Aluminum Nanoarrays for Plasmon-Enhanced Light Harvesting

The practical limits of coinage-metal-based plasmonic materials demand sustainable, abundant alternatives with a wide plasmonic range of the solar energy spectrum. Aluminum (Al) is an emerging alternative, but its instability in aqueous environments critically limits its applicability to various light-harvesting systems. Here, we report a design strategy to achieve a robust platform for plasmon-enhanced light harvesting using Al nanostructures. The incorporation of mussel-inspired polydopamine nanolayers in the Al nanoarrays allowed for the reliable use of Al plasmonic resonances in a highly corrosive photocatalytic redox solution and provided nanoscale arrangement of organic photosensitizers on Al surfaces. The Al-photosensitizer core-shell assemblies exhibited plasmon-enhanced light absorption, which resulted in a 300% efficiency increase in photo-to-chemical conversion. Our strategy enables stable and advanced use of aluminum for plasmonic light harvesting.