The Fabrication Of Nanostructured Ag₂S/Cu₂O-Co₃O₄ Catalyst And Its Applications For Several Organic-pollutants Degradation

With the increasingly serious environmental pollution, people’s life is threatened and it is very urgent for us to consider this problem. Semiconductor photocatalysis technology is a kind of light-driven activation of the catalyst, and it is widely explored because the technology is simple, high efficiency and low cost. In this paper, we prepared Ag₂S/Co₃O₄ and Cu₂O/Co₃O₄ nanocomposite catalysts used a two-step method, and analyzed their structure characteristics. Meanwhile, the catalytic activity of fabricated heterostructure nanomaterials with different auxiliary reagents（PMS, O3, H2O2） was explored. Moreover, the degradation mechanisms of Ag₂S/Co₃O₄ and Cu₂O/Co₃O₄ catalysts occurred in degradation processes were been studied.According to the SEM images, we founded the optimized reaction time for Co₃O₄ growth was 6 h, and the diameter of Co₃O₄ nanorods around 300 nm. With a high resolution SEM, Ag2 S or Cu2 O nanoparticles have been successfully attached to the Co₃O₄ surface. The XRD and TEM confirm the unique（111）,（220） and（311） planes of Co₃O₄ nanorods, and the（121） planes of Ag2 S. The high resolution TEM shows the average particle size of Ag2 S nanoparticles（15±1 nm）. The XPS results exhibited that there were two track peaks of Co2 p at 780.54 eV（Co2p 3/2） and 795.94 eV（Co2p 1/2）, adding the facts that the spin of energy separated between this two peaks was 15.4 eV and the peak area ratio was 2:1, and it confirmed that the fabricated cobalt oxide was Co₃O₄. Meanwhile, Ag3d5/2 and Ag3d3/2 spin-orbit photoelectron at 367.75 eV and 373.75 eV, Cu2p1/2 and Cu2p3/2 spin-orbit photoelectron at 952.1 eV å’Œ 932.1 eV were also given in the fabricated nanomaterials. The analyzed data confirmed the e xistence of Ag2 S and C u2 O in fabricated heterostructured Ag₂S/Co₃O₄ and Cu₂O/Co₃O₄ catalysts. According to the PL and UV-Vis characterization, the PL intensity and the band energy of Co₃O₄ load by Ag2 S or C u2 O decreased obviously.In order to test the catalytic activity of Ag₂S/Co₃O₄ and Cu₂O/Co₃O₄ catalysts under the functions of visible light and different pro-oxidants, we selected Basic Green（BG1）, methylene blue（MB） and phenol as targets. The degradation process of BG1 in PMS and O3 system indicated that the O3 system showed more efficient and cleaner. It should noted that the free radicals occurred in PMS and O3 system were-?OH and-?O2-. Meanwhile, the MB and phenol degradation with Cu₂O/Co₃O₄ was also investigated, especially the phenol degradation process assisted by PMS and H2O2. The free radicals occurred in PMS and H2O2 system were-?O2- and h+ respectively.