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
The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst wa...The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst was characterized by X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, X-ray photoelectron spectroscopy （XPS）, transmission electron microscope （TEM）, NH3 temperature programmed desorption （NH3-TPD）, N2 adsorption-desorption and CO uptake. The effect of AI on benzofuran （BF） HDO performance was investigated. The result indicates that the incorporation of AI into the SBA-15 support can promote the formation of much uniform, smaller, highly dispersed N2P particles on the catalyst. The AI also contrib- utes to suppress the enrichment of P and promote more exposed Ni sites on the surface. In addition, the incorporation of AI can enhance the acid strength. The total deoxygenated product yield over Ni2P/AI-SBA-15 reached 90.3%, which is an increase of 19.4%, when compared with that found for Ni2P/SBA-15 （70.9%）.展开更多
Developing of high-performance and low-cost electrocatalysts is of great significance to reduce the overpotential and accelerated the reaction rate of oxygen evolution in water splitting and related energy conversion ...Developing of high-performance and low-cost electrocatalysts is of great significance to reduce the overpotential and accelerated the reaction rate of oxygen evolution in water splitting and related energy conversion applications.Herein,Fe,O-dual doped Ni2P(Fe,O-Ni2P)nanoarray is successfully synthesized on carbon cloth demonstrating enhanced electrocatalytic activity and stability for oxygen evolution reaction(OER)under alkaline media.The as-synthesized Fe,O-Ni2P nanoarray exhibits obviously improved OER performance with a low overpotential of 210 mV at 10 mA cm^-2 current density and a Tafel slope of48 mV dec^-1,as well as long-term durability.The strong coupling interaction induced changes in electronic structure lead to relatively higher oxidation state and stronger oxidation ability of the Fe,O-Ni2P nanoarray,together with the high electrochemical surface area and good conductivity contribute to the superior OER performance.This work highlights the anion-cation dual doping strategy may be an effective method for fabrication of catalysts relating to energy conversion applications.展开更多
Transitional metal phosphides with array-like structure grown on conductive support materials are promising bifunctional catalysts for the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).In this stu...Transitional metal phosphides with array-like structure grown on conductive support materials are promising bifunctional catalysts for the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).In this study,a method was developed to synthesize directly porous Ni2P nanosheet arrays and Ni2P nanoparticles onto nickel foam via a hydrothermal reaction followed by a phosphorization process.Mechanistic studies revealed that the allomorphs of Ni2P nanosheets and Ni2P nanoparticles in the array-like structure were formed via the Kirkendall effect and Ostwald ripening.A fully functional water electrolyzer containing Ni2P as electrodes for the OER and HER exhibited promising activity and stability.At 10 mA·cm^−2,a Ni2P cell voltage of 1.63 V was obtained,which was only 0.05 V smaller than that found for Pt/C/NF||RuO2/NF cell.The enhanced electrocatalytic performance resulted from the favorable porosity of the Ni2P arrays and the synergistic effect between Ni2P nanosheets and Ni2P nanoparticles.展开更多
Two-dimensional(2 D)heterostructural Ni2 P/rGO is successfully fabricated by in-situ phosphating selfassembled NiO/rGO composites and shows the enhanced electrochemical performances.In this design,the rGO sheets effec...Two-dimensional(2 D)heterostructural Ni2 P/rGO is successfully fabricated by in-situ phosphating selfassembled NiO/rGO composites and shows the enhanced electrochemical performances.In this design,the rGO sheets effectively reduce the lattice strain created during the phase transformation from NiO to Ni2 P,thereby maintaining ultrathin nanostructures of Ni2 P.The resulting Ni2 P/rGO layered heterostructure gives the composite plenty of pores or channels,good electrical conductivity and well-exposed active sites.Density functional theory(DFT)calculation further demonstrates that the Fermi energy level and electron localize of near Ni atoms in Ni2 P is higher than that of NiO,which endow Ni2 P with faster and more reversible redox reactivity in dynamic.Benefiting from their structural and compositional merits,the as-synthesized Ni2 P/rGO exhibits high specific discharge capacity and excellent rate performance.Furthermore,a hybrid supercapacitor built with Ni2 P/rGO and activated carbon shows a high specific energy of 38.6 Wh/kg at specific power of 375 W/kg.展开更多
文摘以镍为金属中心、对二甲苯二磷酸为有机配体,构筑了一种有机磷酸类Ni-MOF前驱体,再经过一步碳化,原位制备出多孔碳包覆Ni_2P纳米颗粒的复合材料.该复合材料保留了前驱体的片状形貌,比表面积可达202 m2/g,复合材料中的Ni_2P纳米颗粒具有良好的结晶度,颗粒均匀且无团聚现象.在锂离子电池性能测试中,该Ni_2P/C复合结构在缓解材料体积膨胀的同时提高了材料的电子和离子电导率,进而提高了材料的电化学性能.在0.2 C的电流密度下,材料首次充、放电比容量分别为247和226 m A·h·g-1,库仑效率可达91.7%,循环200圈后,库仑效率接近100%.
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.
文摘The Al-doped Ni2P/AI-SBA-15 catalyst with high hydrodeoxygenation （HDO） activity was synthesized by tem- perature programmed reduction at a relatively low reduction temperature of 400 ℃. The as-prepared catalyst was characterized by X-ray diffraction （XRD）, H2 temperature-programmed reduction （H2-TPR）, X-ray photoelectron spectroscopy （XPS）, transmission electron microscope （TEM）, NH3 temperature programmed desorption （NH3-TPD）, N2 adsorption-desorption and CO uptake. The effect of AI on benzofuran （BF） HDO performance was investigated. The result indicates that the incorporation of AI into the SBA-15 support can promote the formation of much uniform, smaller, highly dispersed N2P particles on the catalyst. The AI also contrib- utes to suppress the enrichment of P and promote more exposed Ni sites on the surface. In addition, the incorporation of AI can enhance the acid strength. The total deoxygenated product yield over Ni2P/AI-SBA-15 reached 90.3%, which is an increase of 19.4%, when compared with that found for Ni2P/SBA-15 （70.9%）.
基金financial support from the National Science Foundation of China(51671094,21606189)China Postdoctoral Science Foundation(2017M612174)+1 种基金Shandong Provincial Natural Science Foundation(ZR2015BQ011)the Science and Technology Project of University of Jinan(XKY1826)。
文摘Developing of high-performance and low-cost electrocatalysts is of great significance to reduce the overpotential and accelerated the reaction rate of oxygen evolution in water splitting and related energy conversion applications.Herein,Fe,O-dual doped Ni2P(Fe,O-Ni2P)nanoarray is successfully synthesized on carbon cloth demonstrating enhanced electrocatalytic activity and stability for oxygen evolution reaction(OER)under alkaline media.The as-synthesized Fe,O-Ni2P nanoarray exhibits obviously improved OER performance with a low overpotential of 210 mV at 10 mA cm^-2 current density and a Tafel slope of48 mV dec^-1,as well as long-term durability.The strong coupling interaction induced changes in electronic structure lead to relatively higher oxidation state and stronger oxidation ability of the Fe,O-Ni2P nanoarray,together with the high electrochemical surface area and good conductivity contribute to the superior OER performance.This work highlights the anion-cation dual doping strategy may be an effective method for fabrication of catalysts relating to energy conversion applications.
基金The authors would like to thank the National Natural Science Foundation of China(Nos.51661008 and 21766032)Key Technology Research and Development Program of Shandong(No.2019GGX103029)for financially supporting this work.
文摘Transitional metal phosphides with array-like structure grown on conductive support materials are promising bifunctional catalysts for the oxygen evolution reaction(OER)and hydrogen evolution reaction(HER).In this study,a method was developed to synthesize directly porous Ni2P nanosheet arrays and Ni2P nanoparticles onto nickel foam via a hydrothermal reaction followed by a phosphorization process.Mechanistic studies revealed that the allomorphs of Ni2P nanosheets and Ni2P nanoparticles in the array-like structure were formed via the Kirkendall effect and Ostwald ripening.A fully functional water electrolyzer containing Ni2P as electrodes for the OER and HER exhibited promising activity and stability.At 10 mA·cm^−2,a Ni2P cell voltage of 1.63 V was obtained,which was only 0.05 V smaller than that found for Pt/C/NF||RuO2/NF cell.The enhanced electrocatalytic performance resulted from the favorable porosity of the Ni2P arrays and the synergistic effect between Ni2P nanosheets and Ni2P nanoparticles.
基金supported by the DNL Cooperation Fund,CAS(No.DNL201915)National Science Foundation for Excellent Young Scholars of China(No.21922815)+1 种基金National Natural Science Foundation of China(No.21975275)Key Research and Development(R&D)Projects of Shanxi Province(No.201903D121007)。
文摘Two-dimensional(2 D)heterostructural Ni2 P/rGO is successfully fabricated by in-situ phosphating selfassembled NiO/rGO composites and shows the enhanced electrochemical performances.In this design,the rGO sheets effectively reduce the lattice strain created during the phase transformation from NiO to Ni2 P,thereby maintaining ultrathin nanostructures of Ni2 P.The resulting Ni2 P/rGO layered heterostructure gives the composite plenty of pores or channels,good electrical conductivity and well-exposed active sites.Density functional theory(DFT)calculation further demonstrates that the Fermi energy level and electron localize of near Ni atoms in Ni2 P is higher than that of NiO,which endow Ni2 P with faster and more reversible redox reactivity in dynamic.Benefiting from their structural and compositional merits,the as-synthesized Ni2 P/rGO exhibits high specific discharge capacity and excellent rate performance.Furthermore,a hybrid supercapacitor built with Ni2 P/rGO and activated carbon shows a high specific energy of 38.6 Wh/kg at specific power of 375 W/kg.
