Study of Li Adsorption on Graphdiyne Using Hybrid DFT Calculations

Theoretical Calculation of Dissolved Gas in Transformer Oil Using the Gas Sensitive Properties of Sc- and Ti-Modified ZrS2

To guarantee the secure functioning of the complete power system and minimize the risks associated with oil-filled transformers during their operation, it is greatly important to carry out gas sensing studies of dissolved gases in transformer research. Through the utilization of first-principles density functional theory calculations, the adsorption energy, electronic characteristics, and recuperation duration of ZrS2 modified with Sc and Ti were examined. The results show that compared to those of the initial ZrS2 material, the doping of TM atoms Sc and Ti significantly improved the adsorption properties of the material, and the adsorption of CO and C2H4 showed chemisorption. The adsorption capacity for gases decrease in the following order: C2H4 > CO > H2. The calculated recovery times indicate that Sc-ZrS2 and Ti-ZrS2 were ideal carbon monoxide sensing materials under the specific conditions. The results of this work can establish a fundamental rationale for the use of ZrS2 in sensing the conditions of oil-immersed transformers.

Chemical properties of superatomic Li3O clusters from a density functional theory perspective: formation of chloride and adsorption behavior on graphynes

Superatomic clusters have received a lot of attention due to their ability to mimic the electronic configurations of individual atoms. Despite numerous studies of these clusters, their ability to mimic the chemical properties of individual atoms is still unclear. This also applies for Li3O/Li3O+ clusters which simulate the Na atom and its ion, but their capabilities to form a salt or be adsorbed on surfaces remain unexplored. In this work, a density functional theory investigation was performed to study the chemical formation and adsorption behavior of the superatomic Li3O cluster. The results show that Li3O mimics the chemical properties of the sodium element to form Li3O chloride and be adsorbed on graphdiyne and γ-graphyne with similar binding energy as the sodium adsorbate cases. Beyond the isolated cluster individuals, superatoms are demonstrated as elements from the 3D periodic table to construct compounds and attach onto solid surfaces.

Graphdiyne/metal oxide hybrid materials for efficient energy and environmental catalysis

Graphdiyne (GDY)-based materials, owing to their unique structure and tunable electronic properties, exhibit great potential in the fields of catalysis, energy, environmental science, and beyond. In particular, GDY/metal oxide hybrid materials (GDY/MOs) have attracted extensive attention in energy and environmental catalysis. The interaction between GDY and metal oxides can increase the number of intrinsic active sites, facilitate charge transfer, and regulate the adsorption and desorption of intermediate species. In this review, we summarize the structure, synthesis, advanced characterization, small molecule activation mechanism and applications of GDY/MOs in energy conversion and environmental remediation. The intrinsic structure-activity relationship and corresponding reaction mechanism are highlighted. In particular, the activation mechanisms of reactant molecules (H2O, O2, N2, etc.) on GDY/MOs are systemically discussed. Finally, we outline some new perspectives of opportunities and challenges in developing GDY/MOs for efficient energy and environmental catalysis.

Proposing TODD-graphene as a novel porous 2D carbon allotrope designed for superior lithium-ion battery efficiency

The category of 2D carbon allotropes has gained considerable interest due to its outstanding optoelectronic and mechanical characteristics, which are crucial for various device applications, including energy storage. This study uses density functional theory calculations, ab initio molecular dynamics (AIMD), and classical reactive molecular dynamics (MD) simulations to introduce TODD-Graphene, an innovative 2D planar carbon allotrope with a distinctive porous arrangement comprising 3-8-10-12 carbon rings. TODD-G exhibits intrinsic metallic properties with a low formation energy and stability in thermal and mechanical behavior. Calculations indicate a substantial theoretical capacity for adsorbing Li atoms, revealing a low average diffusion barrier of 0.83 eV. The metallic framework boasts excellent conductivity and positioning TODD-G as an active layer for superior lithium-ion battery efficiency. Charge carrier mobility calculations for electrons and holes in TODD-G surpass those of graphene. Classical reactive MD simulation results affirm its structural integrity, maintaining stability without bond reconstructions at 2200 K.

Chemistry, Functionalization, and Applications of Recent Monoelemental Two-Dimensional Materials and Their Heterostructures

The past decades have witnessed a rapid expansion in investigations of two-dimensional (2D) monoelemental materials (Xenes), which are promising materials in various fields, including applications in optoelectronic devices, biomedicine, catalysis, and energy storage. Apart from graphene and phosphorene, recently emerging 2D Xenes, specifically graphdiyne, borophene, arsenene, antimonene, bismuthene, and tellurene, have attracted considerable interest due to their unique optical, electrical, and catalytic properties, endowing them a broader range of intriguing applications. In this review, the structures and properties of these emerging Xenes are summarized based on theoretical and experimental results. The synthetic approaches for their fabrication, mainly bottom-up and top-down, are presented. Surface modification strategies are also shown. The wide applications of these emerging Xenes in nonlinear optical devices, optoelectronics, catalysis, biomedicine, and energy application are further discussed. Finally, this review concludes with an assessment of the current status, a description of existing scientific and application challenges, and a discussion of possible directions to advance this fertile field.

Carbon Nanostructures Doped with Transition Metals for Pollutant Gas Adsorption Systems

The adsorption of molecules usually increases capacity and/or strength with the doping of surfaces with transition metals; furthermore, carbon nanostructures, i.e., graphene, carbon nanotubes, fullerenes, graphdiyne, etc., have a large specific area for gas adsorption. This review focuses on the reports (experimental or theoretical) of systems using these structures decorated with transition metals for mainly pollutant molecules' adsorption. Furthermore, we aim to present the expanding application of nanomaterials on environmental problems, mainly over the last 10 years. We found a wide range of pollutant molecules investigated for adsorption in carbon nanostructures, including greenhouse gases, anticancer drugs, and chemical warfare agents, among many more.

Hydrogen-substituted graphdiyne/graphene as an sp/sp2 hybridized carbon interlayer for lithium-sulfur batteries

To overcome the shuttle effect in lithium-sulfur (Li-S) batteries, an sp/sp2 hybridized all-carbon interlayer by coating graphene (Gra) and hydrogen-substituted graphdiyne (HsGDY) with a specific surface area as high as 2184 m2 g-1 on a cathode is designed and prepared. The two-dimensional network and rich pore structure of HsGDY can enable the fast physical adsorption of lithium polysulfides (LiPSs). In situ Raman spectroscopy and ex situ X-ray photoelectron spectroscopy (XPS) combined with density functional theory (DFT) computations confirm that the acetylenic bonds in HsGDY can trap the Li+ of LiPSs owing to the strong adsorption of Li+ by acetylenic active sites. The strong physical adsorption and chemical anchoring of LiPSs by the HsGDY materials promote the conversion reaction of LiPSs to further mitigate the shuttling problem. As a result, Li-S batteries integrated with the all-carbon interlayers exhibit excellent cycling stability during long-term cycling with an attenuation rate of 0.089% per cycle at 1 C over 500 cycles.

Application of accelerated long-range corrected exchange functional [LC-DFT(2Gau)] to periodic boundary condition systems: CO adsorption on Cu(111) surface

Several different types of density functional theory (DFT) exchange correlation functionals were applied to a periodic boundary condition (PBC) system [carbon monoxide (CO) adsorbed on Cu(111): CO/Cu(111)] and the differences in the results calculated using these functionals were compared. The exchange correlation functionals compared were those of Perdew-Burke-Ernzerhof (PBE) and those of long-range corrected density functional theory (LC-DFT), such as LC-ωPBE(2Gau) and LC-BLYP(2Gau). Solid state properties such as the partial density of states were calculated in order to elucidate the detailed adsorption mechanisms and back-bonding peculiar to the CO/Cu(111) system. In addition, our benchmark analysis of the correlations among the orbitals of CO and Cu metal using LC-DFT reasonably was in line with the experimentally observed adsorption site. The computation time was reasonable, and other numerical results were found to agree well with the experimental results and also with the theoretical results of other researchers. This suggests that the long-range Hartree-Fock exchange integral should be included to correctly predict the electronic nature of PBC systems.

Fundament and Application of Graphdiyne in Electrochemical Energy

The artificial synthesis of graphdiyne (GDY) in 2010 successfully fills the blank of low temperature preparation of all-carbon allotropes. GDY is an emerging two-dimensional (2D) planar carbon material composed of benzene rings moieties (sp² carbon atoms), butadiyne (sp carbon atoms) linkers, and well dispersed electron-rich cavities, forming a large π-conjunction structure. GDY has attracted increasing attention in many fields. GDY is the first carbon material with both 2D fast transfer channels for electrons and 3D channels for ions. The 2D electron-rich all-carbon nature endows GDY with considerable conductivity and tunable electronic properties, and the in-plane cavities give it intrinsic selectivity and accessibility for electrochemically active metal ions. In addition, its easy preparation under mild conditions well complements the disadvantages of the traditional sp²-hybridized carbon materials (carbon nanotubes, graphene, and graphite) in the highly efficient synthesis and processing for potential electrochemical applications. As an all-carbon material, the unique advantages of GDY in both structure and preparation match well the urgent demands in key materials for solving many challenging problems in recent electrochemical areas and beyond. During the last decade since the first preparation of GDY, it has already achieved much enlightening and creative progress in both fundamental scientific research and forward-looking applications. This Account is intended not to summarize all this progress in preparation and applications but to outline some newly reported interesting phenomena in both high-quality preparation and electrochemical applications. This Account mainly discusses the recent progress in electrochemical applications: (i) constructing new concepts and new functions in electrochemical interfaces for realizing highly active electrochemical catalysts in the fields of water splitting and oxygen reduction reaction and (ii) building a highly stable conductive network and electrochemical interface for reversible energy storage. In the field of electrochemical catalysis, based on current studies of structural advantages and superior performance, atomic catalysis with metal atoms anchored in GDY is encouraging, owing to the desirable immobilizing capability of electron-rich dialkyne cavities toward metal atoms and corresponding electron transfer. For high-energy batteries, the in situ growth of the all-carbon GDY on the various battery electrodes shows great promise for solving key practical problems (safety, long lifespan, high power), which are ascribed to weak interfacial stability. In addition, the perspective application of GDY to broader interfacial modifications is described, bringing new choices for solving the interfacial challenges in various energy storage devices.

First-principles study of structural, elastic and electronic properties of naphyne and naphdiyne

The structural, elastic and electronic properties of 2D naphyne and naphdiyne sheets, which consist of naphthyl rings and acetylenic linkages, are investigated using first-principles calculations. Both naphyne and naphdiyne belong to the orthorhombic lattice family and exhibit the Cmmm plane group. The structural stability of naphyne and naphdiyne are comparable to those of experimentally synthesized graphdiyne and graphtetrayne, respectively. The increase of acetylenic linkages provides naphdiyne with a larger pore size, a lower planar packing density and a lower in-plane stiffness than naphyne. Naphyne is found to be an indirect semiconductor with a band gap of 0.273 eV, while naphdiyne has no band gap and has a Dirac point. The band gaps of naphyne and naphdiyne are found to be modified by applied strain in the elastic range. These facts make naphyne and naphdiyne potential candidates for a wide variety of membrane separations and for fabrication of soft and strain-tunable nanoelectronic devices.

Naphyne and naphdiyne exhibit comparable stability to synthesized graphdiyne and graphtetrayne, and they show potential applications on membrane separations and fabrication of strain-tunable nanoelectronic devices.