Synergistic co-catalyst strategies for photo-thermal CO2 reduction into value-added fuels: A critical review on mechanisms, challenges, and future prospects

Converting carbon dioxide (CO2) into valuable chemicals and fuels using solar energy remains a crucial process for enterprises dedicated to reduce the greenhouse gas (GHG) emissions. However, the currently utilized systems offer unsatisfactory efficiency due to high energy consumption and catalyst deactivation. To address these issues a co-catalyst photo-thermal reduction of CO2 can be adopted for large-scale implementation. This occurs as a result of light incident lowering thermal reaction's energy barrier and producing mild reaction kinetics. In conversion of CO2, photothermal synthesis with a robust and inexpensive catalyst is crucial. It has been seen recently the significant advancements with a comprehensive approach of co-catalyst mechanism of reaction of photothermal, structure-activity relationship, control, monitoring, and regulation of co-catalyst photo-thermal composition and structure. The essential operating concept of reducing CO2 using co-catalyst photo-thermal mechanism and CO2 hydrogenation reaction pathways are covered and discussed in detail. The discussion of cocatalyst photo-thermal mechanism, therefore includes a range of co-catalysts, such as metals, metal-nitrides, metal-phosphides, metal-sulfides, metal-oxides, Layered double hydroxides (LDH) and their derivatives, and metal-carbides. Additionally, a summarized discussion on the co-catalyst photo-thermal process for CO2 reduction is also provided. This process includes hydrogenating CO2 into methane, methanol, hydrocarbons, dry reforming methane with CO2, dehydrogenating CO2 aided ethane, propane (hydrocarbons) and splitting CO2 by thermochemistry. This review also discusses the viewpoints and difficulties of converting CO2 using a cocatalyzed photo-thermal reduction technique. This review's primary goal is to provide a detailed description of the co-catalyst photo-thermal catalyst's design, the process by which CO2 reduction occurs, and the applications of co-catalyst transformation of technology.