Ternary Metal Chalcogenide Heterostructure (AgInS2–TiO2) Nanocomposites for Visible Light Photocatalytic Applications

Hybrid nanoarchitectures of AgInS 2 and TiO 2 photocatalysts were prepared by using a modified sol-gel method. The experimental results reveal that these nanocomposites display enhanced visible light absorption and effective charge carrier separation compared to their pristine parent samples (AgInS 2 or TiO 2 ). 0.5 wt % AgInS 2 loading was found to be the optimum concentration for photocatalytic applications. More than 95% of doxycycline degradation was achieved within 180 min of solar light illumination. Similarly, the dopant concentrations at lower values (<2 wt %) exhibited 300 times higher H 2 generation rate under visible light irradiation compared to AgInS 2 and TiO 2 . The microbial strains ( Escherichia coli and Staphylococcus aureus ) exhibited a 99.999% reduction within half an hour of simulated solar light illumination. The computational investigation was employed to understand the structural, electronic, and the dielectric properties of AgInS 2 and TiO 2 composites. The improved photocatalytic results are explained as a result of the decreased rate of exciton recombination. The current investigation opens up new insights into the use of novel ternary heterostructure nanocomposites for improved visible light activity.