Abstract. Growing ZnO on Si via low-cost CBD is difficult owing to the large lattice mismatch between ZnO and Si and the intricate control of nanoparticle aggregation. In this work, a Pt buffer layer and addition of SiO2 on the chemical solution were introduced. The effect of these parameters on the resulting morphology and composition were investigated using SEM-EDX and FTIR. Pt-coated Si showed higher density of ZnO nanostructure growth than bare Si due to the additional nucleation sites provided by Pt. Moreover, SiO2 addition resulted to a different ZnO nanostructure.