Optical properties of a graphene nanofluid for direct absorption solar collectors

作者：Miguel Sainz Mañas, Cyril Caliot, Christophe Escape, Françoise Bataille, Gilles Flamant · 发表于：Next Materials · 年份：2025 · DOI：10.1016/j.nxmate.2025.100798 · 被引用次数：2 · 研究领域：Solar Thermal and Photovoltaic Systems、Photovoltaic System Optimization Techniques、Solar-Powered Water Purification Methods

Graphene-based materials exhibit unique physical properties that are valuable for a wide range of applications. In the energy sector, this 2D carbon nanomaterial is primarily valued for its mechanical strength and electrical conductivity. However, the optical properties of graphene could enhance the performance of new-generation solar thermal collectors. This study investigates experimentally and numerically the optical properties of graphene nanoparticles dispersed in water. Spectrophotometric measurements, combined with Monte-Carlo ray-tracing simulations, permitted to determine the optical properties of the dispersion and the specific contribution of graphene particles. The influence of the shape and size of these carbonaceous particles is analyzed by comparing results from two different modeling approaches: namely, the Mie theory and the discrete dipole approximation. The results indicate that high extinction coefficients at low graphene concentrations (below 1 g/L) can be attributed to the high absorption properties of the particles. Additionally, the size and shape of the particles significantly affect both the absolute value of extinction and the spectral optical behavior of graphene. Graphene nanoplatelets with thicknesses below 10–20 nm and high length-to-thickness ratios optimize the absorption capacity of the nanofluid in the UV-Visible solar spectrum. Further, a bimodal particle size distribution is found to accurately reproduce the optical properties of the graph...