Density Functional Theory Studies of Doping and Curvature Effects on the Electrocatalytic Hydrogen Evolution Activity of Carbon Nanotubes

Abstract

Using low-cost, efficient, and stable nonprecious alternatives for Pt-based catalysts is important for electrocatalytic hydrogen evolution reaction (HER), and carbon nanotubes (CNTs) with atom doping have shown great potential in electrocatalytic HER. In this work, we have systematically investigated the HER catalytic activities for a series of different curvature CNT (n,n) (n = 5–9), doped with atomic N or N and Co via the first-principle computation. The computed results indicate that H binding capability increases with the curvature increase for the CNTs and N-CNTs. Through manipulating the number of N atoms and the curvature, the N-CNTs can exhibit the optimal considerable ΔG H* values and can be used as an HER catalyst comparable to metal Pt. Moreover, the hydrogen adsorption/desorption can be balanced through the Co atom doped inside the mN y -CNT (n,n) systems because of the charge transfer. The Co/1N-CNT (8,8), Co/1N-CNT (9,9), Co/2No-CNT (9,9), and Co/2Np-CNT (9,9) revealed the ideal HER activity, which could be a promising catalyst for hydrogen production. Meanwhile, the strength of the H adsorption energy of the systems can be correlated to the C p z band center. Thus, the HER catalytic activity of CNT (n,n) (n = 5–9) can be reasonably regulated through doping atoms and designing low-cost and high-performance carbon-based electrocatalysts.

Recent Advances in Carbon‐Based Electrodes for Energy Storage and Conversion

“…Recently, it was also shown that different curvatures of N‐doped CNTs could also increase the HER activity of the CNTs as increasing the curvature increased the H binding ability of both pure and doped CNTs. [ 535 ]…”

“…Recently, it was also shown that different curvatures of N-doped CNTs could also increase the HER activity of the CNTs as increasing the curvature increased the H binding ability of both pure and doped CNTs. [535] 6.4. Fullerene-Based Electrocatalytic HER Fullerenes possess unique chemical and physical properties with their spherical cage and hollow interior structure that have been exploited in a wide variety of applications.…”

Curvature effects on the bifunctional oxygen catalytic performance of single atom metal–N–C

“…Recent experimental and theoretical studies have both indicated that the active sites of such MN 4 -based SACs are centralized at the metal single-atoms attached to four pyridine nitrogen atoms anchored in the extended carbon matrix. To directly probe the atomic and electronic structures of these catalytic sites in different curvature environments, the carbon matrices are represented in this work by a series of single-walled carbon nanotubes (SWNTs) of various diameters, 22,35,36 as illustrated in Fig. 1.…”

Computational screening toward transition metal doped vanadium carbides in different crystal planes for efficient hydrogen evolution: a first-principles study

“…T Δ S H is the entropic contribution of H*, which is equal to 0.203 eV under standard conditions ( T = 298 K and P = 1 bar) in this calculation. Δ E H* is the adsorption energy of a single H atom, which can be calculated as the following equation: 43,44 …”

“…The exchange current density ( i 0 ) at pH = 0 can be defined as: 43,44 where the rate constant k 0 is set to be 1 and k B is the Boltzmann constant.…”