Surface-enriched ultrafine Pt nanoparticles coupled with defective CoP as efficient trifunctional electrocatalyst for overall water splitting and flexible Zn-air battery

Developing multifunctional electrocatalysts toward energy-related reactions could reduce the cost and improve the utilization efficiency of raw materials. Herein, defective CoP decorated with ultrafine Pt nanoparticles (Pt/d-CoP/NPC) with multifunctional electrocatalytic performances is prepared via facile pyrolysis and following chemical reduction process. The as-synthesized Pt/d-CoP/NPC owns high half-wave potential of 0.82 V for oxygen reduction reaction with excellent stability in 0.1 mol/L KOH. Density functional theory calculations demonstrate that the adsorption energy of *OO at Pt/d-CoP/NPC is stronger compared to Pt, yielding higher catalytic activity for ORR. Moreover, the resultant electrocatalyst possesses excellent catalytic activities with low overpotentials toward hydrogen evolution reaction (33 mV in 1 mol/L KOH, 6 mV in 0.5 mol/L H2SO4 and 70 mV in 1 mol/L PBS) and oxygen evolution reaction (320 mV) at 10 mA/cm2. Water-splitting and rechargeable Zn-air batteries assembled with the as-synthesized Pt/d-CoP/NPC as electrodes exhibit outstanding activity and long-range stability. Remarkably, sustainable energies and homemade Zn-air battery can efficiently drive the Pt/d-CoP/NPC electrolyzer with sumless hydrogen bubbles generated, verifying the potential applications for renewable energy storage.(c) 2023, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.