Expert development of Hetero structured TiS2-TiO2 nanocomposites and evaluation of electron acceptors effect on the photo catalytic degradation of organic Pollutants under UV-light

In this work, TiO2 co-doped TiS2 nanocomposite were synthesized by a simple co-precipitation method and used as a photocatalyst in the presence of H2O2 for the oxidation of Acid black 1 (AB1) dye under UV light. Highly effective TiO2 co-doped TiS2 was characterized with X-ray diffraction, high-transmission electron microscope images, high-resolution electron microscope images, Diffuse reflectance spectroscopy and photoluminescence spectra. The TiS2-TiO2 nanoparticles have high-specific surface area (101 m(2) g(-1)) and optical bandgap energy of 2.02 eV. Under artificial light, only 58% of AB 1 (100 mL; 20 mg L-1) was photo catalytically degraded by TiS-TiO2 in 90 min reaction. However, after adding H2O2, the photocatalytic activity of TiS-TiO2 was significantly improved, reaching 86% of dye removal. Tests using scavengers of reactive species and Electron paramagnetic resonance spectroscopy (EPR) analysis revealed that h(+) and (OH)-O-center dot are the main species in this system. Based on the experimental results, the mechanism of AB 1 photodegradation in the presence of TiS-TiO2 and H2O2 was proposed. By this mechanism, the (OH)-O-center dot can be formed by direct water oxidation or by H2O2 reduction, as the electron transfer from the conduction band of TiS-TiO2 to H2O2 is thermodynamically favorable. Moreover, the H2O2 retards the electron-hole recombination in TiS-TiO2, thus increasing its photocatalytic activity. Given its high efficiency for degrading AB 1 in water, TiS-TiO2 revealed to be a promising photocatalyst to be tested in the oxidation of emerging pollutants for the environmental decontamination.

Automated summary

In this study, TiO2 co-doped TiS2 nanocomposite was synthesized and used as a highly effective photocatalyst for the oxidation of Acid black 1 (AB1) dye in the presence of H2O2 under UV light. The nanocomposite showed high-specific surface area and optical bandgap energy, contributing to its photocatalytic activity. Addition of H2O2 improved the photocatalytic efficiency by retarding electron-hole recombination in TiS-TiO2, ultimately degrading the dye effectively.