Zeolite NaY-mediated oxidation of dyes with H2O2: unique heterogeneous non-transition metal center cleavage of H2O2 under visible light irradiation

This study investigated the visible-light catalysis mediated by zeolite NaY on the oxidation of dyes with H₂O₂. The results demonstrated that zeolite NaY acts as a sink for the electron from the photo-excited dye in the heterogeneous catalysis. Furthermore, the electron can effectively activate H₂O₂ to produce ^·OH radical that is a powerful oxidant for the oxidation of dye at room temperature. The effects of the framework topology, Si/Al ratio, and exchangeable cation of the zeolite on the oxidation of various dyes were also shown.     

Liquid fragility of the unsaturated polyester resin

Curing behaviors of the unsaturated polyester resin (UPR) containing 1–1.8 wt% methyl ethyl ketone peroxide (MEKP) initiator are investigated. The viscosity, gelation and vitrification transition of the UPR-MEKP systems are examined using the rotating viscometer and differential scanning calorimetry (DSC). A liquid fragility parameter, M _c, defined as the viscosity variation rate of the liquids towards the curing temperature is presented. It is found that M _c has a good negative relation with the glass transition temperature (T _g) in the systems. M _c can be used for predicting the stability of the cured amorphous systems. The relationship between the liquid and cured thermoset polymer systems is studied from both the thermodynamic and kinetic point of view.     

Photo-electrochemical water splitting system with three-layer n-type organic semiconductor film as photoanode under visible irradiation

A three-layer structure of n-type organic semiconductors(PTCDA/PTCDA:PCBM/PCBM) is successfully identified as photoanode for photoelectrochemical water oxidation during the overall splitting of water into hydrogen/oxygen in a nearly stoichiometric ratio(H2:O2=2:1) under visible irradiation(λ > 420 nm).A possible charge separation mechanism under visible light illumination was also proposed.     

TiO_2光催化降解氯酚类有机污染物的反应机理

氯酚类有机污染物具有较高毒性、难生物降解和强生物累积性等特点,成为较受关注的一类优先控制污染物.我们总结了氯酚TiO2光催化降解机理研究方面的最新进展,阐述了直接光解、·OH氧化、1O2氧化、O(3P)氧化、O2·氧化、导带电子还原和表面络合物电子转移等氯酚光降解途径与机理.重点讨论了O2在氯酚吸附、光催化降解乃至矿化过程中的重要作用.     

Zeolite NaY-mediated oxidation of dyes with H2O2: unique heterogeneous non-transition metal center cleavage of H2O2 under visible light irradiation

This study investigated the visible-light catalysis mediated by zeolite NaY on the oxidation of dyes with H2O2. The results demonstrated that zeolite NaY acts as a sink for the electron from the photo-excited dye in the heterogeneous catalysis. Furthermore, the electron can effectively activate H2O2 to produce ·OH radical that is a powerful oxidant for the oxidation of dye at room temperature. The effects of the framework topology, Si/Al ratio, and exchangeable cation of the zeolite on the oxidation of various dyes were also shown.     

Zeolite NaY-mediated oxidation of dyes with H_2O_2: unique heterogeneous non-transition metal center cleavage of H_2O_2 under visible light irradiation

This study investigated the visible-light catalysis mediated by zeolite NaY on the oxidation of dyes with H2O2. The results demonstrated that zeolite NaY acts as a sink for the electron from the photo-excited dye in the heterogeneous catalysis. Furthermore, the electron can effectively activate H2O2 to produce ?OH radical that is a powerful oxidant for the oxidation of dye at room temperature. The effects of the framework topology, Si/Al ratio, and exchangeable cation of the zeolite on the oxidation of various dyes were also shown.     

Supported noble metal nanoparticles as photo/sono-catalysts for synthesis of chemicals and degradation of pollutants

This review summarizes the utilization of supported noble metal nanoparticles (such as Au/TiO2, Au/ZrO2, Ag/AgCl) as efficient photo/sono-catalysts for the selective synthesis of chemicals and degradation of environmental pollutants. Supported noble metal nanoparticles could efficiently catalyze the conversion of solar energy into chemical energy. Under UV/visible light irradiation, important chemical transformations such as the oxidation of alcohols to carbonyl compounds, the oxidation of thiol to disulfid...     

Photocatalytic debromination of decabromodiphenyl ether by graphitic carbon nitride

The graphitic carbon nitride(g-C3N4) is found to be an efficient photocatalyst for the reductive degradation of decabromodiphenyl ether(BDE209) under UV irradiation(>360 nm).g-C3N4 was prepared by heating dicyandiamide.X-ray diffraction,X-ray photoelectron spectroscopy,and UV-vis spectra were used to characterize the properties of as-prepared catalysts.The photoreductive degradation kinetics of BDE209 was further investigated under different reaction conditions.The degradation of BDE209 is a stepwise process,and the bromines at meta positions are much more susceptible to remove than those at the ortho and para positions.A possible photoreductive mechanism was also proposed.     

可见光照射下SiW12O40^4-／Resin光催化剂活化H2O2降解染料的研究

将杂多酸（SiW12O40^4-）负载到阴离子交换树脂上，得到SiW12O40^4-／Resin（SWR）固相光催化剂，在可见光的照射下，可以有效地活化H2O2降解染料．以罗丹明B（RhodamineB，RhB）为模型化合物，研究了不同条件下RhB的降解动力学，以及降解过程中其UV—vis光谱及体系的总有机碳（Total Organic Carbon，TOC）变化情况，结果表明RhB的共轭芳环结构被破坏，矿化率为24．2％．其它染料如孔雀绿（Malacllite Green，MG）和吖啶橙（Acridine Orange，AO）等也可以被降解和矿化．催化剂的循环实验表明SWR固相光催化剂易于分离，并且具有良好的稳定性，可以重复利用．     

Novel 2H-pyrazolo[4,3-c]hexahydropyridine derivatives: Synthesis, crystal structure, fluorescence properties and cytotoxicity evaluation against human breast cancer cells

A series of novel 2H-pyrazolo[4,3-c]hexahydropyridine derivatives (II) have been designed and synthesized. The target compounds have been identified by elemental analysis and spectral (¹H NMR, IR, and MS) data and the absolute configuration of compound (II ₁ ) was confirmed by single crystal X-ray diffraction. The cytotoxicity of the target compounds have been evaluated in vitro against two human breast cancer cell lines MCF-7 and MDA-MB-231 by MTT assay. Most compounds exhibited good inhibition, and compounds II ₂₁ (IC₅₀ = 4.7 μM for MCF-7 and IC₅₀ = 9.3 μM for MDA-MB-231), II ₃₃ (IC₅₀ = 2.4 μM for MCF-7 and IC₅₀ = 4.2 μM for MDA-MB-231) and II ₄₀ (IC₅₀ = 3.3 μM for MCF-7 and IC₅₀ =8.6 μM for MDA-MB-231) displayed better inhibitory activity than 5-fluorouracil (IC₅₀ = 4.8 μM for MCF-7 and IC₅₀ = 9.6 μM for MDA-MB-231, respectively). Flow cytometric analysis and DNA fragmentation suggest that II ₃₃ is cytotoxic and able to induce the apoptosis of MCF-7 cells. The fluorescence properties of compounds II ₁ , II ₆ , II ₁₁ , II ₁₆ , II ₂₃ , II ₂₈ , and II ₃₅ were also studied and compound II ₂₈ afforded the highest photoluminescence quantum yield (38%).