1D/3D trepang-like N-modified carbon confined bimetal carbides and metal cobalt: Boosting electron transfer via dual Mott-Schottky heterojunctions triggered built-in electric fields for efficient hydrogen evolution and tri-iodide reduction

Abstract

Tailoring the electronic structure of active centres is a critical strategy for improving the activity of catalysts, but its implementation still remains challenging. Herein, advanced 1D/3D trepang-like N-modified carbon confined Co and Co6Mo6C2 nanoparticles (namely Co6Mo6C2/Co@NC), a dual Mott-Schottky heterojunctions catalyst, is elaborately fabricated by utilizing bimetallic-ZIF and phosphomolybdic acid hydrate. The robust built-in electric field triggered by the dual Mott-Schottky heterojunctions composed of the Co6Mo6C2 and Co with N-modified carbon contact interfaces (Co6Mo6C2|NC and Co|NC) is favorable for transferring electrons and optimizing the electronic structures of the active centres near the Co6Mo6C2|NC and Co|NC interfaces. The 1D/3D Co6Mo6C2/Co@NC achieves a small Tafel slope of 58 mV dec−1. The photovoltaic device assembled with the Co6Mo6C2/Co@NC delivers a power conversion efficiency of 8.45 %. This work not only provides a new avenue for synthesizing high-performance carbon-confined metal and carbide electrocatalysts but also offers valuable insights into the synergistic effect of dual Mott-Schottky heterojunctions.