Several strategies to improve the Ag/CaTiO₃ (Ag/CTO) photocatalysts for selective photocatalytic CO₂ reduction with water to form CO are shortly reviewed, such as fabrication of well–structured fine crystal photocatalysts with moderate size, modification of Ag NPs cocatalyst with size control or additives, enhancement of surface CO₂ adsorption, development of dual cocatalyst, and improvement of photoabsorption.

Abstract

The rapid increase of carbon dioxide (CO₂) in the atmosphere has sparked a global enthusiasm for carbon recycling. Photocatalytic CO₂ reduction with water into carbon–containing products has attracted much attention since it can convert solar energy to the chemical potential of the products and CO₂ to valuable compounds at the same time. One of the main products in the photocatalytic reaction system is carbon monoxide (CO), a useful compound for the one-carbon chemistry and related ones. The current shortage of this system is the low production efficiency, demanding us to improve the activity of the photocatalyst. In this perspective article, by taking a calcium titanate (CaTiO₃, CTO) photocatalyst with silver cocatalyst (Ag/CTO) and so on as examples that can promote the selective photocatalytic CO₂ reduction with water, we shortly review some strategies to improve the photocatalytic activity such as fabrication of well–structured crystal photocatalysts, development of the surface property and cocatalyst, improvement of surface CO₂ adsorption, and improvement of photoabsorption. These concepts will be widely applied and contribute to further development of photocatalytic systems.