TiO₂/g-C₃N₄ heterojunctions: In situ fabrication mechanism and enhanced photocatalytic activity

Abstract

In situ fabrication of TiO₂/g-C₃N₄ (TCN) heterojunctions was achieved by a modified sol–gel method. TG analysis was employed to determine the content of TiO₂ in TCN composites. XRD, FTIR, TEM and HRTEM were used to analyze the phase composition, functional groups, morphology and microstructure of as-obtained products, respectively. Based on the measurement of surface Zeta potential of g-C₃N₄, a possible mechanism on in situ fabrication of TCN heterojunctions was concluded. The control experiments indicated that TCN heterojunctions exhibited better photocatalytic performance than either TiO₂ or g-C₃N₄, suggesting that the enchanced photocatalytic activity could be realized by TCN heterojunctions. Then, the evaluation of parameters affecting the photocatalytic performance of TCN heterojunctions was investigated. Even after five cycles, TCN heterojunctions still maintained high photocatalytic activity, exhibiting the good photocatalytic stability. UV-vis absorption spectra showed that almost all MB molecules were decomposed in the photocatalytic process. Finally, the possible mechanism on enhanced photocatalytic performance of TCN heterojunctions was discussed.

Keywords

TiO₂ / g-C₃N₄ / heterojunctions / photocatalytic mechanism

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Acknowledgements

This work was financially supported by the National Natural Science Foundation of China (Grant Nos. 51404083 and 21273060), the Natural Science Foundation of Heilongjiang Province (E2015065) and the Program for New Century Excellent Talents in Heilongjiang Provincial Universities (1253-NCET-010).

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2016 Higher Education Press and Springer-Verlag Berlin Heidelberg