Du Yingying,Yang Ping,Liu Yunshi,Zhao Jie,He Haiyan,Miao Yanping
TiO2 films consisted of small nanoparticles were fabricated via a spinning coating method on fluorine doped in tin oxide (FTO) slide glass. After calcination, the films were subsequently sensitized by CdSe quantum dots (QDs) using mercaptopropionic acid (MPA) as a bifunctional
surface modifier. Upon UV light irradiation, CdSe QDs inject electrons into TiO2 nanoparticles, thus resulting in the generation of photocurrent in QD-sensitized solar cell. The results indicate that TiO2 films sensitized by CdSe QDs have achieved 1.5-fold enhancement
in photocurrent compared with pure TiO2 films, indicating that CdSe QDs can improve the photocurrent by promoting the separation of photoinduced charge carriers. In addition, the photocurrent enhances as the thickness of TiO2 films increased. Such improved photoelectrochemical
performance is ascribed to the basis of improved interfacial charge transport of the TiO2-CdSe composite films. Combining QDs on TiO2 thin films is a promising and effective way to enhance the photoelectrochemical performance, which is important in QD-sensitized solar
cell application.
With the increasing concerns regarding bacterial adaption to nanomaterials , it is critical to explore the main mechanism behind the adaptive morphogenesis of microorganisms . In this work, the biofilms formed from activated sludge exposed to 5 and 50 mg/L nTiO 2 in the dark had increased biomass and selectively enriched pathogens . To further elaborate adaptive mechanism of biofilm formation induced by nTiO 2 , the protein response and protein phosphorylation modification of Escherichia coli K12 were determined using integrative systems biology analyses of proteomics and phosphoproteomics. Results identified that E. coli cultivated with nTiO 2 considerably upregulated iron acquisition, and regulated protein phosphorylation states associated with of transcription and translation and biofilm formation relative to unexposed controls. Accordingly, bacteria increased siderophores and exopolysaccharide content (increased by about 57% and 231%, respectively), and enhanced resistance to transcriptional inhibitory antibiotics. Moreover, a dose of an iron chelator, i.e., deferoxamine mesylate salt, effectively retarded the biofilm development of bacteria exposed to 50 mg/L nTiO 2 . Overall, this work will provide a new insight for biofouling control, and contribute to an improved understanding of microbial adaption to nanomaterials.
In this work, a low-temperature method for creating nanostructured TiO 2 thin films with controlled morphologies for the photocatalytic degradation of the persistent antibiotic pollutant ofloxacin in water is presented. A Ti–H₂O₂ interaction was used to produce hydrogen titanate nanowires, which were subsequently converted into three different nanostructures: anatase nanowires by calcined at 450°C, porous nanorods and hierarchical nanoflowers by treating at 80°C for 72 hours with hot water and sulfuric acid, respectively. Controls over surface area, hydroxyl group contents, and crystal phase composition were made possible by these post-treatments. With a reaction rate constant of 0.72 h⁻¹ and a photocatalytic efficiency of 98% ofloxacin degradation in 4 hours under UV light, TiO 2 nanoflowers outperformed commercial benchmark P25 mixed phase TiO 2 nanoparticle films (0.64 h⁻¹) among the different nanostructures. The mixed anatase-rutile phase, high surface area of 49.1 m²/g, large pore volume of 0.15 mL/g, and numerous surface hydroxyl groups are responsible for the superior performance. These results show that morphology-engineered TiO 2 films can be used to treat water effectively through photocatalysis.