In-situ synthesis of WO3 nanoplates anchored on g-C3N4 Z-scheme photocatalysts for significantly enhanced photocatalytic activity

The Z-scheme photocatalysts of WO3/g-C3N4 composites with WO3 nanoplates anchored on the surface of g-C3N4 were synthesized by in-situ acidic precipitation and following calcination procedure. The resultant photocatalysts were characterized by various analytical techniques. This face-to-face intimate contact between g-C3N4 and plate-like WO3 not only increases the interfacial contact areas, but also facilitates the transfer and separation of photogenerated charge carriers. The photocatalytic activities of degradation Rhodamine (RhB) solution over WO3/g-C3N4 composites were evaluated under visible light irradiation. The enhanced photocatalytic activity of WO3/g-C3N4 composite could be attributed to the formation of the Z-scheme heterojunction system based on the active species trapping and hydroxyl radicals photoluminescence (PL) detection experiments. Furthermore, electrochemical impedance spectroscopy (EIS) and transient photocurrent measurements confirm the more efficient separation and transfer of photogenerated charge carriers on the WO3/g-C3N4 composite than that of pure WO3 or g-C3N4. This work would provide new insights into the design and preparation of face-to-face contact heterojunction photocatalysts for organic contaminant removal.