Joint Electrons and Photons Transfer from Dual-Functional WO3:Yb,Er to Zn0.5Cd0.5S for Efficient H2 Evolution

Utilization of the near-infrared (NIR) light in the solar spectrum is critical for efficiency improvement of photocatalytic H2 evolution. However, common semiconductors have low response to the NIR light and narrow bandgap semiconductors have inappropriate redox potentials. Here, the study presents a new dual-functional up-conversion strategy in one sensitizer for promoting photocatalytic hydrogen production reactions by converting NIR light to visible light and high-energy electrons simultaneously, via photon-photon conversion and photo-electronic process, respectively. Using WO3:Yb,Er as the sensitizer and Zn0.5Cd0.5S as the hydrogen evolution reaction catalyst, a photocatalytic hydrogen release rate of 24.3 mmol g-1 h-1 under simulated solar-light has been achieved without using any co-catalyst. After loading Ni2P as a co-catalyst, the photocatalytic hydrogen production performance can be further improved to 41.3 mmol g-1 h-1 at 10 degrees C and 93.3 mmol g-1 h-1 under non-temperature-controlled conditions, exceeding most photocatalysts. This work offers a new strategy to improve the NIR light utilization of the solar-light for promoting photocatalytic hydrogen generation through synergistic photo-optical, photo-electronic, and photo-thermal effects.