Photocatalysis And Adsorption Performance Of Pyrolysis Products Derived From Zn,Ce,Co-organic Complexes

Nanoscale metal oxide has incomparable advantages as its small size, the large reactants contact area and the large volume when comparing with the massive material.Metal oxides especially the semiconductor materials are playing a very important role in photocatalytic area. Throughout the preparation methods of metal oxides, the thermal decomposition process by using the metal organic frameworks as precursors can be an effective method which has been a favourite of researchers. In this paper, we synthesized several metal organic complexes centered in Zn, Ce, Co ions using the hydrothermal method, then ZnO, CeO₂, Co3O₄, CeO₂@C, Co3O₄@C nanomaterials with obvious photocatalytic and adsorption performance are obtained by thermal decomposition methods in air and nitrogen.Two novel metal organic frameworks MOF-072, MOF-076 centered in Zn ion have been synthesized and used as the precusors to obtain ZnO-072, ZnO-076 nanomateials by the thermal decomposition in air. During 150 min UV-light irradiation, the degradation rate of Cr（VI） over ZnO-072 and ZnO-076 can reach 100%, while the degradation rate of Cr（VI）in the presence of MOF-076 was only 35%. In addition, under the same conditions, the photocatalytic activity was 1.5 times higher than the figure of constract sample ZnO-c, the maintained structure and the morphology demonstrate the high stability of the samples before and after thermal docomposition.A kind of Ce-metal organic complex has been synthesized by the hydrothermal method. Ce-Air and Ce-N2 have been obtained by using Ce-complex as the precursor under different atmosphere.Though the degradation rate of MB can reach 80% over Ce-Air and CeO₂-c in UV-light degradation process, the degradation time of Ce-Air was 30 min shorter than CeO₂-c. N2-adsortion and desorption expriments verified the fact that mesoporous Ce-N2 can be used as an effective adsorbents as its high surface area（132m2/g）,the adsorption capacity reached 120mg/g when the initial concentration was 50mg/L.The Co-complex has been successfully prepared using the hydrothermal method.Co-Air and Co-N2 have been obtained by using Co-complex as the precursor under different atmosphere. The degradation rate of Co-Air can reach to 70% which is 10%higher than that of Co3O₄-c during 350 min UV-light irradiation. The sample Co-N2 possesses the surface area of 148m2/g, the adsorption capacity is 35mg/g when the initial concentration is 50mg/L, lower than that of Ce-N2.