Abstract Efficiency is an important factor in the utilization of solar energy. Direct absorption solar energy collectors (DASCs), a new generation collector of converting solar irradiation into heat directly by nanofluids, is regarded as a promising solution for capturing solar energy with high efficiency. Both good stability and high absorption ability are crucial for nanofluids to be an ideal working fluid of DASCs. In this work, we synthesize hyperstable Ti3C2Tx-H2O nanofluids as the working fluids of DASCs and investigate its photothermal conversion performance. The results show that the maximum conversion efficiency of thin-layer Ti3C2Tx nanofluids achieves 91.9% at a very low mass fraction of 0.02 wt%, which is higher than that of multi-layer Ti3C2Tx samples. Based on the experimental results, a simulation model is built to observe the radiation energy transformation in DASCs and results show that better photothermal performance of thin-layer MXene Ti3C2Tx stems from its stronger localized surface plasmon resonance (LSPR) effect. Besides, the coupling effect and the shape of Ti3C2Tx particles also play important roles in photothermal absorption and conversion. Based on our experimental and numerical results, the Ti3C2Tx-H2O nanofluids have great potential in solar energy harvesting.

中文翻译：

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通过局部表面等离子体共振显着吸收 MXene Ti3C2Tx 纳米流体的太阳能

摘要 效率是太阳能利用的重要因素。直接吸收太阳能集热器（DASCs）是一种通过纳米流体直接将太阳辐射转化为热量的新一代集热器，被认为是一种高效捕获太阳能的有前途的解决方案。良好的稳定性和高吸收能力对于纳米流体成为 DASC 的理想工作流体至关重要。在这项工作中，我们合成了超稳定的 Ti3C2Tx-H2O 纳米流体作为 DASC 的工作流体，并研究了其光热转换性能。结果表明，薄层 Ti3C2Tx 纳米流体的最大转换效率在 0.02 wt% 的极低质量分数下达到 91.9%，高于多层 Ti3C2Tx 样品。根据实验结果，建立了一个模拟模型来观察 DASC 中的辐射能量转换，结果表明薄层 MXene Ti3C2Tx 更好的光热性能源于其更强的局域表面等离子体共振 (LSPR) 效应。此外，Ti3C2Tx 粒子的耦合效应和形状在光热吸收和转换中也起着重要作用。基于我们的实验和数值结果，Ti3C2Tx-H2O 纳米流体在太阳能收集方面具有巨大的潜力。