Synthsis Of Hollow Cu₂O Submicrospheres By SDS-PVP Soft Template And Studies On Properties

Hollow cuprous oxide (Cu₂O) submicrospheres were prepared by simply reducing CuSO4 with N2H4·H2O in the soft template of SDS-PVP necklace-like cluster. XRD pattern shows that the synthesized hollow submicrospheres are pure Cu₂O crystals. The N2 adsorption– desorption isotherms indicate the presence of the inhomogeneous mesopores and macropores. SEM images demonstrate the products are submicrospheres with rough suface and uniform size. The growing progress of the Cu₂O hollow submicrospheres was illustrated by TEM images, and explained by the secondary assembly induced by the the SDS-PVP nacelace-like soft clusters template.The optical properties of Cu₂O hollow submicrospheres was investigated by UV-vis absorption spectroscopy, Cu₂O hollow submicrospheres had a characteristic absorption peaks, and with the decrease of the size of Cu₂O hollow submicrospheres, the characteristic absorption peaks considerably blue-shifted from the absorption of bulk Cu₂O. According to the semiconductor equation, a classical Tauc approach was further employed to estimate the Eg value of Cu₂O hollow submicrospheres.At the same time, the using of UV - visible absorption spectroscopy is to track the reaction process and found that the pure Cu₂O crystals assembled into Cu₂O hollow submicrospheres, the characteristic absorption peak red-shifted with the increase of the size; The photoluminescence spectra of Cu₂O hollow submicrospheres was recorded on fluorescence spectrophotometer, at the same excitation wavelength, the intensity increased while the size reducing which indicated the increase of the photocatalytic activity.The methyl orange solution was photocatalytically degraded with Cu₂O hollow submicrospheres as catalyst. The time of degradation, the effects of the dosage of Cu₂O hollow submicrospheres, the different size of Cu₂O hollow submicrospheres were tested. The experimental results indicated that the best ratio of Cu₂O hollow submicrospheres and methyl orange solution was 0.6 g·L-1, the photocatalysis activity increased with the decrease of Cu₂O hollow submicrospheres size. Moreover, after repetitively using the catalyst for 5 times, its photocatalytic degradation rate could remain above 80%.The electrochemical properties of Cu₂O hollow submicrospheres were preliminary investigated using the Cu₂O hollow submicrospheres modified glassy carbon electrode. The results indicated that the cyclic voltammgrams of Cu₂O hollow submicrospheres on the surface of electrode appeared a pair of symmetrical redox peaks, which were corresponded to the center Cu (â…¡) / Cu (â… ) of Cu₂O hollow submicrospheres. The peak currents were linear to the scan rate, indicating the electrochemical reaction of Cu₂O hollow submicrospheres was a surface controlled process.