Preparation, Characterization and Photocatalytic Property of p-CoO/n-CdS Compound Semiconductor Photocatalyst

The photocatalysts CdS and p-n coupled semiconductor photocatalysts CoO/CdS (p-CoO/n-CdS) were prepared using cadmium acetate, lauryl mercaptan, cobalt acetate, and stearic acid by a new method. The structural and optical properties of CdS and p-CoO/n-CdS were characterized by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), N-2 adsorption-desorption, and ultraviolet-visible diffuse reflection spectroscopy (UV-Vis DRS). The results showed that the particles of CoO compactly connected with the particles of CdS in the p-CoO/n-CdS. The particle size of CdS was about 100 nm and the crystalloid of CdS was hexagon spiauterite. The particle size of CoO was about 10 nm, and the distribution of particles size was uniform. The results of UV-Vis DRS showed that the nano. CdS particles could absorb the visible light at wavelengths between 400 and 550 nm which is characteristic absorption of CdS in the visible region. The photocatalytic activity of the photocatalyst was evaluated by photocatalytic degradation of methyl orange (MO). The results showed that the photocatalytic activity of p-CoO/n-CdS was much higher, which was 2.2 times than that of CdS on the photocatalytic degradation of methyl orange. The results of photocorrosion test showed that the photocorrosion rate of CdS was two or more times than that of p-CoO/n-CdS, which indicated that CoO coupled with CdS could effectively restrain the photocorrosion of CdS.