Defected boron nitride nanosheet as an electronic sensor for 4-aminophenol: A density functional theory study

Abstract

Abstract Recently, an experimental work has shown that generating a point defect in the structure of a boron nitride (BN) nanosheet makes it an electronic sensor for 4-aminophenol (4-AP) detection. Here, we performed a density functional theory (DFT) investigation to explain the origin of experimental observations at molecular level. We found that 4-AP would be preferentially absorbed via its oxygen atom on a B atom of a pristine or defective BN (D-BN) nanosheet with an adsorption energy of −7.2 or −19.3 kcal/mol. It was also found that the work function, electrical conductance, and HOMO-LUMO gap of the pristine BN nanosheet were not sensibly changed by the 4-AP adsorption. By the adsorption of 4-AP on the D-BN nanosheet, the conductance of 4-AP/D-BN complexes was predicted to be 746.0 times higher than that of a bare D-BN. Moreover, by creating a defect, the response of the BN nanosheet to 4-AP increased from 4.7 to 746.0. Being a promising electronic sensor as shown experimentally, D-BN can generate an electronic signal at the presence of 4-AP. This phenomenon is interpreted on the basis of orbital, chemical, and structural analyses. The recovery time was 0.13 s for 4-AP desorption from the D-BN surface, representing a short time. Our results also showed that the D-BN nanosheet could selectively detect the 4-AP molecule at the presence of ethanol (C2H5OH), H2O, CO, O2, and H2 molecules.