Integration of WO_x/1D C₃N₄/2D C₃N₄ multi-junction through in-situ “PTA-Mel” ionic microenvironment for efficient aromatic wastes degradation via charge carrier separation improvement

High photogenerated carrier recombination inhibits the widespread application of graphite-phase carbon nitride (g-C₃N₄). Construction of junctions is an effective strategy but still under challenges, such as tedious procedure and limited efficiency. Herein, WO_x/1D g-C₃N₄/2D g-C₃N₄ multi-junction with enhanced separation of photogenerated carriers was one-pot integrated through in-situ “PTA-Mel” ionic microenvironment by mixing phosphotungstic acid (PTA) and melamine (Mel). Protonated Mel by PTA contributed to the formation of 1D g-C₃N₄ and the decomposition of [P(W₃O₄₀)₄]^3- produced WO_x. 1D g-C₃N₄ and WO_x with oxygen-vacancy deficient provided channels and caves for photoelectrons transfer, respectively. Compared with pure g-C₃N₄, the degradation rate constants of Rh B and tetracycline hydrochloride (TC) by WO_x/1D g-C₃N₄/2D g-C₃N₄ are 2.34 and 1.45 times high respectively due to the excellent visible light absorption and improved photogenerated carrier separation. This method could be extended to the design of multiple heterojunctions in one photocatalyst through a facile process.