Heterostructured Ag/g-C3N4/TiO2 with enhanced visible light photocatalytic performances

BACKGROUND Titanium dioxide (TiO2) is considered as one of the most potential photocatalysts among various oxide semiconductor photocatalysts. In order to improve the photocatalytic performance of TiO2-based photocatalysts, it is pivotal to explore an efficient method to promote the separation of photoexcited charges, accelerate the carrier transmission efficiency and enhance visible-light absorption. RESULTS In this study, heterostructured Ag/g-C3N4/TiO2 ternary photocatalysts were successfully constructed using a facile accessible route. The structures, morphologies, chemical compositions and optical properties of the obtained composites were characterized by various analytical methods. The performance of the ternary photocatalysts was then tested for degradation of Rhodamine B (RhB) under visible light irradiation. The specimen prepared by loading 2% silver (Ag) nanoparticles onto the composites showed the best photocatalytic activity towards RhB degradation (99.7%) with satisfactory stability. The degradation rate using ternary photocatalyst reached 0.0179 min(-1), almost 20- and 2.3-folds higher than those of pure TiO2 and binary sample. To gain better insights, a possible photocatalytic enhancement mechanism was also proposed. CONCLUSION The improved photocatalytic properties were attributed to the heterostructure between TiO2 and graphite carbon nitride (g-C3N4) as well as the loading Ag nanoparticles. The formation of the heterostructure between TiO2 and g-C3N4, combined with the load of Ag nanoparticles created a synergistic effect, leading to the enhanced photocatalytic performance. Overall, these findings look promising for future photodegradation of organic pollutants. (c) 2019 Society of Chemical Industry