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
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
以石墨烯、Ni SO4、K2S2O8(饱和)、氨水、蒸馏水为反应物,经过常温回流制备得到Ni OOH/Ni(OH)2含量不同的石墨烯/Ni OOH/Ni(OH)2复合材料。扫描电子显微镜法(SEM)表征显示,Ni(OH)2/Ni OOH在石墨烯表面上形成多孔结构,负载了多孔Ni OOH/N...以石墨烯、Ni SO4、K2S2O8(饱和)、氨水、蒸馏水为反应物,经过常温回流制备得到Ni OOH/Ni(OH)2含量不同的石墨烯/Ni OOH/Ni(OH)2复合材料。扫描电子显微镜法(SEM)表征显示,Ni(OH)2/Ni OOH在石墨烯表面上形成多孔结构,负载了多孔Ni OOH/Ni(OH)2的石墨烯又进行了层层堆积。电化学性能测试显示,电极材料GP/Ni-5性能最佳,其在电流密度为100 m A/g时,首次可逆比容量为1 287.4 m Ah/g,80次循环后比容量保持在830 m Ah/g,而纯Ni OOH/Ni(OH)2首次可逆比容量为2 400.6 m Ah/g,80次循环后比容量已降至405.9 m Ah/g,表明石墨烯的加入大大提高了材料的稳定性。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
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
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
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。
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.
文摘以石墨烯、Ni SO4、K2S2O8(饱和)、氨水、蒸馏水为反应物,经过常温回流制备得到Ni OOH/Ni(OH)2含量不同的石墨烯/Ni OOH/Ni(OH)2复合材料。扫描电子显微镜法(SEM)表征显示,Ni(OH)2/Ni OOH在石墨烯表面上形成多孔结构,负载了多孔Ni OOH/Ni(OH)2的石墨烯又进行了层层堆积。电化学性能测试显示,电极材料GP/Ni-5性能最佳,其在电流密度为100 m A/g时,首次可逆比容量为1 287.4 m Ah/g,80次循环后比容量保持在830 m Ah/g,而纯Ni OOH/Ni(OH)2首次可逆比容量为2 400.6 m Ah/g,80次循环后比容量已降至405.9 m Ah/g,表明石墨烯的加入大大提高了材料的稳定性。
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.
