Hydrothermal synthesis of porous copper microspheres towards efficient 4-nitrophenol reduction

Abstract A facile one-pot approach has been presented to synthesize porous Cu microspheres (PCMs) with diameters of 2⿿5 μm. The self-organised growth mechanism is proposed according to the product formation order of CuxO nanoparticles, Cu nanobranches (CNBs), PCMs, solid Cu microspheres (SCMs) and distorted Cu microspheres. The experimental parameters of reaction time, temperature and reactant amounts can be used to regulate the kinetics of nucleation and crystallization, and further control the morphologies and porosities of the Cu products. Compared with the as-synthesized CNBs, SCMs and the commercial Cu powders, the PCMs show improved catalytic activity for the reduction of 4-nitrophenol to 4-aminophenol, demonstrating the significance of the porous structures. Furthermore, this porous Cu catalyst exhibits superior recycle and long-term air stabilities, which makes it a highly attractive candidate for industrial applications at low cost.