Enhanced hydroxylation and carbon dioxide uptake on nanotextured silver oxide

Nanotexturing of silver substrates with silver (I) oxide, Ag2O, is demonstrated using a one-step laser micro-machining process. Where ablation of the silver substrate took place, a highly textured nanoscale topography is generated. In contrast, a film-like oxide is formed next to the machined areas. Interestingly, it was observed that Ag2O formed within the laser tool path was significantly more reactive towards atmospheric H2O and CO2 compared to the film-like oxide, leading to the formation of silver carbonate, Ag2CO3, only in this region. The ability to generate a periodic topography, in the form of a bulls-eye grating, combined with periodic surface chemistry, consisting of alternating regions of Ag2O and Ag2CO3 is also shown. Depending on the machining parameters and tool path used, the surfaces can become quite optically active. When combined with the propensity of a nanotextured Ag2O surface to react with carbon dioxide and water, an attractive system for applications involving photocatalytic CO2 reduction, CO2 capture and storage, and artificial photosynthesis is realized.