Enhanced photodegradation of azo dye by Ag2O/SnO2@g-C3N4 nanocomposite

In the present work, we performed a comparative photodegradation study of common synthetic dye Rhodamine B used in the textile industry and as an illegal additive in food under two different light sources (natural sunlight and artificial white light-emitting diode) using catalytic assistance of Ag2O/SnO2@g-C3N4 nanocomposites. The Ag2O/SnO2@g-C3N4 was prepared by fabricating optimal mass ratios of two different metal oxides (Ag2O and SnO2) nanoparticles over the photoactive polymer graphitic carbon nitride (g-C3N4) in two steps of a rational synthesis approach. Structural and morphological characterizations of nanocomposites are carried out using various characterization tools. Photoluminescence spectroscopy confirmed the maximum delayed recombination of photogenerated charge carriers (e(-) and h(+)) in the ternary heterostructure among others counterparts making it a suitable choice for photocatalytic applications. Under Sunlight irradiation, the optimal combination in ternary composites 25% Ag2O/SnO2@g-C3N4 exhibit 7.8 times faster rate constant for azo dye degradation than pure g-C3N4, while under the white light (LED) irradiation, 33% Ag2O/SnO2@g-C3N4 of ternary composite excels with 3.5 times more rate constant to pure g-C3N4. The enhanced degradation performance is attributed to the optimal combination (1:1) of metal oxides over the g-C3N4 structures resulting in more harvest of photons and causing a higher generation of active species for enhanced catalytic activity without leaching of metal traces. The ternary heterostructure with 25% metal oxides loading exhibits similar to 80% catalytic efficiency after 3rd recycles and enhanced mineralization under exposure of sunlight.

Automated summary

In this study, the Ag2O/SnO2@g-C3N4 nanocomposites were used for the photodegradation of Rhodamine B. It was found that the nanocomposites exhibited high catalytic activity and degradation efficiency.