<span>Fabrication of nanoporous au-ag thin films using magnetron sputtering deposition and etching process</span>

The hierarchical nanoporous structure is often described as a corrosion-derived, bi-continuous porous network of interconnected ligaments. Nanoporous metallic materials have attracted much interest as they hold great potential for advanced applications in various areas. In this study, nanoporous Au-Ag thin films were formed on the n-doped Si (110) wafers, using magnetron sputtering deposition and subsequent electrochemical etching in HF solution. The etched Au0.12Ag0.23Si0.65 film had a highly rough surface, including ligaments in sizes of 30-40 nm and small pore channels with cross sizes of 10-30 nm on SEM analysis. AES depth profiling data showed that Ag atoms tended to distribute more on the surface than underlying regions after the dealloying process. The thicknesses of films before and after etching were approximately 150 nm and 100 nm, respectively. The nanoporous film exhibited a significant current response toward the electrochemical oxidation of phenol at 0.7 V. The results indicate that the as-fabricated nanoporous Au-Ag structure with the mentioned characteristics can be studied further for potential applications in chemical and biochemical areas.