Enhanced Photocatalytic Performance of ZnO through Coupling with Carbon Materials

Abstract

Photocatalytic degradation of organic pollutants is an effective way to overcome environmental pollution. During the past few years, carbon materials have demonstrated great potential to improve photocatalytic performance of ZnO nanomaterials. This review will comment on recent developments of carbon materials (including fullerene, carbon nanotube, and graphene) coupling to improve photocatalytic performance of ZnO for photodegradatation of organic pollutants. The effects of carbon materials on enhancing photocatalytic performance of ZnO include enhancing structure stability, increasing amounts of active sites of pollutant adsorption, boosting electron acceptor formation and transport, enhancing photosensitization, narrowing band gap, etc. Moreover, basic mechanisms how carbon materials enhance photocatalytic activity of ZnO materials are discussed according to the interaction between ZnO and carbon materials. Finally, concluding remarks and current challenges are highlighted with perspectives for future developments of ZnO-based carbon photocatalysts. This review aims at recent research advances on ZnO-based carbon photocatalysts developed for photocatalysis of organic contaminant degradation.

Hollow ZnO microspheres functionalized with electrochemical graphene oxide for the photodegradation of salicylic acid

“…This latter is oen ascribed to pyrolysis of the labile oxygen containing functional groups, yielding CO, CO 2 , and steam. 1, 6,23 The fact that a higher weight loss is observed for GO conrms that the chemical method yields to a larger extent of oxidation with respect to the electrochemical one. The nal mass loss at 600 C is attributed to the sublimation or burning of the damaged graphite regions or the decomposition of the carbon squeleton.…”

“…4,5 Nevertheless, as the band gap of this metal oxide is quite large (3.37 eV), further improvement in the photocatalytic activity has been reported by making composites with carbon-based materials. 6 In particular, graphene oxide (GO) presents different functional groups such as carboxylic acid, hydroxyl, and epoxide groups on its two-dimensional surface that allows functionalization with metal oxides. [7][8][9][10] Additionally to improve the band gap increasing the exciton generation, GO effectively transports the charges to the surface of ZnO nanostructures.…”