A Hydrothermal Route to Ag-Cu2O/ZnO Heterointerfaced Nanocomposite: Delving into the Synergistic Influence in Visible Light-Driven Synthesis of 1,4-disubstituted 1,2,3-triazoles.

We report a versatile hydrothermal route to synthesize an Ag-Cu2O-decorated ZnO heterointerfaced nanocomposite (Ag-Cu2O/ZnO) for visible-light-driven synthesis of 1,4-disubstituted 1,2,3-triazoles. Extensive characterization with various physicochemical techniques, viz., UV-vis spectroscopy, ICP-OES, FESEM-EDX with elemental mapping, HRTEM with SAED, powder XRD, and XPS, affirmed the formation of Ag-Cu2O nanoparticles on the surface of ZnO. ICP-OES analysis showed an ultralow content of Ag (0.000645 mmol) and Cu (0.00761 mmol) in Ag-Cu2O/ZnO. This heterointerfaced nanocomposite exhibited outstanding photocatalytic efficiency toward the azide-alkyne cycloaddition reaction, affording pharmaceutically important 1,4-disubstituted 1,2,3-triazoles with moderate to excellent yields (up to 98%) under green and sustainable reaction conditions. Surprisingly, the decoration of Ag-Cu2O bimetallic nanoparticles on the surface of ZnO nanoparticles (NPs) reduced the band gap of ZnO NPs and provided active catalytic sites through a synergistic electron-transfer effect. In addition, the nanocomposite exhibited a reduced electron-hole recombination rate, an extended lifespan, and excellent light-harvesting capability. As a result, Ag-Cu2O/ZnO demonstrated excellent photocatalytic efficiency over its monometallic counterparts, substantiating the cooperative influence of the two metals. Notably, the nanocomposite demonstrated magnificent recyclability over six cycles without an apparent loss of activity or structural integrity. Our findings provide experimental validation of a green and sustainable alternative to conventional harsh protocols for the synthesis of 1,4-disubstituted 1,2,3-triazoles.