Enhancement of Photocatalytic H 2 Evolution on CdS by Loading MoS 2 as Cocatalyst under Visible Light Irradiation

Loading TMDs as co-catalysts to form semiconductor-semiconductor junctions and create more interfaces can greatly enhance charge separation and transport in semiconductor photocatalysts.

“In photocatalytic HERs, charge separation and transport in semiconductor photocatalysts can be greatly enhanced through loading TMDs as co-catalysts to form semiconductor-semiconductor junctions and create more interfaces. [ 36-38 ]”

TMDs as co-catalysts possess comparable catalytic performance with noble metals.

“Notably, these TMDs, as co-catalysts, were demonstrated to possess comparable catalytic performance with noble metals.”

TMD nanosheets have lower cost compared to noble metals.

“Due to the lower cost of TMD nanosheets compared to noble metals, great efforts have been devoted to the preparation of TMD-based composites to improve the photocatalytic hydrogen evolution activity. [ 37,40,46 ]”

Thermal annealing can prepare TMD-based photocatalysts such as MoS2/CdS and WS2/CdS, which show high photocatalytic HER activity.

“By impregnating host materials with TMD precursors (e.g., (NH 4 ) 2 MoS 4 , (NH 4 ) 2 WS 4 ) followed by high-temperature calcination, the Li group prepared TMD-based photocatalysts, such as MoS 2 /CdS [ 37,83 ] and WS 2 /CdS, [ 38 ] which showed high photocatalytic HER activity.”

The photocatalytic activity of CdS (150 μmol g−1 h−1) was increased by up to 28 times with only loading 1 wt% of WS2 (4200 μmol h−1 g−1) and 36 times with only loading 0.2 wt% of MoS2 (ca. 5400 μmol h−1 g−1).

“The photocatalytic activity of CdS (150 µmol g -1 h -1 ) was increased by up to 28 times with only loading 1 wt% of WS 2 (4200 µmol h -1 g -1 ) and 36 times with only loading 0.2 wt% of MoS 2 (ca. 5400 µmol h -1 g -1 ).”