Abstract
The present work offers beneficial method for Hg (II) elimination from aqueous solution. ZnIn2S4/g-C3N4 nanocomposites were synthesized using a sol-gel approach. The prepared ZnIn2S4/g-C3N4 nanocomposites were applied for Hg (II) photoreduction under visible light. Diverse portions of ZnIn2S4 nanoparticles (NPs) were incorporated to g-C3N4 in the formation of ZnIn2S4/g-C3N4 nanocomposites. Morphological investigation of the constructed nanocomposites demonstrated that ZnIn2S4 NPs were successfully incorporated to g-C3N4 as highly dispersed particles with particle size ranging from 8 up to 12 nm over its layered structure. Surface analysis revealed that synthesized ZnIn2S4/g-C3N4 nanocomposites were of mesoporous texture. Photoactivity experiments illustrated that remediation efficiency of Hg (II) utilizing the constructed 3 wt.% ZnIn2S4/g-C3N4 photocatalyst with the load of 2.4 g/L reached 100% when illuminated by visible light for 1 h. Furthermore, Hg (II) removal rate utilizing ZnIn2S4/g-C3N4 photocatalyst at 3 wt.% ZnIn2S4 NPs incorporation was found in the order of 5.5 and 4.1 times greater when related to those over pure g-C3N4 and pure ZnIn2S4 NPs. The major attribution for such achievement is correlated to some consequences like, ease and fast motion of the various species within the mesoporous texture, microscopic particle size of the incorporated NPs, restricted bandgap of the nanocomposite and the extended separation between the induced charges. 3 wt.% ZnIn2S4/g-C3N4 photocatalyst was recycled successfully for Hg2+ elimination, up to five cycles, without marked loss in the removal efficiency. The findings of this research revealed that ZnIn2S4/g-C3N4 nanocomposite could be approved as powerful, durable and stable photocatalyst for remediation of toxic pollutants from wastewater.