Effects of Adsorbents Used as Supports for Titanium Dioxide Loading on Photocatalytic Degradation of Propyzamide

Abstract

Photodecomposition in aqueous solution of 3,5-dichloro-N-(3-methyl-1-butyn-3-yl)benzamide, whose popular name is propyzamide, was investigated using naked TiO 2 and TiO 2 -loaded adsorbent supports as photocatalysts. The adsorbent supports used were zeolite (mordenite), silica, and activated carbon. The use of adsorbent supports was found to enhance the rate of mineralization of propyzamide and to reduce the concentration of solution-phase intermediates. The experimental results suggest that the adsorbent support concentrates a target substrate of low solutionphase concentration on its surface, providing the substrate-rich environment at the adsorbent/TiO 2 interface. This concentration effect results in an enhanced rate of propyzamide mineralization. The intermediates are also retained on the adsorbent support and subsequently decomposed, thereby reducing the concentration of possibly toxic intermediates in the bulk solution. ES950483K X Abstract published in Advance ACS Abstracts, February 15, 1996.FIGURE 7. Distribution of intermediates detected by GC/MS analysis after irradiation for 15 min. The open and hatched parts represent the fraction of intermediates dissolved in the solution phase and adsorbed on the photocatalyst, respectively. The photocatalyst used was naked TiO2 (a) and 70 wt % TiO2/AC (b). For experimental conditions, see the caption of Figure 2. FIGURE 8. Reaction mode of photoinduced mineralization of propyzamide over naked TiO2 (a) and TiO2-loaded adsorbent (b).

Synthesis and Characterization of Novel Plasmonic Ag/AgX-CNTs (X = Cl, Br, I) Nanocomposite Photocatalysts and Synergetic Degradation of Organic Pollutant under Visible Light

“…1 Since the giant π-conjugation between CNTs and TBP molecules, CNTs would adsorb TBP molecules from the solution, and thus facilitate the photocatalytic degradation of TBP at the catalyst surface. 46 The band gap of AgCl and AgI are also obtained as 2.92 and 2.86 eV, respectively, which is quite close to that of AgBr. So the photocatalytic mechanism of other photocatalysts should be similar to Ag/AgBr-CNTs.…”

Modification of Carbon Nanotube for Synthesis of Titania Nanotube (Tint)-Carbon Nanotube (Cnt) Composite

“…By mixing photocatalyst and adsorbent, it is expected the contact between photocatalyst with pollutant become more effective. Further, used adsorbent is not require to be regenerated because pollutant sticked on absorbent will degraded in situ by photo-catalyst so that saturation of absorbent can be avoided [6], [7].…”

“…Based on the previous research, it was known that the use of adsorbent as buffer can increase the rate of photo-degradation for various pollutants [6]. Used adsorbent was porous media, so that photocatalyst could get into pores or sticked on absorbent surface.…”

Preparation and Photocatalytic Performance of MWCNTs/TiO2Nanocomposites for Degradation of Aqueous Substrate

“…In particular, some porous materials have been reported to improve the catalytic performance of TiO 2 as a coadsorbent with a very porous and high adsorption capacity when used to support TiO 2 [13,[17][18][19]. Among them, carbon nanotubes received extensive attention because of their unique structure and properties, since found in 1993 [20].…”