Enhanced Photocatalytic Activity of Powders (P25) via Calcination Treatment

Wang, Guohong; Xu, Lin; Zhang, Jun; Yin, Tingting; Han, Dandan

doi:10.1155/2012/265760

Cited by 134 publications

(120 citation statements)

References 54 publications

Supporting

Mentioning

103

Contrasting

Unclassified

Order By: Relevance

“…EDX analysis further confirmed the presence of Ti, and the TiO2 content of the composite particles was estimated to be 36.6 ± 4.1 wt % ( Figure S4, Table S1). TiO2 nanocrystals are known to partially sinter at the temperatures applied during the synthesis [24], which is proposed to be the mechanism of TiO2 adhesion [34,35]. XRD revealed the presence of anatase and rutile phases in the FPCs, characteristic of the mixed-phase TiO2 nanocrystals used [36], confirming that the calcination step did not significantly affect the crystal phase of the particles.…”

Section: Resultsmentioning

confidence: 85%

“…A heterocoagulation and sintering process was used to adhere photocatalytic TiO 2 nanoparticles to a high strength glass microbubble (GMB) core, wherein the TiO 2 and GMBs were mixed together at a pH between their respective isoelectric points to induce electrostatic attraction, followed by high temperature calcination to fix the nanoparticles in place. Thermal sintering has been previously demonstrated to promote strong adhesion of immobilized TiO 2 to glass supports [21][22][23], although reducing specific surface area of the TiO 2 in the process [24]. Floating photocatalysts synthesized previously have used plastic supports susceptible to photocatalytic degradation [25][26][27][28][29][30], or fragile materials such as perlite [31][32][33], which sink upon breaking.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

Leshuk

Krishnakumar

Livera

et al. 2018

Water

View full text Add to dashboard Cite

Abstract:Oil sands process-affected water (OSPW), generated from bitumen extraction in the Canadian oil sands, may require treatment to enable safe discharge to receiving watersheds, as dissolved naphthenic acids (NAs) and other acid extractable organics (AEO), identified as the primary toxic components of OSPW, are environmentally persistent and poorly biodegradable. However, conventional advanced oxidation processes (AOPs) are impractically expensive to treat the volumes of OSPW stockpiled in the Athabasca region. Here we prepared floating photocatalysts (FPCs) by immobilizing TiO 2 on glass microbubbles, such that the composite particles float at the air-water interface for passive solar photocatalysis. The FPCs were demonstrated to outperform P25 TiO 2 nanoparticles in degrading AEO in raw OSPW under natural sunlight and gentle mixing conditions. The FPCs were also found to be recyclable for multiple uses through simple flotation and skimming. This paper thus demonstrates the concept of a fully passive AOP that may be scalable to oil sands water treatment challenges, achieving efficient NA reduction solely through the energy provided by sunlight and natural mixing processes (wind and waves).

show abstract

Section: Resultsmentioning

confidence: 85%

Section: Resultsmentioning

confidence: 99%

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

Leshuk

Krishnakumar

Livera

et al. 2018

Water

View full text Add to dashboard Cite

show abstract

“…• , the samples responded to the visible light again, which is attributed to the appearance of rutile phase TiO 2 (Hoffmann et al, 1995;Góska et al, 2008;Wang et al, 2012). The plots of the transformed Kubelka-Munk functions as a function of light energy are shown in Fig.…”

Section: Uv-vis Analysismentioning

confidence: 92%

Effect of TiO2 calcination temperature on the photocatalytic oxidation of gaseous NH3

Zhang

et al. 2014

Journal of Environmental Sciences

View full text Add to dashboard Cite

a b s t r a c tCarbon-modified titanium dioxide (TiO 2 ) was prepared by a sol-gel method using tetrabutyl titanate as precursor, with calcination at various temperatures, and tested for the photocatalytic oxidation (PCO) of gaseous NH 3 under visible and UV light. The test results showed that no samples had visible light activity, while the TiO 2 calcined at 400°C had the best UV light activity among the series of catalysts, and was even much better than the commercial catalyst P25. The catalysts were then characterized by X-ray diffractometry, Brunauer-Emmett-Teller adsorption analysis, Raman spectroscopy, thermogravimetry/differential scanning calorimetry coupled with mass spectrometry, ultraviolet-visible diffuse reflectance spectra, photoluminescence spectroscopy and in situ diffuse reflectance infrared Fourier transform spectroscopy. It was shown that the carbon species residuals on the catalyst surfaces induced the visible light adsorption of the samples calcined in the low temperature range (< 300°C). However, the surface acid sites played a determining role in the PCO of NH 3 under visible and UV light over the series of catalysts. Although the samples calcined at low temperatures had very high SSA, good crystallinity, strong visible light absorption and also low PL emission intensity, they showed very low PCO activity due to their very low number of acid sites for NH 3 adsorption and activation. The TiO 2 sample calcined at 400°C contained the highest number of acid sites among the series of catalysts, therefore showing the highest performance for the PCO of NH 3 under UV light.

show abstract

“…Its higher activity can be attributed to the presence of AuNRs with anisotropic shape whereas UCA-TiO 2 Au 650 • C contains spherical NPs with lower absorbance in the visible range. Additionally, the calcination at high temperature promotes the rutile formation and the growing of particles reducing the TiO 2 photoactivity [63]. It is remarkable that UCA-TiO 2 450 • C showed a MB degradation considerably lower than the other TiO 2 samples.…”

Section: Photocatalysis Experimentsmentioning

confidence: 96%

Photocatalytic Activity of TiO2/AuNRs–SiO2 Nanocomposites Applied to Building Materials

et al. 2018

View full text Add to dashboard Cite

In this work, the self-cleaning and photocatalytic properties of mesoporous TiO 2 /AuNRs-SiO 2 composites (namely UCA-TiO 2 Au) prepared by a simple and low-cost technique were investigated toward application in building materials. Mesoporous photocatalytic nanocomposites coating the surface of stone and other building materials are a very promising approach to address relevant questions connected with the increasing atmospheric pollution. We tested three types of preformed TiO 2 /AuNRs nanostructures in order to evaluate the effect of AuNRs on the photocatalytic activity of resulting coatings deposited on the surface of a popular building limestone. The resulting nanocomposites provide crack-free surface coatings on limestone, effective adhesion, improve the stone mechanical properties and impart hydrophobic and self-cleaning properties. Photocatalytic characterization involved the degradation of a target compound (Methylene blue; MB) under direct exposure to simulated solar light using TiO 2 P25 Evonik (TiO 2 P25) as a reference material. Moreover, these coatings upon irradiation by simulated solar light were successfully employed for the photocatalytic oxidation of carbon soot. The experimental results revealed that UCA-TiO 2 Au samples are the best performing coating in both MB bleaching and soot degradation.

show abstract

Enhanced Photocatalytic Activity of Powders (P25) via Calcination Treatment

Cited by 134 publications

References 54 publications

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

Floating Photocatalysts for Passive Solar Degradation of Naphthenic Acids in Oil Sands Process-Affected Water

Effect of TiO2 calcination temperature on the photocatalytic oxidation of gaseous NH3

Photocatalytic Activity of TiO2/AuNRs–SiO2 Nanocomposites Applied to Building Materials

Contact Info

Product

Resources

About