Low-Potential Overall Water Splitting Induced by Engineered CoTe2–WTe2 Heterointerfaces

Abstract

Heterointerfaces in the form of nanostructures can drastically improve electrochemical water splitting. This study is geared toward the design and development of cobalt telluride (CoTe2)-tungsten telluride (WTe2) nanostructures with good porosity and a high specific surface area, leading to faster overall water splitting kinetics. This is attributed to the enhanced synergistic effects of Co and W atoms, which regulate electron transfer and give rise to optimum binding energy for reaction intermediates. CoTe2–WTe2 nanostructures have demonstrated a low oxygen evolution reaction overpotential of 184 mV @ 10 mA cm–2 and a low hydrogen evolution reaction overpotential of 178 mV @ 10 mA cm–2 in alkaline solution. A two-electrode cell with CoTe2–WTe2 nanostructures as both the anode and the cathode exhibits a low cell potential of 1.52 V at a current density of 10 mA cm–2 with good stability for 50 h (7.8% reduction in current density). This study emphasizes the significance of heterointerface design in transition metal telluride electrocatalysts.