#Scidavis emission spectrum full

Last but not least, the bonding way of polythiophene and TiO 2 heterojunction determines the photogenerated charge separation and transfer capacity. Meanwhile, the wavelength of the conjugated polymer optical response used in the above study is almost below 600 nm, which cannot be effectively utilized in the visible band. However, the poor stability for long term application was not mentioned in above experiments, or the decolorization rate of organic pollutants was only about 60% after three repetitions. PTh can be coated on the surface of metal oxides, act easily as a sensitizer to metal oxides 29. The polythiophene/TiO 2 composites had attracted widespread attention for degradation of various dye 25, 26, 27, 28, which have been shown to effectively lower the band gap by allowing greater adsorption in the visible region and prevent the recombination of photoelectrons and holes. Polythiophene (PTh) and its derivatives, have been widely explored in the field of environmental governance thanks to their easy to synthesize, long-time stability, high carrier migration efficiency, and controllable narrow band gap. In this heterojunction, the conjugated polymers as p-type donor materials can serve as one of the best photosensitizers 23, 24. The conjugated polymers/TiO 2 heterojunction might be a promising strategy to adresss above issues. Most recently, conjugated polymers as the useful organic semiconductors, due to their ability of light absorption and well-tuned energy levels, attract a mass of attention for their promising applications in visible-light responsive pollutant degradation.

#Scidavis emission spectrum full

Unfortunately, the mismatched energy level, full visible-light-responsive range and high charge separation efficiency are still challenging to tune and control for achieving high-efficient photocatalysts. The TiO 2/semiconductors heterojunction photocatalysts have been proved to be a valid mean of optimizing the photocatalytic activity via improving visible-light responsive ability and the efficiency of photo-generated electron-hole separation 18, 19, 20, 21, 22. However, the poor carrier separation efficiency and invisible-light responsiveness are the huge obstacles for their practical application 16, 17. As one of the most promising catalysts, TiO 2 has demonstrated successful performances in degrading organic pollutants with the merits of excellent chemical stability, low-cost, nontoxic and redox capability 15. So far, the wide-bandgap metal-semiconductors such as TiO 2, ZrO 2, ZnO, and SrTiO 3 as popular photocatalysis materials have been widely used 11, 12, 13, 14. Semiconductor photocatalysis is one of promising techniques to degrade these water contaminations 7, 8, 9, 10. Nowadays, severe water contamination caused by the release of dyes, antibiotics, drugs, and phenolic pollutants become an urgent issue to be addressed 1, 2, 3, 4, 5, 6. This work provided a new effective strategy of designed and explored organic semiconductor-inorganic heterojunction photocatalysts with broaden absorption, repeatability and high-charge mobility. Thus, by regulating the dosage of polymers, the 15% PTET-T-COOH/TiO 2 showed the optimized photocatalytic activity with excellent chemical stability, and its kinetic rate constant was determined to be 41.7 times of that of TiO 2. The energetic “lock-in effect” between PTET-T-COOH and TiO 2 through carboxyl groups and hydroxyl groups interaction has been proved to greatly improve the interface charge transfer ability and suppress the electron-hole recombination in PTET-T-COOH/TiO 2.

Their heterojunction with TiO 2, i.e, PTET-T/TiO 2 (C1) and PTET-T-COOH/TiO 2 (C2), exhibited outstanding photocatalytic activity for degrading Rhodamine B, methylene blue and tetracycline. Herein, two novel linear conjugated polymers poly (PTET-T) and poly (PTET-T-COOH) were successfully synthesized by a simple Stille coupling reaction. To design novel conjugated polymers and improve interfacial interaction with semiconductor is one of directions to develop high-efficient photocatalysts with harvesting photons and boosting catalytic activities.