High photocatalytic performance by engineering Bi2WO6 nanoneedles onto graphene sheets

Abstract

A facile sonochemical method was developed in this study to engineer Bi₂WO₆ (BWO) nanoneedles onto graphene sheets, producing a graphene/BWO composite. BWO was in situ formed on reduced graphene oxide during ultrasonic processing, and the subsequent thermal treatment produced BWO nanoneedles which were homogeneously dispersed on the surface of graphene sheets; these needles, with a cross section size of ∼450 nm at the bottom and an average length of 2500 nm, grew nearly vertically on the sheets. When used as a photocatalyst, the composite produced a high quantity 23.61 μmol h⁻¹ of O₂ from water, 4.79 times higher than that by neat BWO powder; it also created H₂ at 234.83 μmol h⁻¹. It was found that the reduction of graphene oxide plays a key role in fabricating nanoneedles and ultrasonication can promote the interaction between graphene and BWO. Thus, the strategy provides an efficient approach for the fabrication of graphene composites containing nanoneedles.