Adsorption mechanism of single OCN− and SCN− upon single-walled BP nanotubes

• The adsorption of OCN− and SCN− on (6, 0), (7, 0) and (4, 4) BPNTs surfaces were investigated using the DFT calculations.
• The NBO analyses indicate that a significant charge transfer has occurred after the adsorption of OCN− and SCN− on (6, 0), (7, 0) and (4, 4) BPNTs.
• The energy gap of the BPNTs has not significantly changed via the adsorption of OCN− and SCN−.
• BPNT may not be potentially applied as OCN− and SCN− sensors.

The chemisorptions of cyanato anion (OCN−) and thiocyanate anion (SCN−) on the surfaces of zigzag and armchair single-walled boron phosphide nanotubes (SWBPNTs) were studied using first-principles theory. The most stable adsorption values for OCN− and SCN− on (6, 0) BPNT are found to be about −3.63 and −2.81 eV, respectively. Numerical results exhibit significant adsorption energies for OCN− and SCN− on both zigzag and armchair BPNTs. Also, orbital interaction is the major molecular interaction in the adsorption process of these two molecules. In addition, the results suggest that the BPNT has low sensitivity to the presence of OCN− and SCN−. We believe that the (7, 0) BPNT cannot be applied as a successful candidate for sensor applications.