Enhanced electrochromic properties of donor–acceptor polymers via TiO2 composite

Highly Efficient Photocatalytic Degradation of Amido Black 10B Dye Using Polycarbazole-Decorated TiO2 Nanohybrids

The present study reports the synthesis of polycarbazole (PCz)-decorated TiO₂ nanohybrids via in situ chemical polymerization of carbazole monomers in TiO₂ dispersions. The ratio of the polymer in the nanohybrid varied between 0.5 and 2 wt %. The synthesized nanohybrids were characterized using infrared and diffuse reflectance spectroscopies, whereas the morphology was analyzed using X-ray diffraction (XRD) and transmission electron microscopy (TEM) techniques. XRD revealed changes in the peak corresponding to the d(001) plane of TiO₂ owing to the interaction between the two components. TEM confirmed the formation of PCz-decorated nanohybrids. Amido Black 10B (AB-10B) was chosen as a model dye for the degradation studies. Sonophotocatalytic degradation of the dye was studied by varying the catalyst and dye concentrations. Results showed that PCz/TiO₂ nanohybrids exhibited a complete degradation of AB-10B dye within a short span of 60-90 min, which was faster than pure TiO₂ and the reported decorated TiO₂ nanohybrids synthesized by other authors. The degraded dye fragments were identified using liquid chromatography-mass spectrometry (LCMS). By varying the loading of PCz in TiO₂, the nanohybrids could be tuned to achieve visible light-driven degradation.

Multichromic Polymers Containing Alternating Bi(3-Methoxythiophene) and Triphenylamine Based Units with Para-Protective Substituents

Two novel triphenylamine-based thiophene derivative monomers, 4-cyano-4′,4″-di(4-methoxythiophen-2-yl)triphenylamine and 4-methoxy-4′,4″-di(4-methoxythiophen-2-yl)triphenylamine, were successfully synthesized. The corresponding polymers including poly (4-cyano-4′,4″-di(4-methoxythiophen-2-yl)triphenylamine) and poly (4-methoxy-4′,4″-di(4-methoxythiophen-2-yl)triphenylamine) were electrochemically synthesized and characterized by multiple test method. The electrochemical measurements and spectroelectrochemical analyses revealed that both of the two polymers had quasi-reversible redox behavior and multi-electrochromic properties. The two polymer films showed reversible electrochemical oxidation, excellent optical contrasts in NIR region (62% at 1070 nm for the first polymer, and 86% at 1255 nm for the second polymer), satisfactory coloration efficiencies and fast switching times. The research on the application of the as prepared polymer in the fabrication of electrochromic device was also conducted, employing PCMTPA or PMMTPA as the anodically coloring materials.