Eco-conscious nanofluids: exploring heat transfer performance with graphitic carbon nitride nanoparticles

Abstract The work explores the heat transfer capabilities of semiconducting graphitic carbon nitride (g-C 3 N 4 ) nanofluids. Also, it presents a sustainable and eco-friendly method for synthesizing g-C 3 N 4 nanoparticles using commercially available rice flour as a natural carbon precursor through hydrothermal treatment. The synthesized sample subjected to various characterizations, including analysis of their structure, morphology, thermal properties, and optical properties. The optical bandgap (2.66 eV) is deduced through Tauc plot analysis and reveals the semiconducting nature of the sample. The formation of g-C 3 N 4 is confirmed by various spectroscopic techniques, including X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), Fourier transform infrared (FTIR), and Raman spectroscopy. Thermogravimetric analysis (TGA) demonstrates the nanoparticles’ excellent thermal stability up to 550 °C, indicating potential applications in heat transfer fluids. The investigation of concentration-dependent thermal diffusivity variation using the sensitive mode mismatched dual beam thermal lens technique highlights the potential of g-C 3 N 4 semiconductor nanofluid as an organic and metal-free additive in industry-demanding coolant applications.