Tuning the composition and nanostructure of Pt/Ir films via anodized aluminum oxide templated atomic layer deposition

Nanostructured metal films have been widely studied for their roles in sensing, catalysis, and energy storage. In this work, the synthesis of compo- sitionally controlled and nanostructured Pt/Ir films by atomic layer deposition (ALD) into porous anodized aluminum oxide templates is demonstrated. Templated ALD provides advantages over alternative synthesis techniques, including improved film uniformity and conformality as well as atomic-scale control over morphology and composition. Nanostructured Pt ALD films are demonstrated with morphological control provided by the Pt precursor exposure time and the number of ALD cycles. With these approaches, Pt films with enhanced surface areas, as characterized by roughness factors as large as 310, are reproducibly synthesized. Additionally, nanostructured PtIr alloy films of controlled composition and morphology are demonstrated by templated ALD, with compositions varying systematically from pure Pt to pure Ir. Lastly, the application of nanostructured Pt films to electrochemical sensing applications is demonstrated by the non-enzymatic sensing of glucose.