Atomic-scale Engineering Of Nanoporous (Ni_xCo_1-x)₃P And Electrocatalytic Performance

Electrochemical conversion and storage are of great significance for the development of green,coordinated and sustainable development.Electrochemical green energy storage and conversion technologies,including nickel-zinc batteries and electrocatalytic small molecule oxidation,have received more and more attention.The catalyst can improve the reaction kinetics and reduce the energy consumption,which is the key factor to achieve high-efficiency and stable electrochemical conversion.In view of the wide application of nickel-based hydroxides,as well as the problems of poor material conductivity and limited electrode reaction kinetics,this topic proposes the atomic-level engineering of nanoporous(Ni_xCo_1-x)₃P and its electrocatalytic performance.The surface active layer was constructed by the reconstruction effect of phosphide,and the M@np-Ni_xCo_1-x（OH）₂（M is a metal atom,np stands for nanoporous）electrode material was obtained;and the redox properties and electrocatalysis of Ni_xCo_1-x（OH）₂by atomic-level engineering were studied.The effect of oxidation（oxygen evolution from water electrolysis,urea oxidation）reaction properties,and the related mechanisms are revealed.The main results of the paper are as follows:（1）Based on the electronic interaction between the M atom and the redox active center in the M@np-Ni_xCo_1-x（OH）₂（M is a metal atom,np stands for nanoporous）electrode material,in the low potential range,study the effect of atomic-level engineering on Ni_xCo_1-x（OH）₂effects of redox properties and reveal the associated mechanisms.Theoretical calculations and experimental results show that the atomic-level engineering of Ag can effectively control the surrounding electronic structure and OH-surface adsorption energy of the Ni_xCo_1-x（OH）₂active site,and promote the interfacial species transport while increasing the active area,thereby greatly improving the material.redox activity.The specific capacity of Ag@np-Ni_xCo_1-x（OH）₂electrode at 10 m A cm^-2can reach 0.835 m A h cm^-2(417.5 m A h cm^-3).The power density and energy density of Ni-Zn batteries based on Ag@np-Ni_xCo_1-x（OH）₂electrodes reach 7.85 W cm^-3and 49.53 m W h cm^-3,respectively,and exhibit good cycling stability and rate performance.（2）Based on the photothermal effect of Ag heavy metal in the Ag@np-Ni_xCo_1-x（OH）₂electrode material,in the high potential range,the effect of atomic-level engineering on the properties of Ni_xCo_1-x（OH）₂electrocatalytic oxidation reaction was studied and revealed related mechanisms.The study shows that the Ag@np-Ni_xCo_1-x（OH）₂electrode exhibits a significant photothermal synergistic effect in the catalytic oxidation reaction.Ag doping can not only significantly increase the active surface area of the electrode,but also promote the generation of hot electron-holes under photothermal conditions,accelerate the kinetic process of the reaction,and improve the catalytic performance.Under laser irradiation,the Ag@np-Ni_xCo_1-x（OH）₂electrode catalyzes the oxygen evolution reaction with lower onset potential（1.47 V）and lower Tafel slope(97 m V dec^-1).The photothermal synergistic electrocatalytic urea oxidation also achieved performance improvement.（3）Ag atomic-level engineering improves the redox responsiveness and photothermal synergistic catalytic properties of Ni/Co active species.The main reasons are:1)Ag atom doping can effectively control the electronic structure and surface adsorption energy,and improve the reaction kinetics;2)The electrochemical active area is increased to promote the mass-charge transport during the reaction;3)The addition of an external field further promotes the catalytic sites activation,photothermoelectric synergistic enhancement of catalytic performance;4)The excellent electronic conductivity of phosphide substrates and the nanoporous structure supporting efficient ion transport provide a solid foundation for high-throughput interfacial reactions.In summary,this topic focuses on atomic-level engineering on nanoporous substrates,focusing on energy storage electrodes and electrocatalytic applications,which reflects the positive effect of atomic-level engineering on nanoporous(Ni_xCo_1-x)₃P nickel-based electrodes.Atomic engineering is an effective way to improve electrode performance,which has universal significance for the design and application of functional electrodes,and provides new opportunities for the flexible design and multi-functional application of nanoporous substrate materials.