A novel and highly efficient Ag3VO4/C3N4/reduced TiO2 microsphere composite was obtained through a hydrothermal and depositional process. The microstructure, individual components with different proportions, and optical properties of the ternary nanocomposites were intensively studied. The prepared ternary composites exhibited superior photocatalytic performance of degradation of methylene blue compared with single component and S1 (C3N4/reduced TiO2) binary composites, demonstrating that the introduction of Ag3VO4 into g-C3N4/r-TiO2 can effectively improve the photocatalytic activity. Recycling experiments confirmed that the nanocomposites exhibited superior cycle performance. The enhanced capability could be attributed to a synergetic effect including the formation of heterojunction, large surface area, improved light absorption, matched energy band structure, and the improved separation efficiency of photogenerated charges coming from dual Z-scheme structure. Particularly, the introduction of Ag3VO4 makes the dual Z-scheme charge transfer pathway completed with improved separation efficiency and stronger redox ability of photogenerated electrons and holes. The work provides a promising method to develop a new dual Z-scheme photocatalytic system to remove environmental pollutant.

Novel plate-stratiform nanostructured Bi12O17Cl2 was studied with its visible-light photocatalytic performance. The Bi12O17Cl2 photocatalyst synthesized by a solid-state reaction was constructed of dozens of primary nanosheets, which were stacked by a parallel array of ultrathin secondary nanosheets. The microstructure and crystal structure of Bi12O17Cl2 primary and secondary nanosheets were discovered by high-resolution transmission electron microscopy and selected-area electron diffraction analyses. Its absorption edge was determined as about 590 nm and the band gap energy was 2.1 eV. The Bi12O17Cl2 nanomaterial exhibited superior visible-light-responsive photocatalytic activity and confirmed successful photodegradation of methyl orange (MO) under visible-light irradiation. The degradation efficiency was up to 97% in 90 min. Furthermore, the Bi12O17Cl2 photocatalyst exhibited excellent photostability and high mineralization capacity for MO photodegradation reaction. The MO photodegradation process was dominated by the direct photocatalytic mechanism. The contribution from its morphology and microstructure to superior photocatalytic activity was discussed.