Superhydrophobic ZnO/TiO2 heterostructure with significantly enhanced photocatalytic activity

• Published in: Journal of materials science. Materials in electronics Vol. 30; no. 11; pp. 10399 - 10407
• Main Authors: Upadhaya, Diliraj, Kumar, Pankaj, Dhar Purkayastha, Debarun
• Format: Journal Article
• Language: English
• Published: New York Springer US 01.06.2019; Springer Nature B.V
• Subjects: Anatase; Borosilicate glass; Catalytic activity; Characterization and Evaluation of Materials; Chemistry and Materials Science; Contact angle; Heterostructures; Hydrophobic surfaces; Hydrophobicity; Materials Science; Methylene blue; Optical and Electronic Materials; Photocatalysis; Sol-gel processes; Spin coating; Thin films; Titanium dioxide; Ultraviolet radiation; Wettability; X-ray diffraction; Zinc oxide
• ISSN: 0957-4522; 1573-482X
• DOI: 10.1007/s10854-019-01381-2

ZnO/TiO 2 and TiO 2 /ZnO thin films were prepared on borosilicate glass slide (BSG) by cost effective sol–gel spin coating technique. The films were characterized using X-ray diffraction, FESEM and FT-IR. The X-ray diffraction reveals the existence of both hexagonal ZnO and anatase TiO 2 phases for ZnO/TiO 2 and TiO 2 /ZnO thin films. In the present work, an effort has been made to systematically study the wettability and photocatalytic activity of ZnO/TiO 2 and TiO 2 /ZnO thin films. The wettability of the films was assessed by measuring the water contact angle (WCA). The WCA of ZnO/TiO 2 and TiO 2 /ZnO was 43.6º and 26.3º respectively. The WCA of the films increases by modifying with octadecanoic acid (OA) where ZnO/TiO 2 shows superhydrophobic nature having WCA of 151.0º. The photocatalytic activities of the films were evaluated by measuring the degradation of methylene blue (MB) and octadecanoic acid under UV light. The photocatalytic efficiency of ZnO/TiO 2 was higher because of the formation of heterostructure which inhibits the charge recombination.