Enhancement of photothermal conversion performance using nanofluids based on bimetallic Ag-Au alloys in nitrogen-doped graphitic polyhedrons
Enhancement of photothermal conversion performance using nanofluids based on bimetallic Ag-Au alloys in nitrogen-doped graphitic polyhedrons
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DOI：
10.1016/j.energy.2019.06.170
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发表时间：
2019-09
期刊：
影响因子：
9
通讯作者：
Guihua Zhu;Lingling Wang;N. Bing;Huaqing Xie;Wei Yu
中科院分区：
文献类型：
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作者：
Guihua Zhu;Lingling Wang;N. Bing;Huaqing Xie;Wei Yu
在宽光谱范围内具有较高太阳能热转换性能的工质是直接吸收式太阳能集热器（DASC）的重要研究对象。具有局域表面等离子体共振（LSPR）效应的金属纳米颗粒和碳纳米材料都具有独特的光谱吸收行为，在DASC中表现出更好的光热性能。本文尝试制备等离子体激元纳米合金和碳纳米材料的复合纳米流体，以实现增强太阳能吸收和光热转换性能。以ZIF-8衍生的氮掺杂石墨多面体（ZNG）为载体，采用吸附-还原法成功负载等离子体激元Ag-Au合金纳米粒子。Ag-Au/ZNG乙二醇纳米流体在较低浓度下在可见光和近红外光谱范围内表现出明显的宽带吸收。与乙二醇相比，所有ZNG纳米流体的光热转换效率均显著提高。等离子体激发的Ag-Au合金纳米粒子进一步提高了光热转换效率，Ag-Au ZNG纳米流体的光热转换效率达到74.35%，而Au/ZNG、Ag/ZNG纳米流体的光热转换效率分别为72.41%、70.35%。本研究为提高纳米流体对太阳能的吸收和太阳能热转换效率提供了一种新的途径。
The working fluids with higher solar thermal conversion performance within broadband spectrum ranges are of great concern for direct absorption solar collectors (DASCs). Both metal nanoparticles with localized surface plasmon resonance (LSPR) effects and carbon nanomaterials have unique spectral absorption behaviors and have shown better photothermal performance in DASCs. In this paper, we attempted to prepare composite nanofluids including plasmonic bimetallic alloy and carbon nanomaterials to realize enhanced solar absorption and photothermal conversion performance. By taking ZIF-8-derived nitrogen-doped graphitic polyhedrons (ZNGs) as carrier, plasmonic bimetallic Ag-Au alloy nanoparticles were loaded on them by an impregnation-reduction method successfully. Ag-Au/ZNGs ethylene glycol nanofluids showed significant broadband absorption in the visible and near-infrared spectrum range at a lower concentration. Comparing to ethylene glycol, the photothermal conversion effeiency of all ZNGs nanofluids increased remarkablely. Plasmonic bimetallic Ag-Au alloy nanoparticles further improved the photothermal conversion efficiency, which was up to 74.35% for Ag-Au ZNGs nanofluids compared with 72.41%, 70.35% for Au/ZNGs, Ag/ZNGs respectively. This work presents a new way to enhance solar energy absorption and improve solar thermal conversion efficiency of nanofluids for DASCs.