Boosting the Photocarrier Separation of PbMoO4 through Facet Collaboration

Boosting photocarrier separation efficiency is a critical step for the catalyst itself or composites based on such catalysts. The use of the reaction raw material to accomplish crystal facet control and ratio optimization is an important and challenging subject in the field of facet engineering, as the activity of the photocatalyst can be improved without introducing impurities. Here, we report the evolution of PbMoO4 from a lamellar to a 26-faceted polyhedron via a wet chemical method. The redox crystal facet ratio does not change the light absorption capacity, but the photocarrier separation efficiency is improved depending on the ratio of oxidized (111)/reduced (001) surfaces. Based on the exposed facet band structure, electrostatic potential, and EDX of photodeposited species, adjacent (101) only contributes to the transport and separation of photogenerated electrons (e–) from (111) to (001), while photogenerated holes (h+) respectively migrate from (101) and (001) to (111) under the different valence band position and electrostatic potential. The collaboration of three crystal planes with a certain ratio maximizes the separation of carriers and produces dramatic changes, such as from the inability of H2O oxidation to the ability of O2 evolution (18.78 μmol/(g·h)). In addition, there are more effective h+ that can simultaneously participate in the oxidation of other substances during the production of reactive oxygen species (ROS). So, a larger ratio of (111)/(001) combined with a harmonized (101) crystal surface makes a PbMoO4 polyhedron that has more excellent photocarrier separation ability and versatile oxidation capacity.