Yarui Wang,Chengzhuo Yu,Sen Wang,Jin Xu,Fanglan Geng,Silong Wang,Jitao Lv,Lixia Zhao,Yawei Wang
Humic acids (HA) released during algal bloom poses a key challenge for efficient photocatalytic degradation of Microcystin-LR (MC-LR) due to their scavenging function on active species. Herein, MIL-101(Fe)/TiO 2 -P25 (M/P) was constructed to diminish the inhibitory effect of HA on the photocatalytic degradation of MC-LR. Results showed that MC-LR could be efficiently removed assigning to the photogenerated holes (h + ) and superoxide radical (O 2 •− ) oxidation under visible light irradiation, where the carboxy groups of D -glutamic acid (Glu) and methyl- D -aspartic acid (MeAsp), and Adda side chain related to MC-LR biotoxicity were selectively destroyed to achieve MC-LR detoxication. More importantly, HA exerted non-inhibitory effect on MC-LR removal by M/P. The counteracting mechanisms were studied. Firstly, the location of TiO 2 in the pore structure of MIL-101(Fe) could occupy the adsorption sites of HA, and decrease the HA adsorption on M/P. Furthermore, XPS analyses suggested the coordination of unsaturated Fe metal sites on the surface of M/P hybrids complexed with –OH and –COOH of HA, which could accelerate the electron transfer and reduce hole consumption. Thus, the inhibitory effect of HA was alleviated during photocatalytic MC-LR treatment. This work offers a possible way to remove MC-LR in an abundant HA matrix water system efficiently.
Vinylsilane compounds are essential chemical feedstocks and intermediates in organic synthesis. A heterogeneous Cu-containing mesoporous ZSM-5 zeolite catalyst developed through an in-situ doping method can be used for preparing vinylsilane compounds via decarboxylative coupling with remarkable catalytic efficiency. The mesoporous structure along with the appropriate surface area and pore volume of the catalyst is likely to be responsible for facilitating mass transfer in the reaction process. Additionally, due to the suitable Brønsted and Lewis acid active sites, adsorption and activation of reactant molecules can be readily triggered to promote the generation of alkoxyl radicals, which is the crucial species to complete the catalytic cycle. Importantly, the transformation exhibits high efficiency, broad substrate scope, and good reusability for at least six cycles.