Highly efficient charge transfer at 2D/2D layered P-La2Ti2O7/Bi2WO6 contact heterojunctions for upgraded visible-light-driven photocatalysis

Abstract

Two-dimensional (2D) layered Perovskite-type La2Ti2O7 has emerged as the most exciting photovoltaic material in the next generation clean energy technologies. This study presents a facile strategy to improve the photocatalytic performance of La2Ti2O7 by energy level engineering via phosphor doping and well-controlled layer-by-layer assembly of stacked P-La2Ti2O7/Bi2WO6 heterojunctions. The non-metal P-type element doping optimizes the electronic configuration and modulates valence states of ions, resulting in enhanced activities of perovskite photocatalyst. Additionally, the integration of 2D Bi2WO6 generates abundant intimate heterogeneous interfacial contacts, which is beneficial for expediting charge separation and effectively suppressing electron–hole pair recombination across the heterojunction, eventually contributing to enhanced photocatalytic efficiency of the system. As a result of synergies, the 2D/2D layered P-La2Ti2O7/Bi2WO6 contact heterojunctions exhibited excellent visible-light-driven photocatalytic activities and sustained cycling performance. An RhB degradation efficiency of up to 99.02% was achieved under visible-light irradiation within 80 min.