Formaldehyde adsorption on Ni doped single-walled carbon nanotube; a DFT study

The structural and electronic properties of Ni doped single-walled carbon nanotubes indicate benefits as new composites that qualify a wide variety of applications as nanostorage devices, nanosensors and nanoplatform in biosensors. Formaldehyde (FO) is the most toxic gas which is being considered as a serious interior pollutant. It wildly employs in decorative materials and some productive while causes respiratory irritation, watery eyes, pulmonary edema, dermatitis and asthma [1]. Due to weak van der Waals interaction of gases with CNT, they are not able to detect a large variety of molecules, such as poisonous gases (e.g. CO), H2, H2O molecules and biomolecules [2]. In this work, within density functional theory (DFT) framework, adsorption of formaldehyde by Ni-loaded on SWCNT surface is studied as a novel chemical sensor for detecting the FO gas. The adsorption processes of the FO molecule on pristine and Ni loaded single-walled nanotube are investigated by using density functional theory (DFT), implementing the Gaussian 09 software. It was found that the FO molecule was interacted with the Ni/SWCNT, and as shown in Fig1 the most stable adsorption configuration was that in which the O atom would prefer to be attached to the Ni atom of Ni/SWCNT with electronic charge transfer from FO to the nanotube. The adsorption energy for the most stable configuration of adsorbed FO on Ni/SWCNT was -1.45 eV. Moreover, the strong binding energies and short binding distances were consistent with the larger charge transfer between the FO molecule and the Ni/SWCNT system. This phenomenon dramatically would increase the electrical conductivity of the nanotube which suggests the potential sensor of Ni/SWCNT for the FO gaseous molecule detection