The availability of well-aligned high quality ZnO nanowires will extend the potential applications of such materials. In this study, a new strategy for fabricating well-aligned high quality ZnO nanowire arrays via a lower temperature chemical vapor deposition method on un-resisted high temperature substrates was reported for the first time. The results indicated that the growth temperature can be decreased to 600 °C using nanodiamond as the reductant. The thermodynamic mechanism of nanodiamond in ZnO nanowire growth was discussed in detail. Finally, the sensitivity performance was confirmed by UV laser illumination, in which the ZnO nanowire grown at low temperature exhibited a comparable UV light response performance to that grown at high temperatures.