Enhancement of the photocatalytic activity of a TiO2/carbon aerogel based on a hydrophilic secondary pore structure

RSC Advances ◽  
2016 ◽  
Vol 6 (72) ◽  
pp. 68416-68423 ◽  
Author(s):  
Hua'nan Cui ◽  
Zhenxing Liang ◽  
JinZhong Zhang ◽  
Hong Liu ◽  
Jianying Shi

The surface/interface synergy effect plays a positive role on the spatial separation and utilization of electrons and holes in photocatalytic process, which suggests a potential strategy for designing high efficiency photocatalysts.

2020 ◽  
Vol 40 (6) ◽  
pp. 487-493
Author(s):  
Chen Wang ◽  
Kun Yan ◽  
Jun Wang ◽  
Siyu Chen ◽  
Jiaming Cui ◽  
...  

AbstractIn this research, we successfully fabricated a novel closed pore polyacrylonitrile (PAN)/polyvinyl pyrrolidone (PVP) composite nanofibrous membrane (PCNM) on the substrate of a commercial polypropylene window mesh. First, smooth and uniform PAN/PVP composite nanofibers (PCNs) were manufactured by blending PAN and PVP with a mass ratio of 5:5 during electrospinning. Subsequently, the prepared PCNs were hot pressed in a vacuum drying oven at a given temperature of 90°C. The morphology and filter efficiency of PCN and PCNM were investigated. It was found that hot-pressing treatment significantly affected the pore structure and orientation of PCNM, which contributed to its closed pore structure and good alignment. The filter efficiency results indicated that the hot-pressed PCNMs have excellent removal efficiency of up to 96.8% of fine particulate matter. This research demonstrates that PCNMs have potential as filters for indoor dust removal and will provide a new idea for the development of air filters.


Catalysts ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 47
Author(s):  
Oleksandr Shtyka ◽  
Viktar Shatsila ◽  
Radoslaw Ciesielski ◽  
Adam Kedziora ◽  
Waldemar Maniukiewicz ◽  
...  

The photocatalytic activity of TiO2 depends on numerous factors, such as the chemical potential of electrons, charge transport properties, band-gap energy, and concentration of surface-active sites. A lot of research has been dedicated to determining the properties that have the most significant influence on the photocatalytic activity of semiconductors. Here, we demonstrated that the activity of TiO2 in the gas-phase reduction of CO2 is governed mainly by the desorption rate of the reaction intermediates and final products. This indicates that the specific surface area of TiO2 and binding strength of reaction intermediates and products are the main factors affecting the photocatalytic activity of TiO2 in the investigated process. Additionally, it was shown that rutile exhibits higher photocatalytic activity than anatase/rutile mixtures mainly due to its high efficiency in the visible portion of the electromagnetic spectrum.


Materials ◽  
2022 ◽  
Vol 15 (2) ◽  
pp. 502
Author(s):  
Liangliang Yue ◽  
Haolan Li ◽  
Qi Sun ◽  
Xiaogang Luo ◽  
Fengshou Wu ◽  
...  

Cancer is one of the major diseases threatening human health. Traditional cancer treatments have notable side-effects as they can damage the immune system. Recently, phototherapy, as a potential strategy for clinical cancer therapy, has received wide attention due to its minimal invasiveness and high efficiency. Herein, a small organic molecule (PTA) with a D-A-D structure was prepared via a Sonogashira coupling reaction between the electron-withdrawing dibromo-perylenediimide and electron-donating 4-ethynyl-N,N-diphenylaniline. The amphiphilic organic molecule was then transformed into nanoparticles (PTA-NPs) through the self-assembling method. Upon laser irradiation at 635 nm, PTA-NPs displayed a high photothermal conversion efficiency (PCE = 43%) together with efficient reactive oxygen species (ROS) generation. The fluorescence images also indicated the production of ROS in cancer cells with PTA-NPs. In addition, the biocompatibility and photocytotoxicity of PTA-NPs were evaluated by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and live/dead cell co-staining test. Therefore, the as-prepared organic nanomaterials were demonstrated as promising nanomaterials for cancer phototherapy in the clinic.


2021 ◽  
Vol 25 (8) ◽  
pp. 100-109
Author(s):  
G. Divya ◽  
D. Sakthi ◽  
A. Priyadharsan ◽  
S. Boobas ◽  
S. Sivakumar

ZnO as a promising photocatalyst has gained much attention for the removal of organic pollutants from water. However, the main drawbacks of the relatively low photocatalytic activity and high recombination rate of photoexcited electron-hole pairs restrict its potential applications. Promoting the spatial separation of photoexcited charge carriers is of paramount significance for photocatalysis because the difference in the band positions makes the potential gradient at the composite boundary. In this work, binary CdS/ZnO and CoTiO3/ZnO are first prepared by dispersion method and then decorated with ZnO particles to construct CdS/CoTiO3/ZnO ternary composites. For this reason, the CdS/CoTiO3/ZnO ternary composites was effectively designed and analyzed for the crystalline structure, light absorption, photoexcitation behavior and surface morphological properties by X-ray diffraction, diffuse reflectance UV/visible absorption spectroscopy, photoluminescence spectroscopy and scanning electron micrograph respectively. The photocatalytic activity was examined by degradation of the dye solution spectrophotometrically. The results of photocatalytic degradation indicated that the CdS/CoTiO3/ZnO ternary composites are much higher than those of bare CdS, CoTiO3, ZnO and any binary composites such as CoTiO3/ZnO and ZnO/CdS. The enhanced activity could be attributed to the drop electron transfer from CdS to ZnO to CoTiO3 through the interfacial potential gradient in the ternary hybrid conduction bands. The enhanced electron transfer of CdS/CoTiO3/ZnO ternary composites was also applicable to degrade other reactive dyes.


2020 ◽  
Vol 10 (5) ◽  
pp. 1299-1310 ◽  
Author(s):  
Patricia Garcia-Muñoz ◽  
Fernando Fresno ◽  
Christophe Lefevre ◽  
Didier Robert ◽  
Nicolas Keller

Synergy effect between photocatalysis and H2O2-mediated heterogeneous photo-Fenton catalysis on highly robust Ti-substituted La1−xTixFeO3 perovskites led to high performances under UV-A light in water treatment.


2016 ◽  
Vol 7 (2) ◽  
pp. 890-895 ◽  
Author(s):  
Ang Li ◽  
Tuo Wang ◽  
Xiaoxia Chang ◽  
Weiting Cai ◽  
Peng Zhang ◽  
...  

The design and synthesis of fine Pt@TiO2@MnOx hollow spheres is described. Pt and MnOx are spatially separated by TiO2 shells. The catalyst exhibits high efficiency of charge-separation and surface-reaction.


2018 ◽  
Vol 20 (7) ◽  
pp. 4787-4792 ◽  
Author(s):  
Da Wang ◽  
Ning Liu ◽  
Zhongnan Guo ◽  
Wenjun Wang ◽  
Liwei Guo ◽  
...  

The spatial separation of the photo-generated electrons and holes between the polar Si-{0001} and non-polar {10−10} crystal facets on 6H-SiC highly improves the photocatalytic activity of water splitting by nearly 5 times.


2019 ◽  
Vol 29 (1) ◽  
Author(s):  
Is Fatimah ◽  
Della Fahrani ◽  
Tia Harmawantika ◽  
Imam Sahroni ◽  
Azlan Kamari ◽  
...  

AbstractPhotocatalyst of hydroxyapatite–nano TiO2 (HAp-nTiO2) was prepared from phosphatation of calcined cockle (Anadara granosa) shells followed by dispersion of nano TiO2 powder into HAp precipitate and calcination at 400 °C for 2 h. The prepared material was characterized using X-ray diffraction, scanning electron microscope–energy dispersive X-ray spectrophotometry, gas sorption analysis, and UV-Vis diffuse reflectance spectrophotometry. The photocatalytic activity of the material was evaluated for methyl violet degradation over photocatalysis and photooxidation mechanism. The results showed that the homogeneous dispersion of TiO2 in the HAp-nTiO2 composite was achieved, as seen in the X-ray diffraction analysis, diffuse reflectance UV-Vis, and gas sorption analyses. The physicochemical and photocatalytic character of the composite exhibited the positive role of HAp as TiO2 support in enhancing the photocatalytic activity with a higher turnover number and reusability property than that of pure TiO2. It was also noted that the HAp-nTiO2 composite demonstrated rapid methyl violet degradation over photooxidation rather than by photocatalytic mechanism.


Sign in / Sign up

Export Citation Format

Share Document