A mass transfer based method for measuring the reaction coefficients of a photocatalyst

Visible light induced electron transfer process over nitrogen doped TiO2 nanocrystals prepared by oxidation of titanium nitride

“…Photocaytalytic degradation of toluene is chosen as the probe reaction to characterize the activity of the prepared samples, as toluene is a typical indoor pollutant [16,17]. The photocatalytic activity experiments of the as-prepared catalysts for the oxidation of toluene in air were performed at room temperature using a 1.8 L photocatalytic reactor.…”

Applicability of a continuous-flow system inner-coated with S-doped titania for the photocatalysis of dimethyl sulfide at low concentrations

“…Similarly, Demeestere et al (2005a) obtained a DMS conversion higher than 90% for at least 180 min of UV irradiation at the IC up to 9.2 AE 0.5 ppm; however, at a higher IC of 22.8 ppm, conversion decreased from 94.2 AE 0.6% during the first 20 min of UV irradiation to 82.0% after 180 min. These IC dependences are likely due to a competitive adsorption between contaminant molecules on the catalyst surface (Zhao and Yang, 2003;Van Gerven et al, 2007;Yang et al, 2007). The competition would be greater at higher ICs.…”

Removal of Low-Concentration Formaldehyde by a Fiber Optic Illuminated Honeycomb Monolith Photocatalytic Reactor

“…Because the hydroxyl radicals act as a major oxidizer in the photocatalytic oxidation of organic chemicals, there may be a correlation between the rate constant of photocatalytic oxidation (k) and the rate constants for the gas-phase reaction with hydroxyl radicals (k OH ) (Atkinson, 1989;Gill and Hites, 2002), and Fig. 6 presents the positive correlation between k and k OH (Obee and Hay, 1997;Yu et al, 2006b;Yang et al, 2007b;Huang, 2008;Lai, 2009). …”

“…In the photocatalytic oxidation, the ultraviolet (UV) radiation with energy above the band-gap of titanium dioxide (TiO 2 ) (wavelength < 385 nm) can induce the formation of electron-hole pairs and generate hydroxyl radicals further on the UV-illuminated TiO 2 surface, and then the oxidation of organic contaminants to H 2 O, CO 2 and other final products is mediated by hydroxyl radicals (Anpo et al, 1991;Yu et al, 2006b;Zuo et al, 2006;Hodgson et al, 2007;Yu and Lee, 2007;Mo et al, 2009Sun et al, 2010Yu et al, 2010;Kandiel et al, 2013;Klementova and Zlamal, 2013;Silva et al, 2013). The key photocatalytic oxidation and reduction processes in the degradation of formaldehyde can be expressed as what follows (Noguchi and Fujishima, 1998;Ao et al, 2004) A variety of photocatalytic reactors have been designed for indoor air purification, such as plate (Yu et al, 2006b;Zuo et al, 2006;Yang et al, 2007b;Yu and Lee, 2007;Chen et al, 2009;Yu et al, 2010), honeycomb monolith (Hodgson et al, 2007;Wu et al, 2013;Yu et al, 2014), annular (Yang et al, 2007a;Shie et al, 2008), packed-bed (Han et al, 2012), and optical fiber (Bourgeois et al, 2012). Among these reactors, the performances of plate [once-flow removal efficiency (ORE): 11-19.6% (Yang et al, 2007b); 50% (Chen et al, 2009)] and annular [ORE: 8-14% (Yang et al, 2007a)] reactors on formaldehyde decomposition were lower than those of the packed-bed [ORE: 40-90% (Han et al, 2012)], optical fiber [ORE: 60% (Bourgeois et al, 2012)] and the honeycomb monolith type [ORE: 35-86% (Hodgson et al, 2007;…”

“…The key photocatalytic oxidation and reduction processes in the degradation of formaldehyde can be expressed as what follows (Noguchi and Fujishima, 1998;Ao et al, 2004) A variety of photocatalytic reactors have been designed for indoor air purification, such as plate (Yu et al, 2006b;Zuo et al, 2006;Yang et al, 2007b;Yu and Lee, 2007;Chen et al, 2009;Yu et al, 2010), honeycomb monolith (Hodgson et al, 2007;Wu et al, 2013;Yu et al, 2014), annular (Yang et al, 2007a;Shie et al, 2008), packed-bed (Han et al, 2012), and optical fiber (Bourgeois et al, 2012). Among these reactors, the performances of plate [once-flow removal efficiency (ORE): 11-19.6% (Yang et al, 2007b); 50% (Chen et al, 2009)] and annular [ORE: 8-14% (Yang et al, 2007a)] reactors on formaldehyde decomposition were lower than those of the packed-bed [ORE: 40-90% (Han et al, 2012)], optical fiber [ORE: 60% (Bourgeois et al, 2012)] and the honeycomb monolith type [ORE: 35-86% (Hodgson et al, 2007;Mo et al, 2009)]. In our previous study, we had successfully improved the removal efficiency of α-pinene to > 90% by using a fiber optic illuminated honeycomb monolith photocatalytic reactor (Yu et al, 2014).…”