Preparation Of NiMo Alloy By Electrodeposition And Its Electrocatalytic Performanc

Hydrogen(H2),as a clean energy with zero carbon emission,has great prospects in replacing the increasingly depleted fossil fuels.Among all kinds of hydrogen production processes,electrolytic water splitting technology has attracted wide attention due to its high purity,mild reaction conditions and environmental friendliness.Methanol oxidation(MOR)is a critical half-reaction in a variety of electrochemical devices and can be operated at low potential(0.103 V(vs.RHE)).MOR instead of OER on the anode side can not only improve the energy utilization efficiency,but also selectively transform into formic acid(HCOOH)with industrial added value.Therefore,it is of great research significance to construct non-noble metal bi-functional catalysts that catalyzed both methanol oxidation(MOR)and hydrogen precipitation(HER).In this study,NiMo alloy is taken as the research object,and the influence of material composition and structure on its electrocatalytic performance is discussed in detail,then some meaningful research results are obtained.The specific research contents are as follows:1.NiMo alloy and NiFe LDH@NiMo-NF heterogeneous materials were prepared in an aqueous solution by electrodeposition,and their electrochemical catalytic properties had been investigated.The overpotentials of NiMo alloy for HER and MOR reaction are 118.3 mV and 1.43 V(vs.RHE)at the current density of 100 mA cm-2.In order to further improve the catalytic activity of the MOR at the anode,the NiFe LDH@NiMo-NF heterostructure was constructed.The results show that the strong electronic coupling between NiFe LDH and NiMo alloys improves the catalytic activity of MOR and HER,When the current density was 100 mA cm-2,the overpotential of HER and MOR were 82.5 mV and 1.407 V(vs.RHE),respectively.The Faraday efficiencies of formic acid production at the anode and hydrogen production at the cathode are about 97%and 100%,respectively,and has good long-term stability.2.To optimize the microstructure of NiMo alloy,NiMo alloy was electrodeposited in Deep Eutectic solvent.The effects of deposition conditions on the microstructure and electrocatalytic performance of NiMo alloy had been investigated.The results indicate that NiMo alloy materials with nano network structure were obtained,which effectively facilitate the exposure of catalytic active sites,improving the electrocatalytic performance,the current density of 100 mA cm-2 can be achieved with only 1.45 V voltage in a methanol-hydrolysis system,and the Faraday efficiencies of both cathode and anode are 98.5%and 100%respectively.3.To investigate the contribution of elements to the catalytic activity,we prepare NiMoCoFeGa high entropy alloy.The results of characterizations prove that high entropy alloy with nanosheet structure has been synthesized.The test results show that the overpotentials of HER and MOR at 100 mA cm-2 are 49.9 mV and 1.36 V,respectively(vs.RHE).In the methanol-water electrolysis system,only 1.42 V voltage can achieve 100 mA cm-2,and the Faraday efficiencies of the cathode and anode are 97.5%and 98.3%respectively,and has good electrochemical stability.