Solar light driven pure water splitting on quantum sized BiVO₄ without any cocatalyst

Photocatalytic water splitting is the most promising process to convert solar energy into high purity chemical fuel (hydrogen), which has received significant attention in recent years. Only several photocatalysts have been reported in the literature for pure water splitting under visible light. Herein we report for the first time quantum sized BiVO₄ can decompose pure water into H₂ and O₂ simultaneously under simulated solar light irradiation without any cocatalysts or sacrificial reagents. By electrochemical measurement, we demonstrate that the significantly different photocatalytic activity of the quantum sized BiVO₄ arises from the negative shift of conduction band edge by a quantum confinement effect and a decreased overpotential for water reduction. Although the generated H₂ and O₂ are nonstoichiometric in the present study, these findings establish the great potential of using quantum sized BiVO₄ photocatalyst and solar energy for overall water splitting.