Acridone as a new kind of visible light photocatalyst has been developed to catalyze metal free atom transfer radical polymerization (ATRP). The photocatalyst possess low excited state potential as can undergo an oxidative quenching pathway to initiate ATRP of vinyl monomers. Kinetic study and light on/off reaction demonstrate the “living”/controlled nature of the polymerization by light. Block copolymers can be achieved by using PMMA as macroinitiator to reinitiate polymerization of other vinyl monomers, which shows highly preserved Br chain-end functionality in the synthesized polymers. Moreover, the polymerization can be conducted under air atmosphere as most photocatalysts need anaerobic condition, which may give inspiration of further application of this kind of photocatalyst. 相似文献
The hypochlorous acid (HCIO) was synthesized from seawater by the Pt/WO3 photocatalyst under visible-light irradiation. The effect of WO3 morphology and Pt loading on the performance of the composite photocatalyst for the production of HCIO has been studied in detail. The study found that among the series of materials, hollow WO3 microspheres with a diameter of about 3 μm loaded with 1.0 wt% Pt have the best HCIO production performance. Over it, 14.52 μM of HClO (1.24 mg/L of free chlorine) was accumulated in 0.5 M NaCl solution after 2 h of visible-light photoirradiation. What is more, the concentration of HClO can reach 4.34 μM (0.354 mg/L free chlorine) in natural seawater for 1 h using this Pt/WO3 photocatalyst. Under visible-light irradiation, the Pt/WO3 photocatalyst has a good broad-spectrum antibacterial activity and the activity of inhibiting marine fouling algae. The Pt/WO3 photocatalyst has high stability and reusability. All these characteristics are conducive to the application in the field of marine antifouling. Moreover, the photocatalytic reaction mechanism was evaluated by studying the photoelectrochemical properties of Pt/WO3/FTO. This research provides a new strategy for replacing the traditional electrolytic marine antifouling system with the visible-light-catalyzed HClO production system.
With the development of green chemistry, it is still a challenge to maintain the unstable valence state of the metal in heterogeneous catalysts and realize new catalytic synthesis methods. In this paper, it is reported that an univalent copper nanocomposite (Cu@Al/SBA-15) can efficiently catalyze the formation of novel amino-containing benzotriazoles with great fluorescence properties in a new synthetic strategy. Subsequently, its application is further verified by an acylation reaction to produce a series of novel benzotriazoles derivatives with high yield. It is worth noting that the Cu@Al/SBA-15 nanocomposites not only enable the reaction completed with high yield in a short time, but can also be recycled many times without a significant reduction in activity, and the leaching of copper and aluminum species in reaction system is negligible. Finally, the detailed and feasible reaction mechanism is also provided. 相似文献
Surface plasmon can trigger or accelerate many photochemical reactions, especially useful in energy and environmental industries. Recently, molecular adsorption has proven effective in modulating plasmon-mediated photochemistry, however the realized chemical reactions are limited and the underlying mechanism is still unclear. Herein, by using in situ dark-field optical microscopy, the plasmon-mediated oxidative etching of silver nanoparticles (Ag NPs), a typical hot-hole-driven reaction, is monitored continuously and quantitatively. The presence of thiol or thiophenol molecules is found essential in the silver oxidation. In addition, the rate of silver oxidation is modulated by the choice of different thiol or thiophenol molecules. Compared with the molecules having electron donating groups, the ones having electron accepting groups accelerate the silver oxidation dramatically. The thiol/thiophenol modulation is attributed to the modulation of the charge separation between the Ag NPs and the adsorbed thiol or thiophenol molecules. This work demonstrates the great potential of molecular adsorption in modulating the plasmon-mediated photochemistry, which will pave a new way for developing highly efficient plasmonic photocatalysts. 相似文献
Conjugated polymers feature promising structure and properties for photocatalytic water splitting. Herein, a hydrolysis strategy was demonstrated to rationally modulate the surface hydrophilicity and band structures of conjugated poly-benzothiadiazoles. High hydrophilicity not only enhances the dispersions of polymeric solids in an aqueous solution but also reduces the absorption energy of water molecules. Besides, both theoretical and experimental results reveal that a more positive valence band potential is generated, which contributes to enhancing the photocatalytic water oxidation performance. Accordingly, the surface-modified conjugated polymers show largely promoted photocatalytic water oxidation activities by deposition of cobalt oxides as cocatalysts. 相似文献
Nonlinear Dynamics - As a simplified model of structures of many kinds, the Euler Bernoulli beam has proved useful for studying vibration suppression. In order to meet engineering design... 相似文献
Nonlinear Dynamics - This paper proposes an optimal parameter design of control scheme for mechanical systems by adopting the Stackelberg game theory. The goal of the control is to drive the... 相似文献
Reaction of 4,4′,4″-nitrilotribenzoic acid (H3L), a C3-symmetric ligand, with the divalent Co(II) salt Co(NO3)2·6H2O in the present of the N-donor ligand 1,2-di(4-pyridyl)ethylene (DPE) affords a new mixed-ligand coordination polymer with the chemical formula of [Co3(TNB)(DPE)2]·2H2O·DMF (1). In this study, CCK-8 assay was used to determine the effect of novel compound on proliferation of gastric cancer cells. The VEGF signaling pathway in gastric cancer cells was determined through employing real-time PCR after treatment of the above complex. Further, molecular docking simulation confirmed that the biological activity was coming from the carboxyl groups through the hydrogen bonding interactions with the receptor protein, the pyridine group only bonded with the Co ion for the formation of the Co complex. 相似文献