Tungsten Oxide/g-C 3 N 4 Heterostructures: Composition, Structure, and Photocatalytic Applications

The construction of heterostructures promotes extending the light adsorption range of graphitic carbon nitride (g-C 3 N 4 ) materials, improving the photogenerated charge carrier separation/transfer efficiency for attaining much enhanced performances. Because defective tungsten oxide (WO x ) materials possess rich composition/morphology and an extended light response in the near-infrared region, WO x is a quite popular nanocomponent for modifying g-C 3 N 4, forming heterostructures that can be used for various photocatalytic applications involving water splitting, CO 2 reduction, NO x removal, H 2 O 2 generation, and related chemical to fuel conversion reactions. In this review, important aspects of WO x /g-C 3 N 4 heterostructure photocatalysts are reviewed to provide paradigms for composition adjustment, structural design, and photocatalytic applications of these materials. The WO x growth control in amorphous and crystalline g-C 3 N 4, adjustment on heterostructure types (e.g., type II and Z-scheme), and the catalytic performances of the composite system are also discussed in detail. Moreover, the effects of synthetic methodologies and preparation parameters on the formation of two-dimensional layered heterostructures are discussed to provide inspiration for the construction of state-of-the-art WO x /g-C 3 N 4 heterostructures that can be utilized for photoredox reactions. The challenges and prospects of the heterostructure formation and the photocatalytic applications of the heterostructures in future research are also summarized.