Chitosan modified Cu2O nanoparticles with high catalytic activity for p-nitrophenol reduction

Chitosan modified cuprous oxide (Cu2O-CTS) were prepared via facile chemical reduction method. The morphology and structure of Cu2O-CTS nanoparticles were characterized by transmission electron microscopy, X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and UV-vis diffuse reflectance spectroscopy. The catalytic ability of Cu2O-CTS, both in photocatalysis and electrocatalysis, was carried out on p-nitrophenol reduction. In comparison with the pristine Cu2O, Cu2O-CTS exhibits improved photocatalytic abilities with the reduction rate increased by 1.7 times. The catalytic capacity increases along with the increased proportion of CTS in Cu2O-CTS nanoparticles. Cu2O-CTS modified electrodes shows enhanced electrocatalytic capacities as well, with more positive reduction peak potential and higher peak current. Based on the experimental results, a catalytic mechanism for p-NP reduction over Cu2O-CTS catalysts is proposed. The improvement might come from the reduced band gap energy after the chitosan modification, thus Cu2O-CTS nanoparticles have higher catalytic activity. On the other hand, the more beneficial (111) crystal surface involves in the improvement as well, which endows Cu2O-CTS stronger activity and interaction with p-nitrophenol.