Fabrication of ZnO-SnO2 nanocomposite and its photocatalytic activity for enhanced degradation of Biebrich scarlet.

The n-n-type ZnO-SnO2 nanocomposite was fabricated using malic acid following a simple one-pot co-precipitation method. The fabricated ZnO-SnO2 nanocomposite was employed as a photocatalyst in the degradation of Biebrich scarlet dye under UV254 light. TEM, SAED, XRD, XPS, EDX, FTIR, and UV spectra have been recorded to characterize the synthesized ZnO-SnO2 nanostructures. TEM studies found that the average particle size was 10-12 nm, and the SAED confirmed the polycrystalline nature of the synthesized nanocomposite. It was found that 97% of 10 mg/L Biebrich scarlet dye was degraded by 25 mg/L of photocatalyst within 40-min irradiation of UV254 light at an optimum pH of 6. Further studies showed that the degradation followed pseudo-first-order kinetics with a rate constant of 5.48 × 10-2 min-1. The fabricated ZnO-SnO2 nanocomposite was reusable up to 8 times; hence, it proved to be an efficient catalyst for the photodegradation of Biebrich scarlet dye.