Facile pH-controlled synthesis of MnWO4 nanoparticles and nanorods and their heterogeneous Fenton-like catalytic activity

MnWO4 nanoparticles and nanorods were respectively synthesized in the different pH of reactant solutions by a hydrothermal method. It was found that the pH of reactant solutions not only determined the purity and morphology of the synthesized MnWO4, but also determined the sizes of MnWO4 nanorods. MnWO4 nanoparticles had bigger specific surface area than the obtained different sizes of MnWO4 nanorods. For the degradation of aqueous methylene blue (MB), MnWO4 nanoparticles showed both larger adsorption capacity and higher Fenton-like catalytic activity as compared with MnWO4 nanorods. The mechanism study results demonstrated that the Fenton-like catalytic activity of MnWO4 is predominantly from WO42–. This study suggests that insoluble metal tungstates are a kind of promising heterogeneous Fenton-like catalysts.