Adsorption and photocatalysis of nanocrystalline TiO2 particles for Reactive Red 195 removal: effect of humic acids, anions and scavengers
In the present study, the coupling of adsorption capacity and photocatalytic efficiency of two different industrially produced titania catalysts was investigated and compared. The azo dye Reactive Red 195 was selected as a model compound. The tested catalysts, PK-10 and PK-180, exhibited different adsorption capacities due to their significant difference in their specific surface, but both have proven to be effective photocatalysts for photodegradation of the studied dye. PK-10 exhibited strong adsorption of the studied dye due to its high specific surface area, while the second studied catalyst, PK-180, demonstrated negligible adsorption of Reactive Red 195. The effect of the pH, the concentration of the catalyst and the initial concentration of the dye appear to affect the photocatalytic rate. The effect of the presence of humic acids and inorganic ions was also examined, while the contribution of various reactive species was indirectly evaluated through the addition of various scavengers. To evaluate the extent of mineralisation of the studied dye, total organic carbon (TOC) measurements during the experiment were also conducted. Besides total colour removal, evident reduction of TOC was also achieved using both catalysts.
KeywordsPhotocatalysis TiO2 nanoparticles Azo dyes RR195 Scavengers Mineralisation
The authors gratefully acknowledge the support by the project ChemPharmNet CZ.1.07/2.4.00/31.0130 coming from European Social Fund and project LO1305 of the Ministry of Education, Youth and Sports of the Czech Republic. The authors thank Josef Kašlík from the Regional Centre of Advanced Technologies and Materials, Faculty of Science, Palacky University in Olomouc for XRD measurements.
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