Enhanced Stability and Charge Separation of InP by Assembling Al2O3 and Metallic Al for Photocatalytic Overall Water Splitting.

Photocatalytic hydrogen evolution from water is a sustainable approach to producing clean energy and promoting sustainable development. However, the low efficiency of photocatalysts under visible light and even near-infrared irradiation remains the current bottleneck in photocatalytic overall water splitting (POWS). Herein, we introduce an Al2O3/InP/Al photocatalyst with high efficiency and stability, which achieved an apparent quantum efficiency of 0.97% at 500 nm and operated for 10 h without significant performance decay. The high quantum efficiency and stability are attributed to the combination of the electron-rich Al reflective layer and Al2O3 protective layer coating, which synergistically facilitate charge separation. Additionally, the newly generated O2 from water over the Al2O3/InP/Al photocatalyst was removed under reduced pressure, thus inhibiting InP photocorrosion and enabling POWS under visible light irradiation. This study offers valuable insights for the development of efficient solar photocatalysts for water splitting.