Bi₇O₉I₃/g-C₃N₄/ZnO ternary heterojunction: dual-function efficiency for boosted photocatalytic methyl orange degradation and antibacterial activity

Abstract

In this work, we aim at the successful development of a Z-scheme Bi₇O₉I₃/g-C₃N₄/ZnO ternary heterojunction. The synthesised heterojunction photocatalysts were found to be capable of degrading over 99.13% of methyl orange (MO) within 60 min of visible light exposure under optimized reaction parameters. Furthermore, the photocatalyst demonstrated significant stability and maintained its photocatalytic efficacy during four experimental cycles. This heterojunction made it easier for the photo-generated electrons to move and separate at the interfaces of the semiconductors. Bi₇O₉I₃/g-C₃N₄/ZnO heterojunctions outperformed Bi₇O₉I₃, ZnO, and g-C₃N₄ in terms of visible-region photocatalytic performance due to the formation of a Z-scheme heterojunction. Furthermore, the Bi₇O₉I₃/g-C₃N₄/ZnO exhibited an inhibition zone of 25 mm and 28 mm against Escherichia coli and Staphylococcus aureus. The minimum inhibitory concentration (MIC) of 15.62 and 62.5 μg/mL against E. coli and S. aureus. According to these findings, the Bi₇O₉I₃/g-C₃N₄/ZnO heterojunction is a great photocatalyst for organic pollutant degradation when exposed to visible light, and it also demonstrates the potential of antibacterial properties against S. aureus and E. coli.

Graphical abstract

Keywords

Photo degradation / Dyes / Wastewater treatment / Antibacterial / SDG 6

Highlight

	● Bi7O9I3/g-C3N4/ZnO ternary heterostructures was successfully synthesised.
	● 99.13% MO degradation was observed under visible-light irradiation for 60 min.
	● Z-type heterojunction formation results in better charge separation of carriers.
	● Excellent antibacterial performance was recorded against both E. coli and S. aureus .
	● MIC of 15.62 and 62.5 μg/mL against E. coli and S. aureus was observed.

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