“…It offers many unique and promising properties, such as a large exciton binding energy (60 meV), high electron mobility, good photocatalytic activity, excellent thermal and chemical stability, large piezoelectric constant and easily modified electric conductivity [188] . Therefore, nanostructured ZnO materials have been studied for many potential applications, including photoluminescence [142,146,189] , gas sensors [173,190,191] , biological applications [166,167,192] , photodetectors [151] , control of surface wettability [152,183,193] , photocatalysts [141,177,186,[194][195][196][197][198] , dye-sensitized solar cells [149] and PEC water splitting [168][169][170][171]199,200] .…”