Development and detailed investigation of metal nanoparticles decorated carbon black/sodium alginate composite beads for catalytic reduction of environmental toxicants and hydrogen production

The discharge of environmental pollutants requires intellectual and rapid solutions to convert them into safer products. Simultaneously, the high energy demands underscore the imperative importance of generating sufficient green energy to fulfill human needs. This study focused on metal nanoparticles (MNPs) decoration on polymeric beads (BDs), employing orange peel derived carbon black (OrP) and sodium alginate polymer (Alg). The resulting Alg-OrP-BDs serve as a versatile platform for the adsorption of different metal ions and their treatment with a potent reducing agent (NaBH₄) yielding modified BDs catalysts: Ag⁰@Alg-OrP-BDs, Ni⁰@Alg-OrP-BDs, Co⁰@Alg-OrP-BDs, Fe⁰@Alg-OrP-BDs, and Cu⁰@Alg-OrP-BDs. These synthesized nanocomposite catalysts were characterized and exhibit remarkable catalytic reduction capabilities against various nitrophenols and dyes. Notably, Cu⁰@Alg-OrP-BDs emerges as an outstanding catalyst, demonstrating high efficiency in the (>98 %) reduction of 4-nitrophenol and methyl orange with the rates of 1.568 min^-1 and 2.185 min^-1, respectively. Furthermore, its parametric study was investigated to explore the efficiency of the selected catalyst in detail. Similarly, the Cu⁰@Alg-OrP-BDs also enhance hydrogen gas production in various conditions, achieving a rate of 1620.37 mL g^-1 of catalyst min^-1. The purity of the hydrogen was determined using a GC-TCD system. Hence, this study pioneers the development and thorough examination of the Cu⁰@Alg-OrP-BDs catalyst, showcasing its exceptional activity and recyclability.