Investigation of the adsorption behaviors of novel Au3 cluster decorated arsenene nanosheets towards thiophene and methanethiol detection: A DFT study

First principles calculations were carried out to describe the interactions between Au_n-arsenene nanosheets and methanethiol/thiophene molecules. Both Au-arsenene and Au₃-arsenene nanosheets exhibit smaller band gap than the pure arsenene system due to the emergence of new energy bands near the Fermi level. Thus, the conductivity and sensor capabilities are significantly enhanced for the Au functionalized arsenene nanosheets. Calculated formation energies of −2.38 eV and −5.37 eV for Au-arsenene and Au₃-arsenene nanosheets indicate their structural stability. The adsorption of methanethiol and thiophene molecules on the Au-arsenene substrates spontaneously occurs due to the negative calculated adsorption energies. Besides, thiophene molecule exhibits the highest adsorption energy (−0.52 eV) on the Au-arsenene substrate through its S atom strongly connected to the Au atom. The moderate adsorption energies indicate the shorter recovery times for sensing applications. Our work sheds light on the exploration of Au-arsenene as an effective candidate for sensing methanethiol and thiophene molecules.