Abstract
Photocatalytic overall water and CO2 conversion splitting under visible light irradiation.
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•Synthesis of phosphorus doped g-C3N4 (P-CN) with its coupling to CdSe quantum dots (QDs).•For band gap engineering conformation DFT and Time depended-DFT were used.•Expending visible-light response of g-C3N4 upto near infra-red region (700 nm).•Photocatalytic Activities for solar fuel production and environmental remediation.
Solar energy harvesting and conversion into useful chemical energy with the aid of semiconductor photocatalysts is a promising technique to solve both energy and environmental issues. This work reports a successful synthesis of CdSe quantum dots (QDs) modified phosphorus doped g-C3N4 (P-CN) for advanced photocatalytic applications. Phosphorus doping and structural coupling with CdSe QDs are shown to significantly extend visible-light response of g-C3N4 up to 700 nm. The optimized sample 4CdSe/P-CN demonstrates enhanced visible-light driven overall water splitting activities for H2 and O2 evolution i.e. 113 and 55.5 μmol.h−1. g−1, respectively, as well as very high photocatalytic CO2 to CH4 conversion efficiency (47 μmol.h−1. g−1). It also exhibit higher activity (78 %) for 2,4-dichlorophenol degradation as compared to pristine CN-sample. Combined photoluminescence, transient/single wavelength photocurrent, photoelectrochemical, and coumarin fluorescence spectroscopy demonstrate that 4CdSe/P-CN nanocomposite exhibit enhanced charge separation efficiency which is responsible for improved visible light catalytic activities. Our work thus provide a new strategy to design low-cost and sustainable photocatalysis with wide visible-light activity for practical overall water splitting and CO2 reduction applications.