Two-dimensional (2D)Ni(OH)_(2) nanosheets can theoretically expose their active sites of 100%.Whereas,their intrinsic easy accumulation and low conductivity lead to weak and unsustainable reaction kinetics.Herein,we p...Two-dimensional (2D)Ni(OH)_(2) nanosheets can theoretically expose their active sites of 100%.Whereas,their intrinsic easy accumulation and low conductivity lead to weak and unsustainable reaction kinetics.Herein,we propose a novel halogen chlorine-triggered electrochemical etching strategy to controllably manage the reaction kinetics of 2D Ni(OH)_(2) nanosheets(EE/Cl-Ni(OH)_(2)).It is found that halogen chlorine doping can adjust the interlamellar spacing flexibly and promote the lattice oxygen activation to achieve controlled construction of superficial oxygen defects at the adjustable voltage.The optimal EE/Cl-Ni(OH)_(2) electrode exhibits a high rate capability and excellent specific capacity of 206.9 mA h g^(-1) at 1 A g^(-1) in a three-electrode system,which is more than twice as high as the pristine Ni(OH)_(2).Furthermore,EE/Cl-Ni(OH)_(2) cathode and FeOOH@rGO anode are employed for developing an aqueous Ni-Fe battery with an excellent energy density of 83 W h kg^(-1),a high power density of 17051 W kg^(-1),and robust durability over 20,000 cycles.This strategy exploits a fresh channel for the ingenious fabrication of highefficiency and stable nickel-based deficiency materials for energy storage.展开更多
Constructing heterojunction is a promising way to improve the charge transfer efficiency and can thus promote the electrochemical properties.Herein,a facile and effective epitaxial-like growth strategy is applied to N...Constructing heterojunction is a promising way to improve the charge transfer efficiency and can thus promote the electrochemical properties.Herein,a facile and effective epitaxial-like growth strategy is applied to NiSe2 nano-octahe-dra to fabricate the NiSe2-(100)/Ni(OH)2-(110)heterojunction.The heterojunction composite and Ni(OH)2(performing high electrochemical activity)is ideal high-rate battery-type supercapacitor electrode.The NiSe2/Ni(OH)2 electrode exhibits a high specific capacity of 909 C g^-1 at 1 A g^-1 and 597 C g^-1 at 20 A g^-1.The assembled asymmetric supercapacitor composed of the NiSe2/Ni(OH)2 cathode and p-phenylenediamine-functional reduced graphene oxide anode achieves an ultrahigh specific capacity of 303 C g^-1 at 1 A g^-1 and a superior energy density of 76.1 Wh kg^-1 at 906 W kg^-1,as well as an outstanding cycling stability of 82%retention for 8000 cycles at 10 A g^-1.To the best of our knowledge,this is the first example of NiSe2/Ni(OH)2 heterojunction exhibiting such remarkable supercapacitor performance.This work not only provides a promising candidate for next-generation energy storage device but also offers a possible universal strategy to fabricate metal selenides/metal hydroxides heterojunctions.展开更多
The rational modulation of electronic structure is highly desirable to develop an efficient alkaline hydrogen evolution reaction(HER)catalyst for renewable energy applications.Metal hydroxide such as Ni(OH)_(2) has be...The rational modulation of electronic structure is highly desirable to develop an efficient alkaline hydrogen evolution reaction(HER)catalyst for renewable energy applications.Metal hydroxide such as Ni(OH)_(2) has been proven useful for promoting alkaline HER,but the performance remains unsatisfactory.Herein,the electronic structure of Ni(OH)_(2) is modulated by the interfacial electron rearrangement between Ni-Ni(OH)_(2) heterojunction.Combined experiments with DFT simulations,the electrons of Ni species accumulate to the interfacial Ni-Ni(OH)_(2) sites,which modifies the d band center for promoting conversion of hydrogen intermediates and narrows the energy gap for boosting charge transfer in the HER process.Thus,the integrated electrode exhibits an efficient HER performance to drive10 mA cm^(-2) at the overpotential of 72 mV with a low Tafel slope of 43 mV dec^(-1).Our work renders a valuable insight for understanding and rationally designing efficient catalysts in alkaline HER.展开更多
Depositing a cocatalyst has proven to be an important strategy for improving the photoelectrochemical(PEC)water-splitting efficiency of photoanodes.In this study,Ni(OH)2 quantum dots(Ni(OH)2 QDs)were deposited in situ...Depositing a cocatalyst has proven to be an important strategy for improving the photoelectrochemical(PEC)water-splitting efficiency of photoanodes.In this study,Ni(OH)2 quantum dots(Ni(OH)2 QDs)were deposited in situ onto anα-Fe_(2)O_(3)photoanode via a chelation-mediated hydrolysis method.The photocurrent density of the Ni(OH)2 QDs/α-Fe_(2)O_(3)photoanode reached 1.93 mA·cm^(−2)at 1.23 V vs.RHE,which is 3.5 times that ofα-Fe_(2)O_(3),and an onset potential with a negative shift of ca.100 mV was achieved.More importantly,the Ni(OH)2 QDs exhibited excellent stability in maintaining PEC water oxidation at a high current density,which is attributed to the ultra-small crystalline size,allowing for the rapid acceptance of holes fromα-Fe_(2)O_(3)to Ni(OH)_(2)QDs,formation of active sites for water oxidation,and hole transfer from the active sites to water molecules.Further(photo)electrochemical analysis suggests that Ni(OH)_(2)QDs not only provide maximal active sites for water oxidation but also suppress charge recombination by passivating the surface states ofα-Fe_(2)O_(3),thereby significantly enhancing the water oxidation kinetics over theα-Fe_(2)O_(3)surface.展开更多
Spherical Ni（OH）2 particles were prepared by an aqueous solution precipitation route. The structure of spherical Ni（OH）2 was investigated by scanning electron microscopy and transmission electron microscopy and co...Spherical Ni（OH）2 particles were prepared by an aqueous solution precipitation route. The structure of spherical Ni（OH）2 was investigated by scanning electron microscopy and transmission electron microscopy and compared with that of traditional Ni（OH）2. The results show that the spherical nickel hydroxide consists of （Ni（OH）2） spheres with a reticulate structure of platelet-like, which is almost arranged radially and the crystalline grains intervene and connect with each other to form a three-dimensional net. The spherical Ni（OH）2 particle is full of pores, crannies between cleave planes. It is supposed that this structure is beneficial to the structural stability for the spherical particles during the charge/discharge processes and can improve the cycle life of the electrode; the pores and the crannies in spherical particles can shorten the proton diffusion distance and speed its velocity, which may result in that the local polarization is lowered. The electrochemical performances of the spherical Ni（OH）2 are improved by enhancing the conducting properties of the crystalline lattice due to its quick proton diffusion.展开更多
采用改进Stober法-化学沉淀法制备了Ni(OH)_(2)/氮掺杂空心碳球复合材料(Ni(OH)_(2)/NHCS)。通过X射线衍射(XRD)、透射电镜(TEM)和N 2吸附-脱附等手段对复合材料进行表征和分析,并采用电化学工作站对复合材料的电化学性能进行测试。研...采用改进Stober法-化学沉淀法制备了Ni(OH)_(2)/氮掺杂空心碳球复合材料(Ni(OH)_(2)/NHCS)。通过X射线衍射(XRD)、透射电镜(TEM)和N 2吸附-脱附等手段对复合材料进行表征和分析,并采用电化学工作站对复合材料的电化学性能进行测试。研究结果表明:相比于纯Ni(OH)_(2)而言,NHCS有效抑制了Ni(OH)_(2)的聚集,从而提高了活性材料的利用率。同时,复合材料的中空结构有利于电解质离子的渗入而缩短电解质离子的传输路径,且降低界面电阻,从而有效提高了复合材料Ni(OH)_(2)/NHCS的电化学性能。Ni(OH)_(2)/NHCS在2 M KOH电解质中,电流密度为0.5 A g^(-1)时可表现出1085 F g^(-1)的高比电容。展开更多
The template effect controlling the structure and morphology of ultrafine particles was described. Ni(OH) 2 powders were prepared by NH 3 coordination precipitation method. The effects of SO 2- 4, NO - 3, Cl -, NH 3, ...The template effect controlling the structure and morphology of ultrafine particles was described. Ni(OH) 2 powders were prepared by NH 3 coordination precipitation method. The effects of SO 2- 4, NO - 3, Cl -, NH 3, pH value on Ni(OH) 2 structure and morphology were investigated experimentally, explained with the theoretical model that the growth units were the polyhedral structure of coordination anions. The results showed that the structure and morphology of Ni(OH) 2 were effectively controlled by the growth units, the dimensions and the linking patterns of the growth units vary with the changes of physical and chemical conditions in the aqueous solution.展开更多
Developing non-noble metal-based electrocatalyst with high catalytic activity is essential for advancing hydrogen energy technologies.This study introduces a hydrothermal method for synthesizing order Ni(OH)_(2) nanos...Developing non-noble metal-based electrocatalyst with high catalytic activity is essential for advancing hydrogen energy technologies.This study introduces a hydrothermal method for synthesizing order Ni(OH)_(2) nanosheets,with H_(3)O_(40)PW_(12)(denoted as PW_(12))loaded onto reduced graphene oxide(rGO)coated on nickel foam(referred to as PW_(12)-Ni(OH)_(2)/rGO).This method contrasts with the electrodeposition of Ni(OH)_(2),where PW_(12) is added to the synthetic system to direct the assembly and morphology of the Ni(OH)_(2) through a hydrothermal reaction.In this work,the nickel foam acts dual roles as both the substrate and the source of nickel for the formation of Ni(OH)_(2).The PW_(12)-Ni(OH)_(2)/rGO nanosheets,when successfully prepared and loaded onto the nickel foam(NF),exhibited superior electrocatalytic activity for the hydrogen evolution reaction(HER)in an alkaline electrolyte,achieving a current density of 10 mA·cm^(-2) at an overpotential of 69 mV.Furthermore,we endeavored to expand the application of this material towards the oxygen evolution reaction(OER)by preparing PW_(12)-(Fe/Co)Ni(OH)_(2)/rGO through the addition of metal cations.This nanocomposite displayed outstanding electrocatalytic activity in alkaline electrolytes,with a current density of 10 mA·cm^(-2)at an overpotential of 211 mV,and demonstrated excellent stability over a 50 h period in a 1 M KOH solution.The results presented in this paper offer an effective strategy for the preparation of polyoxometalate-based inorganic materials with diverse functionalities,applicable to both HER and OER.展开更多
Although glucose electrochemical sensors based on enzymes play a dominant role in market,their stability remains a problem due to the inherent nature of enzymes.Therefore,glucose sensors that are independent on enzyme...Although glucose electrochemical sensors based on enzymes play a dominant role in market,their stability remains a problem due to the inherent nature of enzymes.Therefore,glucose sensors that are independent on enzymes have attracted more attention for the development of stable detection devices.Here we present an enzyme-free glucose sensor based on Ni(OH)_(2)and reduced graphene oxide(rGO).The as-fabricated sensor still exhibits excellent electrocatalytic activity for detecting glucose under enzyme independent conditions.The enhanced catalytic performance may due to synergistic effect as follows:(i)the interaction between the Ni2+andπelectron of graphene induces the formation of theβ-phase Ni(OH)_(2)with higher catalytic activity;(ii)the frozen dry process works as a secondary filtration,getting rid of poorly formed Ni(OH)_(2)particles with low catalytic activity;(iii)the rGO network with good conductivity provides a good electronic pathway for promoting electron transfer to reduce the response time.Based on the synergistic effect,the sensor exhibits a wide linear detection range from 0.2µmol/L to 1.0µmol/L and a low detection limit(0.1µmol/L,S/N=3).The excellent detection performance,as well as the easy and low-cost preparation method,suggests the promising applicability of the sensor in the glucose detection market.展开更多
通过电化学剥离协同制备了3D Ni(OH)_(2)/石墨烯复合电极薄膜材料,高品质石墨烯均匀地生长在三维Ni(OH)_(2)表面,电化学性能测试表明,在2 m A/cm^(2)电流密度条件下,该电极薄膜具有优异的比电容(266 m F/cm^(2)),经过1万次的连续充放电...通过电化学剥离协同制备了3D Ni(OH)_(2)/石墨烯复合电极薄膜材料,高品质石墨烯均匀地生长在三维Ni(OH)_(2)表面,电化学性能测试表明,在2 m A/cm^(2)电流密度条件下,该电极薄膜具有优异的比电容(266 m F/cm^(2)),经过1万次的连续充放电循环测试仍然保留94.1%的容量性能。该方法为大规模生产新型高性能电极薄膜材料提供了一个简单的制备策略。展开更多
基金supported by the Opening Project of State Key Laboratory of Advanced Chemical Power Sourcesthe Guizhou Provincial Science and Technology Projects(QKHJC-ZK[2021]YB057)+1 种基金the Growth Project of Young Scientific and Technological Talents in Colleges and Universities of Guizhou Province(QKHJCKYZ[2021]252)the Reward and Subsidy Fund Project of Guizhou Education University(Z20210108)。
文摘Two-dimensional (2D)Ni(OH)_(2) nanosheets can theoretically expose their active sites of 100%.Whereas,their intrinsic easy accumulation and low conductivity lead to weak and unsustainable reaction kinetics.Herein,we propose a novel halogen chlorine-triggered electrochemical etching strategy to controllably manage the reaction kinetics of 2D Ni(OH)_(2) nanosheets(EE/Cl-Ni(OH)_(2)).It is found that halogen chlorine doping can adjust the interlamellar spacing flexibly and promote the lattice oxygen activation to achieve controlled construction of superficial oxygen defects at the adjustable voltage.The optimal EE/Cl-Ni(OH)_(2) electrode exhibits a high rate capability and excellent specific capacity of 206.9 mA h g^(-1) at 1 A g^(-1) in a three-electrode system,which is more than twice as high as the pristine Ni(OH)_(2).Furthermore,EE/Cl-Ni(OH)_(2) cathode and FeOOH@rGO anode are employed for developing an aqueous Ni-Fe battery with an excellent energy density of 83 W h kg^(-1),a high power density of 17051 W kg^(-1),and robust durability over 20,000 cycles.This strategy exploits a fresh channel for the ingenious fabrication of highefficiency and stable nickel-based deficiency materials for energy storage.
基金the NSFC(Grant Nos.21875285 and 21805155)Taishan Scholars Program(ts201511019)+1 种基金Key Research and Development Projects of Shandong Province(2019JZZY010331)the Fundamental Research Funds for the Central Universities(19CX05001A).
文摘Constructing heterojunction is a promising way to improve the charge transfer efficiency and can thus promote the electrochemical properties.Herein,a facile and effective epitaxial-like growth strategy is applied to NiSe2 nano-octahe-dra to fabricate the NiSe2-(100)/Ni(OH)2-(110)heterojunction.The heterojunction composite and Ni(OH)2(performing high electrochemical activity)is ideal high-rate battery-type supercapacitor electrode.The NiSe2/Ni(OH)2 electrode exhibits a high specific capacity of 909 C g^-1 at 1 A g^-1 and 597 C g^-1 at 20 A g^-1.The assembled asymmetric supercapacitor composed of the NiSe2/Ni(OH)2 cathode and p-phenylenediamine-functional reduced graphene oxide anode achieves an ultrahigh specific capacity of 303 C g^-1 at 1 A g^-1 and a superior energy density of 76.1 Wh kg^-1 at 906 W kg^-1,as well as an outstanding cycling stability of 82%retention for 8000 cycles at 10 A g^-1.To the best of our knowledge,this is the first example of NiSe2/Ni(OH)2 heterojunction exhibiting such remarkable supercapacitor performance.This work not only provides a promising candidate for next-generation energy storage device but also offers a possible universal strategy to fabricate metal selenides/metal hydroxides heterojunctions.
基金supported by the National Natural Science Foundation of China(Grant Nos.U1864207 and 51902232)。
文摘The rational modulation of electronic structure is highly desirable to develop an efficient alkaline hydrogen evolution reaction(HER)catalyst for renewable energy applications.Metal hydroxide such as Ni(OH)_(2) has been proven useful for promoting alkaline HER,but the performance remains unsatisfactory.Herein,the electronic structure of Ni(OH)_(2) is modulated by the interfacial electron rearrangement between Ni-Ni(OH)_(2) heterojunction.Combined experiments with DFT simulations,the electrons of Ni species accumulate to the interfacial Ni-Ni(OH)_(2) sites,which modifies the d band center for promoting conversion of hydrogen intermediates and narrows the energy gap for boosting charge transfer in the HER process.Thus,the integrated electrode exhibits an efficient HER performance to drive10 mA cm^(-2) at the overpotential of 72 mV with a low Tafel slope of 43 mV dec^(-1).Our work renders a valuable insight for understanding and rationally designing efficient catalysts in alkaline HER.
基金National Natural Science Foundation of China(21571186,61704182)R&D Funds for basic Research Program of Shenzhen(JCYJ20150831154213681)+1 种基金“Guangdong TeZhi plan”Youth Talent of Science and Technology(2014TQ01C102)Scientific Research Foundation of Shandong University of Science and Technology for Recruited Talents(2014RCJJ002)。
文摘Depositing a cocatalyst has proven to be an important strategy for improving the photoelectrochemical(PEC)water-splitting efficiency of photoanodes.In this study,Ni(OH)2 quantum dots(Ni(OH)2 QDs)were deposited in situ onto anα-Fe_(2)O_(3)photoanode via a chelation-mediated hydrolysis method.The photocurrent density of the Ni(OH)2 QDs/α-Fe_(2)O_(3)photoanode reached 1.93 mA·cm^(−2)at 1.23 V vs.RHE,which is 3.5 times that ofα-Fe_(2)O_(3),and an onset potential with a negative shift of ca.100 mV was achieved.More importantly,the Ni(OH)2 QDs exhibited excellent stability in maintaining PEC water oxidation at a high current density,which is attributed to the ultra-small crystalline size,allowing for the rapid acceptance of holes fromα-Fe_(2)O_(3)to Ni(OH)_(2)QDs,formation of active sites for water oxidation,and hole transfer from the active sites to water molecules.Further(photo)electrochemical analysis suggests that Ni(OH)_(2)QDs not only provide maximal active sites for water oxidation but also suppress charge recombination by passivating the surface states ofα-Fe_(2)O_(3),thereby significantly enhancing the water oxidation kinetics over theα-Fe_(2)O_(3)surface.
基金Project(50134020) supported by the National Natural Science Foundation of China
文摘Spherical Ni（OH）2 particles were prepared by an aqueous solution precipitation route. The structure of spherical Ni（OH）2 was investigated by scanning electron microscopy and transmission electron microscopy and compared with that of traditional Ni（OH）2. The results show that the spherical nickel hydroxide consists of （Ni（OH）2） spheres with a reticulate structure of platelet-like, which is almost arranged radially and the crystalline grains intervene and connect with each other to form a three-dimensional net. The spherical Ni（OH）2 particle is full of pores, crannies between cleave planes. It is supposed that this structure is beneficial to the structural stability for the spherical particles during the charge/discharge processes and can improve the cycle life of the electrode; the pores and the crannies in spherical particles can shorten the proton diffusion distance and speed its velocity, which may result in that the local polarization is lowered. The electrochemical performances of the spherical Ni（OH）2 are improved by enhancing the conducting properties of the crystalline lattice due to its quick proton diffusion.
文摘采用改进Stober法-化学沉淀法制备了Ni(OH)_(2)/氮掺杂空心碳球复合材料(Ni(OH)_(2)/NHCS)。通过X射线衍射(XRD)、透射电镜(TEM)和N 2吸附-脱附等手段对复合材料进行表征和分析,并采用电化学工作站对复合材料的电化学性能进行测试。研究结果表明:相比于纯Ni(OH)_(2)而言,NHCS有效抑制了Ni(OH)_(2)的聚集,从而提高了活性材料的利用率。同时,复合材料的中空结构有利于电解质离子的渗入而缩短电解质离子的传输路径,且降低界面电阻,从而有效提高了复合材料Ni(OH)_(2)/NHCS的电化学性能。Ni(OH)_(2)/NHCS在2 M KOH电解质中,电流密度为0.5 A g^(-1)时可表现出1085 F g^(-1)的高比电容。
文摘The template effect controlling the structure and morphology of ultrafine particles was described. Ni(OH) 2 powders were prepared by NH 3 coordination precipitation method. The effects of SO 2- 4, NO - 3, Cl -, NH 3, pH value on Ni(OH) 2 structure and morphology were investigated experimentally, explained with the theoretical model that the growth units were the polyhedral structure of coordination anions. The results showed that the structure and morphology of Ni(OH) 2 were effectively controlled by the growth units, the dimensions and the linking patterns of the growth units vary with the changes of physical and chemical conditions in the aqueous solution.
基金supported by the National Natural Science Foundation of China(Nos.21831001,21801014,22171024,and 22202037)the Fundamental Research Funds for the Central Universities(No.2412023QD019)supported by the Analysis&Testing Center of Beijing Institute of Technology.
文摘Developing non-noble metal-based electrocatalyst with high catalytic activity is essential for advancing hydrogen energy technologies.This study introduces a hydrothermal method for synthesizing order Ni(OH)_(2) nanosheets,with H_(3)O_(40)PW_(12)(denoted as PW_(12))loaded onto reduced graphene oxide(rGO)coated on nickel foam(referred to as PW_(12)-Ni(OH)_(2)/rGO).This method contrasts with the electrodeposition of Ni(OH)_(2),where PW_(12) is added to the synthetic system to direct the assembly and morphology of the Ni(OH)_(2) through a hydrothermal reaction.In this work,the nickel foam acts dual roles as both the substrate and the source of nickel for the formation of Ni(OH)_(2).The PW_(12)-Ni(OH)_(2)/rGO nanosheets,when successfully prepared and loaded onto the nickel foam(NF),exhibited superior electrocatalytic activity for the hydrogen evolution reaction(HER)in an alkaline electrolyte,achieving a current density of 10 mA·cm^(-2) at an overpotential of 69 mV.Furthermore,we endeavored to expand the application of this material towards the oxygen evolution reaction(OER)by preparing PW_(12)-(Fe/Co)Ni(OH)_(2)/rGO through the addition of metal cations.This nanocomposite displayed outstanding electrocatalytic activity in alkaline electrolytes,with a current density of 10 mA·cm^(-2)at an overpotential of 211 mV,and demonstrated excellent stability over a 50 h period in a 1 M KOH solution.The results presented in this paper offer an effective strategy for the preparation of polyoxometalate-based inorganic materials with diverse functionalities,applicable to both HER and OER.
基金supported by the Beijing Natural Science Foundation,China(No.2232069)the National Natural Science Foundation of China(No.21875266).
文摘Although glucose electrochemical sensors based on enzymes play a dominant role in market,their stability remains a problem due to the inherent nature of enzymes.Therefore,glucose sensors that are independent on enzymes have attracted more attention for the development of stable detection devices.Here we present an enzyme-free glucose sensor based on Ni(OH)_(2)and reduced graphene oxide(rGO).The as-fabricated sensor still exhibits excellent electrocatalytic activity for detecting glucose under enzyme independent conditions.The enhanced catalytic performance may due to synergistic effect as follows:(i)the interaction between the Ni2+andπelectron of graphene induces the formation of theβ-phase Ni(OH)_(2)with higher catalytic activity;(ii)the frozen dry process works as a secondary filtration,getting rid of poorly formed Ni(OH)_(2)particles with low catalytic activity;(iii)the rGO network with good conductivity provides a good electronic pathway for promoting electron transfer to reduce the response time.Based on the synergistic effect,the sensor exhibits a wide linear detection range from 0.2µmol/L to 1.0µmol/L and a low detection limit(0.1µmol/L,S/N=3).The excellent detection performance,as well as the easy and low-cost preparation method,suggests the promising applicability of the sensor in the glucose detection market.
文摘通过电化学剥离协同制备了3D Ni(OH)_(2)/石墨烯复合电极薄膜材料,高品质石墨烯均匀地生长在三维Ni(OH)_(2)表面,电化学性能测试表明,在2 m A/cm^(2)电流密度条件下,该电极薄膜具有优异的比电容(266 m F/cm^(2)),经过1万次的连续充放电循环测试仍然保留94.1%的容量性能。该方法为大规模生产新型高性能电极薄膜材料提供了一个简单的制备策略。
