Tailoring interfacial S-scheme heterojunction and porous ternary nanocomposite: its highly efficient CO2 reduction in an aqueous solution

A calcination-assisted hydrothermal method was used to successfully prepare a series of porous boron nitride/Cu/Al2O3 composites. All of these nanocomposites were found to have efficient separation and migration for photoexcited electron-hole pairs, which provide an abundance of photoinduced electrons for the CO2 redox reaction and holes for the water oxidation reaction, which can be used for the photoreduction of CO2. The charge carrier process of the pBN/Cu/Al2O3 nanocomposites labeled as the S-scheme heterojunction system contributed to the prompt separation and transfer of photogenerated charge carriers. The introduction of porous boron nitride (pBN) supplies adsorbed CO2 to the surface of Cu/Al2O3 while suppressing undesirable side reactions. The addition of the basic salt NaHCO3 enhances S-scheme CO2 reduction because of the efficient supply of hydrated CO2 molecules to the photocatalyst surface. Thus, the photocatalytic CO2 reduction test further confirmed that the formation of the hybrid pBN/Cu/Al2O3 efficiently increases the methanol production rate. The excellent photocatalytic properties of pBN/Cu/Al2O3 are anticipated to be of great significance for the development of photocatalyst materials for CO2 reduction tests, as well as the tunable chemical and structural properties of pBN at advanced levels, given the electrochemical and surface structural tunability of pBN/Cu/Al2O3.