Facile synthesis of PVA-supported ZnS nano-cottons as recyclable catalyst for the efficient reduction of p-nitrophenol and photodegradation of solochrome dark blue under the sunlight irradiation

In this study, we introduce a highly effective, dual-purpose, and recyclable zinc sulfide catalyst supported on polyvinylalcohol (ZnS@PVA). The catalyst was synthesized using a wet chemical approach and thoroughly analyzed through various spectroscopic and microscopic techniques, including UV–Vis, PL, FT-IR, PXRD, SEM, and EDX. Analysis revealed that the catalyst comprises a mixture of zinc blende cubic and Wurtzite-ZnS phases, with crystallite dimensions of approximately 4.3 nm and 4.9 nm, respectively. The catalyst’s direct band gap was determined to be 4.75 eV. The efficacy of the synthesized catalyst was evaluated in two applications: First, the photocatalytic reduction of 0.5 mmol p-nitrophenol (P-NP) using 20 mg catalyst and 57 mg NaBH4 under sunlight into p-aminophenol (P-AP), achieving an impressive 95% conversion rate within 90 min. Second, the photodegradation of 30 ppm, 100 mL Solochrome dark blue (SDB) dye using 40 mg catalyst at pH 6.0 reaching 90% efficiency in 80 min. Furthermore, the catalyst demonstrated excellent reusability, maintaining its catalytic performance for five consecutive cycles after simple filtration and recovery.