Visible‐light‐driven photocatalytic degradation using Mn‐doped SrMoO4 nanoparticles

Mn‐doped SrMoO4 nanocrystals were synthesized by thermal decomposition of metal–organic salt in an organic solvent with the doping content in the range 0–12 mol%. The structures, morphologies and optical properties were characterized using various techniques. The results suggest that Mo sites in the SrMoO4 lattice are substituted by the Mn dopant, the adsorption bands are found to be shifted toward the visible light region and the band gap becomes narrower correspondingly. The photocatalytic performance of the as‐synthesized product was determined using the degradation of methylene blue by visible light irradiation. The photocatalytic performance is enhanced with Mn doping, and the optimal degradation rate is 85% in 140 min for 5 mol% Mn doping. The enhanced photocatalytic activity with Mn doping may be ascribed to the energy band adjustment and effective photogenerated electron–hole separation caused by the Mn doping. A possible photocatalytic mechanism is also discussed. SrMoO4:Mn sample has a good photocatalytic activity for methylene blue degradation. Electron spin resonance analysis suggests both •OH and •O2− radicals play a crucial role in the photocatalytic oxidation process for the Mn‐doped SrMoO4.