Enhanced photocatalytic degradation of remazol black under visible light illumination through s doped tio2 (S-tio2) nanoparticles: Operational factors and kinetic study

The degradation of Remazol Black (RBB) by S-TiO2 photocatalyst was investigated. X-ray diffraction, fourier-transform infrared spectroscopy, scanning electron microscopy, transmission electron microscopy, and UV-vis specular reflectance spectroscopy has been used to characterize S-TiO2. The results suggested that the optical absorption edge of TiO2 was red-shifted by the addition of S dopants and the bandgap energy was 3.02 eV. The sulfur species were found to be evenly dispersed on the TiO2 crystal lattice as cationic sulfur (S6+) which corresponds to the cationic substitution on TiO2. The particle size decreased to 4-14 nm after S doping, which indicates that the addition of S dopants has contributed to an improvement in the photocatalyst surface area. The degradation of RBB was achieved 94 after 120 min visible light irradiation, a remarkable increase compared to bare TiO2 which was only able to degrade 48 of RBB at the same time. Optimization of the pH showed that the optimum pH for RBB degradation was 3.0, and the photocatalyst dose was 0.8 g L-1. Kinetic study showed that S-TiO2 photocatalytic degradation of RBB followed the pseudo-second-order kinetics model. Reducing the bandgap has been found to increase the activity of photodegradation in the visible light region. © 2021 Global NEST.