Regulating oxidation states of Cu nanowires for enhanced catalytic reduction of 4-nitrophenol

Abstract The construction of highly efficient and low-cost catalysts is crucial for the reduction reaction of 4-nitrophenol (4-NP). Herein, we provide a simple processing method, including vacuum storage, natural oxidation, and heating oxidation, that effectively regulates the surface oxidation state of copper nanowires and produces copper nanowires with different oxidation states (such as Cu, Cu2O, and CuO). Research has found that CuNW-N (Cu nanowires for vacuum storage) catalysts with a surface composition of 67.9% Cu0, 20.6% Cu+, and 11.5% Cu2+ exhibit the best catalytic performance for the reduction of 4-nitrophenol (4-NP) and their reaction rate constant reaches 0.791 min−1. This work provides a feasible catalyst preparation strategy for the efficient catalytic reduction of 4-NP.