Co4N–WNx composite for efficient piezocatalytic hydrogen evolution

Abstract

A dual-phase transition metal nitride (TMN) based Co₄N–WN_x system has been fabricated using nitridation of CoWO₄. The interface between centrosymmetric Co₄N and non-centrosymmetric WN_x promotes charge carrier separation. This system also shows piezoelectric behavior. The piezoelectric property has been proved using piezoelectric force microscopy (PFM) measurements. In addition, modulating the non-centrosymmetric structure of Co₄N–WN_x allows a hydrogen production rate of about 262.7 μmol g⁻¹ h⁻¹ in pure water. We also show that the piezocatalytic hydrogen evolution efficiency is satisfactory. Co₄N–WN_x can also help achieve simultaneous piezocatalytic hydrogen production and RhB degradation. This work provides a novel strategy for designing efficient piezocatalytic materials.