通过两步液相法合成了生长在泡沫镍上的具有多孔结构的纳米Ni3S2,分别用XRD,SEM对材料进行了物相和微观形貌表征,并利用电化学工作站测试了其电化学性能.实验结果表明,利用(NH4)2S2O8氧化泡沫镍时反应温度应在70℃以上,反应时间在3 h以...通过两步液相法合成了生长在泡沫镍上的具有多孔结构的纳米Ni3S2,分别用XRD,SEM对材料进行了物相和微观形貌表征,并利用电化学工作站测试了其电化学性能.实验结果表明,利用(NH4)2S2O8氧化泡沫镍时反应温度应在70℃以上,反应时间在3 h以上,合成的电极材料表面呈多孔薄层的三维结构,孔径大小分布广,并且薄层之间没有互相重叠的现象.循环伏安曲线及恒流充放电曲线显示,Ni3S2电极材料具有良好的可逆性,明显的电池电容特点.当电流密度增大10倍时,比电容只下降了35.5%,具有良好的倍率性能.由交流阻抗谱图可知,高频区电阻率为0.91Ω,低频区直线斜率大,表明材料具有良好的导电性.当电极材料充放电次数从0增加到1 000次时,比电容由1 015.4 F g^-1增加到1 222.7 F g^-1,增加了20.4%,表明制备的Ni3S2具有良好的循环稳定性.展开更多
采用一步固相煅烧工艺制备了碳纳米管原位封装Ni3S2纳米颗粒(Ni3S2@CNT),并研究了其作为钠离子电池(SIBs)负极材料的电化学性能.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、循环伏安测试、恒流充放电以及交流阻抗...采用一步固相煅烧工艺制备了碳纳米管原位封装Ni3S2纳米颗粒(Ni3S2@CNT),并研究了其作为钠离子电池(SIBs)负极材料的电化学性能.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、循环伏安测试、恒流充放电以及交流阻抗等研究了Ni3S2@CNT的物相结构、形貌特征以及电化学性能.电化学测试表明,材料在100 mA·g^(-1)电流密度下,放电容量可以达到541.6 m Ah·g^(-1),甚至在2000 mA·g^(-1)的大电流密度下其放电比容量也可以维持在274.5 m Ah·g^(-1).另外,材料在100 mA·g^(-1)电流密度下,经过120周充放电循环后其放电和充电比容量仍然可以保持在374.5 m Ah·g^(-1)和359.3 m Ah·g^(-1),说明其具有良好倍率性能和循环稳定性能.良好的电化学性能归因于这种独特的碳纳米管原位封装Ni3S2纳米颗粒结构.碳纳米管不但可以提高复合材料的导电性,也可以缓冲Ni3S2纳米颗粒在反复充放电过程中产生的体积膨胀效应,明显改善了Ni3S2@CNT负极复合材料的电化学性能.展开更多
A binder-free Ni3S2 electrode was prepared directly on a graphene-coated Ni foam (G/Ni) substrate through surface sulfiding of substrate using thiourea as the sulfur source in this work. The Ni3S2 showed a flower-li...A binder-free Ni3S2 electrode was prepared directly on a graphene-coated Ni foam (G/Ni) substrate through surface sulfiding of substrate using thiourea as the sulfur source in this work. The Ni3S2 showed a flower-like morphology and was uniformly distributed on the G/Ni surface. The flower-like Ni3S2 was composed of cross-arrayed nanoflakes with a diameter and a thickness of 1-2 μm and -50 nm, re- spectively. The free space in the flowers and the thin feature of Ni3S2 buffered the volume changes and relieved mechanical strain during re- peated cycling. The intimate contact with the Ni substrate and the fixing effect of graphene maintained the structural stability of the Ni3S2 electrode during cycling. The G/Ni-supported Ni3S2 maintained a reversible capacity of 250 mAh·g^-1 after 100 cycles at 50 mA·g^-1, demon- strating the good cycling stability as a result of the unique microstructure of this electrode material.展开更多
Transition metal compounds are attractive for their significant applications in supercapacitors and as non-noble metal catalysts for electrochemical water splitting.Herein,we develop Ni3 S2 nanorods growing directly o...Transition metal compounds are attractive for their significant applications in supercapacitors and as non-noble metal catalysts for electrochemical water splitting.Herein,we develop Ni3 S2 nanorods growing directly on Ni foam,which act as multifunctional additive-free Ni3 S2@Ni electrode for supercapacitor and overall water splitting.Based on PVA-KOH gel electrolyte,the assembled all-solid-state Ni3 S2@Ni//AC asymmetric supercapacitor delivers a high areal energy density of 0.52 mWh cm^-2 at an areal power density of 9.02 MW cm^-2,and exhibits an excellent cycling stability with a capacitance retention ratio of 89%after 10000 GCD cycles at a current density of 30 mA cm^-2.For hydrogen evolution reaction and oxygen evolution reaction in 1 M KOH,Ni3 S2@Ni electrode achieves a benchmark of 10 mA cm^-2at overpotentials of 82 mV and 310 mV,respectively.Furthermore,the assembled Ni3 S2@Ni‖Ni3 S2@Ni electrolyzer for overall water splitting attains a current density of 10 mA cm^-2 at 1.61 V.The in-situ synthesis of Ni3 S2@Ni electrode enriches the applications of additive-free transition metal compounds in high-performance energy storage devices and efficient electrocatalysis.展开更多
In the original publication,Figure S4 is an ancillary image to compare the specific surface areas of TiO2/Ni3S2 and Ni3S2 samples and it was incorrectly published.To better serve our readers,the correct figure is prov...In the original publication,Figure S4 is an ancillary image to compare the specific surface areas of TiO2/Ni3S2 and Ni3S2 samples and it was incorrectly published.To better serve our readers,the correct figure is provided in this correction.The BET values are correct and unaffected.The corresponding figure caption,data analysis and conclusions are not affected and thus not to be changed.The authors would like to apologize for any inconvenience caused.展开更多
Nano Research volume 13,pages2130–2135(2020)Cite this article 376 Accesses 2 Citations Metrics details Abstract Developing efficient and stable oxygen evolution reaction(OER)electrocatalysts via doping strategy has w...Nano Research volume 13,pages2130–2135(2020)Cite this article 376 Accesses 2 Citations Metrics details Abstract Developing efficient and stable oxygen evolution reaction(OER)electrocatalysts via doping strategy has well-documented for electrochemical water splitting.Herein,a homogeneous structure(denoted as Co/Ce-Ni3S2/NF)composed of Co and Ce dual doped Ni3S2 nanosheets on nickel foam was synthesized by a facile one-step hydrothermal method.Co and Ce dopants are distributed inside the host sulfide,thereby raising the active sites and the electrical conductivity.Besides,the CeOx nanoparticles generated by part of the Ce dopants as a cocatalyst further improve the catalytic activity by adding defective sites and enhancing the electron transfer.As a consequence,the obtained Co/Ce-Ni3S2/NF electrode exhibits better electrocatalytic activity than single Co or Ce doped Ni3S2 and pure Ni3S2,with low overpotential(286 mV)at 20 mA-cm^−2,a small Tafel slope and excellent long-term durability in strong alkaline solution.These results presented here not only offer a novel platform for designing transition metal and lanthanide dual-doped catalysts,but also supply some guidelines for constructing catalysts in other catalytic applications.展开更多
A highly active and stable oxygen evolution reaction (OER) electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni3Sa@graphene@Co9S8 (Ni3S2@G@Co9S8), a sandwich- stru...A highly active and stable oxygen evolution reaction (OER) electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni3Sa@graphene@Co9S8 (Ni3S2@G@Co9S8), a sandwich- structured OER electro-catalyst, was grown in situ on nickel foam; it afforded an enhanced catalytic performance when highly conductive graphene is introduced as an intermediary for enhancing the electron transfer rate and stability. Serving as a free-standing electrocatalytic electrode, Ni3S2@G@Co9S8 presents excellent electrocatalytic activities for OER: A low onset overpotential (2 mA·cm^-2 at 174 mV), large anode current density (10 mA·cm^-2 at an overpotential of 210 mV), low Tafel slope (66 mV·dec^-1), and predominant durability of over 96 h (releasing a current density of N 14 mA·cm^-2 with a low and constant overpotential of 215 mV) in a 1 M KOH solution. This work provides a promising, cost-efficient electrocatalyst and sheds new light on improving the electrochemical performance of composites through enhancing the electron transfer rate and stability by introducing graphene as an intermediary.展开更多
In this paper,Co9S8/Ni3S2 nanoflakes(NFs)with sulfur deficiencies were grown in-situ on N-doped graphene nanotubes(NGNTs).They were successfully prepared through electrodeposition followed by hydrogenation treatment,w...In this paper,Co9S8/Ni3S2 nanoflakes(NFs)with sulfur deficiencies were grown in-situ on N-doped graphene nanotubes(NGNTs).They were successfully prepared through electrodeposition followed by hydrogenation treatment,which is able to act as a self-supported electrode for asymmetric supercapacitors(ASCs).Combining the defect-rich active materials with highly conductive skeletons,the hybrid electrode N-GNTs@sd-Co9S8/Ni3S2NFs show ultrahigh specific capacity of^304 mA hg^-1 and prominent rate capability(capacity retention ratio of^85%even at 100 Ag^-1),and deliver a long cycling lifespan of^1.9%capacitance loss after 10000 cycles.In addition,an ASC was constructed using the as-synthesized composite electrode as the positive electrode and active carbon(AC)as the negative electrode.The fabricated device shows a high energy density of^45.1 Wh kg^-1 at^3.4 kW kg^-1 and superior cycling stability.This work substantiates a smart strategy to fabricate novel composite electrode materials for next-generation supercapacitors by incorporating riched deficiencies into nanostructures.展开更多
Recently,because of excellent electrical conductivities and many active sites,transition metal sulfides have been utilized as efficient electrodes for supercapacitors.Herein,we synthesize hierarchical MoS2/Ni3S2 struc...Recently,because of excellent electrical conductivities and many active sites,transition metal sulfides have been utilized as efficient electrodes for supercapacitors.Herein,we synthesize hierarchical MoS2/Ni3S2 structures grown on nickel foam by a facile one-pot hydrothermal process.The as-fabricated asymmetric hybrid capacitor based on hierarchical MoS2/Ni3S2 electrode exhibit a specific capacitance of^1.033 C/cm2 at1 mA/cm2.Furthermore,the hybrid capacitor unveils an energy density of 35.93 m W h/cm3 at a power density of 1064.76 mW/cm3.The observed results clearly revealed that the synthesized MoS2/Ni3S2 structure might be used as potential electrode material for future energy storage devices.展开更多
Exploring cost-effective and highly-active oxygen evolution reaction(OER)electrocatalysts is a pressing task to propel water electrolysis for green hydrogen production.Herein,we constructed a class of Fe-doped and Sen...Exploring cost-effective and highly-active oxygen evolution reaction(OER)electrocatalysts is a pressing task to propel water electrolysis for green hydrogen production.Herein,we constructed a class of Fe-doped and Senriched Ni_(3)S_(2)nanowires electrocatalysts for optimizing the target intermediates adsorption to decrease the OER overpotentials at various current densities.The optimal Ni_(3)S_(2)-1.4%Fe electrocatalyst possesses the most active sites and exhibits an ultralow overpotential of 190 mV at 10 mA cm^(-2) with an excellent stability of>60 h,exceeding the majority of recently-reported Ni_(3)S_(2)-based electrocatalysts.The trivalence Fe-doping not only reduces the electron density of the Ni center,but also enables the sulfur enrichment on the Ni_(3)S_(2) surface,which greatly improves the intrinsic activity and the number of target intermediates(*OOH).A novel methanol-assisted electrochemical evaluation further reveals that the Ni_(3)S_(2)-1.4%Fe electrocatalyst demonstrates a weaker binding ability to*OH with the rapid generation of*OOH species,and thus gives a lower apparent activation energy compared with the surface sulfur reduced ones.This work provides a new perspective for regulating the adsorption of intermediates through doping strategy.展开更多
文摘通过两步液相法合成了生长在泡沫镍上的具有多孔结构的纳米Ni3S2,分别用XRD,SEM对材料进行了物相和微观形貌表征,并利用电化学工作站测试了其电化学性能.实验结果表明,利用(NH4)2S2O8氧化泡沫镍时反应温度应在70℃以上,反应时间在3 h以上,合成的电极材料表面呈多孔薄层的三维结构,孔径大小分布广,并且薄层之间没有互相重叠的现象.循环伏安曲线及恒流充放电曲线显示,Ni3S2电极材料具有良好的可逆性,明显的电池电容特点.当电流密度增大10倍时,比电容只下降了35.5%,具有良好的倍率性能.由交流阻抗谱图可知,高频区电阻率为0.91Ω,低频区直线斜率大,表明材料具有良好的导电性.当电极材料充放电次数从0增加到1 000次时,比电容由1 015.4 F g^-1增加到1 222.7 F g^-1,增加了20.4%,表明制备的Ni3S2具有良好的循环稳定性.
文摘采用一步固相煅烧工艺制备了碳纳米管原位封装Ni3S2纳米颗粒(Ni3S2@CNT),并研究了其作为钠离子电池(SIBs)负极材料的电化学性能.通过X射线衍射(XRD)、扫描电子显微镜(SEM)、透射电子显微镜(TEM)、循环伏安测试、恒流充放电以及交流阻抗等研究了Ni3S2@CNT的物相结构、形貌特征以及电化学性能.电化学测试表明,材料在100 mA·g^(-1)电流密度下,放电容量可以达到541.6 m Ah·g^(-1),甚至在2000 mA·g^(-1)的大电流密度下其放电比容量也可以维持在274.5 m Ah·g^(-1).另外,材料在100 mA·g^(-1)电流密度下,经过120周充放电循环后其放电和充电比容量仍然可以保持在374.5 m Ah·g^(-1)和359.3 m Ah·g^(-1),说明其具有良好倍率性能和循环稳定性能.良好的电化学性能归因于这种独特的碳纳米管原位封装Ni3S2纳米颗粒结构.碳纳米管不但可以提高复合材料的导电性,也可以缓冲Ni3S2纳米颗粒在反复充放电过程中产生的体积膨胀效应,明显改善了Ni3S2@CNT负极复合材料的电化学性能.
基金financially supported by the Scientific and Technological Project of State Grid Corporation of China
文摘A binder-free Ni3S2 electrode was prepared directly on a graphene-coated Ni foam (G/Ni) substrate through surface sulfiding of substrate using thiourea as the sulfur source in this work. The Ni3S2 showed a flower-like morphology and was uniformly distributed on the G/Ni surface. The flower-like Ni3S2 was composed of cross-arrayed nanoflakes with a diameter and a thickness of 1-2 μm and -50 nm, re- spectively. The free space in the flowers and the thin feature of Ni3S2 buffered the volume changes and relieved mechanical strain during re- peated cycling. The intimate contact with the Ni substrate and the fixing effect of graphene maintained the structural stability of the Ni3S2 electrode during cycling. The G/Ni-supported Ni3S2 maintained a reversible capacity of 250 mAh·g^-1 after 100 cycles at 50 mA·g^-1, demon- strating the good cycling stability as a result of the unique microstructure of this electrode material.
基金supported by the National Natural Science Foundation of China[grant no.51701022]。
文摘Transition metal compounds are attractive for their significant applications in supercapacitors and as non-noble metal catalysts for electrochemical water splitting.Herein,we develop Ni3 S2 nanorods growing directly on Ni foam,which act as multifunctional additive-free Ni3 S2@Ni electrode for supercapacitor and overall water splitting.Based on PVA-KOH gel electrolyte,the assembled all-solid-state Ni3 S2@Ni//AC asymmetric supercapacitor delivers a high areal energy density of 0.52 mWh cm^-2 at an areal power density of 9.02 MW cm^-2,and exhibits an excellent cycling stability with a capacitance retention ratio of 89%after 10000 GCD cycles at a current density of 30 mA cm^-2.For hydrogen evolution reaction and oxygen evolution reaction in 1 M KOH,Ni3 S2@Ni electrode achieves a benchmark of 10 mA cm^-2at overpotentials of 82 mV and 310 mV,respectively.Furthermore,the assembled Ni3 S2@Ni‖Ni3 S2@Ni electrolyzer for overall water splitting attains a current density of 10 mA cm^-2 at 1.61 V.The in-situ synthesis of Ni3 S2@Ni electrode enriches the applications of additive-free transition metal compounds in high-performance energy storage devices and efficient electrocatalysis.
文摘In the original publication,Figure S4 is an ancillary image to compare the specific surface areas of TiO2/Ni3S2 and Ni3S2 samples and it was incorrectly published.To better serve our readers,the correct figure is provided in this correction.The BET values are correct and unaffected.The corresponding figure caption,data analysis and conclusions are not affected and thus not to be changed.The authors would like to apologize for any inconvenience caused.
基金We acknowledge the financial support from the National Natural Science Foundation of China(Nos.21871121 and 21431002)Fundamental Research Funds for the Central Universities(No.Lzujbky-2018-ot01).
文摘Nano Research volume 13,pages2130–2135(2020)Cite this article 376 Accesses 2 Citations Metrics details Abstract Developing efficient and stable oxygen evolution reaction(OER)electrocatalysts via doping strategy has well-documented for electrochemical water splitting.Herein,a homogeneous structure(denoted as Co/Ce-Ni3S2/NF)composed of Co and Ce dual doped Ni3S2 nanosheets on nickel foam was synthesized by a facile one-step hydrothermal method.Co and Ce dopants are distributed inside the host sulfide,thereby raising the active sites and the electrical conductivity.Besides,the CeOx nanoparticles generated by part of the Ce dopants as a cocatalyst further improve the catalytic activity by adding defective sites and enhancing the electron transfer.As a consequence,the obtained Co/Ce-Ni3S2/NF electrode exhibits better electrocatalytic activity than single Co or Ce doped Ni3S2 and pure Ni3S2,with low overpotential(286 mV)at 20 mA-cm^−2,a small Tafel slope and excellent long-term durability in strong alkaline solution.These results presented here not only offer a novel platform for designing transition metal and lanthanide dual-doped catalysts,but also supply some guidelines for constructing catalysts in other catalytic applications.
基金The work was supported by the National Natural Science Foundation of China (NSFC) (Nos. 61525402 and 5161101159), Key University Science Research Project of Jiangsu Province (No. 15KJA430006), QingLan Project, National Postdoctoral Program for Innovative Talents (No. BX201600072), China Postdoctoral Science Foundation (No. 2016M601792).
文摘A highly active and stable oxygen evolution reaction (OER) electrocatalyst is critical for hydrogen production from water splitting. Herein, three-dimensional Ni3Sa@graphene@Co9S8 (Ni3S2@G@Co9S8), a sandwich- structured OER electro-catalyst, was grown in situ on nickel foam; it afforded an enhanced catalytic performance when highly conductive graphene is introduced as an intermediary for enhancing the electron transfer rate and stability. Serving as a free-standing electrocatalytic electrode, Ni3S2@G@Co9S8 presents excellent electrocatalytic activities for OER: A low onset overpotential (2 mA·cm^-2 at 174 mV), large anode current density (10 mA·cm^-2 at an overpotential of 210 mV), low Tafel slope (66 mV·dec^-1), and predominant durability of over 96 h (releasing a current density of N 14 mA·cm^-2 with a low and constant overpotential of 215 mV) in a 1 M KOH solution. This work provides a promising, cost-efficient electrocatalyst and sheds new light on improving the electrochemical performance of composites through enhancing the electron transfer rate and stability by introducing graphene as an intermediary.
基金supported by the National Natural Science Foundation of China(Grant Nos.51672144,51572137,51702181)the Key Research and Development Program of Shandong Province(Grant No.2019GGX102055)+3 种基金the Natural Science Foundation of Shandong Province(Grant Nos.ZR2017BB013,ZR2019BEM042)the Higher Educational Science and Technology Program of Shandong Province(Grant Nos.J17KA014,J18KA001,J18KA033)the Taishan Scholars Program of Shandong Province(Grant No.201511034)the Overseas Taishan Scholars Program。
文摘In this paper,Co9S8/Ni3S2 nanoflakes(NFs)with sulfur deficiencies were grown in-situ on N-doped graphene nanotubes(NGNTs).They were successfully prepared through electrodeposition followed by hydrogenation treatment,which is able to act as a self-supported electrode for asymmetric supercapacitors(ASCs).Combining the defect-rich active materials with highly conductive skeletons,the hybrid electrode N-GNTs@sd-Co9S8/Ni3S2NFs show ultrahigh specific capacity of^304 mA hg^-1 and prominent rate capability(capacity retention ratio of^85%even at 100 Ag^-1),and deliver a long cycling lifespan of^1.9%capacitance loss after 10000 cycles.In addition,an ASC was constructed using the as-synthesized composite electrode as the positive electrode and active carbon(AC)as the negative electrode.The fabricated device shows a high energy density of^45.1 Wh kg^-1 at^3.4 kW kg^-1 and superior cycling stability.This work substantiates a smart strategy to fabricate novel composite electrode materials for next-generation supercapacitors by incorporating riched deficiencies into nanostructures.
基金supported by State Key Laboratory of New Ceramic and Fine Processing Tsinghua University(No.KF201807)
文摘Recently,because of excellent electrical conductivities and many active sites,transition metal sulfides have been utilized as efficient electrodes for supercapacitors.Herein,we synthesize hierarchical MoS2/Ni3S2 structures grown on nickel foam by a facile one-pot hydrothermal process.The as-fabricated asymmetric hybrid capacitor based on hierarchical MoS2/Ni3S2 electrode exhibit a specific capacitance of^1.033 C/cm2 at1 mA/cm2.Furthermore,the hybrid capacitor unveils an energy density of 35.93 m W h/cm3 at a power density of 1064.76 mW/cm3.The observed results clearly revealed that the synthesized MoS2/Ni3S2 structure might be used as potential electrode material for future energy storage devices.
基金supported by the National Natural Science Foundation of China(21838003)the Innovation Program of Shanghai Municipal Education Commission,and the Fundamental Research Funds for the Central Universities(222201718002).
文摘Exploring cost-effective and highly-active oxygen evolution reaction(OER)electrocatalysts is a pressing task to propel water electrolysis for green hydrogen production.Herein,we constructed a class of Fe-doped and Senriched Ni_(3)S_(2)nanowires electrocatalysts for optimizing the target intermediates adsorption to decrease the OER overpotentials at various current densities.The optimal Ni_(3)S_(2)-1.4%Fe electrocatalyst possesses the most active sites and exhibits an ultralow overpotential of 190 mV at 10 mA cm^(-2) with an excellent stability of>60 h,exceeding the majority of recently-reported Ni_(3)S_(2)-based electrocatalysts.The trivalence Fe-doping not only reduces the electron density of the Ni center,but also enables the sulfur enrichment on the Ni_(3)S_(2) surface,which greatly improves the intrinsic activity and the number of target intermediates(*OOH).A novel methanol-assisted electrochemical evaluation further reveals that the Ni_(3)S_(2)-1.4%Fe electrocatalyst demonstrates a weaker binding ability to*OH with the rapid generation of*OOH species,and thus gives a lower apparent activation energy compared with the surface sulfur reduced ones.This work provides a new perspective for regulating the adsorption of intermediates through doping strategy.