Photocatalytic activity of Zn-Cu-S alloy for the removal of dye pollutant: Synthesis, characterization, optimization and DFT insights. (June 2023) - Zarei, Saeid
Highlights: After milling process, a dominant crystalline phase, Cu5 Zn8 alloy, was achieved. Both adsorptive and photocatalytic activities of synthesized alloy were revealed. Pseudo-second-order kinetic model displayed the EBT adsorption properly. The maximum dye removal (∼87%) and adsorption capacity (222.8 mg/g) were obtained. The involved electronic transition states of frontier orbitals were estimated. Abstract: This study synthesized Zn-Cu-S alloy powder using mechanical alloying to eliminate EBT dye pollution. Multiple techniques were used to characterize the alloyed materials. The formation of intermetallic phase, Cu5 Zn8, was realized, after 35 h milling process. After light irradiation, both the adsorption and photocatalytic activity of the alloyed material were observed. The EBT removal process was optimized by varying pH, lamp power, and alloy dosage (g/L) parameters. Response surface plots were employed to investigate the removal percentage of dye. Isotherm and kinetic models were utilized to investigate EBT uptake. The maximum adsorption capacity (qmL ) of 222.8 mg/g was significantly higher than previously reported values. The maximum removal rate was determined to be approximately 87%. DFT calculations estimated the optimized geometry of the ground state of a semiconductor alloy by frontier molecular orbitals and explained the origin of the alloy photocatalyst's electronic transitions. Graphical abstract: Image, graphical abstract