3D laminated graphitic carbon nitride decorating with 2D / 2D Bi 2 WO 6 / rGO nanosheets for selective photoreduction of CO 2 to CO

Abstract

A novel Bi2WO6/rGO/3D-GCN composite with 2D/2D/3D heterojunction is synthesized by a simple microwave-assisted method and used as a visible-light-responsive photocatalyst in the CO2 reduction. The chemical properties and morphology of prepared photocatalysts are identified by a variety of analytic tools and spectroscopies. As a result, the heterojuncted Bi2WO6/3D-GCN exhibits superior CO2 reduction performance as compared to the pristine 3D-GCN, which may be caused by the intimate contact between Bi2WO6 and 3D-GCN. The harvest of visible-light absorption, reduced charge transfer resistance and suppressed recombination of electron-hole pairs are accountable for surpassing performance of Bi2WO6/3D-GCN. Upon further incorporation of rGO into Bi2WO6/3D-GCN heterojunction, the photocatalytic production of CO can be notably boosted by ca. 7.9-fold higher than 3D-GCN, suggesting the key contribution of rGO in facilitating the interfacial charge transfer kinetics and increasing CO2 uptake. This work exemplifies a time and energy-saving method to prepare the unique 3D GCN with laminated hexagonal structure which can serve as a shuttle for Bi2WO6 heterojunction and rGO incorporation. This Bi2WO6/rGO/3D-GCN photocatalyst could offer the potential applications in the natural solar conversions of CO2.