We first report the fabrication of submillimeter-sized Au plates (up to about I mm in size) through the simple thermal decomposition of HAUCl(4) in two-component ionic liquids of 1-butyl-3-methylimidazolium hexafluorophosphate (C4ImPF6) and 1-octyl-3-methylimidazolium hexafluorophosphate (C8ImPF6), which were about ten times larger sizes than those from the single-component ionic liquid of the either.