Piezo-enhanced photocatalysis of MoS2/Bi4O5Br2/PVDF-HFP film for wastewater purification

To date, the piezoelectric field has been demonstrated as a promising approach to inhibit the recombination of photogenerated carrier in photocatalyst applications. Herein we propose a MoS2/Bi4O5Br2/PVDF-HFP piezo-photocatalytic film in the organic pollutants remediation. MoS2/Bi4O5Br2 as the photocatalytic material is incorporated to poly(vinylidene fluoride)-hexafluoro propylene (PVDF-HFP) as the supporting layer via a simple phase transition method. The polarised electric field generated on PVDF-HFP and MoS2/Bi4O5Br2 under aeration synergised with the built-in electric field formed between MoS2/Bi4O5Br2 Z-scheme heterojunction to promote the interfacial charge transfer. The degradation rates of rhodamine B (RhB) and tetracycline hydrochloride (TC) under aeration and visible light irradiation in 60 min reached 98.9% and 92.2%, respectively. Meanwhile, density functional theory calculations (DFT) further demonstrated the effective charge separation and transfer induced by the Z-scheme charge transfer mechanism constructed by MoS2 composite with Bi4O5Br2, as well as the synergistic effect of the double electric field in favour of suppressing carrier recombination. This work provides an interesting solution for effectively combining piezoelectric catalysis with photocatalysis.