A comparative study of preparation methods of nanoporous TiO2 films for microfluidic photocatalysis

Wang, N.; Ling, Lei; Zhang, Xuming; Tsang, Yuen Hong; Chen, Y.; Chan, Helen L. W.

doi:10.1016/j.mee.2010.12.051

Cited by 35 publications

(16 citation statements)

References 12 publications

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“…The inclusion of noble metals limits the process temperature to a few hundred degrees, while high-temperature annealing of the mixture is often needed to increase the crystallization and thus the photoreactivity of the semiconductor [116,[182][183][184]. Some other problems are related to the stability of the metal/semiconductor mixture.…”

Section: Adverse Effects Of Metal Nanoparticlesmentioning

confidence: 99%

Plasmonic photocatalysis

et al. 2013

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Plasmonic photocatalysis has recently facilitated the rapid progress in enhancing photocatalytic efficiency under visible light irradiation, increasing the prospect of using sunlight for environmental and energy applications such as wastewater treatment, water splitting and carbon dioxide reduction. Plasmonic photocatalysis makes use of noble metal nanoparticles dispersed into semiconductor photocatalysts and possesses two prominent features-a Schottky junction and localized surface plasmonic resonance (LSPR). The former is of benefit to charge separation and transfer whereas the latter contributes to the strong absorption of visible light and the excitation of active charge carriers. This article aims to provide a systematic study of the fundamental physical mechanisms of plasmonic photocatalysis and to rationalize many experimental observations. In particular, we show that LSPR could boost the generation of electrons and holes in semiconductor photocatalysts through two different effects-the LSPR sensitization effect and the LSPR-powered bandgap breaking effect. By classifying the plasmonic photocatalytic systems in terms of their contact form and irradiation state, we show that the enhancement effects on different properties of photocatalysis can be well-explained and systematized. Moreover, we identify popular material systems of plasmonic photocatalysis that have shown excellent performance and elucidate their key features in the context of our proposed mechanisms and classifications.

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Section: Adverse Effects Of Metal Nanoparticlesmentioning

confidence: 99%

Plasmonic photocatalysis

et al. 2013

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“…Removal rate of MO got higher by increasing the residence time. 100% discoloration was obtained after 40 s. As reported by Wang [24], TiO 2 film based photocatalytic microreactor was prepared and used for degradation of methylene blue (MB). 55% of the MB with an initial concentration of 24 ppm was converted after 70 s. In the work of Li [30], a novel optofluidic microreactor with photocatalyst coated on the fiberglass was developed and used for degradation of MB.…”

Section: Catalytic Performancementioning

confidence: 93%

Glass capillaries with TiO 2 supported on inner wall as microchannel reactors

Shen

Wang

et al. 2015

Chemical Engineering Journal

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“…Photocatalysis typically utilizes semiconductor materials to absorb light and excite electron-hole pairs for further chemical reactions [2], offering a promising solution for solar energy conversion and environmental remediation [3]. As one of the prominent semiconductor photocatalysts, titanium dioxide (TiO 2 ) has drawn considerable attention in the mineralization of harmful organic substances thanks to its superior properties of nontoxicity, high chemical stability, high photostability, abundance in nature, and low cost [4][5][6]. However, the photocatalytic efficiency of TiO 2 in visible light is low as it is limited by its wide bandgap (3.2 eV).…”

Section: Introductionmentioning

confidence: 99%

Microfluidic Reactors for Plasmonic Photocatalysis Using Gold Nanoparticles

et al. 2019

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This work reports a microfluidic reactor that utilizes gold nanoparticles (AuNPs) for the highly efficient photocatalytic degradation of organic pollutants under visible light. The bottom of microchamber has a TiO 2 film covering a layer of AuNPs (namely, TiO 2 /AuNP film) deposited on the F-doped SnO 2 (FTO) substrate. The rough surface of FTO helps to increase the surface area and the AuNPs enables the strong absorption of visible light to excite electron/hole pairs, which are then transferred to the TiO 2 film for photodegradation. The TiO 2 film also isolates the AuNPs from the solution to avoid detachment and photocorrosion. Experiments show that the TiO 2 /AuNP film has a strong absorption over 400-800 nm and enhances the reaction rate constant by 13 times with respect to the bare TiO 2 film for the photodegradation of methylene blue. In addition, the TiO 2 /AuNP microreactor exhibits a negligible reduction of photoactivity after five cycles of repeated tests, which verifies the protective function of the TiO 2 layer. This plasmonic photocatalytic microreactor draws the strengths of microfluidics and plasmonics, and may find potential applications in continuous photocatalytic water treatment and photosynthesis. The fabrication of the microreactor uses manual operation and requires no photolithography, making it simple, easy, and of low cost for real laboratory and field tests.2 of 11 resonance (LSPR) due to the collective oscillation of free electrons in response to the excitation of irradiant light. The LSPR effect can drastically enhance the visible response of TiO 2 photocatalysis for solar energy capture, environmental redemption, and selective organic photosynthesis [5,7,9,10]. Moreover, the direct physical contact of the noble metal NPs and the TiO 2 photocatalysts would form a Schottky junction to suppress the recombination of electron-hole pairs [8,11].Typical photodegradation systems involve the suspension of TiO 2 nanopowders in an aqueous solution of a bulky container. With the stirring, the TiO 2 nanopowders have full contact with the dissolved organic pollutants, resulting in a large specific surface area (SSA, defined as the total surface area per unit of mass) and high photodegradation efficiency. However, the suspended TiO 2 nanopowders absorb and scatter light, causing rapid decay, and thus an uneven distribution of the irradiant light. What is more problematic is the requirement of post processing, namely the nanopowders have to be separated from the solution after the reaction [12][13][14]. To avoid these problems, immobilized systems have been developed to fix the TiO 2 photocatalysts on a support, but they tend to have a small SSA and low efficiency [15].Microfluidic reactors have attracted much attention and have been proposed to tackle the drawbacks of photocatalytic processes [14,[16][17][18][19][20]. They inherit many advantages from microfluidics technology, such as small dimensions, high surface-to-volume (S/V) ratio, easy control of flow rates, short molecular diffusion distance,...

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A comparative study of preparation methods of nanoporous TiO2 films for microfluidic photocatalysis

Cited by 35 publications

References 12 publications

Plasmonic photocatalysis

Plasmonic photocatalysis

Glass capillaries with TiO 2 supported on inner wall as microchannel reactors

Microfluidic Reactors for Plasmonic Photocatalysis Using Gold Nanoparticles

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