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
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 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
Design and development of high-efficiency and durable oxygen evolution reaction(OER)electrocatalysts is crucial for hydrogen production from seawater splitting.Herein,we report the in situ electrochemical conversion o...Design and development of high-efficiency and durable oxygen evolution reaction(OER)electrocatalysts is crucial for hydrogen production from seawater splitting.Herein,we report the in situ electrochemical conversion of a nanoarray of Ni(TCNQ)2(TCNQ=tetracyanoquinodimethane)on graphite paper into Ni(OH)_(2) nanoparticles confined in a conductive TCNQ nanoarray(Ni(OH)_(2)-TCNQ/GP)by anode oxidation.The Ni(OH)_(2)-TCNQ/GP exhibits high OER performance and demands overpotentials of 340 and 382 mV to deliver 100 mA·cm^(−2) in alkaline freshwater and alkaline seawater,respectively.Meanwhile,the Ni(OH)_(2)-TCNQ/GP also demonstrates steady long-term electrochemical durability for at least 80 h under alkaline seawater.展开更多
Graphene quantum dots(GQDs)/Ni(OH)_(2) composites on carbon cloth(G-NH//CC) are prepared through simple hydrothermal reactions. The resulting G-NH//CC is employed as a binder-free electrode of supercapacitors. Due to ...Graphene quantum dots(GQDs)/Ni(OH)_(2) composites on carbon cloth(G-NH//CC) are prepared through simple hydrothermal reactions. The resulting G-NH//CC is employed as a binder-free electrode of supercapacitors. Due to the enhanced electrical conductivity and efficient ion transport by the addition of GQDs, the G-NH//CC electrode exhibits enhanced electrochemical performances. Specifically, the GNH//CC delivers a maximum specific capacitance of 1825 F g^(-1) at a current density of 1 A g^(-1) as well as a good cycle stability of 83.5 % capacity retention after 8000 cycles. Additionally, all-solid-state symmetric supercapacitor(SSC) is assembled with G-NH//CC composites as both positive and negative electrodes.The fabricated SSC exhibits a high energy density of 80.8 Wh kg^(-1)at a power density of 2021 W kg^(-1). The present study provides a facile and efficient strategy to prepare high-performance electrode materials for advanced electrochemical energy storage devices.展开更多
Developing efficient and promising non-noble catalysts for oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) is vital but still a huge challenge for the clean energy system. Herein, we have integrate...Developing efficient and promising non-noble catalysts for oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) is vital but still a huge challenge for the clean energy system. Herein, we have integrated the active components for OER(Ni(OH)_(2)) and HER(Ni S_(2) and Ni(OH)_(2)) into Ni(OH)_(2)@NiS_(2) heterostructures by a facile reflux method. The in-situ formed Ni(OH)_(2) thin layer is coated on the surface of hollow Ni S2 nanosphere. The uniform Ni(OH)_(2)@NiS_(2) hollow sphere processes enlarge the electrochemically active specific surface area and enhance the intrinsic activity compared to NiS_(2) precursor, which affords a current density of 10 m A cm^(-2) at the overpotential of 309 m V and 100 m Acm^(-2) at 359 m V for OER. Meanwhile, Ni(OH)_(2)@NiS_(2) can reach 10 m A cm^(-2) at 233 m V for HER, superior to pure NiS_(2). The enhanced performance can be attributed to the synergy between Ni(OH)_(2) and NiS_(2). Specifically, Ni(OH)_(2) has three functions for water splitting: providing active sites for hydrogen adsorption and hydroxyl group desorption and working as real OER active sites. Moreover, Ni(OH)_(2)@NiS_(2) displays great stability for OER(50 h) and HER(30 h).展开更多
Regulable loading of Ni(OH)_(2) crystals by using three dimensionally ordered mesoporous carbon(3DOMC)as a support is achieved through a confined growth strategy accompanied by steam-assisted crystallization.Dual form...Regulable loading of Ni(OH)_(2) crystals by using three dimensionally ordered mesoporous carbon(3DOMC)as a support is achieved through a confined growth strategy accompanied by steam-assisted crystallization.Dual forms of high-crystalline nanosheet-like Ni(OH)_(2) severally distribute within mesopores or over the outer surface of 3DOMC particles depending on the loading amount(3%^(−1)5%)of Ni(OH)_(2).Benefitted from the highly hybrid combination and efficient electrolyte diffusion,the obtained Ni(OH)_(2)/carbon nanocomposites exhibit an excellent electrochemical performance,and the optimal sample of 6%_Ni(OH)_(2)/3DOMC with confined extrasmall Ni(OH)_(2) nanosheets as dominant shows the highest specific capacitance of 552.5F.g^(−1) at 1.0A⋅g^(−1),which is 330%higher than the contrast sample by using actived carbon as the support.Furthermore,the assembled hybrid supercapacitor by using 6%_Ni(OH)_(2)/3DOMC and 3DOMC as positive and negative electrodes displays an energy density of 11.7 Wh.kg^(−1) at 288.1 W.kg^(−1) and a superior charge/discharge stability.It is expected that the flexible component,well-defined structure,and superior electrochemical performance could promote a great application potential of Ni(OH)_(2)/3DOMC nanocomposites as supercapacitor electrodes and in other energy storage devices.展开更多
Dye-sensitized photocatalysis has been extensively studied for photocatalytic solar energy conversion due to the advantage in capturing long-wavelength photons with a high absorption coefficient.The rational integrati...Dye-sensitized photocatalysis has been extensively studied for photocatalytic solar energy conversion due to the advantage in capturing long-wavelength photons with a high absorption coefficient.The rational integration of photosensitizer with semiconductor and cocatalyst to collaboratively operate in one system is highly desired.Here,we fabricate a Ni(OH)_(2)-loaded titanate nanosheet(Ni(OH)_(2)/H_(2)Ti_(6)O_(13))composite for high-performance dye-sensitized photocatalytic CO_(2) reduction.The ultrathin H_(2)Ti_(6)O_(13) nanosheets with negative surface charge provide an excellent support to anchor the dye photosensitizer,while the loaded Ni(OH)2 serves as an adsorbent of CO_(2) and electron sink of photoelectrons.As such,the photoelectrons derived from the[Ru(bpy)3]Cl_(2) sensitizer can be targeted transfer to the Ni(OH)_(2) active sites via the H_(2) Ti_(6)O_(13) nanosheets linker.A high CO production rate of 1801μmol g^(-1) h^(-1) is obtained over the optimal Ni(OH)_(2)/H_(2)Ti_(6)O_(13),while the pure H_(2)Ti_(6)O_(13) shows significantly lower CO_(2) reduction performance.The work is anticipated to trigger more research attention on the rational design and synthesis of earth-abundant transition metal-based cocatalysts decorated on ultrathin 2D platforms for artificially photocatalytic CO_(2) reduction.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。
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supported by the National Natural Science Foundation of China(No.22072015)the Opening Fund of Key Laboratory of Chemical Biology and Traditional Chinese Medicine Research(Hunan Normal University)Ministry of Education(2020-02).
文摘Design and development of high-efficiency and durable oxygen evolution reaction(OER)electrocatalysts is crucial for hydrogen production from seawater splitting.Herein,we report the in situ electrochemical conversion of a nanoarray of Ni(TCNQ)2(TCNQ=tetracyanoquinodimethane)on graphite paper into Ni(OH)_(2) nanoparticles confined in a conductive TCNQ nanoarray(Ni(OH)_(2)-TCNQ/GP)by anode oxidation.The Ni(OH)_(2)-TCNQ/GP exhibits high OER performance and demands overpotentials of 340 and 382 mV to deliver 100 mA·cm^(−2) in alkaline freshwater and alkaline seawater,respectively.Meanwhile,the Ni(OH)_(2)-TCNQ/GP also demonstrates steady long-term electrochemical durability for at least 80 h under alkaline seawater.
基金supported by Basic Science Research Program through the National Research Foundation of Korea (NRF) funded by The Ministry of Education (NRF-2018R1D1A1B07047042)。
文摘Graphene quantum dots(GQDs)/Ni(OH)_(2) composites on carbon cloth(G-NH//CC) are prepared through simple hydrothermal reactions. The resulting G-NH//CC is employed as a binder-free electrode of supercapacitors. Due to the enhanced electrical conductivity and efficient ion transport by the addition of GQDs, the G-NH//CC electrode exhibits enhanced electrochemical performances. Specifically, the GNH//CC delivers a maximum specific capacitance of 1825 F g^(-1) at a current density of 1 A g^(-1) as well as a good cycle stability of 83.5 % capacity retention after 8000 cycles. Additionally, all-solid-state symmetric supercapacitor(SSC) is assembled with G-NH//CC composites as both positive and negative electrodes.The fabricated SSC exhibits a high energy density of 80.8 Wh kg^(-1)at a power density of 2021 W kg^(-1). The present study provides a facile and efficient strategy to prepare high-performance electrode materials for advanced electrochemical energy storage devices.
基金financially supported by the National Natural Science Foundation of China (52174283)。
文摘Developing efficient and promising non-noble catalysts for oxygen evolution reaction(OER) and hydrogen evolution reaction(HER) is vital but still a huge challenge for the clean energy system. Herein, we have integrated the active components for OER(Ni(OH)_(2)) and HER(Ni S_(2) and Ni(OH)_(2)) into Ni(OH)_(2)@NiS_(2) heterostructures by a facile reflux method. The in-situ formed Ni(OH)_(2) thin layer is coated on the surface of hollow Ni S2 nanosphere. The uniform Ni(OH)_(2)@NiS_(2) hollow sphere processes enlarge the electrochemically active specific surface area and enhance the intrinsic activity compared to NiS_(2) precursor, which affords a current density of 10 m A cm^(-2) at the overpotential of 309 m V and 100 m Acm^(-2) at 359 m V for OER. Meanwhile, Ni(OH)_(2)@NiS_(2) can reach 10 m A cm^(-2) at 233 m V for HER, superior to pure NiS_(2). The enhanced performance can be attributed to the synergy between Ni(OH)_(2) and NiS_(2). Specifically, Ni(OH)_(2) has three functions for water splitting: providing active sites for hydrogen adsorption and hydroxyl group desorption and working as real OER active sites. Moreover, Ni(OH)_(2)@NiS_(2) displays great stability for OER(50 h) and HER(30 h).
基金the National Natural Science Foundation of China(Nos.21978238,21878248,and 21978055)Natural Science Foundation of Shaanxi Provincial Department of Education(No.21JY041).
文摘Regulable loading of Ni(OH)_(2) crystals by using three dimensionally ordered mesoporous carbon(3DOMC)as a support is achieved through a confined growth strategy accompanied by steam-assisted crystallization.Dual forms of high-crystalline nanosheet-like Ni(OH)_(2) severally distribute within mesopores or over the outer surface of 3DOMC particles depending on the loading amount(3%^(−1)5%)of Ni(OH)_(2).Benefitted from the highly hybrid combination and efficient electrolyte diffusion,the obtained Ni(OH)_(2)/carbon nanocomposites exhibit an excellent electrochemical performance,and the optimal sample of 6%_Ni(OH)_(2)/3DOMC with confined extrasmall Ni(OH)_(2) nanosheets as dominant shows the highest specific capacitance of 552.5F.g^(−1) at 1.0A⋅g^(−1),which is 330%higher than the contrast sample by using actived carbon as the support.Furthermore,the assembled hybrid supercapacitor by using 6%_Ni(OH)_(2)/3DOMC and 3DOMC as positive and negative electrodes displays an energy density of 11.7 Wh.kg^(−1) at 288.1 W.kg^(−1) and a superior charge/discharge stability.It is expected that the flexible component,well-defined structure,and superior electrochemical performance could promote a great application potential of Ni(OH)_(2)/3DOMC nanocomposites as supercapacitor electrodes and in other energy storage devices.
基金The authors gratefully acknowledge the financial support from the National Natural Science Foundation of China(21905049,21902030,22108129,and 21677036)the Award Program for Minjiang Scholar Professorshipthe Natural Science Foundation of Fujian Province(2020J01201).
文摘Dye-sensitized photocatalysis has been extensively studied for photocatalytic solar energy conversion due to the advantage in capturing long-wavelength photons with a high absorption coefficient.The rational integration of photosensitizer with semiconductor and cocatalyst to collaboratively operate in one system is highly desired.Here,we fabricate a Ni(OH)_(2)-loaded titanate nanosheet(Ni(OH)_(2)/H_(2)Ti_(6)O_(13))composite for high-performance dye-sensitized photocatalytic CO_(2) reduction.The ultrathin H_(2)Ti_(6)O_(13) nanosheets with negative surface charge provide an excellent support to anchor the dye photosensitizer,while the loaded Ni(OH)2 serves as an adsorbent of CO_(2) and electron sink of photoelectrons.As such,the photoelectrons derived from the[Ru(bpy)3]Cl_(2) sensitizer can be targeted transfer to the Ni(OH)_(2) active sites via the H_(2) Ti_(6)O_(13) nanosheets linker.A high CO production rate of 1801μmol g^(-1) h^(-1) is obtained over the optimal Ni(OH)_(2)/H_(2)Ti_(6)O_(13),while the pure H_(2)Ti_(6)O_(13) shows significantly lower CO_(2) reduction performance.The work is anticipated to trigger more research attention on the rational design and synthesis of earth-abundant transition metal-based cocatalysts decorated on ultrathin 2D platforms for artificially photocatalytic CO_(2) reduction.
