Nanocoating Thin Film Applications on Water Treatment

Abstract

The main objective of this study is to determine the photocatalytic degradation efficiencies of the persistent compounds in wastewater by using new generation photocatalytic potassium lanthanum titanates (K2Ln2Ti3O10) materials. With this concept, the influence of pH, pollutant concentration and light intensity are investigated in details. The disadvantage of the current treatment methods is the sludge production. Sol-gel method is applied to produce newly developed photocatalysyts in order to oxidize the pollutants in water. DTA, FTIR, XRD, SEM, XPS and AFM analyses were performed to determine the thermal, structural and morphological characterization of the photocatalysts, respectively. To provide the highest activity, new generated K2Ln2Ti3O10 (Ln= La, Nd, Gd, Sm and Dy) photocatalytic thin films were produced on Si (100) substrates and the degradation experiments were analyzed. The photocatalytic performances of methylene blue (MB) were carried out in a solar box ATLAS SUNTEST CPS+ which simulates solar radiation. On the other hand, ANOVA test for K2La2Ti3O10 was used to understand the effectiveness of the variables. The pH (3-7-10) and light intensity (250 and 750W/m2) were selected as variables for an initial concentration of 10-5 M methylene blue. The maximum degradation ratio of MB was obtained 99.87% at pH 10 and 750W/m2 by using K2La2Ti3O10. The same procedure with different precursors is applied to produce different doped K2La2Ti3O10 thin films. Dopant precursors were selected as Sm, Dy, Gd and Nd as mentioned above. The maximum degradation ratio of MB among the doped photocatalyst was obtained 98% by K2La1,1Gd0,9Ti3O10 and K2La1,5Gd0,5Ti3O10 at the same conditions.