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

Heterointerfaces in the form of nanostructures can drastically improve electrochemical water splitting. This study is geared toward the design and development of cobalt telluride (CoTe 2 )-tungsten telluride (WTe 2 ) 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. CoTe 2 –WTe 2 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 CoTe 2 –WTe 2 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.