The role of Diethanolamine as stabilizer in controlling morphology, roughness and photocatalytic activity of ZnO coatings in sonophotodegradation of methylene blue

Abstract

ZnO thin films with various molar ratio of Diethanolamine were manufactured on the glass plates by using the sol-gel method and ZnO particles immobilized on glasses with easy and inexpensive dip-coating method. Effect of different Diethanolamine mole ratio of 0.5, 1, 1.5 and 2 on the morphology, roughness, crystalline structure and photocatalytic activity of ZnO coatings was studied by applying XRD, AFM, DRS, FESEM and FTIR analysis. The XRD patterns revealed that with increasing the Diethanolamine concentration crystalline size and peak intensity of ZnO decreased. AFM images showed that mole ratio of Diethanolamine had a great role in the ZnO coatings roughness so that samples with mole ratio 1 and 2 of diethanolamine had the best and the worst surface roughness, respectively. FESEM images of samples have good agreement with XRD and AFM analysis. According to the FTIR spectra of prepared samples the fingerprint region of ZnO is between 700–500 cm−1 which the intensity of peaks has been changed in each sample. Effect of different mole ratio of Diethanolamine on the photocatalytic activity of ZnO nanostructured films in sonophotodegradation of methylene blue under visible light irradiation in a batch photoreactor equipped by ultrasound probe. The best performance of photocatalyst was achieved by DZ2 content. Also, the effect of operating parameters such as pH, concentration of MB, various Ultrasound Irradiation Power and the number of photocatalytic coatings on sonophotodegradation of methylene blue on the activity of DZ2 coatings were evaluated. The results showed that the coatings with mole ratio 1 and 2 of Diethanolamine had the highest and the least photocatalytic performance.