Three-dimensional porous spherical TiO2–Bi2WO6 decorated graphene oxide nanosheets photocatalyst with excellent visible light catalytic degradation of ethylene

Abstract

Porous spherical graphene oxide/TiO2–Bi2WO6 (GTB) composite photocatalysts with different graphene oxide (GO) additions (0, 0.5, 1, 1.5, 2 wt%) are synthesized using hydrothermal and surface-deposition methods. The crystal phase composition, morphology, chemical composition, specific surface area and photoluminescence ability of the catalyst were characterized, and their photodegradation performance was evaluated. The results showed that the catalytic effect of TiO2–Bi2WO6 was significantly improved by appropriate GO addition. The 1.5% GTB provided the best synergistic effect of ethylene photocatalytic degradation, and the reaction rate constant, K′, values was 1.25 × 10−3 min−1 which is 15 times that of TiO2, two times that of Bi2WO6, and 1.25 times that of TB microspheres. This was mainly due to the formation of a ternary heterojunction between GO, TiO2 and Bi2WO6 through the interfacial interaction, which increased the specific surface area, reduced the bandgap, enhanced the utilization of visible light and inhibited the recombination of photogenerated electron–hole pairs, thus showing higher visible photocatalytic activity. GTB photocatalyst also had good stability and reusability.