Synthesis and characterization of polythiophene/titanium dioxide composites

Synthesis of TiO2, TiO2/PAni, TiO2/PAni/GO nanocomposites and photodegradation of anionic dyes Rose Bengal and thymol blue in visible light

Nowadays, fast-growing industrialization has resulted in the release of enormous amounts of contaminants such as toxic dyes into water bodies and leading to cause health and environmental risks. In this regard, we prepared inorganic nanocomposites for the treatment of toxic dyes. Hence, we synthesized TiO₂/PAni/GO nanocomposites and examined them by using XRD, SEM, TEM, UV-Vis spectroscopy, BET analysis, and a photoluminescence investigation. In addition, band gap energies of the nanocomposites were determined, and Total Organic Carbon (TOC) testing was used to determine dye degradation levels. The photocatalytic degradations of Thymol Blue and Rose Bengal dyes were investigated at different dye concentrations, illumination periods, solution pH values, and photocatalyst dosages. By using TiO₂/PAni/GO, TiO₂/PAni, and TiO₂ at neutral pH, a photocatalyst dose of 1600 mg/L, and exposure to visible light, Thymol Blue and Rose Bengal were photodegraded 85-99%, 60-97%, and 10-20%, respectively, at a concentration of 25 ppm (180 min). Reductions in the TOCs confirmed their photodegradation, and a kinetic study revealed photodegradation followed first-order kinetics. This study shows the coating of polyaniline (PAni) and graphene oxide (GO) on TiO₂ improved its ability to photodegrade Thymol Blue and Rose Bengal dye.

Predicting the trend and utility of different photocatalysts for degradation of pharmaceutically active compounds: A special emphasis on photocatalytic materials, modifications, and performance comparison

The rapid rise in the healthcare sector has led to an increase in pharmaceutically active compounds (PhACs) in different aqueous bodies. The toxicity of the PhACs and their ability to persist after conventional treatment processes have escalated research in the field of photocatalytic treatment. Although different photocatalysts have been successful in degrading PhACs, their inherent drawbacks have severely limited their application on a large scale. A substantial amount of research has been aimed at overcoming the high cost of the photocatalytic material, low quantum yield, the formation of toxic end products, etc. Hence, to further research in this field, researchers must have a fair idea of the current trends in the application of different photocatalysts. In this article, the trends in the use of various photocatalysts for the removal of different PhACs have been circumscribed. The performance of different groups of photocatalysts to degrade PhACs from synthetic and real wastewater has been addressed. The drawbacks and advantages of these materials have been compared, and their future in the field of PhACs removal has been predicted using S-curve analysis. Zinc and titanium-based photocatalysts were efficient under UV irradiation, while bismuth and graphene-based materials exhibited exemplary performance in visible light. However, iron-based compounds were found to have the most promising future, which may be because of their magnetic properties, easy availability, low bandgap, etc. Different modification techniques, such as morphology modification, doping, heterojunction formation, etc., have also been discussed. This study may help researchers to clarify the current research status in the field of photocatalytic treatment of PhACs and provide valuable information for future research.

A comprehensive review on the photocatalytic activity of polythiophene-based nanocomposites against degradation of organic pollutants

Photocatalytic activity of polythiophene-based nanocomposites.

Time-dependent DFT and experimental study on visible light photocatalysis by metal oxides of Ti, V and Zn after complexing with a conjugated polymer

Tuning the photoactive behavior of transition metal oxide (Ti₂O₄, V₂O₅, Zn₃O₃) cluster units by structural modifications with polythiophene.

The grafting density and thickness of polythiophene-based brushes determine the orientation, conjugation length and stability of the grafted chains

A self-templating surface-initiated method combining ATRP and oxidative polymerization leads to the formation of ladder-like polythiophene-based brushes with a 90–100 mer conjugation length.

Facile synthesis of a polythiophene/TiO2 particle composite in aqueous medium and its adsorption performance for Pb(ii)

A polythiophene/TiO₂ particle composite was synthesized by a facile and green method in aqueous medium to adsorb Pb²⁺ ions from aqueous solution, and both of synthesis and adsorption mechanism were proposed.

Conductive polythiophene-based brushes grafted from an ITO surface via a self-templating approach

Conductive polythiophene-based brushes grafted from an indium tin oxide substrate were fabricated as promising materials with directional conductivity feature for potential optoelectronic applications.

Visible light induced photocatalytic reduction of Cr(VI) over polymer-sensitized TiO2 and its synergism with phenol oxidation

In this study, both Cr(VI) reduction and phenol oxidation induced by polymer-sensitized TiO(2) were investigated under visible light. Study of the reaction mechanism indicated that poly(fluorene-co-thiophene) (PFT) acted as a semiconductor and was by itself able to reduce Cr(VI) under visible light irradiation. When coupled with TiO(2), PFT served not only as the electron donor for Cr(VI) reduction, but also as a sensitizer. Upon irradiation by visible light, electrons in the sensitizing PFT polymer are excited and are transferred to the conduction band of TiO(2). PFT-catalyzed reduction of Cr(VI) was significantly promoted by the presence of phenol, and synergism between Cr(VI) reduction and phenol degradation was demonstrated both by analysis of the FT-IR spectrum of PFT/TiO(2) and by measuring the effect of repeated use of PFT/TiO(2) on its photocatalytic efficiency. The results provide a cost-effective method to remove organic and inorganic pollutants simultaneously in the complex wastewater.

Polythiophene composites: a review of selected applications

Conducting polymers (CPs) provide a class of processible, film forming semiconductors and metals. Electrical and optical properties of CPs, similar to those of metals and semiconductors, and the attractive properties associated with conventional polymers such as ease of synthesis and processing, has given these polymers a wide range of applications in the microelectronics industry, in biological field and also as humidity, chemical and mechanical sensors. The principal interest in the use of polymers lies in the scope for low cost manufacturing. Organic polymers offer several advantages over analogous inorganic semiconductors, the most important of which are the processability and the large surface film technology together with the possibility of tuning the polymer properties through a chemical design of the constituent units. In contrast, problems of environmental stability and the inability to process these into useful devices constitute the main drawbacks of organic materials. To set a material suitable for applications in various technological fields one has to improve the processability, mechanical strength and environmental stability of the polyheterocycles: one method adopted to do this is synthesizing the composites of conducting polymers within a matrix of insulating polymers. In this paper, the science of conducting polymers will be discussed. A review from literature on selected applications of organic devices based on conducting polythiophene and its composites will be discussed with a view to targeting the areas of future research in this topic.

Facile optimal synthesis of inherently electroconductive polythiophene nanoparticles

The straight dope: Polythiophene (PTh) nanoparticles with a narrow size distribution were successfully synthesized by a chemical oxidative polymerization (see image). The highest conductivity of virgin PTh is 3.1x10(-4) S cm(-1) and can be dramatically enhanced to 50 S cm(-1) by doping in iodine vapor.Polythiophene (PTh) nanoparticles were successfully synthesized by a simple chemical oxidative polymerization in the presence of a very small amount of cetyltrimethylammonium bromide (CTAB). The polymerization yield, particle size, bulk electrical conductivity, and solubility of the PTh nanoparticles have been optimized by adjusting the CTAB/FeCl(3) oxidant/thiophene monomer ratio, thiophene concentration, polymerization temperature, and reaction time. The structure of the PTh nanoparticles was systematically characterized by IR and UV/Vis spectroscopy, wide-angle X-ray diffraction, laser particle-size analysis, field-emission scanning electron microscopy (SEM), and transmission electron microscopy (TEM). It was found that the number-average diameter (D(n)) and size polydispersity index (PDI) of the particles decrease significantly from 4.19 microm and 1.21 to 203 nm and 1.056, respectively, with a slightly increasing CTAB concentration. SEM and TEM reveal that the PTh particle size is reduced to 67 and 36 nm, respectively. The conductivity increases on raising the FeCl(3)/thiophene ratio or on lowering the CTAB concentration and polymerization temperature. A moderate monomer concentration and polymerization time are very beneficial for achieving highly conducting PTh. The highest conductivity of virgin PTh is 3.1x10(-4) S cm(-1) and can be further elevated to 50 S cm(-1) by doping in iodine vapor. Under optimized polymerization conditions, the significant variation of the conductivity of the PTh particles in virgin and doped states was well confirmed by the intensity and wavelength of the UV/Vis spectral band owing to the large pi conjugation. The PTh particles demonstrate uncommon characteristics including easy synthesis, low cost of production, large pi-conjugated structure, high conductivity, solution processability, and extensive potential for further application.