Recent Trends in Hydrogen Generation Using TiO2-Based Photocatalyst via Photocatalytic Water Splitting

Hydrogen energy becomes one of the ideal alternative fuels apart from conventional fossil fuels owing to its clean, renewable, and environmentally friendly nature. Solar fuel generation via photocatalytic water splitting has become the most efficient approach to producing hydrogen. The TiO₂ photocatalyst is the most explored material for hydrogen generation due to its unique features, including photostability, being inexpensive, and being nontoxic. However, it suffers from a wide bandgap (≈3.20 eV), which hinders its large-scale production and commercial viability. Herein, a strategic approach of coupling TiO₂ with low-bandgap materials is reviewed and discussed. Also, modifications of morphology, crystal structure, and composition are also discussed. The rate of hydrogen production of TiO₂-based photocatalysts, charge carrier transfer and migration, and oxidation of the hole scavenger are reviewed and presented. Lastly, future research needs, perspectives, and challenges of TiO₂-based photocatalysts that must be overcome to fully utilize them in photocatalytic hydrogen production through water splitting are discussed.