Modifying lewis base on TiO2 nanosheets for enhancing CO2 adsorption and the separation of photogenerated charge carriers

[Display omitted] •TiO2/[WO4]2− composites were prepared via in-situ ion exchange strategy for the first time.•[WO4]2− as a lewis base was used to improve the CO2 adsorption.•[WO4]2− as a lewis base was used to promote the carriers’ separation.•TiO2/[WO4]2− significantly improved the CO yield compared to that of pristine TiO2. TiO2 is one of the most studied in photocatalytic CO2 filed, while its efficiency was seriously limited by the weak adsorption ability for CO2 and low separation efficiency of charge carriers. Here a lewis base [WO4]2− was used to modify TiO2 via an in-situ ion exchange strategy. It was found that the prepared samples showed better performance in CO2 adsorption and carriers’ separation. As a result, the TiO2/[WO4]2− composites had exhibited good activities in photocatalytic CO2 reduction. The amount of generated CO was over 19 times that of the pure TiO2 and it was even much better than precious metal (Ag, Au) modified TiO2. Our experiment proves that this kind of modifying Lewis base method is an efficient strategy for enhancing the CO2 reduction activity of semiconductor photocatalysts.