title: Facile, green encapsulation of cobalt tetrasulfophthalocyanine monomers in mesoporous silicas for the degradative hydrogen peroxide oxidation of azo dyes.
abstract: A facile and green approach that improves the catalytic lifetime of cobalt tetrasulfophthalocyanine (CoTSPc) for the degradation of dyes is presented. Structurally ordered mesoporous silicas (MCM-41, MCM-48 and SBA-15), microporous aluminosilicates (ZSM-5) and macroporous alumina (γ-Al(2)O(3)) with different pore sizes were selected for the immobilization of CoTSPc, and a wide range of pH conditions (pH values from 4 to 12) were tested with the CoTSPc immobilization procedure. In the catalytic oxidation study, CoTSPc that was immobilized to MCM-41 silica (CoTSPc@MCM-41) prepared at a pH of 12 showed the longest catalytic lifetime. The TOC removal and discoloration of C. I. Acid Red 73 was approximately 60% and 82%, respectively, in the presence of CoTSPc@MCM-41 with H(2)O(2) after 3h. These results indicate that MCM-41, which has a matching size between its mesopores (30 Å) and CoTSPc molecules (25 Å), can prevent CoTSPc molecules from aggregating and improve its catalytic lifetime. In addition, the ability of CoTSPc@MCM-41 to degrade other dyes, and the reuse studies, demonstrated that CoTSPc@MCM-41 could be reused for the degradation of most common dyes.
authors.affiliation: Institute of Environmental Science, Zhejiang University, Hangzhou 310058, China.
authors.forename: Chensi
authors.initials: C
authors.lastname: Shen
authors.forename: Yuezhong
authors.initials: Y
authors.lastname: Wen
authors.forename: Zhenlu
authors.initials: Z
authors.lastname: Shen
authors.forename: Jing
authors.initials: J
authors.lastname: Wu
authors.forename: Weiping
authors.initials: W
authors.lastname: Liu
mesh_terms: D001391:Azo Compounds / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D006861:Hydrogen Peroxide / Q000737:chemistry*; D006863:Hydrogen-Ion Concentration; D007211:Indoles / Q000737:chemistry*; D009942:Organometallic Compounds / Q000737:chemistry*; D010084:Oxidation-Reduction; D012822:Silicon Dioxide / Q000737:chemistry*; D013056:Spectrophotometry, Ultraviolet
chemical_list: D001391:Azo Compounds; D004396:Coloring Agents; D007211:Indoles; D009942:Organometallic Compounds; C052738:cobalt tetrasulfophthalocyanine; D012822:Silicon Dioxide; D006861:Hydrogen Peroxide