Advanced environmental remediation using enhanced performance of hollow ZnO@SnIn₄S₈ core-shell nanorod arrays for hazardous ion and organic pollutant removal

Herein, novel hollow ZnO and ZnO@SnIn₄S₈ core-shell nanorods (NRs) with controlled shell thickness were developed via a facile synthesis approach for the efficient photocatalytic remediation of organic as well inorganic water pollutants. The introduction of SnIn₄S₈ shell layer coating over ZnO enhances visible light absorption, efficient exciton-mediated direct charge transfer, and reduces the band gap of ZnO@SnIn₄S₈ core-shell nanorods. The ZnO@SnIn₄S₈ core-shell nanorods show efficient solar-light driven catalytic efficiency for the disintegration of industrial dye (orange G), degradation of tetracycline, and reduction of hazardous Cr (VI) ions in aquatic systems. The measured photocurrent density of ZnO@SnIn₄S₈ core-shell NRs under illumination of simulated solar light was about nine times higher than ZnO NRs. It has been revealed that charge transfer resistance (R_CT) of ZnO@SnIn₄S₈ core-shell NRs was doubled after the illumination of solar light. The developed ZnO@SnIn₄S₈ core-shell NRs photocatalyst efficiently decontaminate about 99.8 ± 02, 99.98 ± 0.01, and 99.8% of methyl orange, tetracycline, and Cr(VI), respectively. Notably, under similar conditions, ZnO was able to display efficiencies of 29.3 ± 0.6, 27.08 ± 1.1 and 31.1 ± 6.3 % of methyl orange, tetracycline, and Cr(VI), respectively. It was also noted that •O₂^‾, •OH radical, and holes were majorly contributed in the photocatalysis process for disintegration of industrial dye (orange G), tetracycline and finally transform to water and carbon dioxide. Overall, this work explores an intense insight and a novel idea for a hollow core-shell nanocomposite for photocatalytic reduction of diverse pollutants.