Bimetallic NiCoP catalysts anchored on phosphorus-doped lignin-based carbon for robust oxygen evolution performance

Oxygen evolution reaction（OER） catalysts are the key core materials that determine the performance of fuel cells,metal-air batteries,electrolytic water decomposition,and other applications.In this work,a green lignin-based non-precious metal OER catalyst was prepared by a simple strategy.Firstly,c arboxylated lignin was used to complex Ni and Co in situ,and then they were placed with sodium hypophosphite in the same tube furnace for upstream and downstream high-temperature calcination to construct a lignin carbon-based Ni-Co bimetallic OER catalyst（NiCoP@C）.The synthesized catalyst is a porous bimetallic phosphide with a three-dimensional network structure and high-density electrochemical active sites.NiCoP@C exhibited favorable catalytic activity for the oxygen evolution reaction（OER） with overpotential of 280 mV at 10 mA·cm-2 and a Tafel slope of 77 mV·dec-1.Additionally,it exhibited remarkable durability during usage.Density functional theory（DFT） calculations revealed that by leveraging the distinctive structure of transition metal phosphide nanoparticles incorporated into a reticulated substrate,the NiCoP@C catalyst offered an increased number of active sites for OER catalysis,significantly enhancing its stability during practical applications.The present study broadens the utilization pathways of biomass to "turn waste into treasure," aligning the development concept of green sustainable development.