Photodeposition of CdSe using Se-TiO2 suspensions as photocatalysts

Nguyen, Vi Nu Hoai; Amal, Rose; Beydoun, Donia

doi:10.1016/j.jphotochem.2005.07.012

Cited by 27 publications

(18 citation statements)

References 44 publications

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“…The photoexcited electrons and holes may diffuse to the surface of the semiconductor, followed by interfacial electron transfer to and from the adsorbed acceptor and donor molecules. The holes are involved in the oxidation reactions, typically the mineralization of organic substances present in the solution [ 54 ]. In the present work, photocatalytic activity tests were conducted by the degradation of the dye, methylene blue in aqueous solution under ultraviolet light irradiation.…”

Section: Resultsmentioning

confidence: 99%

Microwave-Assisted Synthesis of Titania Nanocubes, Nanospheres and Nanorods for Photocatalytic Dye Degradation

et al. 2008

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TiO2nanostructures with fascinating morphologies like cubes, spheres, and rods were synthesized by a simple microwave irradiation technique. Tuning of different morphologies was achieved by changing the pH and the nature of the medium or the precipitating agent. As-synthesized titania nanostructures were characterized by X-ray diffraction (XRD), UV–visible spectroscopy, infrared spectroscopy (IR), BET surface area, photoluminescence (PL), scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and atomic force microscopy (AFM) techniques. Photocatalytic dye degradation studies were conducted using methylene blue under ultraviolet light irradiation. Dye degradation ability for nanocubes was found to be superior to the spheres and the rods and can be attributed to the observed high surface area of nanocubes. As-synthesized titania nanostructures have shown higher photocatalytic activity than the commercial photocatalyst Degussa P25 TiO2.

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Section: Resultsmentioning

confidence: 99%

Microwave-Assisted Synthesis of Titania Nanocubes, Nanospheres and Nanorods for Photocatalytic Dye Degradation

et al. 2008

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“…38 Sonochemical, photodeposition, and chemical bath deposition of CdSe on TiO 2 nanoparticles and nanotubes has also been studied for photocatalysis applications. [39][40][41] However, the use of QDs to improve TiO 2 -based solar cell efficiency is still an area of active exploration.…”

Section: Introductionmentioning

confidence: 99%

Nitrogen-Doped and CdSe Quantum-Dot-Sensitized Nanocrystalline TiO₂ Films for Solar Energy Conversion Applications

et al. 2008

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Nitrogen-doped titanium dioxide (TiO 2 /N) nanoparticle thin films have been produced by a sol-gel method with hexamethylenetetramine (HMT) as the dopant source. The synthesized TiO 2 /N thin films have been sensitized with CdSe quantum dots (QDs) via a linking molecule, thioglycolic acid (TGA). Optical, morphological, structural, and photocurrent properties of the thin films with and without QD sensitization have been characterized by AFM, TEM, XPS, Raman spectroscopy, UV-visible spectroscopy, and photoelectrochemistry techniques. AFM measurements reveals that films with thicknesses of 150 and 1100 nm can be readily prepared, with an average TiO 2 particle size of 100 nm. TEM shows a uniform size distribution of CdSe QDs utilized in sensitizing the TiO 2 /N films. Doping of the TiO 2 crystal lattice by HMT was confirmed to be 0.6-0.8% by XPS. Differences in crystal phase caused by the precursors HMT, nitric acid, and poly(ethylene glycol) (PEG) are elucidated using XRD and Raman spectroscopy. The resultant crystal phase of TiO 2 /N varies but is a mixture of anatase, brookite, and rutile phases. UV-visible absorption spectra show that N doping of TiO 2 causes a red-shifted absorption into the visible region, with an onset around 600 nm. Nitrogen doping is also responsible for the enhanced photocurrent response of the TiO 2 /N nanoparticle films in the visible region relative to undoped TiO 2 films. In addition, CdSe QDs linked to TiO 2 /N nanoparticles using TGA were found to significantly increase the photocurrent and power conversion of the films compared to standard TiO 2 /N films without QD sensitization. The incident photon-to-current conversion efficiency (IPCE) is 6% at 400 nm for TiO 2 /N-TGA-CdSe solid-state solar cells and 95% for TiO 2 /N-TGA-CdSe films near 300 nm in a Na 2 S electrolyte, which is much higher than that of undoped TiO 2 with QD sensitization or TiO 2 /N without QD sensitization. The power conversion efficiency (η) was found to be 0.84% with a fill factor (FF%) of 27.7% with 1100 nm thick TiO 2 /N-TGA-CdSe thin films. The results show that combining nitrogen doping with the QD sensitization of TiO 2 thin films is an effective and promising way to enhance the photoresponse in the near-UV and visible region, which is important for potential photovoltaic (PV) and photoelectrochemical applications.

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“…These photoexcited electron–holes might diffuse to the surface of the semiconductor resulted in the interfacial electron transfer. The oxidation reactions in the solution are caused by holes which resulted in the mineralization of organic substances [50]. In the photocatalytic process, OH • radicals formed which are governed by OH groups and or physisorbed H 2 O.…”

Section: Resultsmentioning

confidence: 99%

Photocatalytic inactivation ofEscherichia coliunder UV light irradiation using large surface area anatase TiO₂quantum dots

et al. 2019

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In this study, high specific surface areas (SSAs) of anatase titanium dioxide (TiO2) quantum dots (QDs) were successfully synthesized through a novel one-step microwave–hydrothermal method in rapid synthesis time (20 min) without further heat treatment. XRD analysis and HR-TEM images showed that the as-prepared TiO2 QDs of approximately 2 nm size have high crystallinity with anatase phase. Optical properties showed that the energy band gap (Eg) of as-prepared TiO2 QDs was 3.60 eV, which is higher than the standard TiO2 band gap, which might be due to the quantum size effect. Raman studies showed shifting and broadening of the peaks of TiO2 QDs due to the reduction of the crystallite size. The obtained Brunauer–Emmett–Teller specific surface area (381 m2 g−1) of TiO2 QDs is greater than the surface area (181 m2 g−1) of commercial TiO2 nanoparticles. The photocatalytic activities of TiO2 QDs were conducted by the inactivation of Escherischia coli under ultraviolet light irradiation and compared with commercially available anatase TiO2 nanoparticles. The photocatalytic inactivation ability of E. coli was estimated to be 91% at 60 µg ml−1 for TiO2 QDs, which is superior to the commercial TiO2 nanoparticles. Hence, the present study provides new insight into the rapid synthesis of TiO2 QDs without any annealing treatment to increase the absorbance of ultraviolet light for superior photocatalytic inactivation ability of E. coli.

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Photodeposition of CdSe using Se-TiO2 suspensions as photocatalysts

Cited by 27 publications

References 44 publications

Microwave-Assisted Synthesis of Titania Nanocubes, Nanospheres and Nanorods for Photocatalytic Dye Degradation

Microwave-Assisted Synthesis of Titania Nanocubes, Nanospheres and Nanorods for Photocatalytic Dye Degradation

Nitrogen-Doped and CdSe Quantum-Dot-Sensitized Nanocrystalline TiO₂ Films for Solar Energy Conversion Applications

Photocatalytic inactivation ofEscherichia coliunder UV light irradiation using large surface area anatase TiO₂quantum dots

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Photodeposition of CdSe using Se-TiO2 suspensions as photocatalysts

Cited by 27 publications

References 44 publications

Microwave-Assisted Synthesis of Titania Nanocubes, Nanospheres and Nanorods for Photocatalytic Dye Degradation

Microwave-Assisted Synthesis of Titania Nanocubes, Nanospheres and Nanorods for Photocatalytic Dye Degradation

Nitrogen-Doped and CdSe Quantum-Dot-Sensitized Nanocrystalline TiO2 Films for Solar Energy Conversion Applications

Photocatalytic inactivation ofEscherichia coliunder UV light irradiation using large surface area anatase TiO2quantum dots

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Product

Resources

About

Nitrogen-Doped and CdSe Quantum-Dot-Sensitized Nanocrystalline TiO₂ Films for Solar Energy Conversion Applications

Photocatalytic inactivation ofEscherichia coliunder UV light irradiation using large surface area anatase TiO₂quantum dots