Synergistic effect of La and Mo co-doping on the enhanced photocatalytic activity of Bi<inf>2</inf>WO<inf>6</inf>

Abstract

We modified Bi2WO6 with co-doping of La and Mo ions for improving photocatalytic performance depending on the variations in physicochemical properties. The results of XRD and XPS suggest the substitutional replacement of Bi and W sites by La and Mo ions in the Bi2WO6. Also, the incorporation of La and Mo into Bi2WO6 is confirmed by the changes of particle size and lattice spacing, and band gap energy of (La, Mo) co-doped Bi2WO6 from TEM and UV–Vis spectra, respectively. From photodegradation testing of methylene blue (MB), the co-dopants of La and Mo ions with the concentration of 0.25 mol% La and 0.25 mol% Mo exhibit the highest photocatalytic activity. The increased photocatalytic activity on the co-doped Bi2WO6 is attributed to absorption to longer wavelength, the separation of electron-hole pairs, the reduction of particle size, and increasing specific surface area. By using different scavengers to examine the photodegradation process, the electrons are discovered to be the main active species.