Seed-mediated growth method to prepare cubic copper nanoparticles

A new and simple method has been reported here which can be applied to control simultaneously the shape and size of the copper nanoparticles, without using any ca p ping agent or template. By this method, cube -shaped copper nanoparticles in the size range ~ 75 –250 nm were formed from smaller spherical co p-per particles. At the first stage, 5–6 nm spherical co p per particles were prepared from aqueous copper sulphate solution by borohydride reduction. In the second stage, these small particles were mixed with ap propriate amount of copper sulphate and sodium ascorbate, which resulted in the production of larger size cu bic copper particles. In the latter step, the new grown larger particles acted as seed and grew larger due to the reduction of copper ions by ascorbate ion on their surfaces. Thus cubic copper nanoparticles of varied size regime were produced by ascorbate ion by var ying the ratio of copper seed particles to copper ion concentrations in solution. M