Porous graphitic carbon nitride with controllable nitrogen vacancies: As promising catalyst for enhanced degradation of pollutant under visible light

Carbon nitride (CN) materials are considered as promising photocatalysts due to the advantages of easy availability and visible light absorption. However, wide band gap and high recombination rates of electron-hole pairs of conventional CN materials remain the bottleneck of the photocatalysts. Therefore, it is necessary to develop an efficient strategy to narrow band gap of CN and accelerate its charge transfer. In addition, the introduction of nitrogen (N) vacancies is an efficient strategy to narrow band gap and reduce recombination rates of electron-hole pairs. Herein, a novel triazole ring-based graphite carbon nitride (g-CN) is developed by one step pathway of NaOH-assisted condensation of triazole rings for the first time. It is found that NaOH can control N vacancies and band gap of g-C3Nx. Meanwhile, the N vacancies of g-CN, gradually increase with the increasing concentration of NaOH in the range of 0.005-0.1 g, suppressing the recombination of photogenerated electron-hole pairs. The proposed g-C3N5 exhibits outstanding photocatalytical and photoelectrochemical performance. Therefore, the study highlights the significance of N vacancies in enhancing the photocatalytical and photoelectrochemical performance of promising g-C3N5. (C) 2015 Published by Elsevier Ltd.