Applied Surface Science, Vol.447, 636-647, 2018
Bi2MoxW1-xO6 solid solutions with tunable band structure and enhanced visible-light photocatalytic activities
Semiconductor photocatalysis is an effective green way to combat water pollution. For the first time, this study reports a novel method to develop Bi2MoxW1-xO6 solid solution with microsphere structure through anion-exchange method. All Bi2MoxW1-xO6 samples exhibit an Aurivillius-type crystal structure without any secondary phase, confirming that in complete solid solutions as the value of x increases, the band gap energy of Bi2MoxW1-xO6 solid solutions decreases, while the optical absorption edge moves to longer wavelength. The Raman spectra research shows an increase in orthorhombic distortion with progressive replacement of W sites in Bi2WO6 with Mo6+ ions. Compared to Bi2MoO6 and Bi2WO6 samples, Bi2Mo0.4W0.6O6 sample displayed best photocatalytic activity and cycling stability for degradation of RhB dye. The enhanced photocatalytic activity of Bi2Mo0.4W0.6O6 sample can be synergetically linked to hierarchical hollow structure, enhanced light absorbance, and high carrier-separation efficiency. Additionally, the hollow Bi2MoxW1-xO6 microspheres formation can be attributed to the Kirkendall effect. (C) 2018 Elsevier B.V. All rights reserved.