Batch to continuous photocatalytic degradation of phenol using TiO2 and Au-Pd nanoparticles supported on TiO2

Abstract

A series of Au-Pd/TiO2 catalysts were synthesized in different weight % using sol-immobilization method. Of the range studied 1%Pd/TiO2 catalyst achieved 86.4% conversion of phenol to CO2 in a standard batch-slurry system utilizing UV. However under recycle or continuous operation Pd leaching from catalyst surface led to gradual deactivation. Au-Pd nanoparticles supported on TiO2 P25 were stable and recyclable, here Au species were found to help to anchor Pd species on TiO2, and no observable Pd leaching occurred. Utilizing UV, 1%Pd/TiO2 showed faster rate of phenol degradation in comparison to Au-Pd/TiO2, while 1%Au/TiO2 and 0.5%Au-0.5%Pd/TiO2 showed faster phenol degradation rates under visible light. The TiO2 P25 support was also found to be active, stable and recyclable in phenol degradation utilizing UV; and was hence considered suitable for continuous operation. However poor oxygen mass transfer led to the formation and lay-down of polymeric species when using a Trickle bed approach. Operation in the Taylor flow regime was demonstrated to increase oxygen saturation and significantly reduced deactivation. Hence continuous photocatalytic degradation of phenol could be achieved using TiO2 under Taylor Flow conditions.

Immobilization of TiO2 Semiconductor Nanoparticles onto Posidonia Oceanica Fibers for Photocatalytic Phenol Degradation

“…A promising alternative to pollutant adsorption is the photocatalytic removal of pollutants. Successful examples for photocatalytic phenol degradation, mainly with titanium dioxide (TiO 2 ) as the photocatalyst, are shown in the literature [7][8][9]. Also the plastic additive bisphenol A (BPA), a representative endocrine disruptor and a compound of high concern, belongs to the group of phenolic compounds and can contaminate waters [10].…”

Photocatalytic Degradation of Levofloxacin by Cu doped TiO2 under Visible LED Light

“…Metal doping is one of the most widely used strategies, which effectively shifting band gap edge towards visible light wavelength and also helps in charge carrier separation [46,47]. There are different metals such as Ag, Au, Fe, Ni, Zn and Cu which are reportedly utilized for development of visible light active metal doped TiO2 nanomaterials [48][49][50][51][52][53]. Copper metal is cheaper and readily available as compared to costlier noble metals.…”

Photocatalytic activity and doping effects of BiFeO3 nanoparticles in model organic dyes

“…The results show improved photoactivity of Pb doped to (95.7 %) compared to the pure BFO material (72.3 %) and TiO 2 (78.6 %). The enhanced photoactivity could be credited to the appropriate Pd contents that enhanced the eÀ trapping capacity, which was helpful in the generation and transmission of the generated eÀ h þ pairs (Yilleng et al, 2018;Jaffari et al, 2019b).…”