Abstract
[Display omitted]
•Herein, spherical flower like Sr-ZnO/g-C3N4 hierarchical composite has been fabricated.•The composite exhibits enhanced photocatalytic activities for pollutant degradation and H2 production.•The enhanced activities are attributed to the obviously promoted charge carrier’s separation.•A Z-scheme mechanism has been proposed for charge separation and transfer.
It is urgent to develop new photocatalytic materials that could optimize H2 generation and efficiently degrade environmentally persistent pollutants. Herein, Sr-ZnO/g-C3N4 spherical flowers composed of hierarchical nano-rods composites have been successfully synthesized via facile single step method and utilized in photocatalysis for efficient degradation of Methylene green (MG) and H2 production under UV–vis irradiation. The resultant Sr-ZnO/g-C3N4 showed enhanced activities for MG degradation (i.e. 96 % in 20 min), and H2 evolution (31.2 μmolh−1 g-1) which is much obvious compared to the bare g-C3N4, ZnO and Sr-ZnO. It is investigated that Sr ion doping has extended the light absorption toward visible light region. The g-C3N4 grafted Sr-ZnO provided an extra boost up absorption spectra in the visible light region compared to bare ZnO. The photoluminescence spectroscopy and photo-electrochemical measurement confirmed excellent photo-generated charge carrier’s separation in the hierarchical structure of spherical flowers. The improved activities are attributed to the combined impact of in-situ doping, hierarchical morphology, and heterojunction formation.