Boosting Hydrogen Production through Water Splitting: N, Ni, and N-Ni Doped ZnO Photocatalysts

This work investigates the potential of N, Ni, and N-Ni-doped ZnO as photocatalysts for hydrogen production through water splitting. Sonochemical techniques were used to synthesize these materials. In contrast to undoped or singly-doped ZnO, N-Ni-double-doped ZnO demonstrated a significantly narrower band gap (2.89 eV) and smaller crystallites (21.60 nm). This led to a remarkable doubling in the hydrogen production rate under UV-visible light irradiation. The combined effect of N and Ni doping effectively promotes efficient charge separation and enhanced light absorption, resulting in significantly increased photocatalytic activity. Furthermore, N-Ni-ZnO demonstrates exceptional stability, retaining over 95% of its initial activity after five cycles. This work paves the way for the development of cost-effective and scalable photocatalysts for sustainable solar hydrogen production.