An efficient ternary photocatalyst Ag/ZnO/g-C3N4 for degradation of RhB and MG under solar radiation

Industrial dyes are the crucial reason for water contamination. Due to their recalcitrant nature, these toxic dyes represent a significant risk to aquatic creatures as well as carcinogens to human beings. The common methods used for the removal of dyes for example electro-coagulation, reverse-osmosis, and ultra-filtration are cumbersome, expensive, and non-repeatable. In this study, a cost-effective, environmentally benign, and recyclable nanocomposite material for effective solar photodegradation of Rhodamine B (RhB) and Malachite green (MG) was discussed. Silver doped ZnO nanoparticle modified g-C3N4 was fabricated by chemical precipitation procedure where melamine was taken as a precursor. The results showed that the modification of g-C3N4 with Ag/ZnO has increased activity under visible light and is suitable for photodegradation when compared to the neat g-C3N4. The percentage of dye degradation increased with an increase in agitation time. The efficiency was almost 97% for RhB in 30 min and 91% for MG with Ag/ZnO/g-C3N4 in 60 min. The deprivation of dye by the photocatalytic nanocomposite was studied using first-order kinetics. The First-order rate constant (K) determined by using ternary nanocomposite Ag/ZnO/g-C3N4 had a greater reactivity than the pure g-C3N4. The most important reactive species in the photocatalytic reaction over Ag/ZnO/g-C3N4 are detected as superoxide radicals (O-2(-center dot)) and hydroxyl radical (OH center dot) by using the quenching test. Several sophisticated techniques like powder XRD, SEM, EDAX, FTIR, and UV-Vis DRS were used for the characterization of synthesized nanocomposites. Doping of Ag nanoparticles has increased the response towards visible light for g-C3N4 and also an increase in the rate of photogenerated electrons thereby reducing electron-hole recombination.

Automated summary

Industrial dyes are a major source of water contamination, and common methods for dye removal are cumbersome and expensive. The study showed that the Ag/ZnO/g-C3N4 nanocomposite material has higher activity under visible light, leading to efficient photodegradation of Rhodamine B and Malachite green.