The Mott–Schottky Co2P/Co heterocatalyst encapsulated by N,P-doped graphene/carbon nanotubes as high-efficiency trifunctional electrocatalysts for cable-type flexible Zn–air batteries and water splitting

Abstract

The preparation of highly efficient and low-priced multi-functional electrocatalysts for the hydrogen evolution reaction (HER), oxygen reduction reaction (ORR), and oxygen evolution reaction (OER) is crucial for robust zinc–air batteries (ZABs) and water electrolyzers. Herein, we report the preparation of novel Mott–Schottky Co₂P/Co heterostructures encapsulated by N,P co-doped graphene and carbon nanotubes (Co₂P/Co@N-CNT/NPG) using an in situ pyrolysis strategy, achieving superior trifunctional catalyst performance for the ORR, OER, and HER. The theoretical calculation indicates that the synergistic effect of the Mott–Schottky catalyst could increase the electron transport, trigger the active sites, and enhance the performance toward the ORR/OER. The Co₂P/Co@N-CNT/NPG-based ZAB displays a considerable peak power density of 145 mW cm⁻², and an outstanding cycle-life of 800 h. Furthermore, the flexible ZAB delivers superior mechanical properties with high flexibility, demonstrating its potential feasibility for practical application. Additionally, the water electrolysis device constructed using Co₂P/Co@N-CNT/NPG electrodes requires a small cell voltage of 1.66 V at 10 mA cm⁻², indicating the impressive ability to apply the catalyst for commercial energy storage and harvesting devices.