Latest progress on the key operating parameters affecting the photocatalytic activity of TiO_2-based photocatalysts for hydrogen fuel production: A comprehensive review

摘要

Photocatalytic hydrogen generation via water splitting is a sustainable, renewable, and promising technology to produce green and clean hydrogen fuel by disassociating water into H-2 and O-2 using TiO2 photocatalyst, and sunlight with negligible impact on the environment, which can fulfill the future requirements of energy. TiO2-based photocatalysts are one of the most effective and widely used photocatalysts for photocatalytic hydrogen production due to their high photostability, abundance, high efficiency, non-toxicity, and low cost. However, TiO2 as a common photocatalyst cannot be easily applied to photocatalysis due to its wide bandgap energy that can only be activated under UV light, which occupies around 2-5% of the solar spectrum and the higher recombination rate of the photogenerated charge carriers before migrating to the surface to split water that restricted its photocatalytic performance. For that, factors such as surface area, particle size, and calcination temperature that affect the photocatalytic activity of TiO2 were highlighted. Additionally, the rational strategies such as doping, composite structure, dyes sensitization, defects engineering, and others that are used in enhancing their activities are described in detail. Importantly, the investigation showed that various parameters such as pH, sacrificial reagent, light intensity, catalyst, cocatalyst loading and catalyst deactivation, have great effects on photocatalytic hydrogen production over TiO2-based photocatalysts. Through reviewing the important state-of-the-art advances on this topic, this comprehensive review may provide new opportunities for designing and constructing highly effective TiO2-based photocatalysts for other applications in photocatalysis.