(a) Shape of TiO₂ sample, (b) photoconductivity experimental set-up.

Novel heterojunctions associating graphitic carbon nitride g-C₃N₄ and S-doped TiO₂ nanoparticles were successfully designed and prepared via a hydrothermal method and used for photocatalytic degradations. The loading in S-TiO₂ nanoparticles on g-C₃N₄ was varied (5, 10 and 20 wt%), and the photocatalysts were characterized by XRD, FT-IR, solid-state UV-visible diffuse reflectance, photoluminescence, XPS, TEM and SEM. The S-TiO₂ (5%)/g-C₃N₄ catalyst exhibits the highest activity for the photocatalytic degradation of the methylene blue (MB) dye under visible light irradiation. The high photocatalytic performance originates from the enhanced separation and transfer of photogenerated charge carriers. The S-TiO₂ (5%)/g-C₃N₄ photocatalyst is stable and can be reused five times without a sharp drop in activity, indicating its high potential for wastewater remediation.

The dynamic response of In₂S₃ films to 4000 ppm of methanol, ethanol and acetone at 350 °C for thicknesses varying from 0.8 μm to 6.1 μm.