Photocatalytic hydrogen generation using TiO2: a state-of-the-art review

Abstract This review is focusing on photocatalytic hydrogen (H 2 ) production as a viable fuel. The limitations of different production methods for H 2 generation and the importance of photocatalytic process are discussed, which renders this process as highly promising to meet the future energy crises. TiO 2 is one of most effective material to generate the H 2 via photocatalytic processes. Therefore, advantages of the catalyst over other semiconductors have been thoroughly analyzed. Starting from synthesis of TiO 2 and factors affecting the whole process of photocatalytic H 2 production have been discussed. Modifications for improvement in TiO 2 and the photocatalytic reaction are critically reviewed as well as the mechanism of TiO 2 modification has been described. Metal doping, non-metal doping, impurity addition and defect introduction processes have been analyzed and the comparison of experimental results is developed based on H 2 production efficiency. A critical review of the literature from 2004 to 2021 concludes that H 2 production as fuel using TiO 2 photocatalytic method is efficient and environment friendly, which have potential for practical applications for H 2 generation.