Fabrication and assembly of two-dimensional TiO2/WO3·H2O heterostructures with type II band alignment for enhanced photocatalytic performance

The recombination of photo-induced charges is one of the main issues to limit the large-scale applications in photocatalysis and photoelectrocatalysis. To improve the charge separation, we fabricate a novel type II 2D ultrathin TiO 2 /WO 3 ·H 2 O heterostructures with the assistance of supercritical CO 2 (SC CO 2 ) in this work. The as-fabricated heterostructures possess high photocatalytic activity for the degradation of methyl orange(MO) and high photocurrent response under simulated solar light (AM 1.5). For the TiO 2 /WO 3 ·H 2 O heterostructures, the MO solution could be degraded by 95.5% in 150   min, and the photocurrent density reaches to 6.5   μA   cm −2 , exhibiting a significant enhancement compared with pure TiO 2 and WO 3 ·H 2 O nanosheets .