scholarly journals Defective crystal plane-oriented induced lattice polarization for the photocatalytic enhancement of ZnO

CrystEngComm ◽  
2020 ◽  
Vol 22 (16) ◽  
pp. 2709-2717 ◽  
Author(s):  
Xiaojuan Bai ◽  
Boxuan Sun ◽  
Xuyu Wang ◽  
Tianshuo Zhang ◽  
Qiang Hao ◽  
...  

The mechanism of the photocatalytic reaction of defective ZnO systems was determined.

1984 ◽  
Vol 49 (10) ◽  
pp. 2222-2230 ◽  
Author(s):  
Viliam Múčka ◽  
Rostislav Silber

The catalytic and physico-chemical properties of low-temperature nickel-silver catalysts with nickel oxide concentrations up to 43.8% (m/m) are examined via decomposition of hydrogen peroxide in aqueous solution. The mixed catalysts prepared at 250°C are composed of partly decomposed silver carbonate or oxide and nickel carbonate or hydroxide decomposed to a low degree only and exhibiting a very defective crystal structure. The activity of these catalysts is determined by the surface concentration of silver ions, which is affected by the nickel component present. The latter also contributes to the thermal stability of the catalytic centres of the silver component, viz. the Ag+ ions. The concentration of these ions varies with the temperature of the catalyst treatment, the activity varies qualitatively in the same manner, and the system approaches the Ag-NiO composition. The catalytic centres are very susceptible to poisoning by chloride ions. A previous exposition of the catalyst to a gamma dose of 10 kGy from a 60Co source has no measurable effect on the physico-chemical properties of the system.


Polymers ◽  
2020 ◽  
Vol 12 (4) ◽  
pp. 850 ◽  
Author(s):  
Ladislav Svoboda ◽  
Nadia Licciardello ◽  
Richard Dvorský ◽  
Jiří Bednář ◽  
Jiří Henych ◽  
...  

In the majority of photocatalytic applications, the photocatalyst is dispersed as a suspension of nanoparticles. The suspension provides a higher surface for the photocatalytic reaction in respect to immobilized photocatalysts. However, this implies that recovery of the particles by filtration or centrifugation is needed to collect and regenerate the photocatalyst. This complicates the regeneration process and, at the same time, leads to material loss and potential toxicity. In this work, a new nanofibrous membrane, g-C3N4/PMMA/PUR, was prepared by the fixation of exfoliated g-C3N4 to polyurethane nanofibers using thin layers of poly(methyl methacrylate) (PMMA). The optimal amount of PMMA was determined by measuring the adsorption and photocatalytic properties of g-C3N4/PMMA/PUR membranes (with a different PMMA content) in an aqueous solution of methylene blue. It was found that the prepared membranes were able to effectively adsorb and decompose methylene blue. On top of that, the membranes evinced a self-cleaning behavior, showing no coloration on their surfaces after contact with methylene blue, unlike in the case of unmodified fabric. After further treatment with H2O2, no decrease in photocatalytic activity was observed, indicating that the prepared membrane can also be easily regenerated. This study promises possibilities for the production of photocatalytic membranes and fabrics for both chemical and biological contaminant control.


2020 ◽  
Vol 339 ◽  
pp. 265-273 ◽  
Author(s):  
Shuohan Yu ◽  
Yiyang Lu ◽  
Fei Gao ◽  
Lin Dong
Keyword(s):  

Nanomaterials ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 1541
Author(s):  
Jie Zhang ◽  
Jia Wang ◽  
Qingjun Zhu ◽  
Binbin Zhang ◽  
Huihui Xu ◽  
...  

A novel AgBr/Ag2MoO4@InVO4 composite photocatalyst with different heterojunction structures was successfully constructed by compounding InVO4 with Ag2MoO4 and AgBr. According to the degradation, antibacterial and free radical trapping data, the photocatalytic antibacterial and antifouling activities of AgBr/Ag2MoO4@InVO4 composite were evaluated, and the corresponding photocatalytic reaction mechanism was proposed. Adding AgBr/Ag2MoO4@InVO4 composite, the degradation rate of ciprofloxacin (CIP) achieved 95.5% within 120 min. At the same time, the antibacterial rates of Escherichia coli (E. coli), Staphylococcus aureus (S. aureus) and Pseudomonas aeruginosa (P. aeruginosa) achieved 99.99%. The AgBr/Ag2MoO4@InVO4 composite photocatalyst showed promising usage in photocatalytic antibacterial and purification areas.


2010 ◽  
Vol 12 (4) ◽  
pp. 53-57 ◽  
Author(s):  
Agata Markowska-Szczupak ◽  
Krzysztof Ulfig ◽  
Barbara Grzmil ◽  
Antoni Morawski

A preliminary study on antifungal effect of TiO2-based paints in natural indoor light The antifungal activity of four commercial photocatalytic paints (KEIM Ecosil ME, Titanium FA, Photo Silicate and Silicate D) in natural indoor light was investigated. The paints contained TiO2 in rutile and anatase crystalline forms as evidenced by means of the X-ray diffraction analysis. In most cases the paints inhibited growth of fungi viz. Trichoderma viride, Aspergillus niger, Coonemeria crustacea, Eurotium herbariorum, and Dactylomyces sp. The KEIM Ecosil ME paint displayed the highest antifungal effect in the light, which could be explained with the highest anatase content. The paint antifungal activity and the fungal sensitivity to the TiO2-mediated photocatalytic reaction both decreased in the following orders: KEIM Ecosil ME > Titanium FA > Photo Silicate > Silicate D and T. viride > Dactylomyces sp. > A. niger > E. herbariorum.


2006 ◽  
Vol 201 (6) ◽  
pp. 3761-3766 ◽  
Author(s):  
Gyung Guk Kim ◽  
Joung Ah Kang ◽  
Ji Hui Kim ◽  
Sun Jae Kim ◽  
Nam Hee Lee ◽  
...  

2012 ◽  
Vol 463-464 ◽  
pp. 189-193
Author(s):  
Kong Zhai Li ◽  
Masaaki Haneda ◽  
Masakuni Ozawa

Maghemite (γ-FeSubscript text2OSubscript text3) and hematite (α-Fe2O3) nanoparticles with various dominant exposure crystal planes were prepared by several different methods. The structure and the reducibility of these materials were investigated by XRD, Raman and H2-TPR technologies, and their catalytic performance for propene oxidation was also discussed. The maghemite (γ-FeSubscript text2OSubscript text3) showed a better reducibility than hematite (α-FeSubscript text2OSubscript text3), but its activity for propene oxidation is relatively lower. The exposure crystal plane of hematite has a significant influence on its catalytic activity for propene oxidation. Among the prepared four samples, the hematite-1 sample showed the best activity. The selective growth of any planes with a relative low density of Fe atoms for the α-FeSubscript text2OSubscript text3 catalyst would lead to an obvious decrease in the catalytic activity.


2008 ◽  
Vol 132 (1-4) ◽  
pp. 153-158 ◽  
Author(s):  
Yoshihisa Matsushita ◽  
Nobuko Ohba ◽  
Tadashi Suzuki ◽  
Teijiro Ichimura

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