Yuan Yang, Dong Changlin, Gu Jiajun, Liu Qinglei, Xu Jian, Zhou Chenxin, Song Guofen, Chen Wenshu, Yao Lulu, Zhang Di
State Key Laboratory of Metal Matrix Composites, School of Materials Science and Engineering, Shanghai Jiao Tong University, Shanghai, 200240, China.
Key Laboratory of Advanced Materials (MOE), School of Materials Science and Engineering, Tsinghua University, Beijing, 100084, China.
Adv Mater. 2020 Apr;32(17):e1907975. doi: 10.1002/adma.201907975. Epub 2020 Mar 11.
Sophisticated metastructures are usually required to broaden the inherently narrowband plasmonic absorption of light for applications such as solar desalination, photodetection, and thermoelectrics. Here, nonresonant nickel nanoparticles (diameters < 20 nm) are embedded into cellulose microfibers via a nanoconfinement effect, producing an intrinsically broadband metamaterial with 97.1% solar-weighted absorption. Interband transitions rather than plasmonic resonance dominate the optical absorption throughout the solar spectrum due to a high density of electronic states near the Fermi level of nickel. Field solar purification of sewage and seawater based on the metamaterial demonstrates high solar-to-water efficiencies of 47.9-65.8%. More importantly, the solution-processed metamaterial is mass-producible (1.8 × 0.3 m ), low-cost, flexible, and durable (even effective after 7 h boiling in water), which are critical to the commercialization of portable solar-desalination and domestic-water-purification devices. This work also broadens material choices beyond plasmonic metals for the light absorption in photothermal and photocatalytic applications.
对于太阳能脱盐、光电探测和热电学等应用，通常需要复杂的超结构来拓宽本质上窄带的等离子体光吸收。在此，通过纳米限域效应将非共振镍纳米颗粒（直径<20 nm）嵌入纤维素微纤维中，制备出一种具有97.1%太阳加权吸收率的本征宽带超材料。由于镍的费米能级附近电子态密度高，带间跃迁而非等离子体共振主导了整个太阳光谱的光吸收。基于该超材料的野外太阳能污水和海水净化展示了47.9 - 65.8%的高太阳能-水效率。更重要的是，这种溶液加工的超材料可大规模生产（1.8×0.3 m），成本低、柔韧性好且耐用（甚至在水中煮沸7小时后仍有效），这对于便携式太阳能脱盐和家用净水设备的商业化至关重要。这项工作还拓宽了光热和光催化应用中光吸收的材料选择范围，超越了等离子体金属。
