Robust binary metal sulphide photocatalyst from design, characterization to photocatalytic application for the efficient degradation of Erichrome black tea

Abstract

Among different types of organic wastes originating from the industrial sector, dyes constitute a major part due to their massive deployment and subsequent elimination. Erichrome Black T (EBT) dye is one of those days, which is incredibly detrimental to sentient (living) creatures due to its significant adverse health properties. Herein, we have focused on the photocatalytic degradation as an efficient process for EBT degradation by employing clean, renewable sources of energy (sunlight irradiations). In this regard, a novel photocatalyst was designed using binary metal sulfide nanoparticles. The solvothermal technique was used to effectively produce iron zinc sulfide nanoparticles (Fe2Zn3S5-NPs). The morphology of the obtained photocatalyst was confirmed by SEM findings, the Fe2Zn3S5-NPs were in the solid powdered form and had a shiny appearance. The average particle size was found to be 61.4 nm. Iron and zinc had noticeable peaks in the EDX spectrum, which corroborated the assertion that the nanoparticles had been fabricated. FTIR spectrum displayed the synthesis of Fe2Zn3S5-NPs functional groups. XRD analysis verified the hexagonal and crystalline structure of zinc and iron nanoparticles with an average crystallite size of 17.84 nm. The bandgap of Fe2Zn3S5-NPs was 1.9 eV using Tauc’s plot and Tauc’s equation. The Fe2Zn3S5-NPs exhibited a superior photocatalytic degradation rate of up to 98.01% for 50 ppm EBT concentration at a catalyst dosage of 0.1 g, pH 3, and for 1 h of solar light irradiation contact. EBT dye photodegraded in the presence of Fe2Zn3S5-NPs following the pseudo-first-order kinetics, and the Fe2Zn3S5-NPs efficiently degraded EBT dye over the course of four cycles, without a noticeable loss in its efficiency. The current study intends to design a novel binary metal sulfide nanoparticles for the efficient and complete removal of dyes from industrial effluents.