Decolorization of Orange-G Aqueous Solutions over C60/MCM-41 Photocatalysts

Abstract

The majority of the photocatalysts studied for azo-dye degradation are based on semiconductor materials. Studies reported on non-semiconducting materials are very scarce. In the present work, we studied the fullerene (C60) ability to accelerate photodegradation of the dye’s azo bond in the presence of ascorbic acid. A series of C60 supported on ordered mesoporous silica (MCM-41) catalysts, containing 1, 3, 6, 9, and 12 wt % of fullerene C60, was studied using Orange G (OG) as representative azo-dye. This study showed that partial decolorization is achieved in the dark by simple adsorption of the dye on the bare surface of the carrier. The extent of decolorization increases with the irradiation of the suspension due to photocatalytic degradation of the azo-bond. This is maximized over the sample containing 3 wt % of C60 and it has been attributed to the best combination of the extent of the dye adsorption with the high intrinsic photocatalytic activity of small C60 clusters predominated in this sample. This catalyst proved to be quite stable upon five subsequent photocatalytic cycles, losing less than 5% of its initial activity. No degradation of OG takes place in the absence of ascorbic acid.

Synergistic impacts of sonolysis aided photocatalytic degradation of water pollutant over perovskite-type CeNiO3nanospheres

“…The synergy criterion, which is the proportion of the sonophotocatalytic reaction rate to the sum of the rate constants of the sonocatalysis and photocatalysis, was used to investigate the contributions from individual processes, as revealed in eqn (13). This parameter was also employed to assess the hybrid system's synergic activity, which encompassed both sonocatalysis and photocatalysis mechanisms: 71,72 Synergistic efficiency S ð Þ¼ k ðSonophotocatalyticÞ k ðSonophotocatalyticÞ þ k ðPhotocatalyticÞ (13) k (Sonophotocatalytic) , k (Sonocatalytic) , and k (Photocatalytic) represent sonophotocatalytic, sonocatalytic, and photocatalytic rate constants, respectively. A positive outcome is signified by a synergistic impact value larger than 1.…”

“…In the aqueous phase, however, the hydrazone state predominates. 13 The primary techniques for eliminating colour constituents from wastewater includes electrocoagulation, chlorination, adsorption, ozonation, and biodegradation. [14][15][16] Furthermore, these traditional techniques are ineffective since dye pollutants are simply converted to secondary pollutants.…”

Recent Progress on Fullerene-Based Materials: Synthesis, Properties, Modifications, and Photocatalytic Applications

“…It was also confirmed that methyl red could be decomposed by SiO 2 /C 60 at the same conditions. Likewise, Kyriakopoulos, et al [ 148 ] successfully fabricated a MCM-41/C 60 photocatalyst via a dry impregnation method. Coupling C 60 with MCM-41 significantly increased the BET of the as-prepared photocatalyst, thus effectively dispersing C 60 clusters as well as strengthening its adsorption ability to pollutant.…”

Solar expedited photodegradation of orange-g using H2O2

“…Water has become polluted by the discharge of industrial effluents that contain hazardous contaminants into water bodies like rivers, streams etc., It produces a negative impact on the environment. Dyes constitute the top rank among the most notorious organic pollutants as they are used as a part of textile, leather, paints,plastics,food, cosmetics, paper, pharmaceutical and dye manufacturing [2][3][4][5].They are synthetic, water-soluble, and dispersible organic compounds that are copious sources of coloured organics [4].…”