DFT Based Material Computations of Metal-doped and Pure Carbon Nanodots for Examining their Enhancement of Sulfur Dioxide Adsorption

Abstract

Carbon nanodots, one of the last members of the nanocarbon family, show superior properties, such as low-cost production, good conductivity, and optical properties, nontoxic behavior, high biocompatibility, and eco-friendly nature. Understanding the effect of metal doping on the modification of the electronic structure of carbon nanodots is critical for enlarging its potential applications. In the present study, in terms of structural, energetic, and electronic analyses, X-doped carbon nanodot structures (X = B, N, Si, Al, Co, Au, Pd, and Pt) and their SO₂ adsorption abilities were examined comprehensively by employing DFT. Results depict that embedding the heavy impurity metals (Pd, Pt) to the nanodot structures does not improve the SO₂ sensing ability of carbon nanodot materials relatively. However, the doping of the low concentrated metals to the carbon nanodots may be one of the best ways for enhancing the SO₂ trapping ability of the carbon nanodot materials since the calculated results having high adsorption energy values indicate SO₂ gas molecule is easily adsorbed on the surface of doped carbon nanodots. This means higher adsorption capability compared to pure ones. Thus, it is suggested that the doped carbon nanodots consisting of B, Si, and N impurity atoms may be good candidates for effective SO₂ sensing (adsorptions).