Catalytic application of second cycle copper-based laboratory waste for synthesis of beta-keto-1,2,3-triazole: A micro circular economy approach

This study follows the circular economy principle to explore the catalytic potential of second-cycle cuprous oxide laboratory waste. Undergraduate students generated cuprous oxide as a second cycle waste during a practical session, where they used an aqueous solution of recycled copper sulfate pentahydrate as a Fehling’s reagent A. The cuprous oxide waste was isolated by a simple filtration method and characterized using infrared spectroscopy, powder X-ray diffraction, X-ray photoelectron spectroscopy, and electron microscopic techniques. The isolated material was used as an active click catalyst to synthesize beta-keto-1,2,3-triazole in an aqueous medium via a one-pot, three-component click reaction. The catalytic activity of the second-cycled cuprous oxide waste was compared with first-cycled cuprous oxide waste and commercial cuprous oxide. We observed that the catalyst was recycled and reused for up to two cycles without significant yield loss. Also, the synthesized beta-keto-1,2,3-triazole was found to show chelating properties towards copper. The catalytic activity of second-cycle Cu-based laboratory waste • Copper-based laboratory waste management, a micro circular economy. • Separation, isolation, and characterization of second-cycle copper-based laboratory waste. • Application of waste-Cu 2 O as an active catalyst for synthesizing β-keto-1,2,3-triazole.