Synergistic improvement of OER/HER electrocatalytic performance of Cu2Te via the introduction of Zr for water electrolysis

Abstract

Sustainable hydrogen generation from electrocatalytic water splitting has attracted broad interest in addressing energy crises and environmental concerns. A novel Cu_1.845Zr₂Te₆ electrocatalyst is synthesized using a facile hydrothermal approach. The morphology of Cu_1.845Zr₂Te₆ nanoparticles changed after substituting Zr⁴⁺, causing a higher density of surface defects. The Cu_1.845Zr₂Te₆ needs 231/220 mV overpotential with a lower Tafel slope of 28/93 mVdec⁻¹ for OER/HER@10 mAcm⁻², along with long-term stability over a long time. Cu_1.845Zr₂Te₆||Cu_1.845Zr₂Te₆ demonstrated a low cell voltage of 1.48 V@10 mAcm⁻² with 47 h stability for overall water-splitting. The assistance of Zr/Te with Cu ensured well-balanced kinetic behavior, as manifested by the synergetic process and redox activity of Cu_1.845Zr₂Te₆. The bimetallic telluride catalyst with tuned electronic structure between extrinsic high valance Zr⁴⁺ species doping and intrinsic positive valency Cu²⁺ species diffusion leads to increased electronic conductivity. This finding presents an inexpensive and readily available catalyst for practical water electrolysis.