Development of semiconducting graphitic carbon nitride nanofluid for heat transfer applications: A mode mismatched thermal lens study

Abstract

The present work delineates the heat transfer potential of the semiconducting graphitic carbon nitride (g-C3N4) nanofluid. The paper also discusses the eco-friendly green synthesis of g-C3N4 nanoparticles from the natural carbon precursor portobello mushroom by the hydrothermal method. The nanoparticles synthesised are subjected to structural, morphological, thermal, and optical characterizations. The flower-like laminar structure of the sample revealed through field emission scanning electron microscope (FESEM) analysis exhibited a semiconducting nature with an optical bandgap of 2.58 eV. The formation of g-C3N4 is confirmed by X-ray diffraction (XRD), Fourier transform infrared (FTIR), X-ray photoelectron (XPS) and Raman spectroscopic analyses. The thermogravimetric analysis (TGA) reveals good thermal stability up to 500 °C, which suggests possible applications in heat transfer fluids. The concentration-dependent thermal diffusivity variation of the g-C3N4 semiconductor nanofluid, investigated using the sensitive mode mismatched dual beam thermal lens technique, divulges its potential as an organic, metal-free additive in engine coolants for automobile applications.