Photocatalytic Processes in Membrane Reactors

Molinari, Raffaele; Caruso, Angela

doi:10.1016/b978-0-08-093250-7.00039-6

Cited by 18 publications

(13 citation statements)

References 195 publications

(206 reference statements)

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“…Since Fujishima and Honda discovered photocatalytic water splitting by means of TiO 2 electrodes in 1972 [13], noticeable works were carried out in order to investigate photocatalytic-based hydrogen generation from water via both photocatalysis and photoelectrochemistry [14]. Particular attention was paid to semiconductor oxides, due to their simple preparation through calcination and their stability toward oxygen generation [15][16][17][18][19]. The water-splitting pathway involves a series of radical reactions initiated by light-driven photocatalyst activation, as deeply described in the literature [3].…”

Section: Introductionmentioning

confidence: 99%

Hydrogen and Oxygen Evolution in a Membrane Photoreactor Using Suspended Nanosized Au/TiO2 and Au/CeO2

et al. 2019

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Photocatalysis combined with membrane technology could offer an enormous potential for power generation in a renewable and sustainable way. Herein, we describe the one-step hydrogen and oxygen evolution through a photocatalytic membrane reactor. Experimental tests were carried out by means of a two-compartment cell in which a modified Nafion membrane separated the oxygen and hydrogen evolution semi-cells, while iron ions permeating through the membrane acted as a redox mediator. Nanosized Au/TiO2 and Au/CeO2 were employed as suspended photocatalysts for hydrogen and oxygen generation, respectively. The influence of initial Fe3+ ion concentration, ranging from 5 to 20 mM, was investigated, and the best results in terms of hydrogen and oxygen evolution were registered by working with 5 mM Fe3+. The positive effect of gold on the overall water splitting was confirmed by comparing the photocatalytic results obtained with the modified/unmodified titania and ceria. Au-loading played a key role for controlling the photocatalytic activity, and the optimal percentage for hydrogen and oxygen generation was 0.25 wt%. Under irradiation with visible light, hydrogen and oxygen were produced in stoichiometric amounts. The crucial role of the couple Fe3+/Fe2+ and of the membrane on the performance of the overall photocatalytic system was found.

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Section: Introductionmentioning

confidence: 99%

Hydrogen and Oxygen Evolution in a Membrane Photoreactor Using Suspended Nanosized Au/TiO2 and Au/CeO2

et al. 2019

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“…Photocatalysts are the semiconductor materials that could promote the water splitting and the degradation of organic contaminations via converting the light energy of irradiation to the chemical energy (redox reaction) of hole-electron pairs, which has attracted intense interests for decades (Molinari et al, 2010 ). The most impressing advantage of photocatalysts is the utilization of unlimited sunlight on the earth, ranging from the ultraviolet to visible light (Zhu and Wang, 2017 ; Di et al, 2018 ; Guo et al, 2018 ; Jiang et al, 2018 ; Ji M. et al, 2018 ; Liang et al, 2018 ; Li et al, 2018 ; Nasr et al, 2018 ; Sivaprakash et al, 2018 ; Xue et al, 2018 ), which benefits the human beings with an alternative approach to get the H 2 /O 2 and self-cleaning in an environment friendly way.…”

Section: Introductionmentioning

confidence: 99%

Visible Light-Responsive Photocatalytic Activity of Boron Nitride Incorporated Composites

et al. 2018

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Photocatalysts are essential to promote the highly efficient applications of solar energy in water splitting and/or the degradation of organic contaminations. Especially, the visible light-responsive photocatalysts could benefit with the cost-effective splitting or degradation due to the unlimited sunlight and the absence of expensive light emitter. In the photocatalysts, the charge transfer rates as well as the hole-electron recombination rate are two critical factors that determine the photocatalytic activity, which could also be affected by the dimension, defects, doping and morphologies controlled by the synthesis methods. Boron nitride (BN) is an ultrawide-bandgap semiconductor, and the combination of BN with the visible light-responsive photocatalysts has been found to be effective in enhancing the photocatalytic activities. Therefore, it should be meaningful to understand the BN incorporated photocatalytic composites in depth, including the synthetic approaches, the activity improving mechanisms and the versatile applications. In this review, we mainly focused on the assembly method of BN incorporated photocatalysts; the activity enhancing mechanism by introducing the BN in the photocatalytic composites as well as the properties and the applications. In the end, we gave a conclusion and an outlook for the BN incorporated photocatalytic composites.

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“…In recent years, the hybrid membrane photoreactor (MPR) systems coupling photocatalysis and membrane process have increasingly attracted research attention. The MPR systems exhibit high effectiveness in retaining the powdered TiO 2 while allowing the photocatalytic degradation (PCD) of the pollutants (Lim et al 2011, Molinari et al 2010, Mozia 2010). Nevertheless, it is rather challenging to design such MPR systems due to the inherent complexities associated with the membrane module and light distribution therein.…”

Section: Knowledge Gap and Research Motivationmentioning

confidence: 99%

“…The hybrid MPR systems with photocatalyst in suspension have increasingly attracted research attentions recently (Lim et al 2011, Molinari et al 2010, Mozia 2010). Flat sheet (Jiang et al 2010, Molinari et al 2002b, Molinari et al 2004, hollow fiber (Chin et al 2007a, Chin et al 2007b, Choo et al 2008b Geissen 2001) and ceramic (Benotti et al 2009, Doll andFrimmel 2005) membrane modules have been used in different membrane processes, such as MF (Benotti et al 2009, Choo et al 2008b, Doll and Frimmel 2005, Xi and Geissen 2001, UF (Chin et al 2007a, Chin et al 2007b) and NF (Molinari et al 2002b, Molinari et al 2004.…”

Section: Membrane Photoreactorsmentioning

confidence: 99%

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Hybrid membrane VIS-LED photoreactor for simultaneous pharmaceuticals degradation and photocatalysts separation

Wang¹

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In recent years, TiO 2-assisted photocatalysis has become a potentially cost-effective and environmentally-sustainable treatment technology for water reclamation and reuse. However, TiO could be photoexcited only under UV irradiation due to its large band gap which hampers its commercial-scale application. In addition, the key challenge for applying the TiO 2 suspension system is that the TiO 2 particles have to be separated from the product water. This study therefore focused on (1) developing visible-light responsive TiO 2-based photocatalysts for photocatalytic degradation (PCD) of pharmaceuticals under visible-light irradiation, and (2) developing hybrid membrane photoreactor (MPR) systems for photocatalyst recovery and reuse in the photoreactor. The first phase of this study was the synthesis of C-sensitized and N-doped TiO 2 (C/N-TiO 2) for PCD of sulfanilamide (SNM) under visible-light-emitting diode (vis-LED) irradiation. It was found that the C/N-TiO 2 calcined at 300 °C (T300) exhibited the highest photocatalytic activity for SNM degradation, due to the presence of optimal content of carbonaceous species (serve as photosensitizer) and the nitrogen doping (lead to the remarkable red shift of absorption edge). The PCD of SNM was more efficient in acidic conditions due to the carbon photosensitizing effect. Bicarbonate, phosphate and silica could inhibit the SNM mineralization to different degrees. T300 exhibited good photochemical stability and its absorption onset could be extended to ca. 600 nm. In order to harness visible light and solar light more efficiently, another novel C-N-S tridoped TiO 2 was synthesized for PCD of tetracycline (TC) under visible-light and simulated solar irradiations in the second phase of this study. It was suggested that the photocatalyst with thiourea : Ti molar ratio of 0.

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Photocatalytic Processes in Membrane Reactors

Cited by 18 publications

References 195 publications

Hydrogen and Oxygen Evolution in a Membrane Photoreactor Using Suspended Nanosized Au/TiO2 and Au/CeO2

Hydrogen and Oxygen Evolution in a Membrane Photoreactor Using Suspended Nanosized Au/TiO2 and Au/CeO2

Visible Light-Responsive Photocatalytic Activity of Boron Nitride Incorporated Composites

Hybrid membrane VIS-LED photoreactor for simultaneous pharmaceuticals degradation and photocatalysts separation

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