Hydrothermal growth of wheatear-shaped ZnO microstructures and their photocatalytic activity

A facile hydrothermal process was developed to synthesize novel wheatear-shaped ZnO microstructures at a low temperature (85∘C\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$85^{\circ }\hbox {C}$$\end{document}) without the assistance of any template agent. X-ray diffraction and field emission scanning electron microscopy were used to characterize the structure and morphology of the samples. Results showed that the length of the ‘wheatear’ was about 5.8μm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$5.8~\upmu \!\hbox {m}$$\end{document} and the section width was 1.2μm\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$1.2~\upmu \!\hbox {m}$$\end{document}. The particles consisted of closely packed nanorods with average diameter of 100 nm. The growth of wheatear-shaped ZnO is very rapid and can be achieved in only 5 min. OH-\documentclass[12pt]{minimal} \usepackage{amsmath} \usepackage{wasysym} \usepackage{amsfonts} \usepackage{amssymb} \usepackage{amsbsy} \usepackage{mathrsfs} \usepackage{upgreek} \setlength{\oddsidemargin}{-69pt} \begin{document}$$\hbox {OH}^{-}$$\end{document}-driven oriented aggregation and multistep nucleation resulted in the formation of wheatear-shaped ZnO microstructures. The product had assembled open structures and it exhibited excellent photocatalytic activity in the degradation of methyl orange under UV-light irradiation.