Piezoelectric-enhanced photocatalytic purification of wastewater containing tetracycline via MoS₂/ZnO heterojunction

Abstract

Piezoelectric enhanced photocatalytic purification of polluted wastewater is currently one of the better strategies for environmental pollution control. This work proposes a novel and efficient approach for the purification of tetracycline hydrochloride (TC) wastewater via core-shell MoS₂/ZnO heterojunction activated by peroxodisulfate (PDS), where the MoS₂/ZnO heterojunction was fabricated via a hydrothermal route. By exploiting the intrinsic piezoelectric properties of both MoS₂ and ZnO, the heterojunction generates an internal electric field that facilitates the separation of photogenerated electron-hole pairs, thereby accelerating the photocatalytic purification. Under the optimized conditions, the TC purification efficiency can reach 91.2% with the collaborative assistance of PDS activation, and the MoS₂/ZnO heterojunction also exhibited excellent recyclability, maintaining a purification efficiency of 90.76% over five cycles. The MoS₂/ZnO heterojunction demonstrated robust photocatalytic activity under visible-light irradiation and aeration, with the purification kinetics conforming to a pseudo-first-order model. And the purification pathways of TC were systematically investigated, and the dominant reactive oxygen species involved in the process were identified. This work elucidates the underlying piezoelectric-photocatalytic mechanism and provides a sustainable strategy for the efficient removal of antibiotic contaminants from aqueous environments, offering significant potential for practical environmental remediation applications.

Keywords

piezoelectric photocatalysis / tetracycline hydrochloride / peroxodisulfate / MoS₂/ZnO heterojunction

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Central South University