Enhanced photocatalytic activity of cadmium-doped Bi2WO6 nanoparticles under simulated solar light

Novel cadmium-doped Bi2WO6 nanoparticles with different Cd contents have been synthesized by a one-step route using ethylene glycol and water as solvents at 180 °C for 12 h. The as-synthesized samples were characterized in detailed by SEM, XRD, EDS, HRTEM, UV–Vis DRS, BET techniques, and so on. The results shown that with the increase of the Cd2+ addition, the crystal structure, lattice space, and absorption edge were not significantly changed and the calculated band gap value was 2.58 eV. However, the flower-like Bi2WO6 sphere was gradually destroyed. Simultaneously, the surface area and photocurrent responses of the catalysts were greatly increased. Photocatalytic activity of the Cd-doped Bi2WO6 samples was determined by monitoring the change of RhB concentration under simulated solar light. The results revealed that cadmium doping greatly improved the photocatalytic efficiency of Bi2WO6. The Bi2WO6 sample with RCd = 0.05 displayed the highest photocatalytic activity, and the degradation rate is about two times greater than pure Bi2WO6. Moreover, the Cd–Bi2WO6 photocatalyst remained stable even after five consecutive cycles. A possible mechanism of photocatalytic activity enhancement on basis of the experimental results was proposed.