Hybrid Structure of Ionic Liquid and TiO₂ Nanoclusters for Efficient Hydrogen Evolution Reaction

Abstract

Hydrogen energy has received significant attention in the renewable energy sector due to its high energy density and environmentally friendly nature. For the efficient hydrogen generation from water, the hydrogen evolution reaction (HER) has to be optimized, which requires a highly efficient electrocatalyst. In this work, a hybrid structure of the ionic liquid (IL) 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (C2mim TfO) and (TiO2) n nanoclusters with n = 2–12 has been investigated in the pursuit of new catalyst materials for effective HER. We have employed state-of-the-art density functional theory (DFT) computations to depict the HER catalytic performance of IL/(TiO2) n hybrid systems through Gibbs free energy (ΔG) and an exchange-current-based “volcano” plot. We have explored the effect of the TiO2 nanoclusters on the structural and electronic characteristics of the IL, calculating the adsorption energy, the energies of the highest occupied (HOMO) and lowest unoccupied molecular orbitals (LUMO), the HOMO–LUMO band gap E g, and the work function ϕ. The variation in size of the TiO2 nanocluster in the IL/(TiO2) n hybrid system was found to have a significant influence on the electronic properties. The obtained results suggest that the ΔG of the hydrogen adsorption is remarkably close to the ideal value (0 eV) for the IL/(TiO2)5 system, which also reflects from the volcano plot, suggesting that this complex is the best HER catalyst among the studied systems; it might be even better than the traditional Pt-based catalyst. Thus, the present work suggests ways for the experimental realization of low-cost and multifunctional IL-based hybrid catalysts for clean and renewable hydrogen energy production.

Ionic Liquid Modified Active Edge‐Rich Antimonene Nanodots for Highly Efficient Electrocatalytic Hydrogen Evolution Reaction

“…It can be thus inferred that the active edge sites engineering by reducing the size of the antimonene nanosheets to expose more edge active sites facilitates enhancing the active surface area, mass and charge transport for high reaction kinetics [23,25,43] . On the other hand, the ionic liquid modified on the surface of AMNDs played a crucial role to facilitate the electron transfer process and acted as an electron acceptor with excellent hydrogen adsorption capacity [28–32] . It is supposed that the synergy effect of active edge sites engineering by reducing the size of antimonene and surface modulation strategy by modifying its surface using ionic liquid endows AMNDs the boosted electrocatalytic activity, kinetics, and stability toward HER.…”

“…[23,25,43] On the other hand, the ionic liquid modified on the surface of AMNDs played a crucial role to facilitate the electron transfer process and acted as an electron acceptor with excellent hydrogen adsorption capacity. [28][29][30][31][32] It is supposed that the synergy effect of active edge sites engineering by reducing the size of antimonene and surface modulation strategy by modifying its surface using ionic liquid endows AMNDs the boosted electrocatalytic activity, kinetics, and stability toward HER.…”

“…Very recently, several researchers have reported that the ionic liquid modification improved the catalytic performance of the catalysts because of its excellent ionic conductivity, tunable chemical properties and good thermostability. [28,30,31] Li and co-workers modified metal-free carbon nanotubes with imidazolium ionic liquids to enhance the electrocatalytic HER. [32] Li et al have proved that more active sites can be exposed at its basal planes/edges by modifying 1T/ 2H-MoS 2 catalyst with ionic liquid (N-butyl pyridinium bromide, [BPy]Br), and thus promote the charge transfer for HER.…”

“…Therefore, it is highly magnetic to explore low‐cost organic intermediates to improve the HER activity of antimonene. Very recently, several researchers have reported that the ionic liquid modification improved the catalytic performance of the catalysts because of its excellent ionic conductivity, tunable chemical properties and good thermostability [28,30,31] . Li and co‐workers modified metal‐free carbon nanotubes with imidazolium ionic liquids to enhance the electrocatalytic HER [32] .…”

A comprehensive multidisciplinary investigation on CO2 capture from diesel engine

“…The experimental investigation on conformational isomerism reveals the existence of both Gauche and Trans conformers (Umebayashi et al 2005). Nevertheless, earlier reports on C 2 mim + cation-based ILs demonstrate that particularly in comparison to the planar conformer, the nonplanar structure possesses less energy (Singh et al 2016a(Singh et al , b, c, 2019Sanchora et al 2019Sanchora et al , 2020Pandey et al 2019Pandey et al , 2020Pandey et al , 2021a. Consequently, the non-planar conformer of C 2 mim + cation to interact with the tetrafluoroborate (BF 4 ) anion was considered in the current work.…”