Efficient visible light driven, mesoporous graphitic carbon nitrite based hybrid nanocomposite: With superior photocatalytic activity for degradation of organic pollutant in aqueous phase

The development of solar light driven photocatalyst for degradation of pollutants in aqueous phase by splitting of water has been an appealing challenge. Herein, visible light induced Na-g-C3N4/DyVO4 nanocomposite with superior photocatalytic activity was synthesized by a facile in situ hydrothermal and ultra-sonication method. The prepared photocatalysts were characterized using standard analytical techniques such as XRD, BET, SEM, EDX, TEM, PT-IR and UV-Vis spectroscopy. The photocatalytic efficiency of prepared material was evaluated by monitoring the degradation of different organic model compounds such as RhB, MO, MB and 4-NP under visible light irradiation as a function of time. The activity was investigated using UV-Vis spectrophotometer and HPLC analysis. Significantly, 15% Na-g-C3N4/DyVO4 nanocomposite possesses superior photocatalytic activity in comparison to the pure forms as well as other composite. The remarkable photocatalytic activity of synthesized composite could be attributed due to generation of heterojunction between Na-g-C3N4 and DyVO4, leading to efficient separation of photogenerated e/h(+) pairs as confirmed by photoluminescence (PL) spectra. The formation of heterojunction between semiconductors also provides synergic effects which can effectively speed up the charge transfer process as well as prolonged lifetime of photogenerated e/h(+) pairs, leading to enhancement in the activity. In addition, experiments of radical scavengers confirmed that h(+) and O-2 are the main reactive species that play an important role for degradation of targeted pollutants. The results also suggest that degradation kinetics of model compounds follows pseudo first order rate as well as displays superb reusability. A possible photocatalytic mechanism for degradation of model compound over Na-g-C3N4/DyVO4 composite has been discussed on the basis of relative band positions of two semiconductors. The present work not only provides a promising visible light induced photocatalyst but also sheds a new insight into the design of highly efficient photocatalyst nanocomposite with versatile photocatalytic applications. (C) 2017 Elsevier B.V. All rights reserved.