Ni nanoparticles-loaded ZnO nanowire as an efficient and stable catalyst for reduction of 4-nitrophenol

An amorphous Ni nanoparticles-loaded ZnO nanowire array is controllably constructed on stainless steel mesh through combined electrodeposition and hydrothermal reaction. Its nano-arrayed structure not only provides a platform to achieve stable and good dispersion of Ni nanoparticles, but also helps improve their ability to adsorb 4-nitrophenolate ions and to capture hydrogen radicals, thereby accelerating the hydrogen transfer from metal hydride complex to 4-nitrophenol. Benefiting from the abovementioned unique features, it outperforms most Ni-based catalysts. While a 30-s re-electrodeposition of Ni can provide it extra 150 min of high catalytic activity towards the reduction of waste 4-nitrophenol to valuable 4-aminophenol, further demonstrating its outstanding reusability. The highly general methodology reported here paves the way to economically and effectively synthesize various other metal nanoparticles-loaded ZnO nanowire arrays on different conductive substrates, which not only enrich the nanowire-arrayed catalysts, but also significantly promote their practical utilizations in a wide range of environment-related fields.