Construction of a 2D/2D WO₃/LaTiO₂N Direct Z-Scheme Photocatalyst for Enhanced CO₂ Reduction Performance Under Visible Light

Abstract

It remains a challenge to search for semiconductor photocatalysts for the overall conversion of carbon dioxide (CO2) with H2O to hydrocarbons. Herein, two-dimensional (2D) WO3 nanosheets were loaded on 2D LaTiO2N microplates to construct a direct Z-scheme photocatalytic system to realize the overall conversion of gas-phase CO2 and H2O without any noble metal cocatalysts or sacrificial reagents under visible light. The optimal performance has been achieved by a WO3/LaTiO2N composite, and the yields of CO and CH4 of 2.21 and 0.36 μmol g–1 h–1 are obtained by reducing CO2, respectively. The total utilized photoelectron number (UPN) has reached 7.3 μmol g–1 h–1, which is approximately 4.3 and 8.7 times higher than that of the pristine LaTiO2N and WO3, respectively. The improved photocatalytic activity for CO2 reduction can be due to the promoted charge separation by the formation of a Z-scheme heterojunction between LaTiO2N and WO3. Moreover, the short charge transfer distance and large contact interface between 2D WO3 and 2D LaTiO2N further accelerate the transfer of photogenerated carriers. This study is anticipated to develop novel perspectives for the reasonable development and preparation of high-efficient 2D/2D Z-scheme photocatalysts for CO2 reduction.