Study on the enhancement of photothermal performance of ZrC-based nanofluids by doping with metal oxides

In the face of growing global energy demand, efficient solar thermal conversion technology is crucial. However, the development of ideal absorbers that closely match the solar spectrum remains challenging. DASC are expected to break through the efficiency bottleneck of traditional collectors by directly absorbing heat through nanofluids. Accordingly, this study investigates the photothermal performance of nanofluids by leveraging the broadband absorption characteristics of zirconium carbide (ZrC) and the ultraviolet–visible synergistic effects of ZnO and CuO. The results showed that the absorption rate of ZrC was 78.58 % at 100 ppm. In the mixed system, the doping of 50 ppm ZnO increased Am to 95.27 %, and the doping of 100 ppm CuO increased to 97.52 %. In terms of maximum temperature rise and photothermal efficiency, the ZrC system was 20.92 °C (79.24 %), the ZrC/ZnO was 24.94 °C and 94.48 %, and the ZrC/CuO was 23.82 °C and 90.24 %. The energy storage ratio (SER) analysis showed that the mixed system was 13.4 %∼18.7 % higher than that of pure ZrC. The study confirmed the excellent photothermal properties of ZrC-based mixed nanofluids in DASC.