A fairly simple method for ZnO nanowire synthesis that I recently came across is the thermal decomposition of zinc acetate dihydrate. Just keep zinc acetate dihydrate salt in a muffle furnace at 300 degrees for around 12 hours and obtain the nanowires. Refer to the paper by Lin et al. titled "Synthesis of ZnO nanowires by thermal decomposition of zinc acetate dihydrate".
u can follow my paper which was published recently in ACS applied material interfaces (Au@ZnO core-shell nano particles) . My method is simple, carried out in just 85 deg C. The particle size will be around 80-120 nm. U can download from my research gate profile.