Synthesis of Sn-WO3/g-C3N4 composites with surface activated oxygen for visible light degradation of dyes

Sn-WO 3 /g-C 3 N 4 composites were synthesized by calcination method. The materials were characterized with different techniques and photocatalytic activities examined by the degradation of anionic methyl orange (MO) and cationic Rhodamine B (RhB) under visible light. 8% Sn-WO 3 /g-C 3 N 4 showed superior degradation efficiency with 87% MO and 99% RhB dye removal within 120 and 50 min of irradiation time, respectively. X-ray photoelectron spectroscopy (XPS) analysis reveals molecular oxygen adsorption on the surface of the as-prepared composite material. The introduction of tin in Sn-WO 3 solid solution with a high atomic Sn:W ratio of 1:2 and the construction of interfacial hetrojunction with graphitic carbon nitride (g-C 3 N 4 ) plays a vital role to enhance the photocatalytic activity of the as-prepared composites by activating oxygen to react with dye molecules.