Copper Oxide-Antimony Oxide Entrapped Alginate Hydrogel as Efficient Catalyst for Selective Reduction of 2-Nitrophenol

Copper oxide-antimony oxide (Cu(2)O-Sb(2)O(3)) was prepared and entrapped inside Na-alginate hydrogel (Alg@Cu(2)O-Sb(2)O(3)). The developed Alg@Cu(2)O-Sb(2)O(3) was used as catalytic reactor for the reduction of 4-nitrophenol (4-NP), 2-nitrophenol (2-NP), 2,6-dinitrophenol (2,6-DNP), methyl orange (MO), congo red (CR), acridine orange (AO), methylene blue (MB) and potassium ferricyanide (K(3)[Fe(CN)(6)]). Alg@Cu(2)O-Sb(2)O(3) was found to be selective and more efficient for the reduction of 2-NP among all the pollutants. Therefore, 2-NP was selected for a detailed study to optimize various parameters, e.g., the catalyst amount, reducing agent concentration, 2-NP concentration and recyclability. Alg@Cu(2)O-Sb(2)O(3) was found to be very stable and easily recyclable for the reduction of 2-NP. The Alg@Cu(2)O-Sb(2)O(3) nanocatalyst reduced 2-NP in 1.0 min, having a rate constant of 3.8187 min(−1).