Waxberry-shaped biomimetic nanoparticles for efficient photothermal conversion.

Novel nanofluids (NFs) based on bio-nanotechnology have enormous potential for solar thermal utilization. The biomimetic nanoparticles (NPs) nanostructures provide new ideas for the design of solar collector medium. Inspired by the biological properties of waxberry, we proposed waxberry-shaped biomimetic nanoparticles (WSBNPs) for solar thermal conversion in this work. Numerical results show TiN WSBNPs exhibit good optical absorption properties compared to Ag- and Au-based WSBNPs. When the volume fraction f v = 5 × 10−6 and the depth h = 15 mm, the photothermal conversion efficiency η abs can reach 93.9%. The mechanistic analysis shows that the high absorption performance of WSBNPs can be attributed to the presence of the "lightning rod" effect on the surface of NPs and the mutual coupling of surface plasmon resonance. The η abs of TiN WSBNPs can reach 90% at a lower penetration h = 11 mm and f v = 5 × 10−6. Meanwhile, the η abs of WSBNPs is proportional to the number of protrusions on the exterior surface. It has been shown that TiN WSBNPs with a raised exterior surface have excellent potential for efficient solar energy utilization. [ABSTRACT FROM AUTHOR]