Al/Co co-doped α-Ni（OH）2 samples were prepared by either ultrasonic co-precipitation method （Sample B） or co-precipitation method （Sample A）. The crystal structure and particle size distribution of the prepared...Al/Co co-doped α-Ni（OH）2 samples were prepared by either ultrasonic co-precipitation method （Sample B） or co-precipitation method （Sample A）. The crystal structure and particle size distribution of the prepared samples were examined by X-ray diffraction （XRD） and laser particle size analyzer, respectively. The results show that Sample B has more crystalline defects and smaller average diameter than Sample A. The cyclic voltammetry and electrochemical impedance spectroscopy measurements indicate that Sample B has better electrochemical performance than Sample A, such as better reaction reversibility, lower charge-transfer resistance and better cyclic stability. Proton diffusion coefficient of Sample B is 1.96×10-10cm2/s, which is two times as large as that （9.78×10-11cm2/s） of Sample A. The charge-discharge tests show that the discharge capacity （308 mA·h/g） of Sample B is 25 mA·h/g higher than that of Sample A （283 mA·h/g）.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
α-Ni(OH)2 was synthesized from a NiCl2 solution by electrodeposition method.In order to conduct a systematic study on the effects of experimental parameters,a series of electrolyte initial pH values,current densities...α-Ni(OH)2 was synthesized from a NiCl2 solution by electrodeposition method.In order to conduct a systematic study on the effects of experimental parameters,a series of electrolyte initial pH values,current densities,electrodeposition temperatures,and electrodeposition time were used.Cyclic voltammetry results demonstrated a side reaction of Ni^2++2e→Ni.The X-ray diffraction analysis,Fourier-transform infrared spectrum,and the color of the product showed that pureα-Ni(OH)2 could be obtained in the initial pH value range of 2−5.86,current density range of 10−25 mA/cm^2,electrodeposition temperature range of 25−35℃,and electrodeposition time range of 1.0−3.0 h.When electrodeposition temperature increased to 45℃,a mixture ofα-Ni(OH)2 and metallic Ni was obtained.A current density higher than 30 mA/cm^2 resulted in the sample with features ofβ-Ni(OH)2.A small amount of metallic Ni existed in the as-prepared sample when current density decreased to 5 mA/cm^2.A slight increase of electrolyte pH was observed with increasing initial solution pH and current density.Electrodeposition mass revealed a slight decrease with initial pH decreasing and showed an almost linear increase with current density increasing.The slope of the curve for electrodeposition mass versus electrodeposition time remained stable in the first 2.0 h and then decreased.展开更多
Aluminum\|cobalt co\|substituted \%α\%\|Ni(OH)\-2 was prepared by means of the titration method in a buffer solution,the structure was characterized by XRD analysis. With above mentioned \%α\%\|Ni(OH)\-2 as the posi...Aluminum\|cobalt co\|substituted \%α\%\|Ni(OH)\-2 was prepared by means of the titration method in a buffer solution,the structure was characterized by XRD analysis. With above mentioned \%α\%\|Ni(OH)\-2 as the positive electrode of a nickel\|metal hydride cell,the discharge performances were examined by constant\|current charge\|discharge experiments. In comparison with the electrodes made of aluminum substituted or cobalt substituted Ni(OH)\-2 materials,the aluminum\|cobalt co\|substituted composite electrodes possess an excellent electrochemical performance and are of practical significance.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
Supercapacitors have attracted much attention in the field of electrochemical energy storage.However,material preparation,stability,performance as well as power density limit their applications in many fields.Herein,a...Supercapacitors have attracted much attention in the field of electrochemical energy storage.However,material preparation,stability,performance as well as power density limit their applications in many fields.Herein,a sponge-like red phosphorus@graphene(rP@rGO)negative electrode and a Ni2P positive electrode were prepared using a simple one-step method.Both electrodes showed excellent performances(294 F g^−1 and 1526.6 F g^−1 for rP@rGO and Ni2P,respectively),which seem to be the highest among all rP@rGO-and Ni2P-based electrodes reported so far.The asymmetric solid-state supercapacitor was assembled by sandwiching a gel electrolyte-soaked cellulose paper between rP@rGO and Ni2P as the negative and positive electrodes.Compared to other asymmetric devices,the device,which attained a high operating window of up to 1.6 V,showed high energy and power density values of 41.66 and 1200 W kg−1,respectively.It also has an excellent cyclic stability up to 88%after various consecutive charge/discharge tests.Additionally,the device could power commercial light emitting diodes and fans for 30 s.So,the ease of the synthesis method and excellent performance of the prepared electrode materials mat have significant potential for energy storage applications.展开更多
Particular kinds of TiO2 nanocrystalline electrodes were sensitized by aluminum phthalocyanines modified with sulfonate groups [ Al（OH） PcSm ]. It was found that in the red region, the electrodes show obvious photoe...Particular kinds of TiO2 nanocrystalline electrodes were sensitized by aluminum phthalocyanines modified with sulfonate groups [ Al（OH） PcSm ]. It was found that in the red region, the electrodes show obvious photoelectrical responses. The surface photovoltage spectra and photocurrent action spectra indicate that in the red region, the monomers of aluminum phthalocyanines have a greater influence on the determination of the photoelectrical response of TiO2 electrodes than the dimers. The dye-sensitized solar cells were obtained by using the aluminum phthalocyaninessensitized TiO2 electrodes and Pt electrodes, which have an open circuit photovoltage of 360 mV, a short circuit photocurrent of 39. 4 μA/cm^2 , a fill factor of 0. 54 and a maximum power output of 7.65 μW/cm^2 under a light intensity of 50 mW/cm^2.展开更多
基金Project (10774030) supported by the National Natural Science Foundation of ChinaProject (2008J1-C161) supported by the Science and Technology Program of Guangzhou City of China
文摘Al/Co co-doped α-Ni（OH）2 samples were prepared by either ultrasonic co-precipitation method （Sample B） or co-precipitation method （Sample A）. The crystal structure and particle size distribution of the prepared samples were examined by X-ray diffraction （XRD） and laser particle size analyzer, respectively. The results show that Sample B has more crystalline defects and smaller average diameter than Sample A. The cyclic voltammetry and electrochemical impedance spectroscopy measurements indicate that Sample B has better electrochemical performance than Sample A, such as better reaction reversibility, lower charge-transfer resistance and better cyclic stability. Proton diffusion coefficient of Sample B is 1.96×10-10cm2/s, which is two times as large as that （9.78×10-11cm2/s） of Sample A. The charge-discharge tests show that the discharge capacity （308 mA·h/g） of Sample B is 25 mA·h/g higher than that of Sample A （283 mA·h/g）.
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Project(U1710257)supported by the National Natural Science Foundation of China。
文摘α-Ni(OH)2 was synthesized from a NiCl2 solution by electrodeposition method.In order to conduct a systematic study on the effects of experimental parameters,a series of electrolyte initial pH values,current densities,electrodeposition temperatures,and electrodeposition time were used.Cyclic voltammetry results demonstrated a side reaction of Ni^2++2e→Ni.The X-ray diffraction analysis,Fourier-transform infrared spectrum,and the color of the product showed that pureα-Ni(OH)2 could be obtained in the initial pH value range of 2−5.86,current density range of 10−25 mA/cm^2,electrodeposition temperature range of 25−35℃,and electrodeposition time range of 1.0−3.0 h.When electrodeposition temperature increased to 45℃,a mixture ofα-Ni(OH)2 and metallic Ni was obtained.A current density higher than 30 mA/cm^2 resulted in the sample with features ofβ-Ni(OH)2.A small amount of metallic Ni existed in the as-prepared sample when current density decreased to 5 mA/cm^2.A slight increase of electrolyte pH was observed with increasing initial solution pH and current density.Electrodeposition mass revealed a slight decrease with initial pH decreasing and showed an almost linear increase with current density increasing.The slope of the curve for electrodeposition mass versus electrodeposition time remained stable in the first 2.0 h and then decreased.
文摘Aluminum\|cobalt co\|substituted \%α\%\|Ni(OH)\-2 was prepared by means of the titration method in a buffer solution,the structure was characterized by XRD analysis. With above mentioned \%α\%\|Ni(OH)\-2 as the positive electrode of a nickel\|metal hydride cell,the discharge performances were examined by constant\|current charge\|discharge experiments. In comparison with the electrodes made of aluminum substituted or cobalt substituted Ni(OH)\-2 materials,the aluminum\|cobalt co\|substituted composite electrodes possess an excellent electrochemical performance and are of practical significance.
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supported by Basic Sci-ence Research Program through National Research Foundation of Korea(NRF)founded by the ministry of Education(NRF-2017R1D1A1B03030456)
文摘Supercapacitors have attracted much attention in the field of electrochemical energy storage.However,material preparation,stability,performance as well as power density limit their applications in many fields.Herein,a sponge-like red phosphorus@graphene(rP@rGO)negative electrode and a Ni2P positive electrode were prepared using a simple one-step method.Both electrodes showed excellent performances(294 F g^−1 and 1526.6 F g^−1 for rP@rGO and Ni2P,respectively),which seem to be the highest among all rP@rGO-and Ni2P-based electrodes reported so far.The asymmetric solid-state supercapacitor was assembled by sandwiching a gel electrolyte-soaked cellulose paper between rP@rGO and Ni2P as the negative and positive electrodes.Compared to other asymmetric devices,the device,which attained a high operating window of up to 1.6 V,showed high energy and power density values of 41.66 and 1200 W kg−1,respectively.It also has an excellent cyclic stability up to 88%after various consecutive charge/discharge tests.Additionally,the device could power commercial light emitting diodes and fans for 30 s.So,the ease of the synthesis method and excellent performance of the prepared electrode materials mat have significant potential for energy storage applications.
基金Supported by the National Natural Science Foundation of China(Nos. 60271020 and 20125513)
文摘Particular kinds of TiO2 nanocrystalline electrodes were sensitized by aluminum phthalocyanines modified with sulfonate groups [ Al（OH） PcSm ]. It was found that in the red region, the electrodes show obvious photoelectrical responses. The surface photovoltage spectra and photocurrent action spectra indicate that in the red region, the monomers of aluminum phthalocyanines have a greater influence on the determination of the photoelectrical response of TiO2 electrodes than the dimers. The dye-sensitized solar cells were obtained by using the aluminum phthalocyaninessensitized TiO2 electrodes and Pt electrodes, which have an open circuit photovoltage of 360 mV, a short circuit photocurrent of 39. 4 μA/cm^2 , a fill factor of 0. 54 and a maximum power output of 7.65 μW/cm^2 under a light intensity of 50 mW/cm^2.
