TiO2–MnOx–Pt Hybrid Multiheterojunction Film Photocatalyst with Enhanced Photocatalytic CO2-Reduction Activity

Photocatalytic CO2 conversion into solar fuels has an alluring prospect. However, the rapid recombination of photogenerated electron–hole pairs for TiO2-based photocatalyst hinders its wide application. To alleviate this bottleneck, a ternary hybrid TiO2–MnOx–Pt composite is excogitated. Taking advantage of the surface junction between {001} and {101} facets, MnOx nanosheets and Pt nanoparticles are selectively deposited on each facet by a facile photodeposition method. This design accomplishes the formation of two heterojunctions: p–n junction between MnOx and TiO2 {001} facet and metal–semiconductor junction between Pt and TiO2 {101} facet. Both of them, together with the surface heterojunction between {001} and {101} facets, are contributive to the spatial separation of the photogenerated electron–hole pairs. Thanks to their cooperative and synergistic effect, the as-prepared composite photocatalyst exhibits a promoted yield of CH4 and CH3OH, which is over threefold of pristine TiO2 nanosheets films. T...