Phosphorus Doping Heterostructure La(OH) 3 @CuO @NF as Advanced Electrocatalysts for Oxygen Reduction Reaction

Abstract Due to the prevailing energy shortages, the quest for new alternative energy sources is growing increasingly urgent. Hydrogen production through water electrolysis has become a crucial method. However, the slow four-electron reaction in oxygen evolution reaction (OER) becomes the main rate-limiting step. In this study, we propose obtaining heterostructure La(OH)3@CuO-P after composite phosphatisation using nickel foam (NF) as the substrate material. The experimental results demonstrate that the heterostructure La(OH)3@CuO exhibits an overpotential of 365mV at a current density of 10mA/cm2 , and displays a Tafel slope value of 114.02mF/dec, a bilayer capacitance of 1.853mF/cm2 for OER in a 1 M KOH solution. After phosphating, the heterostructure La(OH)3@CuO-P exhibits exceptional catalytic performance with only 215 mV overpotential, a Tafel slope value of 79.36 mV/dec, and a bilayer capacitance of 34.73mF/cm2 at a current density of 10mA/cm2 . Moreover, it also exhibits relatively stable performance during cyclic voltammetry testing for up to1000 cycles. Analyses suggest that the formation of a heterojunction structure in La(OH)3@CuO-P effectively addresses the issues of insufficient conductivity of La(OH)3 and tendency for CuO monomer aggregation while maintaining excellent properties for each component. The substitutional P atom doping not only adjusts the electronic structure and optimizes the adsorption free energy of -OH but also reduces sample size and increases catalytic active sites, thereby further enhancing the OER performance of the material.