Rational fabrication of Bi2WO6 decorated TiO2 nanotube arrays for photocatalytic degradation of organic pollutants

Photocatalysis shows great potential in pollution degradation without environmental harm. Herein, TiO2 nanotube arrays (TNTAs) were prepared on titanium mesh by an anodic oxidation method, and Bi2WO6/TiO2 nanocomposites (BWO/TNTAs) with different Bi2WO6 contents were synthesized by a hydrothermal method. The Bi2WO6 nanosheets decorated on TNTAs significantly improved the photocatalytic degradation of tetracycline (TC). 0.2BWO/TNTAs exhibited the degrading rate of 92.2% within 180 min under visible light. The enhancement of photocatalytic performance was ascribed to the II-type mechanism via Bi2WO6 coupled with TiO2, which further extended the visible light absorption range and promoted the charge separation. In addition, •OH is the main active species to dominate the degradation of TC. The possible decomposition mechanism of TC was proposed by gradual loss of hydroxyl groups and C-ring cleavage. It provides a feasible strategy to remove organic pollutants for wastewater treatment.