Bimetallic Ni-Hf tellurides as an advanced electrocatalyst for overall water splitting with layered g-C3N4 modification

Abstract

Impressive developments have been achieved in the field of bifunctional electrocatalysts for the overall water splitting in alkaline and weak alkaline electrolytes but still challenging. Herein, we have coupled the early and later transition metals to form novel bimetallic tellurides electrocatalyst for overall water splitting by simple one-step hydrothermal. Because of the large specific surface area of g-C3N4 as substrates, the as-prepared NiTe-HfTe2/g-C3N4 displays appealing electrocatalytic activity and satisfactory stability in both oxygen evolution reaction and hydrogen evolution reaction in alkaline media. Furthermore, the electrolytic cell with two electrodes assembled by NiTe-HfTe2/g-C3N4 demonstrates the same excellent performance in overall water splitting. The strong electronegativity of Te and the synergistic effect between Ni and Hf together contribute to the overall water splitting process. This work provides a novel strategy for the design of bifunctional transition metal–based electrocatalyst to achieve efficient and stable overall water splitting.