Yuanqing Song

Structure and Photocatalytic Activity of Polythiophene/TiO2 Composite Particles Prepared by Photoinduced Polymerization

Polythiophene/titanium dioxide (PTh/TiO2) composite particles were synthesized via the photoinduced polymerization of thiophene in a TiO2-chloroform suspension. The resultant composite particles were characterized by BET analysis, scanning electron microscopy, laser particle size analysis, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy (XPS), and ultraviolet-visible diffuse reflectance spectroscopy (UV-Vis DRS). The XPS spectra indicated that a strong interaction exists between the S sites of the polymer backbone and the TiO2 particles. The UV-Vis DRS spectra showed that the resultant composite particles are responsive to visible light. The photocatalytic activities of the PTh/TiO2 composite particles were examined through the degradation processes of a rhodamine B (RhB) solution under UV irradiation and visible light irradiation. The degradation ratios of the RhB solution were found to be 76% and 98% after UV irradiation (180 min) and visible light irradiation (10 h), respectively. The photocatalysis reactive mechanisms under UV irradiation and visible light irradiation were investigated using disodium ethylenediamine tetraacetate (EDTA-2Na, hole scavenger) and furfuryl alcohol (radical scavenger). The oxidant from the holes and the radicals are competitive. Under UV irradiation, photogenerated holes are the main active species while under visible light irradiation the radicals are the main oxidant for the degradation of RhB.

TiO2/T-PVA Composites Immobilized on Cordierite: Structure and Photocatalytic Activity for Degrading RhB Under Visible Light

AbstractA novel immobilized visible light-active photocatalyst (TiO2/polyvinyl alcohol after thermal treatment (T-PVA)/cordierite honeycomb (CHC)) was successfully prepared by a simple and convenient method combining sol–gel and thermal treatment using tetrabutyl titanate (TBOT) as the titanium source, polyvinyl alcohol (PVA) as the precursor of conjugated polymer, and CHC as the support. The synthesized photocatalyst was characterized by X-ray diffraction, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, ultraviolet–visible diffuse reflectance spectroscopy, and field emission scanning electron microscopy. The results showed that PVA was dehydrated to produce conjugated unsaturated T-PVA. The T-PVA not only extended the response spectrum of TiO2 to visible light region, but also strengthened the adhesion of TiO2 to CHC. The TiO2/T-PVA/CHC showed both outstanding adsorption properties and excellent photocatalytic performance under visible light on the decolorization of Rhodamine B. Over eight cycles, the photocatalyst continued to maintain perfect photocatalytic activity, showing good stability. FigureSchematic illustration of TiO2/T-PVA/CHC composite photocatalyst

Study on the photophysical and electrochemical property and molecular simulation of broadly absorbing and emitting perylene diimide derivatives with large D–π–A structure

To obtain broadly absorbing perylene derivatives with the synchronous impact of the intrinsic π–π* transition of a large conjugated system and intramolecular charge transfer (ICT), we report here the facile synthesis and physical characterization of new N,N′-(di-n-octyl)-3,4,9,10-perylenetetracarboxylic acid diimides (PDI) bearing benzyl-substituted quinoline-4(1H)-ylidene-methyl units as effective donors on the 1,7-positions (C1) and 1-position (C2). Compared to unsubstituted PDI, C1 and C2 both show a pronounced bathochromic shift to the near-infrared region, a high molar extinction coefficient, concentration-dependent π–π-stacking-induced fluorescence and a low LUMO energy level. The investigation of spectroscopic properties and molecular simulation reveal an effective ICT character in compounds C1 and C2. All the properties and analysis indicate that the derivatives are efficient at solar harvesting and are potential candidate materials for use in photovoltaic devices and photocatalysts.

Study of the Thermal Decomposition Behavior of Poly(vinyl alcohol) with NaHSO4

The thermal decomposition behavior of poly(vinyl alcohol) (PVA) with NaHSO4 at 280∼290°C as well as the optical characteristics and the thermal stability of the resulting thermally decomposed PVA were investigated by means of UV-Vis spectroscopy, Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, and thermogravimetric analysis. The results suggest that (1) the elimination reactions of side groups in PVA with NaHSO4 can occur under our conditions resulting in formation of carbon–carbon double and triple bonds; (2) most of the carbon–carbon double bonds were conjugated; (3) the PVA thermally treated with NaHSO4 could absorb light in the region of 190∼600 nm; (4) the thermal stability of the resulting PVA was better than that of PVA without thermal treatment; and (5) compared with the thermal reaction of PVA without NaHSO4, the addition of NaHSO4 can promote the thermal elimination of side groups of PVA.