The role of nanostructure morphology of nickel-infused alumina on solar-thermal energy conversion

Solar-thermal energy conversion can be useful in many applications, including water desalination, and thermal energy storage. In this regard, using spectrally-selective solar absorbers is vital due to their high solar absorptance and low thermal emittance. While selective absorbers can be created using a wide range of nanomaterials, the underlying geometry may control the overall performance of solar-thermal energy conversion. With different geometries, it is possible to obtain a wide range of optical responses ranging from broadband to selective absorption of light. In this study, we focus on the role of nanostructure morphology of nickel-infused alumina (Ni/NPA) based spectrally-selective solar absorbers. This study demonstrates the use of the design of experiments to analyze the effect of various geometric factors on the resulting optical response of Ni/NPA in the context of solar-thermal energy conversion. We show how this approach can provide a unique insight into the role of various geometric factors on the solar absorptance and thermal emittance of Ni/NPA-based absorbers, and demonstrate how it can guide the development of spectrally-selective materials. We believe a similar approach can be useful in the development of other optical materials for different applications. (paper)