The plasmonic effect of silver nanofluids in the solar energy harvesting

Abstract In this study, the plasmonic effect enabled by silver nanoparticles (AgNps) is evaluated for the enhancement of thermal performance in micro solar collectors. AgNps were synthesized via chemical reduction process using silver nitrate at varying concentrations (0.1, 0.2, 0,3, and 0.4 ml) and pH conditions (5.5–10.5). The creation of evenly spread nanoparticles with a size of 10–15 nm was confirmed by UV–vis spectroscopy and TEM analysis. The best results were seen when the pH was 10.5 and the concentration of silver nitrate was 0.2 ml (102 mg l −1 ). Zeta potential measurements indicated good colloidal stability under these conditions. Thermal conductivity tests showed that nanofluids with AgNps enhanced the base fluid’s conductivity by up to 25% under simulated solar irradiation at 100% intensity. The plasmonic effect was evaluated in both homogeneous (AgNps are dispersed in a base fluid) and heterogeneous systems (AgNps immobilized on anionic resins). The observed maximum temperature difference of 1.4 °C was achieved at pH 10.5, silver concentration of 0.2 ml, and 2 suns irradiation. These findings highlight the potential of AgNp-based nanofluids to significantly enhance the solar energy harvesting systems, providing a promising avenue for advancing renewable energy technologies.