Synthesis of Al/Cu core–shell particles through optimization of galvanic replacement method in alkaline solution

Abstract

Abstract In this work, Al/Cu core–shell particles were successfully synthesized through an optimized galvanic replacement method. For this purpose, a uniform and dense copper layer was deposited on aluminum particles in an alkaline solution. The effects of four deposition factors, i. e. (i) molar ratio EDTA-2Na/CuSO4 · 5H2O, (ii) molar ratio CuCl2/Al powder, (iii) pH and (iv) temperature were systematically studied and optimized using the Taguchi orthogonal (L9) method. It was observed that molar ratio EDTA-2Na/CuSO4 · 5H2O and temperature are the most affecting factors in the deposition process. By increasing their levels, copper deposition increases within a specified time. The X-ray diffraction and scanning electron microscopy/ energy-dispersive X-ray spectroscopy results revealed the formation of homogeneous nanostructured Cu shells around Al particles. The results revealed that to achieve maximum copper deposition on Al powder; molar ratio EDTA-2Na. 2H2O/CuSO4. 5H2O, molar ratio CuCl2/Al powder, pH and temperature of the deposition bath should be 2.0, 0.05, 8.8 and 55 °C, respectively.