Adsorption of cyanogen halides (X-CN; X = F, Cl and Br) on pristine and Fe, Mn doped C60: A highly potential gas sensor

Abstract

Reliable monitoring of toxic and pollutant gases is a prime concern of the technological and scientific communities, simulated by the terrible environmental pollution crisis. Herein, we systematically investigated the gas (X-CN; X = F, Cl, Br) sensing mechanism of pristine, transition metal (Fe and Mn) doped fullerene C60 using first-principles calculations. The pure C60 surface show quite weak adsorption behavior towards X-CN gas molecules that gives rise to physisorption in these complexes, while chemisorption is observed for the Fe, Mn doped C60/X-CN configurations. Moreover, the prominent adsorption strength, moderate charge transfer and appreciable electronic conductivity demonstrates high sensitivity of metal doped C60 cage towards cyanogen halide gas molecules. The simulated electronic band structure and optical absorption spectra using HSE06 hybrid functional show strong variations after the adsorption of X-CN gases, revealing the potential capability of metal doped C60 as reliable gas sensor. Especially, the band gaps of Fe, Mn doped C60/X-CN complexes were reduced from that of pure counterpart, representing a strong signal for the detection of cyanogen halide gases. Further, the sensitivity of X-CN gases were correlated with π electron occupancy of the host materials. As we extol the remarkable sensitivity of fullerene C60, we believe that these findings may capture widespread attention towards wearable chemical sensors for future applications.