Catechol Sensing Performance of Pd-Functionalized Two-Dimensional Polyaramid: A DFT Investigation

Abstract

Catechol (Cc) molecule adsorption on a pristine and transition metal (TMs = Sc, Pd, and Cu)-functionalized twodimensional polyaramid (2DPA) monolayer is systematically studied by the first-principles density functional theory method. The weak physisorption (−0.29 eV) and charge transfer of the Cc molecule with p-2DPA result in a very quick recovery time (150 μs), hindering the Cc sensing capability of p-2DPA. Although TM functionalization greatly improved the adsorption ability, the Pdfunctionalized 2DPA was shown to be the best choice for Cc adsorption due to the reasonable adsorption energy of −1.39 eV and expedited charge transfer between the Cc and Pd atom. The change of band gap and, hence, the conductivity of the Pd-2DPA system in response to the adsorption of the Cc molecule demonstrate its higher sensitivity than that of p-2DPA. The work function sensitivity of Pd-2DPA upon the Cc adsorption is also investigated. In addition to the change in the electronic properties, the change in the optical properties of Pd-2DPA after Cc adsorption is also analyzed. The structural stability of Pd-2DPA is validated by performing ab initio molecular dynamics simulations at 300 K. The complete desorption of the Cc molecule from Pd-2DPA is attained by annealing the material at 550 K under visible light (τ = 5.4 s) and at 450 K under UV light (τ = 3.7 s). Moreover, the higher diffusion energy barrier of +1.35 eV confirmed that the functionalized Pd atoms did not diffuse through the crystal to form clusters. This study could lay a theoretical foundation for developing possibly new-generation sensors for detecting Cc molecules.

Transition Metal (Cu, Pd, and Ag)-Modified Nb2S2C Monolayer for Highly Efficient Catechol Sensing: A First-Principles Investigation

“…The work function sensitivity ( S ϕ ) of pristine- and TM-modified Nb 2 S 2 C monolayers after the interaction with the Cc molecule can be calculated using the following equation S ϕ = normalΔ ϕ ϕ substrate × 100 % The S ϕ of pristine Nb 2 S 2 C monolayer toward Cc molecule is 10%, while for Pd-, Ag-, and Cu-modified Nb 2 S 2 C monolayers is 20, 30, and 25%, respectively. This calculation implies that the TM-modified Nb 2 S 2 C monolayer exhibits improved sensitivity over the pure monolayer.…”

“…Furthermore, the biosensor exhibited notable attributes, including good selectivity, stability, repeatability, and reproducibility. Other 2D materials, such as MXenes, SnSe nanosheets, and 2D polymers like polyaramid, have also been explored for Cc detection . MXenes, with their metal-like conductivity and redox-active sites, offer rapid transduction of chemical signals, while SnSe nanosheets provide enhanced sensitivity due to their unique electronic properties. , …”