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Abstract A polycrystalline Cu foam with sub-micron ligament sizes was formed by creating a non-woven fabric via electrospinning with a homogeneous mixture of polyvinyl alcohol(PVA)-and copper acetate(Cu(Ac) 2 ). Thermogravimetric measurement of the electrospun fabric of the precursor solution is reported. Oxidizing the precursor fabric at 773K formed an oxide nano-foam; subsequent heating at 573K with a reducing gas transformed the CuO nano-foam to Cu with a similar ligament and meso-scale pore size morphology. A cross-section prepared by focused ion beam lift-out shows the polycrystalline structure with multi-scale porosity. The mechanical property of the Cu nano-foam is measured by nano-indentation. The load-depth curves and deduced mechanical properties suggest that additional intra-ligament pores lead to unique structure-property relations in this non-conventional form of metal.
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An Easy‐to‐Fabricate 2.5D Evaporator for Efficient Solar Desalination
Abstract Solar‐driven steam generation, whereby solar energy is harvested to purify water directly, is emerging as a promising approach to mitigate the worldwide water crisis. The scalable application of conventional 3D evaporators is hindered by their complex spatial geometries. A 2.5D structure is a spatial extension of a 2D structure with an addition of a third vertical dimension, achieving both the feasibility of 2D structure and the performance of 3D structure simultaneously. Here, an interconnected open‐pore 2.5D Cu/CuO foam‐based photothermal evaporator capable of achieving a high evaporation rate of 4.1 kg m−2h−1under one sun illumination by exposing one end of the planar structure to air is demonstrated. The micro‐sized open‐pore structure of Cu/CuO foam allows it to trap incident sunlight, and the densely distributed blade‐like CuO nanostructures effectively scatter sunlight inside pores simultaneously. The inherent hydrophilicity of CuO and capillarity forces from the porous structure of Cu foam continuously supply sufficient water. Moreover, the doubled working sides of Cu/CuO foam enlarge the exposure area enabling efficient vapor diffusion. The feasible fabrication process and the combined structural features of Cu/CuO foam offer new insight into the future development of solar‐driven evaporators in large‐scale applications with practical durability.
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- PAR ID:
- 10387616
- Publisher / Repository:
- Wiley Blackwell (John Wiley & Sons)
- Date Published:
- Journal Name:
- Advanced Functional Materials
- Volume:
- 31
- Issue:
- 27
- ISSN:
- 1616-301X
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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