Invited feature articleEnhanced visible-light driven photocatalytic activity of hybrid ZnO/g-C3N4 by high performance ball milling

•Heterojunction between ZnO and g-C3N4 was formed by ball milling.•ZnO/g-C3N4 photocatalyst showed superior photocatalytic activity compared to pristine ZnO.•The OH radicals are the dominant active species in photocatalytic process.

The ZnO/g-C3N4 photocatalyst was prepared by ball milling and demonstrated enhanced photocatalytic degradation of RhB under visible light irradiation. The photocatalyst is consisted of ZnO and g-C3N4 heterojunctions formed by the shear stress during the mechanical treatment. The addition of g-C3N4 can improve the photocatalytic performance of ZnO under visible light. The heterojunction formed between ZnO and g-C3N4 decreased the recombination rate of photogenerated carriers and improved the photocatalytic activity of the ZnO/g-C3N4 hybrids. The optimal ZnO/g-C3N4 photocatalyst with 10 wt% g-C3N4 showed a degradation efficiency of 51.3% for RhB under visible light, which is 2.1 times higher than that of pristine ZnO. The electron paramagnetic resonance (EPR) measurement showed that the OH radicals are the dominant active species in photocatalytic process under both full solar spectrum and visible light irradiation. And the OH radical generation is much more efficient under full solar spectrum than that under visible light due to the UV response of ZnO. This work provides a simple method for the design and preparation of novel heterojunction photocatalysts.

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