Preparation Of Highly Efficient Electrocatalyst Based On NiFe LDH

Because of the limited reserves of traditional energy,it is important for people to develop new clean energy.Hydrogen（H₂）,possessing zero carbon content and the highest gravimetric energy density,is widely considered as an emissions-free alternative fuel to satisfy our needs sustainably in the future.It is anticipated to produce H₂ by water splitting,because it can achieve the storage of massive energy by molecular transformation without producing green-house gases and other pollutants.LDHs is considered as a potential catalyst for water electrolysis.After investigation,herein,low-cost and simple synthetic NiFe LDH was selected as the research object.NiFe LDH can be directly grown on the nickel foam by hydrothermal synthesis.Furthermore,with only 180 m V overpotential to reach the current density of 10 m A cm^-2 for OER.But the interaction between the adsorbed H_ads and electronegative oxygen are so strong that H_ads is hard to be combine into H₂.The poor HER catalytic activity restricts the application of LDH in related areas.Previous studies have concentrated on either the incorporation of other compounds benefit to water dissociation or the surface deformation of the catalysts to improve the HER catalytic activity of LDHs.These methods can promote the HER activity of LDHs in alkaline media by increasing the number of active reaction sites or introducing new component with certain characteristics,but cannot fundamentally alter the nature of catalysts basically.Element doping can weaken the interaction between the adsorbed H_ads and electronegative oxygen in LDHs.So that the HER activity of NiFe LDH will be greatly improved.Base on the theoretical foundation,doping in NiFe LDH materials with Mn,Co,P and other elements were executed.The modified sample whit P doping by vapor method exhibited good HER performance,only requiring an overpotential of 125 m V to reach the current density of 10 m A cm^-2.NiFe LDH and P-NiFe LDH were used as anode and cathode materials for overall water splitting,in which only 1.62 V voltage was required to reach the current density of 10 m A cm^-2,with a maintaining for 14 h.Furthermore,the electrocatalytic oxidation reaction of some organic matter was carried out in the anode chamber to replace the OER reaction by us.It can reduce the potential required for overall electrochemical reaction.On the other hand,it also can generate products with more commercial value and economic benefits.The results show that,when suing 5-Hydroxymethylfurfural（HMF）as substrate in anodic reaction,the hydrogen evolution reaction and oxidation of HMF can be realized at 1.385 V.The conversion of HMF can reach 98%,and the FE and selectivity to FDCA are close to100%.