title: Photocatalytic activity and photocorrosion of atomic layer deposited ZnO ultrathin films for the degradation of methylene blue.
abstract: ZnO ultrathin films with varied thicknesses of 7-70 nm were prepared at 200 °C on Si and fused quartz substrates by atomic layer deposition (ALD). The impact of film thickness and annealing temperature on the crystallinity, morphology, optical bandgap, and photocatalytic properties of ZnO in the degradation of methylene blue (MB) dye under UV light irradiation (λ = 365 nm) has been investigated deeply. The as-deposited 28 nm thick ZnO ultrathin film exhibits highest photocatalytic activity, ascribed to the smallest band gap of 3.21 eV and proper thickness. The photocorrosion effect of ALD ZnO ultrathin films during photocatalytic process is observed. The presence of MB significantly accelerates the dissolution of ZnO ultrathin films. The possible photoetching mechanism of ZnO in MB solution is proposed.
authors.affiliation: National Laboratory of Solid State Microstructures and Department of Materials Science and Engineering, College of Engineering and Applied sciences, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, People's Republic of China.
authors.forename: Yan-Qiang
authors.initials: YQ
authors.lastname: Cao
authors.forename: Jun
authors.initials: J
authors.lastname: Chen
authors.forename: Hang
authors.initials: H
authors.lastname: Zhou
authors.forename: Lin
authors.initials: L
authors.lastname: Zhu
authors.forename: Xin
authors.initials: X
authors.lastname: Li
authors.forename: Zheng-Yi
authors.initials: ZY
authors.lastname: Cao
authors.forename: Di
authors.initials: D
authors.lastname: Wu
authors.forename: Ai-Dong
authors.initials: AD
authors.lastname: Li