Development of High-Performance Overall Water Splitting Using 2D Black Phosphorus-based Heterostructure

Photocatalytic process for hydrogen production from water is of great significance as it involves inexpensive semiconductor photocatalyst, driven by renewable solar energy and free from any carbon footprints. Most of the scientists engaged in the field of photocatalysis believe that the significant advancement in the field would be driven by its association with photocatalytic materials and nanotechnology. The proposal, therefore, aims to design novel photocatalytic compositions capable of absorbing a wide spectrum of solar radiations for the overall water splitting. The potential compositions include TiO2/BP/Bi2S3, TiO2/BP/Cs2O, WO3/BP/Bi2S3 and WO3/BP/Cs2O. Besides optical properties, another desirable feature attribute is efficient surface and interfacial charge transfer kinetics. The proposed compositions would address two main issues; (1) absorption of a wide solar spectrum covering ultraviolet, visible, near and mid-infrared regions and (2) efficient electron-hole pair separation through double Z-scheme for higher solar to hydrogen conversion efficiency. In the proposed double Z-scheme, CBs electrons that has low potential will transferred to the hole of the materials that have high positive CB. Thus, electrons will accumulate in high positive potential while hole accumulate in high negative potential. The conditions for desired compositions will be optimized and characterized using standard techniques. The performance of the as-prepared photocatalysts will be investigated by monitoring the water splitting process. Experience gained in this study will pave the way for designing more double Z-scheme systems for a solar H2 production and wide practical applications as one of effective green technology. It is worth mentioning that the proposed research falls directly under two main directed research areas at KFUPM, namely (i) renewable energy and (ii) nanotechnology.