Reversible Hydrogen Storage Media by g-CN Monolayer Decorated with NLi4: A First-Principles Study

Abstract

A two-dimensional graphene-like carbon nitride (g-CN) monolayer decorated with the superatomic cluster NLi4 was studied for reversible hydrogen storage by first-principles calculations. Molecular dynamics simulations show that the g-CN monolayer has good thermal stability at room temperature. The NLi4 is firmly anchored on the g-CN monolayer with a binding energy of −6.35 eV. Electronic charges are transferred from the Li atoms of NLi4 to the g-CN monolayer, mainly due to the hybridization of Li(2s), C(2p), and N(2p) orbitals. Consequently, a spatial local electrostatic field is formed around NLi4, leading to polarization of the adsorbed hydrogen molecules and further enhancing the electrostatic interactions between the Li atoms and hydrogen. Each NLi4 can adsorb nine hydrogen molecules with average adsorption energies between −0.152 eV/H2 and −0.237 eV/H2. This range is within the reversible hydrogen storage energy window. Moreover, the highest achieved gravimetric capacity is up to 9.2 wt%, which is superior to the 5.5 wt% target set by the U.S. Department of Energy. This study shows that g-CN monolayers decorated with NLi4 are a good candidate for reversible hydrogen storage.

Metal Organic Frameworks Derived Layered Double Hydroxide Nanosheets for Electrochemical Energy Storage and Conversion

“…The facile and adjustable chemical composition thus increases the demand of its application in supercapacitors. [21] Besides, when MOFs work as a template, the larger specific surface area and consequently their short electrochemically active pathways can be inherited, leading to an increase in the specific capacitance and structural robustness in long-term cyclability. [22] For example, Cheng et al synthesized hierarchical MOFs-derived NiCo 2 S 4 @Mo-doped Co-LDH arrays and applied them in supercapacitors, as illustrated in Figure 3a.…”

“…[22] For example, Cheng et al synthesized hierarchical MOFs-derived NiCo 2 S 4 @Mo-doped Co-LDH arrays and applied them in supercapacitors, as illustrated in Figure 3a. [21] They first synthesized NiCo 2 S 4 nanowire@ZIF-67 core-shell structure and then etched it at room temperature. The as-prepared Co-LDH exhibited the nanosheet morphology.…”

“…By gradually transforming the MOFs through stepwise adjustments and combining it with other materials for modification, they were able to control the morphology and structure of the resulting Reproduced with permission. [21] Copyright 2023, MDPI.…”

“…(f) Specific capacitance of the NiCo2S4 and the NiCo 2 S 4 @Mo-doped Co-LDH electrodes at different current densities. (g) Cycling performances of the NiCo 2 S 4 @Mo-doped Co-LDH electrode at a current density of 10 A g À 1 .Reproduced with permission [21]. Copyright 2023, MDPI.…”

Computational Investigation of a Reversible Energy Storage Medium in g-B5N3 Decorated by Lithium

“…Creating a qualitative link between structural attributes and functional characteristics provides valuable guidance for the development of novel energy storage materials. − However, the comprehensive characterization of adsorption performance through experimental methods remains challenging and expensive for researchers. − Therefore, utilizing systematic computational studies will be instrumental in the initial evaluation of the newly proposed materials. − In the recent studies conducted by Qi et al, it was observed that a novel 2D material, g-B 5 N 3 , demonstrates heightened carrier mobility and outstanding optical performance . Expanding upon the analysis of its electronic properties, we propose that it represents a promising candidate for applications in hydrogen storage.…”