A review of strategies to improve the performance of photocatalysts for CO2 reduction

One of the main gases that contribute to the greenhouse effect is carbon dioxide (CO2), which is also an important industrial resource. The reduction of CO2 through a chemical reaction driven by solar energy has the potential to not only reduce CO2 emissions but also address energy problems. The photocatalytic reduction of CO2 to produce valuable products has been extensively explored and studied as a promising research approach. However, many of the original materials exhibit low or no catalytic activity, which hinders their direct use in the photocatalytic reduction of CO2. Therefore, appropriate strategies are needed to enhance the activity of photocatalysts. Several factors significantly affect the photocatalytic performance of catalysts, including their ability to adsorb CO2 and other reactants, their band gap and light absorption ability, their capability to separate and transfer photo-generated charge carriers, and their ability to combine electrons and holes. We summarized and discussed the latest developments in ideas and methods for enhancing the activity of different photocatalysts, and raised corresponding problems, concerns, and insights on the current research status. By providing an in-depth understanding of photocatalyst modification strategies, this review offers suggestions for improving their performance, ultimately highlighting the research challenges and prospects for the development of photocatalytic CO2 reduction technology.