Large Adsorption Energy Research Articles

Facet-Specific Photocatalytic Degradation of Extracellular Antibiotic Resistance Genes by Hematite Nanoparticles in Aquatic Environments.

The persistence of extracellular antibiotic resistance genes (ARGs) in aquatic environments has attracted increasing attention due to their potential threat to public health and the environment. However, the fate of extracellular ARGs in receiving water remains largely unknown. This study investigated the influence of hematite nanoparticles, a widespread natural mineral, on the photodegradation of extracellular ARGs in river water. Results showed that under exposure to visible light, hematite nanoparticles, at environmental concentrations, resulted in a 3-5 orders of magnitude reduction in extracellular ARGs. This photodegradation of extracellular ARGs is shown to be facet-dependent; the (001) facet of hematite demonstrates a higher removal rate than that of the (100) facet, which is ascribed to its enhanced adsorption capability and higher hydroxyl radical (•OH) production. Density functional theory (DFT) calculations corroborate this finding, indicating elevated iron density, larger adsorption energy, and lower energy barrier of •OH formation on the (001) facet, providing more active sites and •OH generation for extracellular ARG interaction. Gel electrophoresis and atomic force microscopy analyses further confirm that the (001) facet causes more substantial damage to extracellular ARGs than the (100) facet. These findings pave the way for predicting the photodegradation efficiency of hematite nanoparticles with varied facets, thereby shedding light on the inherent self-purification capacity for extracellular ARGs in both natural and engineered aquatic environments.

Ultraviolet enhanced inorganic graphenylene-like ZnMgX2 (X=O, S) for sensitive and reversible detection of toxic formaldehyde at room temperature: A first-principles study

This study investigates the interaction between formaldehyde (HCHO) and newly predicted graphenylene-like ZnMgX2 (X=O, S) monolayers based on first-principles calculations. It was found that the adsorption performance of HCHO molecule on pure ZnMgX2 monolayers was favorable and exothermic in nature, exhibiting no need for the presence of a metal support. Their experimental feasibility was proven through various analyses, including the evaluation of cohesive energy, phonon dispersion and ab initio molecular dynamics (AIMD) simulations. The results of the topological analysis indicate that the examined monolayers are stabilized by the mixed ionic-covalent bond. By systematically analyzing the adsorption energy, charge transfer, band gap, work function and presence of competing gases (H2O, N2, O2 and H2), their detection sensitivity and response times were determined. Under the presence of ultraviolet (UV) irradiation, the ZnMgO2 system demonstrates suitability as an electronic sensor for HCHO detection at room temperature, while ZnMgS2 with its large adsorption energy has the potential to be used for scavenging HCHO. Further investigation into the adsorption of H2O and O2 yields supporting evidence for high selectivity and improved recovery time of HCHO and potential formation of hydroxyl (•OH) and superoxide (O2•−) radicals, thereby establishing favorable conditions for eventual catalytic degradation of HCHO. This study will serve as a theoretical foundation for the development of HCHO gas sensors intended for both small-scale and industrial applications.

Engineering Fluorine‐rich Double Protective Layer on Zn Anode for Highly Reversible Aqueous Zinc‐ion Batteries

AbstractThe high thermodynamic instability and side reactions of Zn‐metal anode (ZMA), especially at high current densities, greatly impede the commercialization of aqueous zinc‐ion batteries (AZIBs). Herein, a fluorine‐rich double protective layer strategy is proposed to obtain the high reversibility of AZIBs through the introduction of a versatile tetradecafluorononane‐1,9‐diol (TDFND) additive in aqueous electrolyte. TDFND molecule with large adsorption energy (−1.51 eV) preferentially absorbs on the Zn anode surface to form a Zn(OR)2− (R=−CH2−(CF2)7−CH2−) cross‐linking complex network, which balances space electric field and controls the Zn2+ ion flux, thus enabling the uniform and compact deposition of Zn (002) crystal planes. Meanwhile, TDFND with low Lowest unoccupied molecular orbital (LUMO, 0.10 eV) energy level is priorly decomposed to regulate the interfacial chemistry of ZMA by building a ZnF2‐rich solid electrode/electrolyte interface (SEI) layer. It is found that a 14 nm‐thick SEI layer delivers excellent structural integrity to suppress parasitic reactions by blocking the direct contact of active water and ZMA. Consequently, the Zn electrode exhibits a superior cycling life over 430 h at 10 mA cm−2 and a high average Coulombic efficiency of 99.8 % at 5 mA cm−2. Furthermore, a 68 mAh pouch cell delivers 80.3 % capacity retention for 1000 cycles.

Engineering Fluorine-rich Double Protective Layer on Zn Anode for Highly Reversible Aqueous Zinc-ion Batteries.

The high thermodynamic instability and side reactions of Zn-metal anode (ZMA), especially at high current densities, greatly impede the commercialization of aqueous zinc-ion batteries (AZIBs). Herein, a fluorine-rich double protective layer strategy is proposed to obtain the high reversibility of AZIBs through the introduction of a versatile tetradecafluorononane-1,9-diol (TDFND) additive in aqueous electrolyte. TDFND molecule with large adsorption energy (-1.51 eV) preferentially absorbs on the Zn anode surface to form a Zn(OR)2- (R= -CH2-(CF2)7-CH2-) cross-linking complex network, which balances space electric field and controls the Zn2+ ion flux, thus enabling the uniform and compact deposition of Zn (002) crystal planes. Meanwhile, TDFND with low Lowest unoccupied molecular orbital (LUMO, 0.10 eV) energy level is priorly decomposed to regulate the interfacial chemistry of ZMA by building a ZnF2-rich solid electrode/electrolyte interface (SEI) layer. It is found that a 14 nm-thick SEI layer delivers excellent structural integrity to suppress parasitic reactions by blocking the direct contact of active water and ZMA. Consequently, the Zn electrode exhibits a superior cycling life over 430 h at 10 mA cm-2 and a high average Coulombic efficiency of 99.8% at 5 mA cm-2. Furthermore, a 68 mAh pouch cell delivers 80.3% capacity retention for 1000 cycles.

Theoretical prediction of hafnium-terminated diamond (100) surface with promising negative electron affinity for electron emission applications

Controlling the chemical termination of diamond surface shows great promise in achieving negative electron affinity (NEA). In this work, we explore the feasibility of obtaining stable NEA properties by hafnium (Hf) termination on bare and oxidized diamond (100) surfaces based on swarm-intelligence structural search and first-principles calculations. The negative adsorption energies demonstrate that Hf-terminated diamond surfaces are energetically favorable. Remarkably, the lowest-energy structure at 0.25 monolayer Hf coverage on an oxidized surface has an extremely large adsorption energy of −11.15 eV, which is consistent with the largest bonding orbital population of 7.28 eV. The most negative NEA values of bare and oxidized surfaces are −3.50 and −3.19 eV at 0.25 monolayer Hf coverage, respectively. Both structures have dynamic stability, and the oxidized surface exhibits excellent thermal stability even up to 1200 K. Owing to their super stability and outstanding NEA properties, Hf-terminated diamond surfaces are suggested as promising candidate materials for electron emission applications.

Density functional theory studies of Ti3C2T x MXene nanosheets decorated with Au for sensing SF6/N2 nitrogen-containing decomposition gases

SF6/N2 mixture is an alternative gas of SF6, which is already used in electrical equipment. When a malfunction occurs , SF6/N2 will decompose and further react with trace water and oxygen to produce nitrogen-containing gases such as NO, NO2, N2O and NF3. It is necessary to monitor these gases to ensure the safe operation of the equipment. This paper is based on density functional theory (DFT), the nanomaterial Ti3C2T x doped with Au atom was selected as sensing material. The result shows that Au/Ti3C2T x has larger adsorption energy when NO and NO2 adsorbed on the surface, the stable structures were conformed more easily with NO and NO2 compared with N2O and NF3. The density of states analysis and the frontier molecule orbital analysis reveal more change of the system before and after NO and NO2 adsorption, suggesting the material showed good sensitivity performance to NO and NO2. Thus, Au/Ti3C2T x is considered to have the potential for sensing NO and NO2.

Borophene as an carrier for mercaptopurine drug: electronic study via density-functional theory computations.

This paper studied MP-B36 interactions through DFT. MP molecules were observed to have a substantial tendency to be adsorbed through their N heads onto B36 at its edge, based on large adsorption energy values. The B atoms at the edges of B36 nanosheets showed higher reactivity than the internal B atoms toward MP. The electronic properties changed upon MP adsorption. The MP-B36 configurations of the highest stability underwent an energy gap reduction of 11-47%. Natural bond orbital (NBO) analysis and molecular electrostatic potential (MEP) analysis were used to evaluate the MP-B36 interaction. The configurations were subjected to geometric optimization at the TPSSH/6-31 + G(d) level of theory, at which frequency analysis was carried out to evaluate the stationary points. These configurations were neutral (Q = 0). The electronic properties of MP dramatically changed upon its interaction with B36 nanosheets. The stable configurations underwent an energy gap reduction, suggesting a chemical signal. The MP molecules were observed to be effectively adsorbed onto the B36 edge within aqueous phases. The MP-B36 configurations were estimated to have relatively large dipole moments. This demonstrated that MP-B36 systems were soluble and dispersed within solar media (e.g., water). It was concluded that B36 nanosheets could serve as efficient MP carriers in nanomedical drug delivery applications.

Metal doping fabricated heterobimetallic nickel-zinc composites and its performance-enhancing sensitivity towards nitrogen dioxide

Monitoring and detecting poisonous nitrogen dioxide (NO2) is greatly challenged by ambiguous knowledge about the sensing mechanism and structures of sensitive materials and reaction intermediates. In particular, synthetic strategies like doping and coupling, although do improve gas-sensing activity, have made the structural identification rather difficult. In the work, we have comprehensively examined nickel-doped zinc oxide (marked as ZON) and its material-coupled composites (ZON/Y) for sensing NO2 by density functional theory. The material (Y) varies from graphitic carbon nitride (CN), graphene (Gr) to cellulose (Cel). It is revealed that the metal doping greatly promotes the NO2 adsorption over the material coupling. This well reproduces the experimental findings that the Ni-doped ZnO has much faster response time than ZnO, ZnO/g-C3N4 and ZnO/graphene. Of all the studied SMs, ZON/CN exhibits superior NO2 gas-sensing performance. Along the reaction pathway, it gives NO2 adsorption free energy of − 0.860 eV, followed by the mildest uphill process of catching the second NO2 (0.320 eV) and the modest downhill process of forming nitrate (−0.680 eV). The large adsorption energy of the initial step is attributed to the fabricated heterobimetallic Ni-Zn sensing active sites. The better sensitivity of ZON/CN is further evidenced by analyses of structures and interfacial bondings.

DFT investigation of metal-decorated silicon carbide nanosheets for the adsorption of NH3

The threat that ammonia (NH3) poses in various human activity environments drives the necessity of sensors of higher sensitivity. Two-dimensional (2D) materials have attracted attention for this particular purpose, with 2D silicon carbide being one prospect for this application. However, this potential use has been relatively unexplored. In this work, we study the adsorption of NH3 on pristine and metal (Li, Na, Mg, Ca, Ag, Au, Cu, Pd, and Ti) decorated silicon carbide monolayers (2D-SiC) using a first-principles approach based on Density-Functional Theory. Energetic analyses were performed to determine the enhancement or deterioration of the NH3 adsorption capacities of the 2D-SiC. The results show that the Ag- and Au-decorated monolayers are the best candidates for NH3 capturing due to the large adsorption energies found in these systems.

Electronic structure and magnetic properties of noble metal (Rh, Ru, Pd, Ag) adsorbed vacancy‐defective arsenene: A first‐principles study

AbstractThe effects of vacancy defects and noble metals (NM = Rh, Ru, Pd, Ag) on the structural stability, electronic structure, and magnetic properties of arsenene were investigated using a first‐principles study. Vacancy defects have a great influence on both the magnetic properties and the band gap of arsenene. With the decrease in defect concentration, the magnetic moment of the vacancy defect system can be increased, and the bandgap transition from metal‐direct–indirect can be realized. After NM adsorption of vacancy defect arsenene, we considered three defect concentrations. It was indicated that there was a large adsorption energy between NM and vacancy‐defective arsenene, indicating that the adsorption system was relatively stable while the change in defect concentration did not have a significant effect on charge transfer. Except for the Ag adsorption system, the defect concentration can effectively modulate the band gap of the adsorption system and make it exhibit various electronic structures, such as semiconductors and metals. In terms of magnetic properties, not all NM atoms can induce arsenene to appear magnetic. Except for the Ag adsorption system, the defect concentration can make the adsorption system exhibit a variety of magnetic properties. It can induce the magnetic state of vacancy‐defective arsenenes or lead to the disappearance of magnetism. The spin polarization of the adsorption system mainly originates from the NM atoms or As atoms around the vacancies.

Computational evaluation of lithium functionalized Penta-BN2 as promising reversible hydrogen storage

Finding advanced hydrogen storage materials with high capacity and high efficiency is a key issue for hydrogen transportation and application. In this study, the first-principles calculation method is used to examine the potential of 2D pentagonal BN2 (Penta-BN2) as an excellent hydrogen storage material. The results indicate that Penta-BN2 has superior metallic and structural stable properties. The pristine Penta-BN2 is found to have weak adsorption energy for H2 molecules, which cannot meet the requirements of hydrogen storage. However, the Li-functionalized Penta-BN2 substrate is found to be relatively excellent to adsorb H2 molecules. A Li atom is bound closely to Penta-BN2 with large adsorption energy reaching more than 3.79 eV, and the 2 × 2 × 1 Penta-BN2 supercell can be suitably accommodated 4 Li atoms. 4Li-functionalized Penta-BN2 stores up to 16H2 molecules with a hydrogen gravimetric density of 8.70 wt%. The adsorption and desorption capacity of the system for H2 molecules under practical temperature and pressure conditions are investigated with semi-empirical calculations. The maximum reversible hydrogen storage capacity is up to 7.92 wt% between the practical condition of 30 atm/233 K for adsorption to 3 atm/358 K for desorption, which is better than other 2D pentagonal materials and boron-nitrogen compounds. The proposed investigations of this work illustrate that Li-functionalized Penta-BN2 is a promising hydrogen storage material with high efficiency, reversibility, and high-capacity characteristics.

Ab-initio calculations on the interaction between OH− and Fe2Mo Laves phase

In the process of heat treatment at high temperature, A2B type intermetallic compound Fe2Mo can precipitate out in the martensitic heat-resistant steel. When the martensitic heat-resistant steel is used in high concentration alkali solution of 7 mol/L, the Fe2Mo Laves phase can dissolve. Meantime, the dissolution behaviors of different shapes of Fe2Mo Laves phase are also distinct. However, there is still no effective micro-mechanism to explain the dissolution behaviors of Fe2Mo Laves phase. Thus, in this work, the adsorption behavior of OH− on Fe2Mo(001), (010), (110) and (112) surfaces was simulated by ab initio calculations. And corresponding electronic effects were comparatively analyzed, the results of which show that the outmost surface of Fe2Mo changed significantly before and after adsorption, demonstrating that the Fe2Mo surface can be influenced by OH−. The results of adsorption energy, Mulliken population, density of states and electronic local function indicate that the Fe2Mo(001) surface has a greater adsorption trend, and the OH−/Fe2Mo(001)-b configuration has the largest adsorption energy. Electrons transfer from OH− to the Fe2Mo surface, and the adsorption type is chemisorption. The results provide a theoretical basis for studying the selective dissolution of Fe2Mo Laves phase in strong alkali solution.

Theoretical study on geometric structures and hydrogen storage in anionic CeH[formula omitted] ([formula omitted] = 2–20) nanoclusters

The geometric structures of anionic CeHn− (n = 2–20) clusters are obtained using crystal structure analysis by particle swarm Optimization(CALYPSO) and density functional theory(DFT). The SDD basis set for Ce atom and the all electron 6-311G ＋ ＋ (D, P) basis set for H atom are set respectively, and the lower-energy isomers in each size for CeHn− (n = 2–20) clusters are re-optimized at the B3LYP level. The photoelectron spectroscopy(PES) for the global minimum of anionic CeHn− (n = 2–20) clusters have been simulated using the Time-Dependent Density Function Theory(TD-DFT) method to determine the authenticity of all the lowest-energy structures obtained. The anionic CeH10− cluster with C2v point group symmetry and an excellent hydrogen storage capacity of 6.7 wt% has been discovered. Chemical bond analysis shows that the internal stability of anionic CeH10− cluster is primarily affected by the interaction between Ce 4f orbital and H 1s orbital, which is formed σ bond at the larger HLG of 4.78 eV. Furthermore, anionic CeH10− cluster has high hydrogen storage capacity, large adsorption energy and good stability, which is expected to be a new nanometer hydrogen storage material. The present work provides guidance for the future synthesis and design of new rare earth(RE) hydrogen storage nanomaterials.

A free base porphyrin as an effective modifier of the cathode interlayer for organic solar cells

Herein, we demonstrate the co-optimization of power conversion efficiency (PCE) and air stability of the organic solar cells (OSCs) by free porphyrin-based buffer of zinc oxide (ZnO) cathode. By combining first-principle calculations and experimental measurements, we investigated the adsorption behaviors and working mechanism of free base porphyrin (TPP) and zinc porphyrin (ZnTPP) on ZnO cathode. The N atoms of TPP are capable of forming Zn—N coordination with the Zn atom of ZnO substrate, thereby generating interfacial dipoles and reducing the work function of ITO/ZnO cathode, which is beneficial for the charge transfer in the OSCs. More importantly, the large adsorption energy between ZnO and TPP, as well as the good compatibility between TPP and the organic layer, enables TPP to act as a “molecular glue” between the inorganic interface and the organic active layers, which improves not only the PCE but also the stability of the devices under high humidity air environment. In contrast, the already coordinated porphyrin ZnTPP has no such positive effects on the device performance when used as ZnO buffer. The results are of great significance for the study of the working mechanism of interlayer buffers in OSCs, and are also of guidance for designing the buffer molecules.

Adsorption of small gas molecules onto the two-dimensional Janus SnSSe monolayer

First-principles electronic structure calculations under density functional theory (DFT), carbon monoxide (CO), nitrogen monoxide (NO), nitrogen dioxide (NO2), ammonia (NH3), and oxygen gas (O2) has been studied to explain the small gas detection capabilities onto the two-dimensional (2D) Janus SnSSe monolayer considering for each different sites. By including van der Waals (vdW) interactions between gas molecules and SnSSe, we have found that NO, NO2 and NH3 from these proposed molecules could be strongly adsorbed on the SnSSe monolayer with large adsorption energies. The charge transfer variation of electronic structures and the partial density of states are discussed. Thus, our results for the potential applications of the SnSSe monolayer in gas sensing provide a theoretical basis as well as an important explanation for the experimental findings.

First-principles study of non-metallic edge-modified zigzag arsenene nanoribbons for CO adsorption

The adsorption of carbon monoxide (CO) by non-metallic (H, B, C, N, O, and F) edge-modified zigzag arsenene nanoribbon (ZAsNR) was investigated based on a density generalized theory first principles approach. The values of binding energy, adsorption energy, energy band structure, and charge transfer were calculated by modeling different non-metallic modified ZAsNR systems. It was shown that CO molecules prefer to be valley-positioned and tilted to adsorb on the ZAsNR surface and that the structures of all adsorption systems are stable. The H, C, N, and F atoms modified ZAsNR systems showed weak CO molecule adsorption and less conductivity variation. The B-atom-modified ZAsNR system has the largest adsorption energy and also a large charge transfer, but since the conductivity, after adsorption, is much smaller than that before adsorption, it indicates that its sensing is significantly weakened when the gas is adsorbed. Therefore, the modifications of H, B, C, N, and F atoms are not suitable for gas-sensing materials. The O-atom-modified ZAsNR system showed a significant increase in charge transfer and significantly changed the carrier concentration, which in turn increased the conductivity of the adsorbed system. This indicates that the O-modified ZAsNR system is expected to be a new sensor material.

DFT investigation of transition metal-doped graphene for the adsorption of HCl gas

Graphene-based toxic HCl gas sensors and adsorption materials are seldom reported. Utilizing density functional theory (DFT), the adsorption energy, charge density, and density of states, the sensitivity and recovery time of HCl gas adsorbed on graphene and six different transition metal-doped graphenes (TMDGs: TM = Ti, V, Cr, Mn, Fe, Co) were investigated. It indicates that TMDG has larger adsorption energy and chemical adsorption capacity than graphene. The Fe-doped graphene (FeDG) demonstrated better adsorption capacity and higher stability even at high temperature. The Mn- and Co-doped graphenes (MnDG & CoDG), exhibited magnetic changes after the adsorption of HCl molecules. Moreover, MnDG has both fast responsiveness and fast recovery time at a certain temperature. Thus, comparative speaking, among the six TMDGs, MnDG is the most suitable material for the detection of HCl gas, its magnetic property implied a novel application in HCl gas sensor.

Gas-Phase Interaction of CO, CO2, H2S, NH3, NO, NO2, and SO2 with Zn12O12 and Zn24 Atomic Clusters.

Atmospheric pollutants pose a high risk to human health, and therefore it is necessary to capture and preferably remove them from ambient air. In this work, we investigate the intermolecular interaction between the pollutants such as CO, CO2, H2S, NH3, NO, NO2, and SO2 gases with the Zn24 and Zn12O12 atomic clusters, using the density functional theory (DFT) at the meta-hybrid functional TPSSh and LANl2Dz basis set. The adsorption energy of these gas molecules on the outer surfaces of both types of clusters has been calculated and found to have a negative value, indicating a strong molecular-cluster interaction. The largest adsorption energy has been observed between SO2 and the Zn24 cluster. In general, the Zn24 cluster appears to be more effective for adsorbing SO2, NO2, and NO than Zn12O12, whereas the latter is preferable for the adsorption of CO, CO2, H2S, and NH3. Frontier molecular orbital (FMO) analysis showed that Zn24 exhibits higher stability upon adsorption of NH3, NO, NO2, and SO2, with the adsorption energy falling within the chemisorption range. The Zn12O12 cluster shows a characteristic decrease in band gap upon adsorption of CO, H2S, NO, and NO2, suggesting an increase in electrical conductivity. Natural bond orbital (NBO) analysis also suggests the presence of strong intermolecular interactions between atomic clusters and the gases. This interaction was recognized to be strong and noncovalent, as determined by noncovalent interaction (NCI) and quantum theory of atoms in molecules (QTAIM) analyses. Overall, our results suggest that both Zn24 and Zn12O12 clusters are good candidate species for promoting adsorption and, thus, can be employed in different materials and/or systems for enhancing interaction with CO, H2S, NO, or NO2.

C6N7 monolayer as an innovative sensor and scavenger for NO, H2S and SO2: A first-principles study

The adsorption, electronic, gas-sensing and capture properties of molecules (NO, H2S, SO2, NO2, NH3, N2, CO, CH4, CO2, and H2O) on the C6N7 monolayer were systematically studied to explore the possibilities of C6N7-based toxic gas sensor and scavenger by using first-principles methods. We found only NO, H2S, and SO2 are adsorbed on the monolayer with large adsorption energy (ranging of -0.853∼-0.931 eV), meanwhile the other molecules are all weakly physisorbed on the monolayer with Ead of -0.193∼-0.547 eV. The NO and H2S adsorption could remarkably affect the electronic properties and work function (Φ) of the C6N7 monolayer, indicating it is highly sensitive and selective towards NO and H2S. The recovery time (τ) of NO and H2S was predicted respectively to be 25 and 1.9 s at 350 K, while the τ of the other molecules was too short to make the sensor device be difficult to measure these gases. The C6N7 monolayer can be promising resistance-type (Φ-type) gas sensors for H2S and NO detection at 350 K. However, the presence of humidity effects the gas sensing of C6N7-based resistance-type sensor, so that it should operate in a dry environment, but as Φ-type sensor can operate regardless of the existence of humidity and concentrations. In addition, the high adsorption capacity and desired recovery time of the C6N7 monolayer make it be an optimal scavenger for toxic gases.

Effect of doping on the sensitivity of Ti2CO2 toward NO: A DFT study

Detecting harmful gasses is important to the public health, and MXenes are promising candidates as effective sensors. The adsorption stability, electronic and magnetic properties of NO molecule on modified Ti2CO2 was explored using density functional theory (DFT), including perfect, vacancy-defected, transition-metal (TM) doped Ti2CO2 substrates. The results indicated that TM-doping was more effective to improve the activity of Ti2CO2 than the introducing of O-vacancy. The large adsorption energies, short interaction distance, and high charge transfer suggested the adsorption of NO on doped Ti2CO2 were chemisorption. Hybridization between the 3d-orbital of TM-dopants and NO molecule play a key role to enhance the stability of NO molecule. It is hoped that these results could provide novel information to design MXene-based sensors.