Optimization of Oxygen Evolution Reaction with Electroless Deposited Ni-P Catalytic Nanocoating

The low efficiency of water electrolysis mostly arises from the thermodynamic uphill oxygen evolution reaction. The efficiency can be greatly improved by rationally designing low-cost and efficient oxygen evolution anode materials. Herein, we report the synthesis of Ni-P alloys adopting a facile electroless plating method under mild conditions on nickel substrates. The relationship between the Ni-P properties and catalytic activity allowed us to define the best conditions for the electroless synthesis of highperformance Ni-P catalysts. Indeed, the electrochemical investigations indicated an increased catalytic response by reducing the thickness and Ni/P ratio in the alloy. Furthermore, the Ni-P catalysts with optimized size and composition deposited on Ni foam exposed more active sites for the oxygen evolution reaction, yielding a current density of 10 mA cm(-2) at an overpotential as low as 335 mV, exhibiting charge transfer resistances of only a few ohms and a remarkable turnover frequency (TOF) value of 0.62 s(-1) at 350 mV. The present study provides an advancement in the control of the electroless synthetic approach for the design and large-scale application of high-performance metal phosphide catalysts for electrochemical water splitting.

Automated summary

This study reports on the synthesis of Ni-P alloys as efficient catalysts for water electrolysis, demonstrating improved catalytic activity by adjusting the thickness and Ni/P ratio of the alloy. Depositing Ni-P catalysts with optimized size and composition on Ni foam resulted in increased active sites for the oxygen evolution reaction, achieving high current densities at low overpotentials. Additionally, the study advances the control of electroless synthetic approaches for designing high-performance metal phosphide catalysts on a large scale for electrochemical water splitting.