Photocatalytic activity of Cu_2O nanoparticles prepared through novel synthesis method of precursor reduction in the presence of thiosulfate

摘要

A novel fabrication of Cu_2O nanoparticles was successfully achieved through the reduction of Cu~(2+) in the interlayer of montmorillonite (denoted as MT). The Cu_2O nanoparticles formed in the clay interlayer (denoted as Cu_2O/MT) had a lamellate shape of 20-100 nm in width and ca. 039 nm in thickness, and thus, the Cu_2O/MT exhibited a higher specific surface area than neat Cu_2O. The Cu_2O/MT was applied to a photocatalyst, and its photocatalytic activity was examined in terms of water reduction (i e H_2 evolution) in the presence of methanol (electron donor). The Cu_2O/MT showed a high photocataiytic activity in comparison with neat Cu_2O; moreover, the photocatalytic activity was improved by loading a Pt catalyst onto the surface of Cu_2O. Based on the dependencies of photocatalytic activity on light intensity as well as methanol concentration, it was revealed that the H_2 evolution from water on Cu_2O/ MT is the rate-determining step. Thus, the active and efficient photocatalysis of Cu_2O/MT was associated with an increase in specific surface area corresponding to the number of active sites.