Improving the photocatalytic performance of a perovskite ZnTiO3 through ZnTiO3@S nanocomposites for degradation of Crystal violet and Rhodamine B pollutants under sunlight

Perovskite ZnTiO3 nanoparticles with the cubic structure were synthesized using the hydrothermal method at 160 degrees C for 12 h and annealed at 750 degrees C for 3 h. ZnTiO3@S NCs (nanocomposites) were prepared through solid-state reaction by ZnTiO3 and sulfur powders with different weight percentages (5-20%) at 550 degrees C for 2 h under Ar in the tube furnace. The crystal structure confirmation, morphology, purity, and surface chemical properties of the prepared samples were investigated by XRD, FT-IR, Fe-SEM, EDX, and BET analyses. The results revealed an increase in surface area, crystal size, and the presence of hierarchical porous in ZnTiO3@S NCs, which are due to the influence of sulfur in the ZnTiO3 structure. The optical properties and photocatalytic activity were evaluated by DRS and UV-Vis analysis, respectively. The band gap energy value obtained from the Tauc plots indicated that it narrowed with sulfur content elevation. The excellent photocatalytic activity of ZnTiO3@S NCs exhibited more than 93% degradation for the organic azo dyes of Crystal violet (CV) and Rhodamine B (RB) as a pollutant in 180 min under natural sunlight irradiation. The kinetic behaviors revealed that RB degradation follows the pseudo-first-order kinetic, according to R-2 (0.9914), while the degradation of the CV follows the pseudo-second-order kinetic.