内的苯酚降解过程主要传质控制过程。
基金the Laboratório de Microscopia do Centro de Ciências e Tecnologia de Materiais(CCTM) by TEM measurements,FAPESP(2011/18246-0,2012/03516-5) and CNPQ(150639/2013-9)for the financial support
摘要PdAuIr/C-Sb2O5·SnO2electrocatalysts with Pd∶Au∶Ir molar ratios of 90∶5∶5,70∶20∶10 and 50∶45∶5 were prepared by borohydride reduction method.These electrocatalysts were characterized by EDX,X-ray diffraction,transmission electron microscopy and the catalytic activity toward formic acid electro-oxidation in acid medium investigated by cyclic voltammetry(CV),chroamperometry(CA)and tests on direct formic acid fuel cell(DFAFC)at 100℃.X-ray diffractograms of PdAuIr/C-Sb2O5·SnO2electrocatalysts showed the presence of Pd fcc phase,Pd-Au fcc alloys,carbon and ATO phases,while Ir phases were not observed.TEM micrographs and histograms indicated that the nanoparticles were not well dispersed on the support and some agglomerates.The cyclic voltammetry and chroamperometry studies showed that PdAuIr/C-Sb2O5·SnO2(50∶45∶5)had superior performance toward formic acid electro-oxidation at 25℃compared to PdAuIr/C-Sb2O5·SnO2(70∶20∶10),PdAuIr/C-Sb2O5·SnO2(90∶5∶5)and Pd/C-Sb2O5·SnO2electrocatalysts.The experiments in a single DFAFC also showed that all PdAuIr/C-Sb2O5·SnO2electrocatalysts exhibited higher performance for formic acid oxidation in comparison with Pd/C-Sb2O5·SnO2electrocatalysts,however PdAuIr/C-Sb2O5·SnO2(90∶5∶5)had superior performance.These results indicated that the addition of Au and Ir to Pd favor the electro-oxidation of formic acid,which could be attributed to the bifunctional mechanism(the presence of ATO,Au and Ir oxides species)associated to the electronic effect(Pd-Au fcc alloys).
摘要The Ti/SnO2-Sb2O5/PbO2 electrode was prepared by electrodeposition method onto Ti substrate with SnO2-Sb2O5 interlayer. Microstructure information of SnO2-Sb2O5 interlayer and PbO2 coating was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). Our study shows that the titanium substrate is completely covered by the SnO2-Sb2O5 solid solution interlayer and the interlayer combines the Ti substrate closely with the PbO2 coating. The electrochemical performance of the Ti/SnO2-Sb2O5/PbO2 electrode was studied by cyclic voltammogram (CV), electrochemical impedance spectros-copy (EIS) and accelerated life test. The results show the electrochemical activity, electrical conductivity and stabil- ity of Ti-substrate lead dioxide electrode are increased. The deactivation process of the Ti/SnOe-Sb2O5/PbO2 elec- trode was also studied by the EIS. The SnO2-Sb2O5 interlayer can effectively prevent the growth of a TiO2 insulating layer between the substrate and the PbO2 coating during the lifetime tests, thus maintain high activity of Ti/SnO2-Sb2O5/PbO2 electrode for 10 times longer than Ti/PbO2 electrode without interlayer.
摘要构建准确可靠的热力学数据库对提钒过程优化以及钒酸盐材料的制备具有重要的应用价值和指导意义。采用封闭铂金坩埚,结合X射线衍射(XRD)与差热分析(DTA)技术,证实了K2O-V2O5体系中K3V5O14为稳定存在的化合物,并试验测定了K2V8O21和KVO3的熔化温度分别为532.4℃和516.5℃。随后采用修正的准化学模型(MQM),引入溶液中第二相邻阳离子短程有序对描述吉布斯自由能的变化。基于CALPHAD框架(CALculation of PHAse Diagram,相图计算),构建了Na2O-K2O-V2O5体系的热力学模型,重现了Na2O-K2O-V2O5体系全组分范围的实验数据和热力学性质,获得了该体系中所有物相一系列自洽的热力学模型参数,最终构建了可靠的热力学数据库。进一步探讨了当前数据库在钒渣钠化焙烧提钒中的应用,明确了含钒物相的迁移规律,确定了最佳的操作温度窗口。
基金supported by the Leading Edge Technology of Jiangsu Province(BK20222009-X.Z.,BK20202008-X.Z.)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)National Undergraduate Innovation Training Program of NUAA(202410287179Y).
摘要Zn-based thermal charging devices,utilizing the synergistic effect of ion thermoextraction and thermodiffusion,are able to efficiently convert thermal energy into electrical energy and storage in the devices,making them a highly promising technology for low-grade heat recovery and utilization.However,the low output power density and energy conversion efficiency resulted by the slow diffusion kinetics of Zn2+hinder their development.Herein,we present a highperformance thermal charging cell design using Zn2+/NH4+hybrid ion electrolyte,which not only maintains the high output voltage of the Zn-based thermoelectric system,but also significantly enhances the output power density due to the fast diffusion kinetics of NH4+.Based on this strategy,the thermal charging cell displays a high thermopower of 12.5 mV K-1and an excellent normalized power density of 19.6 mW m-2K-2at a temperature difference of 35 K.The Carnot-relative efficiency is as high as 12.74%.Moreover,it can operate continuously for over 72 h when the temperature difference persists,achieving a balance between thermoelectric conversion and output.This work provides a simple and effective strategy for the design of high-performance thermal charging cells for low-grade heat conversion and utilization.