Green synthesized silver based bimetallic nanoparticles enable sustainable wastewater treatment

Efficient, economical, and sustainable degradation of harmful pollutants is a major challenge in wastewater treatment. This study demonstrates a green synthesis route for the synthesis of AgAu and AgCo bimetallic nanoparticles using Colocasia esculenta stem extract as both a reducing and capping agent. These nanoparticles exhibit well-defined crystalline phases with controlled morphology. Distinct surface plasmon resonance bands verify alloy formation and strong electronic interaction between constituent metals. Phytochemical analysis of the extract reveals flavonoids, phenolics, and terpenoids as the key biomolecules mediating reduction and capping. Catalytic degradation of Rhodamine B with sodium borohydride shows that AgCo BNPs achieve almost complete degradation in nearly half the time compared to AgAu BNPs, owing to enhanced electron transfer facilitated by AgCo coupling. The results highlight the potential of incorporating earth-abundant transition metals into bimetallic systems to reduce noble metal usage while maintaining efficient and sustainable catalytic wastewater remediation.