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The g-C 3 N 4 porous nanosheets with different loading amount of Ag nanoparticles (NPs) are successfully prepared by a simple liquid-phase reduction method. These Ag/g-C 3 N 4 composites have an improved photocatalytic performance for decomposing organic pollutants compared with that of pure g-C 3 N 4 nanosheets. Many measurements have been used for characterizing the samples, such as XRD, FTIR, UV-Vis DRS, PL, XPS, EDS, SEM, and TEM. In Ag/g-C 3 N 4 , the Ag NPs are uniformly coated on the g-C 3 N 4 surface, the diameter is mainly in the range of 8~18 nanometers. Loading of Ag NPs expand the response to the visible light for g-C 3 N 4 and increasing the producing rate of photogenerated e − -h + pairs. The loading of silver NPs obviously enhances the photocatalytic activity of C 3 N 4 nanosheets toward the Rhodamine B (RhB) decomposition under the simulated sunlight irradiation. With different loading amounts of Ag NPs, Ag/g-C 3 N 4 (3 wt% of Ag) showed the highest photocatalytic activity for RhB decomposition among these as-prepared samples, which is 10 times of the rate of pure C 3 N 4 . Based on the experimental results, a possible photocatalytic mechanism for Ag/g-C 3 N 4 is proposed.

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.