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The potential for decorating single Li, Na, or K atoms onto BeS monolayers and their subsequent hydrogen storage performance were investigated using first-principle density functional theory (DFT) calculations. The single-atom Li, Na, or K exhibited strong adhesion to the BeS monolayer, with binding energies of −2.662 eV, −1.982 eV, or −1.669 eV, respectively. Each Li or Na atom on BeS demonstrated the ability to capture four H 2 molecules, while a single K atom could bind only three H 2 molecules. Notably, Li exhibited stronger binding with stored H 2 compared to Na or K. Moreover, by increasing the number of Li atoms on each side of the BeS monolayer to nine, the storage of H 2 molecules was improved to a total of 54, concomitant with an advantageous average adsorption energy of −0.236 eV. This enhancement resulted in a significant increase in the hydrogen storage capacity to 6.514 wt%. Molecular dynamics simulations indicated a desorption temperature of approximately 450 K, with the 18 Li atoms remaining strongly bonded to the BeS due to their high diffusion energy of 0.578 eV. Thus, the Li-decorated BeS monolayer emerges as a promising substrate for achieving exceptional and reversible hydrogen storage performance. • Alkali-metal atom (Li, Na, or K) could be well dispersed on the BeS monolayer. • Li atom shows a stronger adsorption strength to H 2 molecules than Na or K. • 18 Li atoms on BeS can capture 54H 2 with an ideal E adsav of −0.236 eV. • Li atoms remain dispersed on BeS even at desorption temperature of the 54H 2. • Li-decorated BeS demonstrates a high hydrogen storage capacity of 6.514 wt%. [ABSTRACT FROM AUTHOR]

Triazine-based graphitic C 3 N 4 (g-C 3 N 4) sheet is considered a promising material for hydrogen storage due to its porous structure and light mass. Decoration with the superalkali cluster for it not only avoids the gathering of metal atoms but also provides more adsorption sites for hydrogen. In this paper, the performance of (NLi 4) n @g-C 3 N 4 (n = 1,2) as a hydrogen storage material is investigated based on first principles calculations. The results indicate that two NLi 4 clusters can be anchored on the 2 × 2 supercell of g-C 3 N 4 with a large binding energy of −4.39eV. Each NLi 4 can adsorb nine hydrogen molecules with an average adsorption energy of −0.20eV. The hydrogen storage capacity of (NLi 4) 2 @g-C 3 N 4 coated by NLi 4 on both sides is approximately 7.4 wt%. The AIMD simulations for (NLi 4) 2 @g–C 3 N 4 –18H 2 show that when the temperature is higher than 254K at ambient pressure, hydrogen molecules are released partially from the system, and 83.3% of hydrogen is released from the adsorption system at 300K. As a result, we predict that g-C 3 N 4 modified by NLi 4 can be used as a potential material for the storage of hydrogen at ambient temperature. [Display omitted] • Superalkali NLi 4 decorated nanomaterials are proposed for hydrogen storage. • NLi 4 clusters can be stably anchored on g-C 3 N 4 monolayer. • Superalkalis effectively solve the aggregation of metal atoms on substrate. • High reversible storage capacities can be achieved at ambient temperature. [ABSTRACT FROM AUTHOR]

In this work, we predict a new two-dimensional metallic carbon-boron material, named Me–C 8 B 5 , which is composed of octagons, pentagons and hexagons. By DFT calculation, we examine the efficacy of hydrogen storage in alkali and alkaline-earth metals modified Me–C 8 B 5 structures. Our findings reveal that these metals exhibit a robust affinity for the Me–C 8 B 5 substrate, characterized by substantial binding energies, thereby mitigating the tendency to form clusters. In particular, the hydrogen storage capacity for Li, Na, Mg and Ca modified Me–C 8 B 5 reach 6.87 wt%, 7.60 wt% and 5.74 wt% and 9.51 wt%, respectively, higher than the DOE requirement of 4.5 wt%. The results of relative energy reveal that the Li-modified system exhibits more appropriate pressure (8.4 bar) and temperature (370 K) for maintaining stable hydrogen storage. Notably, the suitable average desorption temperatures coupled with the stability exhibited in AIMD simulations indicate that Me–C 8 B 5 scaffolds modified with metals Li, Na, Mg, and Ca may possess viable practical applications in the realm of reversible hydrogen storage. These outcomes are anticipated to stimulate the pursuit and continued refinement of novel, superior two-dimensional materials for hydrogen storage. [Display omitted] • Me–C 8 B 5 : A new two-dimensional metallic carbon-boron material. • Using DFT, H 2 storage in alkali and alkaline earth metal decorated Me–C 8 B 5 is reported. • Ca decorated Me–C 8 B 5 possesses ultrahigh gravimetric H 2 uptake (9.51 wt%). • The stability of adsorption systems is proved by ab-initio MD simulations. [ABSTRACT FROM AUTHOR]

The high-nickel cathode LiNi 0.8 Co 0.1 Mn 0.1 O 2 (NCM811), a material already commercialized, faces a critical challenge in its diminished stability, leading to a decline in battery performance. This study addresses this issue by employing LiNbO 3 as a fast ion conductor with varying concentrations to enhance the performance of the NCM811 material. Particularly noteworthy is the optimal performance observed with a 3% LiNbO 3 coating, where the NCM811 exhibits a capacity retention of 87.10% after 200 cycles at 1 C, and a discharge capacity of 160 mAh•g−1 at a 5 C rate, surpassing the Pristine's 69.57% cycle retention and 139 mAh•g−1 at 5 C. Density Functional Theory (DFT) calculations reveal that the LiNbO 3 coating not only reduces the migration barrier for Li+ within the NCM811 but also lowers the migration barrier for Li+ from the NCM811 layer to the LiNbO 3 layer. Theoretical calculations further unveil that the binding energy between NCM811 and the byproduct HF in the electrolyte is lower than the binding energy between LiNbO 3 surface and HF, confirming the effective inhibition of HF corrosion by the LiNbO 3 layer. This work provides an in-depth analysis of the mechanism behind the improved performance of NCM811 materials through surface coating with LiNbO 3. [ABSTRACT FROM AUTHOR]

Metal-decorated carbon-containing two-dimensional nanomaterials have gained attention as potential hydrogen storage materials. In this study, we carried out first-principles calculations to systematically screen the metal-decorated biphenylene (M−BP) as potential candidates for hydrogen storage media. The selected metals include alkali, alkaline earth, and 3d and 4d transition metal (TM) series. We find that all considered M−BP are stable as illustrated through their negative binding energies. The interaction and adsorption modes of adsorbed hydrogen depend on the type of metal. Alkali, alkaline earth, and closed shell TM exhibit weak physisorption, while those TM with partially filled d orbitals display moderate to strong interaction with Kubas and dissociative modes of adsorption, respectively. The adsorption strength between metal atom and hydrogen plays an important role in determining the efficiency of the hydrogen storage materials. In addition, from the maximum number of adsorbed H 2 molecules and free energies of adsorption, we estimated the gravimetric capacity of considered M−BP at operating conditions of fuel cells (0.1 MPa, 233–473 K). Accordingly, Ca- and Sc-decorated BP were proposed as promising candidates, exhibiting working capacities of 6.66 and 6.40 wt%, respectively. This study underlines that the interaction between hydrogen and M−BP serves as a key component in determining efficiency of hydrogen storage materials and provides valuable guidance for the advancement of sophisticated hydrogen storage materials. • Stability of M−BP is illustrated through negative binding energies. • Adsorption strength determines efficiency of M-BP. • Proposed Ca- and Sc-BP as promising candidates. • High gravimetric capacity up to 6.66 wt%. • Suitable desorption temperatures of 280–370 K. [ABSTRACT FROM AUTHOR]

Solid oxide fuel cells (SOFCs), as important energy equipment, have excellent characteristics, including low pollution and high catalytic activity. The cathode, which is the key component of an SOFC, plays a vital role in practical applications. Herein, we study the properties of Ln 0.125 Sr 0.875 Co 0.875 Ta 0.125 O 3-δ (Ln = La, Sm, and Nd, abbreviated as LSCT, SSCT, and NSCT, respectively) cathode materials both theoretically and experimentally. The conductivity of LnSCT gradually decreased with decreasing Ln3+ ionic radius. Density of states (DOS) analysis indicated that LSCT has the highest conductivity owing to the band center of Co 3d being closer to O 1s. Density functional theory (DFT) calculations showed that the SSCT sample has the lowest oxygen vacancy formation energy, which facilitated the formation of oxygen vacancies. The binding energy results show that SSCT and NSCT have relatively good structural stability compared to LSCT. The polarization impedance values of LSCT, SSCT, and NSCT at 700 °C are 0.105, 0.069, and 0.304 Ω cm2, respectively. The CO 2 sensitivity of LSCT, SSCT, and NSCT was evaluated by calculating the CO 2 adsorption energy and performing impedance tests under different CO 2 concentrations. These results indicate that LSCT and SSCT have better CO 2 tolerance than NSCT. At 700 °C, for Ln = La, Sm, and Nd, the maximum power of NiCu-SDC/SDC/LSGM/LnSCT electrolyte-supported fuel cell reached 430, 462, and 382 mW cm−2, respectively. These findings provide a reference for the future design and development of SOFCs cathode material. [ABSTRACT FROM AUTHOR]

Our rigorous investigation, employing first principles-based dispersion-corrected density functional theory (DFT-D) and second-order Møller-Plesset perturbation theory (MP2) methods, has illuminated the remarkable promise of lithium-decorated organic linkers of Covalent Organic Frameworks (COFs). We have computationally designed 36 complexes with nine pure linkers of COFs and Li-decorated linkers, and these designed linkers show the physisorption of H 2 molecules. The synergy of Li atoms with these linkers shows a Li binding energy about −0.5 to −1.3 eV, which enables each Li atom to capture two H 2 molecules with an average ΔH per H 2 molecule about -0.02 to -0.20 eV. We computationally obtained a significant weight percentage (wt.%) of H 2 uptake, with a maximum of wt.% for the molecular structure of Linker-3 using DFT-D methods. The true highlight of our work is the average binding enthalpy of -0.20 eV per H 2 molecule when coupled with Li-decorated Linker-5. Our study unveils the intricate interplay between dispersion and electrostatic forces that play a dominant role in binding enthalpy. We performed GCMC simulations in our designed pure COFs to study the H 2 uptake at 77 K and 298 K at varying low and high-pressure ranges. COF-IITI appears more effective in absolute H 2 loading than the Pristine COF because of its larger surface area. This groundbreaking research is essential for realizing efficient, secure, compact, and cost-effective hydrogen storage materials. It aligns perfectly with the ambitious goals set by the U.S. Department of Energy, propelling us closer to a sustainable energy future. [Display omitted] • A Li-decoration technique is proposed to enhance H 2 uptake in COF's linkers. • The Li binding energy for COF's linkers lies in the range of -0.5 to -1.3 eV. • The H 2 binding enthalpy in Li-decorated linkers satisfies the physisorption. • Dispersion and electrostatic interactions play a major role in binding enthalpy. [ABSTRACT FROM AUTHOR]

In this work, in situ-generated cobalt oxide was infused into g-BCN to fabricate a heterocomposite (CoBCN) with multiple active sites. The electronic structure of CoBCN was further modified via the introduction of n- (Ni) and p-(Fe) type metals to investigate the activities of CoBCN-type materials with loosely bound electrons for electrocatalytic hydrogen evolution reaction (HER), oxygen evolution reaction (OER), and oxygen reduction reaction (ORR) which symbolize the reduction/oxidation of water and reduction of fuel gas oxygen that goes on in concurrent electrocatalytic and fuel cell. Experimental results indicated that not only the electronic nature of the surface but also the binding energy between the involved metals and intermediates varied accordingly for the association/dissociation steps, resulting in the superiority of p-doped materials in HER and the n-doped material in the OER and ORR. The HER activity was governed by Fe–CoBCN with an overpotential of 97 mV (@ 10 mA cm−2), whereas Ni–CoBCN showed superior performance for the OER and ORR with an overpotential and E 1/2 of 130 mV (@ 10 mA cm−2) and 0.79 V, respectively. p-/n-effect on CoBCN material for its multifunctional electrocatalytic activity for HER, OER and ORR. [Display omitted] • Fe and Ni oxide were doped individually to observe the p-/n-effect. • Fe–CoBCN dominated HER with a low overpotential due to facile Cat-H interaction. • Ni–CoBCN outperformed for OER and ORR with a low overpotential and E 1/2. [ABSTRACT FROM AUTHOR]

2-Methyl-4-nitroaniline (MNA), an intermediate in the synthesis of azo dyes, is widely distributed in various environmental media and organisms. Although there is speculation regarding MNA's potential to be hepatotoxic, the underlying mechanisms of its hepatotoxicity and its definitive diagnostic process remain largely unexplored. In this research. In the present study, we initially predicted the toxicity and possible toxic effect pathways of MNA using ProTox-II, and found that MNA binds to the PPARγ receptor (binding energy －6.118 kcal/mol) with a potential PPARγ agonist effect. Subsequently, in vivo exposure evaluation was conducted on Wistar rats to assess the impact of MNA after a 90-day exposure period, by detecting serum biochemical indexes, hematological indexes, urinary indexes, inflammatory factors, liver histopathological observations and liver tissue PPARγ mRNA expression. The results showed that MNA causes liver function abnormalities, liver histopathological changes and inflammatory response, along with a pronounced increase in PPARγ mRNA levels. This study suggests that the hepatotoxic mechanism of MNA may be related to its possible upregulation of PPARγ expression, increased liver dysfunction and inflammatory responses. Based on these results, the benchmark dose lower limit (BMDL) of 1.503 mg/kg for male Wistar rats was also established, providing a vital benchmark for determining the safety threshold of MNA. Our data highlight the hepatotoxic mechanism of MNA and contribute to a better understanding of its potential etiological diagnosis. [Display omitted] • MNA causes liver histopathological changes, dysfunction and inflammatory response. • MNA binds to the PPARγ receptor and upregulates PPARγ mRNA expression. • The BMDL value of 1.503 mg/kg for MNA in male Wistar rats was determined. [ABSTRACT FROM AUTHOR]

Intermolecular interactions between drug and co-former are crucial in the formation, release and physical stability of co-amorphous system. However, the interactions remain difficult to investigate with only experimental tools. In this study, intermolecular interactions of co-amorphous curcumin-piperine (i.e., CUR-PIP CM) during formation, dissolution and storage were explored by integrating experimental and modeling techniques. The formed CUR-PIP CM exhibited the strong hydrogen bond interaction between the phenolic OH group of CUR and the C O group of PIP as confirmed by FTIR, ss 13C NMR and molecular dynamics (MD) simulation. In comparison to crystalline CUR, crystalline PIP and their physical mixture, CUR-PIP CM performed significantly increased dissolution accompanied by the synchronized release of CUR and PIP, which arose from the greater interaction energy of H 2 O-CUR molecules and H 2 O-PIP molecules than CUR-PIP molecules, breaking the hydrogen bond between CUR and PIP molecules, and then causing a pair-wise solvation of CUR-PIP CM at the molecular level. Furthermore, the stronger intermolecular interaction between CUR and PIP was revealed by higher binding energy of CUR-PIP molecules, which contributed to the excellent physical stability of CUR-PIP CM over amorphous CUR or PIP. The study provides a unique insight into the formation, release and stability of co-amorphous system from MD perspective. Meanwhile, this integrated technique can be used as a practical methodology for the future design of co-amorphous formulations. [Display omitted] [ABSTRACT FROM AUTHOR]

• One-step mecahnochemical modification of activated carbon has lower carbon emission. • Species of polymeric aluminum regulated fluoride uptake performance. • Stronger binding energy between Al and F caused better anti-interference performance. • Formation of Al FOH would be more likely than Al F OH. • Enrichment of fluoride was verified by XPS characterization. Defluoridation of coal mining water is of great significance for sustainable development of coal industry in western China. A novel one-step mechanochemical method was developed to prepare polymeric aluminum modified powder activated carbon (PAC) for effective fluoride removal from coal mining water. Aluminum was stably loaded on the PAC through facile solid-phase reaction between polymeric aluminum (polyaluminum chloride (PACl) or polyaluminum ferric chloride (PAFC)) and PAC (1:15 W/W). Fluoride adsorption on PACl and PAFC modified PAC (C-PACl and C-PAFC) all reached equilibrium within 5 min, at rate of 2.56 g mg-1 sec-1 and 1.31 g mg-1 sec-1 respectively. Larger increase of binding energy of Al on C-PACl (Al F bond: 76.64 eV and Al FOH bond: 77.70 eV) relative to that of Al on C-PAFC (Al F bond: 76.52 eV) explained higher fluoride uptake capacity of C-PACl. Less chloride was released from C-PACl than that from C-PAFC due to its higher proportion of covalent chlorine and lower proportion of ionic chlorine. The elements mapping and atomic composition proved the stability of Al loaded on the PAC as well as the enrichment of fluoride on both C-PACl and C-PAFC. The Bader charge, formation energy and bond length obtained from DFT computational results explained the fluoride adsorption mechanism further. The carbon emission was 7.73 kg CO 2 -eq/kg adsorbent prepared through mechanochemical process, which was as low as 1:82.3 to 1:8.07 × 104 compared with the ones prepared by conventional hydrothermal methods. [Display omitted] [ABSTRACT FROM AUTHOR]

Two-Dimensional carbon-based materials as a potential hydrogen storage medium have attracted great attention. In this study, various key aspects such as structure, electronic properties, stability, and hydrogen storage performance of Na-modified Irida-Graphene (IG) were thoroughly investigated using density functional theory (DFT) calculation methods. The calculation results show that the binding energy of Na atoms with the substrate is 1.51 eV, far exceeding the cohesive energy. The AIMD results reflect the good thermal stability of the model. One Na atom can adsorb up to 5H 2 molecules. The IG loaded with eight Na atoms on both sides can adsorb 32H 2 molecules, achieving a hydrogen storage capacity of 7.82 wt % , far exceeding the US DOE target of 5.5 wt %. The calculated Van 't Hoff equation indicates a desorption temperature of 248 K for the model. Moreover, reversible hydrogen storage can be achieved at medium to low pressures, with desorption temperatures ranging from 285 K to 417 K. These results suggest that Na-Modified IG models are candidate materials for reversible hydrogen storage under near-ambient conditions. [Display omitted] • Sodium modification of Irida-Graphene enhances its hydrogen adsorption capacity. • The interaction between IG-Na and H 2 was analyzed using the IGMH method. • The hydrogen storage capacity of IG-Na medium reaches 7.82%. [ABSTRACT FROM AUTHOR]

Combined contamination of Organophosphate esters (OPEs) and heavy metal has been concerning on their potential threaten to human health through food chain. In order to estimate effects of OPEs and heavy metal's combined contamination on crop, the growth of rice seedlings, pollutant accumulations and their involved in transcript regulation pathway under OPEs and Cd contamination were investigated. In results, only single OPEs pollution improved the biomass of rice, while single Cd pollution inhibited the growth of plants. Although the combined contaminations of OPEs and Cd also showed negative effect for plant growth, OPEs could alleviate the negative effect of Cd on rice. The Octanol-water partition coefficients (log K ow) of OPEs were positively correlated with root concentration factor (RCF) values in the trend line and negatively correlated with shoot concentration factor (SCRF) and translocation factor (TF). OPEs and Cd inferred with each other's accumulations in plants through reducing RCF, SCRF and TF. After addition of Cd, the expressions of OsTIL, OsLTP4, OsLTPL1 , and OsMLP423 genes involved in OPEs accumulation were downregulated. Moreover, the presence of Cd also affected the binding sites and binding energy of the four proteins with OPEs. Meanwhile, the expression of OsNramp1, OsNramp5, OsHMA2, OsGS1 , and OsPCS1 genes involved in Cd accumulation and toleration were also downregulated after addition of OPEs. These results suggested that OPEs and Cd directly repressed each other gene transcript involved in accumulation and toleration process. [Display omitted] • OPEs reduced the negative effects of Cd on plant biomass. • RCF, SCRF, and TF of OPEs and Cd were interfered with other each. • OPEs and Cd inhibited the expression of each other's transporter genes. [ABSTRACT FROM AUTHOR]

Hydrogen storage is indeed fundamental to utilizing H 2 effectively, and porous carbon materials have emerged as highly promising supports for this purpose. γ-Graphyne (γGy) possesses abundant chemical bonds, considerable porosity, and exceptional chemical stability, positioning it as a promising candidate for hydrogen storage and transport applications. In this study, we conducted density functional theory calculations to investigate the potential of Li- and Na-loaded γGy as hydrogen storage materials. Our findings reveal that the hydrogen storage capacity (HSC) of Na-loaded γGy falls significantly short of expectations, whereas Li-loaded γGy demonstrates a notably higher HSC. Subsequently, our calculations indicate that B-doping of γGy does not promote favorable HSC, whereas N-doping exhibits a beneficial effect. Furthermore, we observed that tensile strain favors the hydrogen storage properties of 4Li@γGy and 4Li@N-γGy, while compressive strain enhances the hydrogen storage characteristics of 4Li@B-γGy. Notably, we discovered the capacity to adjust the valence band center of Li (ɛ VB), consequently influencing the hydrogen storage performance of γGy. Our investigation suggests that increased overlap between ɛ VB in Li-loaded graphyne and the effective alignment of H 2 and the supporting structure augments the binding force between Li and H 2 , thereby amplifying the HSC. [Display omitted] • Li-loaded γ-Graphyne stores H 2 via Valence-like interaction. • B- and N-doping can enhance storage capacity of Li-loaded γ-Graphyne. • Valence band center of Li tuned by strain achieve efficient adsorption-desorption. [ABSTRACT FROM AUTHOR]

The use of lithium-decorated phosphorene for hydrogen storage is significantly limited due to metal aggregation on substrates. Despite considerable research and effort in the literature to address this issue, no one has succeeded in enhancing the capacity of phosphorene through metal atom decoration. Based on density functional theory (DFT) and AIMD simulations, superalkali NLi 4 -decorated black phosphorene monolayer is developed as a new hydrogen storage solid-state material. Our results show that the NLi 4 -cluster exhibits a significant binding energy of −3.18 eV when attached to one side of the phosphorene on a stable site, indicating a strong affinity between the NLi 4 -cluster and phosphorene surfaces. Moreover, 2(NLi 4)@phosphorene can store up to 30H 2 molecules with a suitable average hydrogen adsorption-energy and a maximum hydrogen storage capacity of 6.8 wt%. Using the van't Hoff equation and increasing the pressure, we find that the desorption temperature is higher than the critical point for hydrogen. AIMD simulations at different temperatures demonstrate the thermal stability of the hydrogenated 2(NLi 4)@phosphorene and the H 2 desorption process. The findings of the present study suggest the potential utilization of the 2(NLi 4)@phosphorene adsorptive material for hydrogen storage applications. [Display omitted] • NLi 4 -decorated black-phosphorene was investigated for reversible H 2 storage using DFT and AIMD simulations. • NLi 4 binds on phosphorene with binding energy of - 3.18 eV at the hollow site. • The wt.%.H 2 adsorption reaches up to 6.8 wt% and meets the US-DOE's standard of 5.5 wt%. • Thermodynamic analysis confirms the efficiency of the H 2 molecules charging/discharging process. [ABSTRACT FROM AUTHOR]

Hydrogen energy is one of promising non-polluting and renewable energy sources. In this paper, we present a first principal study of hydrogen storage in pure C 60 fullerene cage and Stone-Wales (SW) defective C 60 cages using density functional theory (DFT) with applying both the exchange functional B3LYP and the dispersion correction wb97xd at 6–31+g(d,2p) basis set. In addition, the counterpoise correction is applied, and the basis set superposition error is calculated. The calculations underscore that the hydrogenation binding energy of C 60 cages occurs through an endothermal process for C 60 H in with a hydrogen binding energy of 0.09 eV and through an exothermal process for C 60 H out , C 60 SW 66 H out , and C 60 SW 65 H out , cages with hydrogen binding energies of −2.17 eV, −2.96 eV, and −2.20 eV, respectively. Remarkably, for the first time, the intermediate hydrogen binding energy is found inside C 60 SW 66 H in fullerene, and C 60 SW 65 H in fullerene cages with energies of −0.26 eV and −0.81 eV, respectively. The hydrogen adsorption inside the cavity of C 60 SW 66 fullerene cage is thermodynamically possible below 289.8 K and entire pressure range considered. Our results highlight, for the first time, that the endohedral cavity of C 60 SW 66 is a promising new medium for hydrogen storage due to its binding energies (−0.26 eV) and its hydrogen storage weight percentage (5.3%) that are close to the optimal conditions specified by DOE for commercial use. In addition, this study opens up a new discovery of Stone-Wales defective C 60 fullerene for further endohedral cavity applications. • New insight into endohedral cavity of Stone Wales C 60 SW 66 is reported. • For the first time, a new promising medium for hydrogen storage inside cavity of C 60 SW 66 is proved. • Binding energies of −0.26 eV and hydrogen storage weight percentage up to 5.3% are achieved inside the cavity of C 60 SW 66. • This study opens a new discovery of the SW defective C 60 fullerene for further endohedral cavity applications. [ABSTRACT FROM AUTHOR]

Simplifying the design of high-performance electrodes via efficient catalyst design is critical for alkaline water electrolysis and supercapacitor applications. Towards that end, we have developed the environmentally benign synthesis of ultrathin nanosheets of NiFe-layered double hydroxides (LDH) with inbuilt oxygen vacancies (V O) in this report. These NiFe-layered double hydroxide (GNiFe-LDH- V O) materials require low overpotentials for the oxygen evolution reaction (OER, η 50 = 200 and η 100 = 220 mV) with a small Tafel slope of 52.21 mV dec−1. The ex-situ characterizations and theoretical calculations suggest that oxygen vacancies configure to a more active state, resulting in the low binding energy of oxo intermediates, and thus much lower overpotential. Besides, it could operate stably for 100 h at current densities of 100 mA cm−2 for OER. It is significant that oxygen vacancies in GNiFe-LDH- V O aid in lowering the main obstacle of multistep OER, which will provide recommendations for the development of high-efficiency catalysts through in situ activation. In addition, GNiFe-LDH- V O exhibits a high areal capacitance of 1.6024 F cm−2 at a current density of 1 mA cm−2, with a capacitance retention ratio of 96.1% after 5000 galvanostatic charge-discharge (GCD) cycles when they are used as supercapacitor electrodes. [Display omitted] • Ultrathin NiFe-LDH nanosheets with oxygen vacancies via in situ green, dissolution-precipitation process. • The introduction of oxygen vacancies generates appropriate electronic conductivity and catalytic activity. • The outstanding performance, was demonstrated through both experimental and theoretical calculations. [ABSTRACT FROM AUTHOR]

In this work, the efficiency of hydrogen storage on Sc 2 N MXenes monolayer is systematically investigated using first-principles calculations. After determining the structural stability of designed monolayer, adsorption sites for the storage of hydrogen atoms (H) and molecules (H 2) are identified. The calculated binding energies have indicated that the hydrogen atoms have favorable adsorption at the center or H site of the Sc atoms and hydrogen molecules are found to be the most stable when adsorbed on the top/T site of Sc atoms. The binding energy assessment identified the chemisorption for hydrogen atoms and Kubas-type interactions for H 2. To further ascertain the suitability of the Sc 2 N monolayer for hydrogen storage various analyses including binding energy, partial density of states (PDOS), electron localization function (ELF), Mullikan charge analysis and Hirshfeld charge analysis are conducted. In order to determine the thermal stability of the Sc 2 N monolayer, desorption temperature with respect to pressure and molecular dynamics study has also been conducted and found the monolayer thermally stable. Desorption isotherms condition with increasing pressure confirms the gravimetric storage uptake. The obtained results have revealed that the hydrogen storage capacity considered monolayer has reached up to 10.8 wt%, which is reasonably high. Hence, the obtained results of hydrogen atom and molecules adsorption have clearly established that Sc 2 N monolayer is as an exemplary, stable, reliable and efficient medium for hydrogen storage applications. • Structural stability of two dimensional Sc 2 N MXene monolayer. • Adsorption of hydrogen atoms and molecules on the Sc 2 N MXene. • Calculations of binding energies of hydrogen atoms and molecules. • Chemisorption and physisorption bonding. • Determination of gravimetric capacity and thermal stability evaluation at 300 K. [ABSTRACT FROM AUTHOR]

The utilization of atom-dispersed Cu-N x site catalysts holds significant promise as a replacement for commercial Pt/C catalyst in the context of oxygen reduction catalysts. However, practical application of these catalysts has been hindered by their insufficient catalytic activity. It is imperative to enhance the oxygen reduction reaction (ORR) catalytic activity of the Cu-N x catalysts by manipulating electronic structure of the Cu-N x site. This study presents the synthesis of a composite catalyst, formed by coupling Cu nanoclusters and Cu-N x catalysts through pyrolysis of protein-Cu2+ gel followed by acid-leaching treatment. The resultant composite catalyst demonstrates superior ORR activity as compared to isolated Cu-N x catalysts under alkaline conditions. Through density functional theory (DFT) calculations, the synergistic mechanism of the coupled Cu nanoclusters and Cu-N x for ORR catalytic activity is elucidated. The proximity of the Cu nanoclusters (Cu 4) to the central Cu atom of Cu-N x (CuN 4) in the composite catalyst causes a shift in the d-band center of the active Cu site towards the Fermi level. This shift strengthens the binding energy of O 2 adsorption, reduces ORR overpotential, and combines with favorable electron transfer from Cu nanoclusters to Cu-N x sites, thereby enhancing ORR activity. These findings contribute novel insights into the enhancement of ORR catalysis performance through the manipulation of electron structures via nano-sized metal clusters. [Display omitted] • Cu-N x and Cu nanoclusters were coupled by simple pyrolysis and acid etching. • As-Formed micropore structure stabilizes Cu-N x sites and enhances ORR activity. • DFT calculations revealed the enhanced ORR activity on the coupled catalysts. • The coupled Cu-N x and Cu nanoclusters catalysts showed superior durability. [ABSTRACT FROM AUTHOR]

The use of solid-state devices is a promising approach to address the current technological requirements for sustainable clean energy applications. Within this context, it has become apparent that density functional theory (DFT) has emerged as a powerful tool to study intrinsic electronic characteristics and shows great potential to lead the way to novel materials exploration. Here, we have investigated H 2 adsorption on Ga 2 C 6 monolayer, a prospective model for the storage of H 2 molecule because of its structural stability. The hydrogen molecules favor being adsorbed at the carbon hexagon center with a binding energy of 0.39 eV. The thermodynamic stability of the Ga 2 C 6 monolayer upon adsorption of 22H 2 molecules was evaluated at room temperature using ab-initio molecular dynamics (AIMD) simulations. It is found from the electronic structure analysis that the semiconducting Ga 2 C 6 sheet maintain its behavior after 22H 2 molecules were adsorbed. Owing to the small activation energy of about 0.0198 eV, the process of H 2 molecule migration at the surface easy proceeds. This investigation demonstrates a strong (G C) gravimetric capacity around 9.65 wt%, and a desorption temperature (T D) around 213.68 K. The above findings imply that the Ga 2 C 6 monolayer may serve as a suitable medium for hydrogen adsorption. [Display omitted] • Ga 2 C 6 is a promising candidate for storing H 2 based on the DFT calculations. • The binding energy Ga 2 C 6 –H 2 is around 0.39 eV. • H 2 /Ga 2 C 6 system contains 9.65 wt% of H in maximum. [ABSTRACT FROM AUTHOR]

Hydrogen, renowned for its abundance and versatility, stands as a significant green energy alternative, especially when produced through water electrolysis. In this study, 2D/2D van der Waals heterostructure with graphene and WS 2 monolayer (GW) is constructed as electrocatalyst for hydrogen evolution reaction (HER). The cohesive energy and the binding energy per area for the GW heterostructure are found to be −0.39 eV and −18.9 meV/Å2 which confirms the structural stability as well as the weak binding of two monolayers. Furthermore, ten 3d transition metals are introduced as single atom catalyst (SAC) in the GW heterostructure (TM@GW) to enhance the catalytic performance. The ΔG H* for all TM@GW shows that there is an enrichment in the HER performance by 47–96 % upon the introduction of SAC, showcasing the superiority of Zn@GW heterostructure with an overpotential of 80 mV and the lowest kinetic barrier of 0.51 eV for the Volmer-Tafel reaction. This investigation provides valuable insight for modeling both van der Waals heterostructures and SACs to enrich catalytic performance. [Display omitted] • HER performance of Graphene/WS 2 van der Waals heterostructure is studied using DFT. • HER performance of TM@GW heterostructure is enhanced by about 47–96%. • Zn@GW vdW heterostructure is found to lowest overpotential of 80 mV. • Zn@GW has the lowest kinetic barrier of 0.51 eV for the Volmer-Tafel reaction. [ABSTRACT FROM AUTHOR]

In this study, DFT calculation is performed to systematically investigate the effect of palladium nanoparticle decoration on the hydrogen storage capacity of β12-borophene. The optimized structures of Pd 4 @β12-borophene indicated that Pd 4 is strongly bonded to β12-borophene with a binding energy value of −3.64 eV, exhibiting good structural and thermodynamic stability. The binding energy of the H 2 molecule over β 12 - borophene enhanced by Pd 4 decoration ranges from −0.108 eV to −0.234 eV/H 2 and can chemically bond up to 5 hydrogen molecules which was in the acceptable range for reversible hydrogen storage. Slight H 2 spillover was observed on Pd 4 decorated β12-borophene. Electronic analysis showed that the metallicity of borophene slightly increases after Pd 4 decoration. The electronegativity of the Pd 4 atoms can stimulate the adsorbed H 2 polarization, further increasing the interactions among them. DOS analysis confirmed the charge transfer and interactions between H and Pd atoms which favors hydrogen adsorption of the system. • Stable positions of Pd 4 cluster over β12-borophene was established by DFT method. • Acceptable adsorption energy range −0.108 eV to −0.234 eV for reversible H 2 storage. • Pd 4 decoration enhance the metallicity of borophene. • Slight H 2 spillover observed on Pd 4 decorated β12-borophene. • The electronegativity of the Pd 4 atoms can stimulate the adsorbed H 2 polarization. [ABSTRACT FROM AUTHOR]

Modifying 2D materials with transition metals (TMs) proves to be an effective approach for enhancing their properties in hydrogen storage. In this article, the hydrogen interaction and adsorption over transition metal (TM) atoms (V, Mn, Fe, and Cu) implanted graphitic carbon nitride (gC 3 N 4) is investigated using density functional theory (DFT). The stability of the TM atom on the gC 3 N 4 surface is studied using binding energy and charge density calculations. The adsorption of H 2 on the gC 3 N 4 and TM-implanted gC 3 N 4 surfaces is studied using adsorption energy, density of states (DOS), projected density of states (PDOS), charge density difference, and Lowdin occupancy analysis. The obtained results show that the Fe-gC 3 N 4 system exhibits the highest adsorption energy of −1.025 eV for one H 2. It is found that each Fe atom implanted on gC 3 N 4 can stably adsorb up to 8H 2 molecules, and the average adsorption energy of the 8H 2 molecules is −0.201 eV/H 2. In the context of practical applications for these materials, desorption is investigated employing the van't Hoff equation. Our findings affirm that the Fe-gC 3 N 4 system can serve as an efficient material for solid-state hydrogen storage. [Display omitted] • First principles study employed to investigate H 2 adsorption properties of g-C 3 N 4 and TM-gC 3 N 4 systems. • PDOS, charge density, and occupancy analysis aid in understanding adsorption behavior across different systems. • Fe-gC 3 N 4 system exhibits exceptional H 2 adsorption capability, adsorbing up to 8H 2 molecules, predominantly in Kubas mode. [ABSTRACT FROM AUTHOR]

Hydrogen storage has garnered significant research attention in recent times due to the favorable qualities of hydrogen as a clean energy reservoir. We adorned hexagonal boron nitride (h-BN) with Fe and Mn to employ it for hydrogen storage purposes. Density functional theory (DFT) utilized to investigate diverse properties, encompassing the hydrogen storage capabilities of h-BN modified with both Fe and Mn. Simulation results revealed that, in its unaltered state, h-BN forms weak van der Waals interactions with H 2 molecules, leading to a binding energy within the range of 0.28 eV and a desorption temperature below 200 K. Furthermore, the study seeks to evaluate the structural stability, electronic characteristics, adsorption tendencies, binding energies, and hydrogen storage capacity. Adsorption energies of H 2 molecules on Fe- and Mn-decorated h-BN falls within the practical range of −0.20 to −0.20 eV for 1H 2 to 14H 2 molecules and −0.17 to −0.20 eV for 1H 2 to 17H 2 molecules respectively making them appropriate for H 2 storage applications. Additionally, hydrogen storing capacity values for Fe- and Mn-decorated h-BN are 6.77 wt % for 14H 2 molecules and 7.03 wt %, for 17H 2 molecules respectively. Hybridization was observed between the states of H 2 and the d states of the system. At elevated temperatures, the molecular dynamics simulations using AIMD techniques significantly enhanced the thermal stability of hydrogen (H 2) molecules when they were adsorbed onto h-BN surfaces decorated with both Fe and Mn, outperforming other experimental conditions or configurations. Based on desorption temperature prediction from the Van't Hoff equation, Fe- and Mn-decorated h-BN exhibit potential as substrate materials for H 2 storage by moderately high temperatures. The results of our current work make recognized that Fe/Mn decorated h-BN monolayers are strong eye-getting base material for hydrogen capacity exhibitions at high temperatures. • DFT study is performed in Fe/Mn decorated hexagonal BN for hydrogen storage. • Fe/Mn atoms revealed robust binding energy (−3.83 eV/3.03 eV) towards h-BN. • H 2 interacted with Fe decorated BN with adsorption energies −0.20 eV (n = 14H 2). • Adsorption energies are in the range of −0.17 to −0.20 eV for Mn decorated h-BN. • The hydrogen storage capacity of Fe/Mn decorated h-BN is 6.77 wt %/7.03 wt %. [ABSTRACT FROM AUTHOR]

Developing highly active and stably non-precious metal electrocatalysts for hydrogen production in alkaline conditions is of paramount importance to hydrogen economy. Herein, nanosheet-assembled hollow nitrogen-doped carbon nanospheres confined with ultrasmall NiSe nanoparticles (NiSe@NC) are synthesized by employing a SiO 2 template-assisted approach. As expected, the as-prepared NiSe@NC electrocatalyst delivers an overpotential of 169 mV at the current density of 10 mA/cm2 without iR -correction, and sustains at least 80 h for continuous operation, far outperforming the NiSe-p catalyst in 1 M KOH medium toward hydrogen evolution reaction (HER). The appealing HER performance is mainly ascribed to the synergy effect between hollow nitrogen-doped carbon and highly active NiSe nanoparticles, which improves catalytically active sites, expedites electron transfer rate and optimizes the electronic structure of NiSe@NC nanomaterial. More strikingly, this study presents the feasible insights for constructing robust cost-effective electrocatalysts towards efficient HER in harsh alkaline media. The nanosheet-assembled hollow nitrogen-doped carbon nanospheres confined with ultrasmall NiSe nanoparticles (NiSe@NC) were successfully synthesized by employing SiO 2 template-assisted approach for alkaline electrocatalytic HER. [Display omitted] • Nitrogen-doped hollow flower-like carbon spheres with encapsulated NiSe nanoparticles was fabricated via SiO 2 template-assisted strategy. • The synergistic effect between NC and NiSe optimized the H* binding energy and thus boosted the HER kinetics. • NiSe@NC owned numerous active sites, high electrical conductivity and optimized electronic structure. • NiSe@NC exhibited the excellent electrocatalytic HER performance in alkaline medium. [ABSTRACT FROM AUTHOR]

High-performance H 2 gas sensors based on monolayer 2D metal oxide α -MoO 3 doped with Pt/Rh has been predicted. With a binding energy of − 5.262 eV/ − 5.877 eV, the substitutional doping of Pt/Rh for Mo is a stable doping. After adsorbing O 2 in air, the band gap of Pt/Rh- α -MoO 3 decreases by 0.62 eV/0.51 eV due to the appearance of the impurity levels and the band narrowing effect. Due to such large decrease, electrons in the valence band can be excited more easily into the conduction band to produce more O 2 (a d s) − , which would oxidize more H 2 to generate H 2 O or hydroxyl along with releasing more electrons to the sensor and increasing the sensor's sensitivity. First losing electrons through adsorbing O 2 molecules in air and then obtaining electrons through adsorbing H 2 molecules in H 2 , the charge variation of the sensor based on monolayer Pt/Rh- α -MoO 3 is 1.487 e/0.394 e for per O 2 /H 2 , which suggests that the sensor may have higher sensitivity and lower detection limit. The larger charge variation is also confirmed by the shift of the Fermi level towards the higher energy direction after adsorbing H 2. • The band gap of Pt/Rh- α -MoO 3 decreases by 0.62 eV/0.51 eV after adsorbing O 2 in air. • First in air then H2 , the charge variation of Pt- α -MoO3 monolayer reaches to a large value of 1.487 e for per O 2 /H 2. • The shift of the Fermi level conforms the larger charge variation. [Display omitted] [ABSTRACT FROM AUTHOR]

Utilizing first-principles calculations about A-B-O binary systems (A = Zr, Hf; B = Ta, Nb) and oxyacetylene ablation tests (2.4 MW/m2, 30 s), the synergistic effects of Hf, Zr, Ta and Nb elements in (Hf-Zr-Ta-Nb)C ceramic were studied. From the aspect of experimental results, the (Hf-Zr-Ta-Nb)C ceramic exhibited the lowest average linear variation rate (−1.2 μm/s) and thinnest oxide layer (∼170 μm), only half the thickness of (Hf–Ta)C ceramic (∼330 μm). From the aspect of protective characteristic of HfO 2 -based oxide layer, Ta enrichment will be easier to bring about structural instability of HfO 2 than Zr and Nb elements, attributed to the easily formed Hf 6 Ta 2 O 17 phase with relatively low melting point. As for ZrO 2 -based solid solutions, the continuous enrichment of Ta and Nb will both cause structural instability, based on the increasing trend of calculated binding energies of Ta or Nb modified ZrO 2 , accompanied by the spontaneous formation trend of Zr 6 Ta 2 O 17 and Zr 6 Nb 2 O 17 low-melting-point phases. [ABSTRACT FROM AUTHOR]

Energy from hydrogen has been looked upon with great favours to encounter the shortage of fossil fuels in energy generation. Safety issues and storage concerns of hydrogen has been a major drawback in this regard. Here, a novel material g–C 3 N 4 –MoS 2 –Ni(OH) 2 is crafted to achieve promisingly sufficient storage capacity for hydrogen. Hydrothermal route is optimized in a best possible way to achieve flower like structure of MoS 2. It is then blended with fine sheets of Ni(OH) 2 and as synthesized g-C 3 N 4 to develop the promising nanocomposite g–C 3 N 4 –MoS 2 –Ni(OH) 2. Morphological investigation using TEM and SEM analyses revealed flower-like structure near fine sheets of Ni(OH) 2 and g-C 3 N 4. Fruitfully, the modified surface of the nanocomposite resulted in an enhanced hydrogen storage capability. The hydrogen sorption experiments were carried out at 150 °C for 15 and 30 min intervals under 10 bar hydrogen pressure, and the hydrogen desorption process was carried out from room temperature (RT) to 200 °C with a ramping rate of 15 °C min−1 in an argon medium with a flow rate of 100 mL min−1. During non-isothermal H 2 desorption, S150 composite exhibits better hydrogen storage capacity of 2.79 and 3.21 wt% under hydrogenation intervals of 15 and 30 min respectively. Furthermore, S150 desorbed 3.7 wt% H 2 in 20 min at isothermal desorption of 200 °C. A ternary structure of g–C 3 N 4 –MoS 2 –Ni(OH) 2 comprising flower like morphology covered by thin sheets of Ni(OH) 2 and g-C 3 N 4 is successfully developed via hydrothermal route. The hydrogenation test carried over the material at 150 °C, 30 min, 10 bar hydrogen gas pressures resulted in release of 3.21 wt% amount of hydrogen at 200 °C with 15 °C min−1 ramping rate under argon medium with 100 mL min−1 gas flow for the above ternary nanocomposite. [Display omitted] • Novel-Flower-like g–C 3 N 4 –MoS 2 –Ni(OH) 2 composites was developed by wet impregnation method. • Metal free ternary composites was achieved for high specific surface area. • First time we reporting better H 2 storage performance for g–C 3 N 4 –MoS 2 –Ni(OH) 2 composites. • Best H 2 storage capacity of 3.21 wt% are observed under 30 min hydrogenation by S150 composite. [ABSTRACT FROM AUTHOR]

[Display omitted] • Synergistic effects of precursors and activation agents on Au selectivity were studied. • The adsorption mechanisms were elucidated via characterization and DFT modeling. • AuCl 4 - presented most stable coordination with binding energy, E b of −4064.15 eV. • The maximum Au uptake of 1679.74 ± 37.66 mg/g was aided by partial reduction. The surging affluent in society, concomitant with increasing global demand for electrical and electronic devices, has led to a sharp rise in e-waste generation. E-wastes contain significant amounts of precious metals, such as gold, which can be recovered and reused, thus reducing the environmental impact of mining new metals. Selective recovery using sustainable and cost-effective materials and methods is therefore vital. This study undertook a detailed evaluation of low-cost biomass-derived activated carbon (AC) for selective recovery of Au from simulated e-waste streams. Utilizing high-performance synthesized H 2 SO 4 -AC, the adsorption mechanisms were explicated through a combination of characterization techniques, i.e., FE-SEM, BET, TGA, XRD, FTIR, XPS, and DFT simulations to conceptualize the atomic and molecular level interactions. Optimization of coordination geometries between model H 2 SO 4 -AC and anionic complexes revealed the most stable coordination for AuCl 4 - (binding energy, E b = -4064.15 eV). The Au selectivity was further enhanced by reduction of Au(III) to Au(0), as determined by XRD and XPS. The adsorption reaction was relatively fast (∼5h), and maximum Au uptake reached 1679.74 ± 37.66 mg/g (among highest), achieved through adsorption isotherm experiments. Furthermore, a mixture of 0.5 M thiourea/1 M HCl could effectively elute the loaded Au and regenerate the spent AC. This study presents radical attempts to examine in detail, the synergistic effects of H 2 SO 4 activation on biomass-derived ACs for selective recovery of Au from complex mixtures. The paper therefore describes a novel approach for the selective recovery of Au from e-wastes using multifunctional biomass-derived H 2 SO 4 -AC. [ABSTRACT FROM AUTHOR]

White single-phase powders of Zn 2 SnO 4 , ZnSn(OH) 6 and Y 2 Sn 2 O 7 were prepared using hydrothermal method. In the 2-naphthol aqueous solutions in which these powders were immersed, ZnSn(OH) 6 and Y 2 Sn 2 O 7 reduced the 2-naphthol concentration in the dark. The concentration-decreasing rate temperature dependence, the activation energy, and the binding energy change suggested that the oxidative decomposition of 2-naphthol resulted from the Mars – van Krevelen (MvK) mechanism of Sn. Near non-occurrence of ion elution in water was confirmed for these materials, except for Zn in Zn 2 SnO 4. Among these samples, Y 2 Sn 2 O 7 exhibited the highest antibacterial and antiviral activities against Escherichia coli , Staphylococcus aureus , bacteriophage Qβ, and bacteriophage Φ6 in the dark. Adsorption attributable to electrostatic interactions between cationic samples and bacteria/viruses and the MvK mechanism were expected to lead to protein denaturation and consequently to antibacterial activity and antiviral activity. For Y 2 Sn 2 O 7 , the specific interaction between Y and phosphate ions possibly improved their antibacterial and antiviral activities. This white, non-eluting material was found to have degrees of high antibacterial and antiviral activity. [ABSTRACT FROM AUTHOR]

[Display omitted] The reactivity of metal surfaces is a cornerstone concept in chemistry, as metals have long been used as catalysts to accelerate chemical reactions. Although fundamentally important, the reactivity of metal surfaces has hitherto not been explicitly defined. For example, in order to compare the activity of two metal surfaces, a particular probe adsorbate, such as O, H, or CO, has to be specified, as comparisons may vary from probe to probe. Here we report that the metal surfaces actually have their own intrinsic/eigen reactivity, independent of any probe adsorbate. By employing unsupervised machine learning algorithms, specifically, principal component analysis (PCA), two dominant eigenvectors emerged from the binding strength dataset formed by 10 commonly used probes on 48 typical metal surfaces. According to their chemical characteristics revealed by vector decomposition, these two eigenvectors can be defined as the covalent reactivity and the ionic reactivity, respectively. Whereas the ionic reactivity turns out to be related to the work function of the metal surface, the covalent reactivity cannot be indexed by simple physical properties, but appears to be roughly connected with the valence-electron number normalized density of states at the Fermi level. Our findings expose that the metal surface reactivity is essentially a two-dimensional vector rather than a scalar, opening new horizons for understanding interactions at the metal surface. [ABSTRACT FROM AUTHOR]

In this article, we constructed an AlN/B 2 SSe heterostructure using B 2 SSe and AlN. Using first-principles calculations, we calculated the stability, electronic structure, optical properties, and photocatalytic properties of the AlN/B 2 SSe heterostructure. Firstly, we consider four high-symmetry stacking configurations of the AlN/B 2 SSe heterostructure: Model I, Model II, Model III, and Model IV. After analysis, Model III and Model IV have the lower binding energy. The stability of the Model III and Model IV of AlN/B 2 SSe heterostructure was determined through phonon spectra. Secondly, the band structure, charge density, work function, and difference charge density of the AlN/B 2 SSe heterostructure were calculated using the HSE06 hybrid density functional. Model III is an indirect bandgap semiconductor with a bandgap of 1.89/3.03 eV at the PBE/HSE06 level, meanwhile, Model IV is also an indirect bandgap semiconductor with a bandgap of 1.47/2.60 eV at the PBE/HSE06 level. The work functions (Φ) of B 2 SSe, AlN, Model III, and Model IV are 6.31 eV, 5.81 eV, 6.02 eV, and 6.08 eV, respectively. This also means that during the heterojunction formation between B 2 SSe and AlN, electrons will transfer from the AlN layer to the B 2 SSe layer until the Fermi level reaches dynamic equilibrium, which creates a built-in electric field between the B 2 SSe and AlN layers. The presence of the built-in electric field promotes the separation of electron-hole pairs. Additionally, applying strain to the AlN/B 2 SSe heterostructure further broadened the range of the optical absorption spectrum. The light absorption range of Model III is extended to 557 nm, and the light absorption range of Model IV is extended to 683 nm. Therefore, the photocatalytic efficiency of AlN/B 2 SSe heterostructure is improved under strain. Finally, the AlN/B 2 SSe heterostructure exhibited good hydrogen evolution efficiency, as observed through HER. These characteristics make the AlN/B 2 SSe heterostructure promising for photocatalytic water-splitting applications. • The structural, optical, mechanical, and electronic properties of the AlN/B 2 SSe heterostructure were studied. • From indirect band gap to direct band gap and then indirect band gap of AlN/B 2 SSe heterostructure under strain. • The band gap first increased and then decreased of AlN/B 2 SSe heterostructure. • Strain can modulate the electronic and optical properties effectively. [ABSTRACT FROM AUTHOR]

In this work, we predicted a new Dirac semimetal, named DTT graphene, composed of decagon, tetragon and tetragon carbon rings. Based on first-principles calculations, we explored the hydrogen storage performance of the alkali metals (Li, Na, K) and alkali-earth metal (Ca) decorated DTT graphene. Remarkably, the metals Li, Na, K and Ca can be strongly bound on DTT graphene with large binding energy instead of forming clusters. And single Li, Na, K and Ca decorated DTT graphene can reach H 2 uptake of 12.3 wt%, 12.0 wt%, 11.8 wt%, and 11.7 wt%, respectively, which significantly exceeds the DoE standard (6.5 wt%). Finally, the ab-initio molecular dynamics calculations at corresponding H 2 desorption temperature verify the feasibility of metallized DTT graphene as a reversible hydrogen storage medium. And these findings are also expected to advance experimental studies. [Display omitted] • DTT graphene: A novel Dirac semimetal with dynamical and thermal stability. • Using DFT, researched H 2 storage for alkali and alkaline earth metal decorated DTT graphene. • Li, Na, K and Ca decorated DTT graphene possess ultrahigh gravimetric H 2 uptake. • Li and Ca groomed DTT graphene realize reversible H 2 storage at near room-temperature. • The electrostatic and van der Waals interactions are responsible for adsorption of H 2. [ABSTRACT FROM AUTHOR]

First-principles density functional theory (DFT) calculations were conducted to investigate the feasibility of single-atom Y decoration on the C 3 N monolayer and its consequent interactions with H 2 molecules. The Y atom preferably and firmly dispersed over a hexatomic-carbon ring within the C 3 N monolayer, exhibiting a high binding energy of −5.124 eV. The Y atom decorated on the C 3 N monolayer demonstrated the capability to adsorb and store one to five H 2 molecules through a typical Kubas interaction, featuring reasonable average adsorption energies ranging from −0.361 eV to −0.265 eV. All the adsorbed H 2 molecules could be fully desorbed from the Y-decorated C 3 N at a temperature approximately reaching 500 K. Moreover, the single-atom Y on the C 3 N showcased a high diffusion energy of 1.976 eV, energetically preventing cluster effects of the dispersed Y atoms. Elevating the number of decorated Y atoms to four on each side of the C 3 N substantially improved the stored H 2 to 40. Consequently, the hydrogen storage capacity of the C 3 N decorated with eight Y atoms surged to an impressive 6.76 wt% with a suitable average adsorption energy of −0.249 eV, meeting the requirements of the U.S. DOE. These results demonstrate that the Y-decorated C 3 N monolayer could be an excellent substrate for exhibiting outstanding and reversible hydrogen storage performance. • Single-atom Y is stably dispersed on C 3 N with a binding energy of −5.124 eV. • One Y atom on C 3 N can capture five H 2 with a suitable average adsorption energy. • All the stored five H 2 will be fully desorbed from the substrate at ∼500 K. • Diffusion energy of Y atoms is as high as 1.976 eV to prevent them forming a cluster. • Hydrogen storage capacity of Y-decorated C 3 N can be improved to 6.76 wt%. [ABSTRACT FROM AUTHOR]

• G. indica extract exhibited time and dose dependent α-amylase inhibitory activity. • Reported major phytocompounds of G. indica were traced by LC-MS analysis. • Simulations predicted gambogic acid is mainly responsible for anti-amylase activity. • Gene set analysis showed G. indica modulated the PI3K-Akt pathway to counter T2DM. Garcinia indica Choisy is traditionally used to manage diabetes mellitus, also used in various herbal formulations, and is indicated as an insulin sensitizer. The present study investigates the hydroalcoholic extract of G. indica Choisy rind as an α-amylase inhibitor, followed by the identification of the probable lead hits via a computational approach. LC-MS analyse were carried out. In vitro assays for alpha amylase were performed at concentrations of G. indica ranging from (1000–125 µg/mL) and acarbose (25–1.56 µg/mL) with inhibition times ranging from 5th to 30th min. In silico study was performed based upon the bioactives traced from LC-MS data retrieved from the PubChem database and predicted for probable targets of diabetes mellitus, followed by a drug-likeness score, probable side effects, and an ADMET profile. In addition, molecular docking and the dynamics of the representative complex were explored using AutoDock Vina and Gromac. In vitro study revealed IC 50 values of 400.5, 526.07, 728.05, 792.7, 848.3, and 897.5 µg/mL and acarbose displayed IC 50 values of <1.56, 6.6, 10.46, 12.6, 14.14, and 15.24 µg/mL respectively. LC-MS analysis identified 17 bioactives, of which 13 showed positive druglikness; among them, 5 bioactives were predicted to modulate AMY2A. The gene set enrichment analysis revealed that AMY2A and gambogic acid possessed high edge counts, with the lowest binding energy of gambogic acid- AMY2A (-11.7 kcal/mol), followed by amentoflavone (-10.6 kcal/mol), volkensiflavone (-9.3 kcal/mol), fukugcide (-8.8 kcal/mol), and garcinol (-7.7 kcal/mol) when compared with acarbose- AMY2A (-7.7 kcal/mol), which also indicates high stability up to 100 ns in molecular simulation. Hydroalcoholic extract of G. indica rind α-amylase inhibitory activity, may be due to the presence of gambogic acid and other bioactives. Thus, it can be speculated that G. indica may possess anti-diabetic activity by reducing the post prandial glucose level. This needs to be further confirmed via enriched fractions or pure substances with inhibitory activity to develop Traditional medicine based new drugs [ABSTRACT FROM AUTHOR]

Mucor circinelloides lipase Lip10 is a dual-functional enzyme with lipolytic activity and phospholipid:diacylglycerol acyltransferase (PDAT) activity in aqueous phase. However, the catalytic properties of Lip10 and its structural characteristics remain unknown. The present study systematically investigated its PDAT activity and lipolytic activity using six phospholipid substrates, 18:0 triacylglycerol and 16:0 1,2-diacylglycerol, predict the 3D structure of Lip10 using AlphaFold2, and evaluated residues' flexibility through molecular dynamics analysis. Lip10 exhibited a preference for phosphorylethanolamine (PE) with a long-chain fatty acyl group and showed the lipolytic activity to 18:0 triacylglycerol and 16:0 1.2-diacylglycerol. 20 mM Mg2+ and Fe2+ can significantly increase the PDAT activity of Lip10 by 50–80%. Molecular docking analysis suggest that the lower binding energy for 18:0 PE with Lip10 contributes to the higher structural stability of the complex of 18:0 PE and Lip10. Mutations of Phe565Asp and Glu318Met increase PDAT activity of Lip10 by 3.6-fold and 2.7-fold, while the TAG content produced by mutants Lip10Phe103Pro, Lip10Ile487Lys and Lip10Phe570Asp decrease by 33%− 43%. The present study demonstrated structural properties of the dual-functional lipase Lip10 and provide a theoretical basis to study its roles in the lipid metabolism of M. circinelloides in the future. [Display omitted] • Lip10 is a dual-functional enzyme with lipolytic activity and PDAT activity in aqueous phase. • Lip10 exhibited stronger PDAT activity when 18:0 PE was used as the substrate. • Lip10 showed the lipolytic activity to 18:0 triacylglycerol and 16:0 1.2-diacylglycerol. • Mutations of Phe565Asp and Glu318Met increase PDAT activity of Lip10 by 3.6-fold and 2.7-fold. • TAG produced by mutants Lip10Phe103Pro, Lip10Ile487Lys and Lip10Phe570Asp decrease by 33%− 43%. [ABSTRACT FROM AUTHOR]

The advent of 2D materials has made physisorption-based H 2 storage a promising alternative to conventional techniques involving high pressure and cryogenic temperature. However, most of the reported 2D materials require the addition of metal atoms or the application of an electric field to meet the U.S. Department of Energy (DoE) target of 6.5% gravimetric storage capacity for practical usage. Based on density functional theory (DFT), we show 2D BC 6 N , in its pristine form, demonstrates a storage capacity of 11.11 wt% with a binding energy of 0.139 eV per H 2. At 1 atm pressure, the desorption occurs at temperatures above 118.23 °C, making the storage fully reversible at experimentally conceivable temperatures. The study of the desorption temperatures at varied external pressures indicates a broad operational range for commercial usage. Such high uptake capacity at ambient conditions makes pristine 2D BC 6 N an ideal candidate for metal-free, reversible hydrogen storage. [Display omitted] • Using DFT, we report H 2 fuel storage capacity of pristine 2D BC 6 N. • H 2 uptake capacity is 11.11 wt%, surpassing the DoE's target of 6.5 wt%. • The adsorption energy, corresponding to maximum storage, is −0.139 eV per H 2. • Desorption happens at 118.23 °C at 1 atm pressure, ideal for room temperature storage. • The storage is physisorption based and is fully reversible under ambient conditions. [ABSTRACT FROM AUTHOR]

Herein, we systematically performed the comparative analysis of 24 transition metals single-atom catalysts (SACs) supported on MXene (Mo 2 CT 2 ; T = O or S) surface for hydrogen evolution reaction (HER) and investigated their electronic structures, geometries, stabilities, selectivity, and catalytic activities by using first-principles calculations. The molecular dynamics and thermal stabilities of MXene (Mo 2 CO 2 and Mo 2 CS 2) monolayers were first investigated by using AIMD simulations and phonon dispersion spectra. Based on the Volmer-Heyrovsky pathway, TM/Mo 2 CO 2 (TM = Ti, V, Cr, Co, Mo, Tc, Ru) and TM/Mo 2 CS 2 (TM = Cr, Mn, Fe, Zn, Tc, Ru, W, Pt) SACs exhibited good catalytic performance for HER and their ΔG H* values are close to the optimum value (ΔG H* → 0). The calculated ΔG H* values of Ti/Mo 2 CO 2 , Mo/Mo 2 CO 2 , Tc/Mo 2 CO 2 , Ru/Mo 2 CO 2 , Zn/Mo 2 CS 2 , W/Mo 2 CS 2 , Cr/Mo 2 CS 2, and Pt/Mo 2 CS 2 are equal or better than Pt (111) catalyst, making them active and selective catalysts for HER. Moreover, Mo/Mo 2 CO 2 and Pt/Mo 2 CS 2 catalysts exhibited outstanding catalytic performance towards HER much better than the Pt (111) catalyst. Therefore, the present investigation would provide a useful guideline for experimentalists to design MXene-based transition metals SACs for HER and other electrochemical applications. [Display omitted] • Twenty-four TM/SACs supported on MXene (Mo 2 CT 2 ; T = O or S) surfaces are investigated for HER. • AIMD simulations and phonon spectra demonstrated the dynamic and thermal stabilities of both surfaces. • The binding energy values of Mo 2 CO 2 and Mo 2 CS 2 range from −1.08 to −7.81 eV and −0.27 to −3.84 respectively. • TM@ Mo 2 CO 2 (TM = Ti, Mo, Tc, Ru) and TM@ Mo 2 CO 2 (TM = Zn, W, Cr, Pt) exhibited excellent performance in HER. [ABSTRACT FROM AUTHOR]

The unsatisfactory activities of nickel-based electrocatalysts in the alkaline hydrogen oxidation reaction (HOR) pose a crucial challenge in the development of hydroxide-exchange membrane fuel cells (HEMFCs). Generally, alloying Ni with Mo or W efficiently promotes HOR in alkaline media by reducing the hydrogen binding energy and increasing the hydroxyl binding energy. However, the alkaline HOR activities of binary alloys still do not meet industrial requirements. Therefore, herein, we report that the alkaline HOR activity of the Ni-based electrocatalyst can be enhanced by preparing a NiMoW ternary alloy (Ni 76 Mo 78 W) fabricated via a hydrothermal process, followed by annealing under a H 2 atmosphere. This as-prepared nickel foam-supported Ni 76 Mo 78 W alloy exhibits excellent HOR catalytic activity (the current density reaches 6.6 mA cm−2 at 100 mV vs. RHE, approximately twice that of the Pt/C electrocatalyst), fast kinetics (exchange current density j 0 of 3.12 mA cm−2), and ultrahigh stability (maintenance of the current density over 80 h). Detailed characterizations reveales that the charge transfer between the alloy components presumably tunes the electronic structure of the alloy and ultimately promotes the HOR. [Display omitted] • Nickel foam supported NiMoW (Ni 76 Mo 78 W/NF) was fabricated through hydrothermal treatment followed by annealing. • The modulated electronic structure and valence states implied the charge transfers between alloy components. • Ni 76 Mo 78 W/NF exhibited efficient activity and fast kinetics for alkaline hydrogen oxidation reaction. • Ni 76 Mo 78 W/NF showed ultrahigh durability toward alkaline HOR that can maintain the current density for over 80 h. [ABSTRACT FROM AUTHOR]

The oxidation behavior of SiC ceramics is vital to assess its lifetime under extreme conditions within nuclear power systems. Employing systematic first-principles calculations, we studied the oxygen (O) properties in 3C-SiC without and with irradiation-induced defects to understand the oxidation mechanism. Interstitial O (O i n t) exhibits two energetically favored states with an energy difference of only 0.02 eV. Two O i n t atoms have a strong mutual attraction, with a binding energy reaching 0.80 eV. The stability of O-related defects with charge was investigated. The formation energy of O at the carbon site (O C) is negative, implying that the dissolution of O in the host carbon site is exothermic. The binding strengths of O i n t and O C with irradiation-induced defects are notably high. The formation energies of O and carbon vacancy clusters (V C m O n) decrease approximately linearly and turn negative as the number of O increases. The binding energy of V C m O n is still very high, indicating a strong attraction between them. Furthermore, Trapping of O by carbon vacancies may reduce the mobility of O. Electronic properties are analyzed to reveal the interaction mechanism between irradiation-induced defects and O. The irradiation-induced defects may enhance the oxidation of SiC due to the strong binding energies. [ABSTRACT FROM AUTHOR]

The structural parameters, optical properties, and dielectric constants at a frequency (f) range of 0.1–20 MHz, and temperature (T) range of 300–400 K of hydrothermally synthesized M/SnO 2 nanocomposites (for simplicity M denotes oxides of Al, Ni, or Mn) were compared. Rietveld refined X-ray powder diffraction (XRD) analysis demonstrated the formation of hexagonal, cubic, or spinel crystal structures of Al 2 O 3 , NiO, or Mn 3 O 4 phases, respectively, besides the tetragonal rutile crystal structure of SnO 2. The impact of Al addition on the optical band gap of SnO 2 is negligible while it decreased or increased by incorporation of Ni or Mn, respectively. The residual lattice dielectric constant of SnO 2 was increased, while the real part of the dielectric constant and the ac conductivity of SnO 2 were decreased by M incorporation. The dielectric parameters are remarkably affected by selected M, T, and f values and their changes agree with the Maxwell-Wagner model. The Q-factor of SnO 2 was increased by M addition while decreased with increasing T. The Ni/SnO 2 obeys the hole conduction at T ≤ 330 K, while Mn/SnO 2 and Ni/SnO 2 obey the electronic conduction at T > 330 K. The binding energy is independent of the chosen T for SnO 2 , whereas it sharply increases for Ni/SnO 2 and slightly decreases for Al/SnO 2 and Mn/SnO 2. The F-factor of SnO 2 was slightly decreased by M addition, but it was increased with T for SnO 2 , Al/SnO 2 , and Mn/SnO 2 while was decreased for Ni/SnO 2. The Cole-Cole plots for M/SnO 2 composites were analyzed, and the components of the equivalent circuit were determined. The electrical impedance, resistance of grains, resistance of grain boundaries, and equivalent resistance of SnO 2 were increased by M incorporation, whereas equivalent capacitance was decreased. The findings recommend the SnO 2 -based nanocomposites for applications in optoelectronics, lithium batteries, supercapacitors, and solar cell devices. [ABSTRACT FROM AUTHOR]

Controlling metal-support interaction (MSI) is considered as an effective strategy to optimize the electronic structure of catalysts and thus promote their catalytic performance. Here, with the strong MSI by both metal core and nitrogen-doped carbon shell, the synthesized Ru supported on N-doped graphene-encapsulated Ni nanoparticles (Ni@NC/Ru) show excellent performance towards hydrogen evolution reaction (HER). It exhibits a very low HER potential of 28 mV at the current density of 10 mA cm−2, and high durability that the potential only increases approximately 7 mV after 10,000 cyclic voltammetry cycles. The high HER performance is attributed to the strong MSI from the tuning effect of Ni metal core and N-dope graphene shell, which optimizes the hydrogen binding energy of the catalysts. This study may shed light on the rational design of superior HER catalysts. • Strong metal-support interaction realized in Ru on N-doped graphene-encapsulated Ni. • Ni@NC/Ru shows an ultra-high HER performance with the ultra-low overpotential. • Both tuning effects from Ni metal core and N dope graphene shell promotes the activity. • The strong metal-support interactions optimized the H binding energy on Ru. [ABSTRACT FROM AUTHOR]

van der Waals heterostructure (vdWH) is an attractive technique to enhance the behavior of two-dimensional materials for designing viable products for electronic, spintronics and clean energy source application. Inspired by the recent synthesized of CrSSe monolayer, we have calculated the structural, electronic, Rashba parameters and photocatalytic properties of MoS 2 -CrXY (X≠Y S, Se, Te) vdWH by using density functional theory calculation. Two different model of MoS 2 -CrXY (X≠Y S, Se, Te) vdWH are presented due to the alternative order of chalcogen atom attached to MoS 2 layer. Phonon band structure, thermal stability and binding energies confirms, the most favorable stacking configuration is dynamically, thermal and energetically feasible. Indirect type-I (MoS 2 -CrXY (X≠Y S, Se)) and type-II (MoS 2 –CrSeTe) band alignment are observed in understudy vdWH. Large Rashba spin splitting is observed in model 2. Electrostatic potential and Bader charge analysis show charges are transferred from MoS 2 layer to CrXY layer, while the potential drop separate charge carrier (holes and electrons) at the interface. Work function and charge density difference are also calculated and presented. A red shift is observed in the position of excitonic peaks from model 1 to model 2. In last we investigated the performance of these vdWH for photocatalytic water splitting at pH = 0. Our results shows that MoS 2 -CrXY (X≠Y S, Se, Te) vdWH may be promising for future nanoelectronics, spintronics and photocatalytic water splitting. • JTMDCs having strong intrinsic dipole and efficient for spintronics applications. • We construct vdWH by vdW stacking of MoS 2 and CrXY monolayer. • Bader charge analysis confirm the charge transfer in these vdWH. • Imaginary part of dielectric function is calculated for understanding the optical properties. • Photocatalytic response confirms that, MoS 2 -CrXY vdWH can split water into O 2 / H 2 O and H + / H 2. [ABSTRACT FROM AUTHOR]

The utilization of heterostructures as photocatalysts for water decomposition is a promising method to tackle contemporary environmental challenges. This research paper presents the design of a direct Z-scheme heterostructure utilizing a monolayer of GeC and a monolayer of arsenene, based on first-principle calculations. The photocatalytic efficiency of this GeC/arsenene van der Waals (vdW) heterostructure in a direct Z scheme has been investigated. The presence of a built-in electric field from the GeC monolayer to the arsenene monolayer has been established through an analysis of band alignment, work function, charge density, and Bader charge. The GeC/arsenene heterostructure exhibits excellent and robust optical absorption efficiency for the sunlight, alongside achieving the maximum solar-to-hydrogen (STH) energy conversion efficiency, amounting to 7.28%, under a biaxial strain of +4%. Furthermore, the Gibbs free energy changes in the hydrogen evolution reaction (HER) and the oxygen evolution reaction (OER) of the GeC/arsenene heterostructure have been calculated. The outcomes indicate that the GeC/arsenene heterostructure is a feasible semiconductor for photocatalytic water splitting. Band edge positions and Z-scheme photocatalytic mechanism of the GeC/arsenene heterojunction. [Display omitted] • GeC/arsenene heterostructure has a built-in electric field from GeC to arsenene layer. • GeC/arsenene heterostructure exhibits a high optical absorption under biaxial tensile strain. • The highest solar-to-hydrogen efficiency of 7.28% is obtained under +4% strain. • High catalytic activity for the hydrogen evolution reaction is confirmed by free energy calculations. [ABSTRACT FROM AUTHOR]

The stability and electronic properties of α Ge nanocrystals and nanoflakes were studied in the [111] and [110] crystallography directions. The findings showed that the electronic properties of the α Ge flakes depend on crystallographic directions, shape, and system size, with well-behaved trends observed as the structure grows. It is demonstrated that the 111- α Ge systems can store one hydrogen molecule per Ge-ring on their surface, with significantly improved capacity when considering the adsorption of Nb atoms on the α Ge surface. The Nb@ α Ge system can store at least three H 2 molecules per Nb atom, with an estimated hydrogen weight percent of 6.11%. An applied strain of about 1% decreased the binding energy by ∼20%, indicating that strain can be an important alternative for engineering the bond between H 2 and the Nb@ α Ge surface. Based on these findings, the α Ge surface is identified as a promising material for hydrogen storage, particularly with Nb atoms adsorbed on its surface, paving the way for further studies on the practical applications of 2D- α -Ge in this field. [Display omitted] • Investigation of the electronic structure of pure and Nb-doped α-Ge nanoflakes. • The Nb atom adsorbed on the α-Ge surface has a high binding energy. • Enhancement of hydrogen storage capacity on α-Ge surface through Nb adatom. • Applied strain effectively modulates the binding energy of the H 2 adatom. • α-Ge surface exhibits promising potential as a material for hydrogen storage. [ABSTRACT FROM AUTHOR]