Synthesis of ZnO2/CuO/ZnO nanocomposite using nanosecond pulsed laser for the reduction of 4-Nitrophenol using NaBH4

Abstract

Efficient catalysts that facilitate the conversion of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) are indispensable for an array of industrial processes. In this study, we synthesized an array of nanostructures including ZnO, CuO, ZnO₂/CuO, and ZnO₂/CuO/ZnO nanocomposites. These materials were then evaluated for their efficacy as catalysts in the reduction of 4-NP. To prepare ZnO₂/CuO nanocomposites, we utilized a pulsed laser ablation technique involving ZnO and CuO in a 5 % hydrogen peroxide solution with a varying concentration of ZnO. The ZnO₂/CuO/ZnO nanocomposites were subsequently fabricated through a post-annealing treatment of the ZnO₂/CuO nanocomposites at a temperature of 200 °C in an air atmosphere. Various analytical methodologies were employed to probe the physicochemical characteristics of the synthesized materials. Our findings revealed that the ZnO₂/CuO/ZnO nanocomposite when fabricated with 5 mg of ZnO nanorods, exhibited superior catalytic performance compared to ZnO, CuO, and ZnO₂/CuO nanocomposites. This research serves a dual purpose: it contributes to the ongoing efforts to develop highly efficient catalysts for the reduction of 4-NP, and it underscores the potential utility of ZnO₂/CuO/ZnO nanocomposites as versatile catalysts. These findings thereby lay the basis for further optimizations and explorations into the catalytic capabilities of ZnO₂/CuO/ZnO.