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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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Graphene petal foams with hierarchical micro- and nano-channels for ultrafast spontaneous and continuous oil recovery
Marine oil contamination remediation remains a worldwide challenge. Siphon action provides a spontaneous, continuous, low-cost and green route for oil recovery. However, it is still limited by the low oil recovery rate due to insufficient internal pathways for oil transport. In this paper, a graphene petal foam (GPF)-based oil skimmer is designed and fabricated by plasma-enhanced chemical vapor deposition (PECVD) for ultrafast self-pumping oil recovery from oil/water mixtures. The hierarchical structure, containing micro- and nano-channels formed by interconnected graphene networks and vertically aligned graphene petals (GPs), respectively, and micro-pores inherited from the 3D interconnected structure of Ni foam, provides multiple fast passages for oil transport. An oil recovery rate of 135.2 L m −2 h −1 is achieved in dark conditions for such oil skimmers, while the value is increased to 318.8 L m −2 h −1 under solar irradiation of 1 kW m −2 because of the excellent solar-heating effect of GPs. Quantitative analyses suggest that 68.8% of such a high oil recovery rate is contributed by the nano-channels and micro-pores, while 31.2% arises from the micro-channels. Our demonstrated GPF oil skimmers exhibit great promise for fast spontaneous and continuous oil contamination cleanup.
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- PAR ID:
- 10328096
- Date Published:
- Journal Name:
- Journal of Materials Chemistry A
- ISSN:
- 2050-7488
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Journal Article:
- https://doi.org/10.1039/D2TA00019A
