Investigation into NanoTiO₂/ACSPCR for Decomposition of Aqueous Hydroquinone

Abstract

The suspended TiO2 powder enjoys free contact with pollutant molecule in a photocatalytic reactor; it can generally achieve better efficiency than the immobilized TiO2 catalysts. However, the separation and reuse of this catalyst powder from treated water often limit its application in practice. An adsorptive activated carbon-supported titanium dioxide photocatalyst TiO2/AC was prepared using nanosized titanium dioxide (anatase) immobilized on activated carbon powder by a novel preparation technique with polyacrylic ester emulsion. Meanwhile, the heterogeneous photocatalytic decomposition of aqueous hydroquinone over the ultraviolet irradiated TiO2/AC photocatalyst was carried out with high decomposition efficiencies in a slurry photocatalytic reactor (SPCR), which provided the effective contact of TiO2/AC photocatalyst and reactant. The pH value, the ratio of TiO2/hydroquinone, the aerating, and the concentration of H2O2 on photocatalytic decomposition of hydroquinone were discussed in detail. Experimental results showed that not only did the photocatalyst have a high adsorption performance and a good photocatalytic activity for hydroquinone but also the catalyst was easily separated from SPCR and recycled as well. Moreover, it was found that the reaction kinetic fixed the pseudo-first-order kinetic equation, which provided a detailed kinetic understanding of photocatalytic degradation of hydroquinone in SPCR.

Syntheses of Carbon Nanotube-Metal Oxides Composites; Adsorption and Photo-degradation

“…This can reduce the recombination of photogenerated electron-hole pairs. This conclusion is supported by the higher activity of the 308 CNT/MO composites and by being CNTs relatively good electron acceptors while semiconductors as good electron donor under illumination (Subramanian et al, 2004;Geng et al, 2008).…”

Functionalization of tungsten oxide into MWCNT and its application for sunlight-induced degradation of rhodamine B

“…12. This supported by being MWCNTs relatively good electron acceptors [40,41]while WO 3 is an electron donor under illumination [42]. Hence, MWCNTs acts as a photogenerated electron acceptor to promote interfacial electron transfer processes.…”

Organic semiconductors for device applications: current trends and future prospects

“…The large surface-to-volume ratio and an extended π-conjugation make MWCNTs form bundles very easily, which can be checked by using stabilizer having functional groups that can covalently bond to the outermost layers. In one way, this appears helpful, but finally it disrupts the electron delocalization causing formation of charge trap sites leading to impaired electrical conduction [143]. Further, these functional groups also introduce additional energy barriers within CNT composites by interrupting the interaction between CNT and the polymeric matrix.…”

“…Besides polymers, appropriate surfactant molecules were also found useful in functionalizing CNTs by studying the influence of the surfactant on dispersion and other properties of CNTs [143,[179][180][181][182][183][184][185][186][187]. Lowering of surface tension due to physical adsorption of the surfactant on the CNT surfaces very effectively prevented the aggregate formations.…”

“…It was also noted that, in water-soluble polymers such as polyethylene glycol, cationic surfactants have some advantages, whereas, in water-insoluble polymers such as polypropylene, CNT dispersion is promoted by a nonionic surfactant [184,185]. The nonionic surfactants treatment deploys a strong hydrophobic attraction between the solid surface and the tail group of surfactant, and once the surfactant is adsorbed onto the additive surface, the surfactant molecules self-assemble into micelle forms [143].…”