Enhanced photocatalytic activity and charge transfer of a TiO2/BiVO4 nanostructured composite Electronic supplementary information (ESI) available. See DOI: 10.1039/c9cy01482a

Fabricating binary composites is an effective method for improving photocatalytic performance, whereas the physics basis is debatable due to the limitations of powder specimens. Here, we investigate the photocatalytic performance of a TiO2/BiVO4 nanostructured composite with well spatially resolved TiO2 and BiVO4, which was epitaxially grown on an yttrium stabilized zirconia (001) substrate by pulsed laser deposition. The nanostructured composite showed a 300% enhancement in the apparent quantum yield of rhodamine B degradation at 440 nm. The electron transfer labeled by Ag photodeposition revealed that the band alignment is type II. Charge spatial separation could improve the utilization of not only photogenerated electrons, but also holes.