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The strong metal–support interactions (SMSI) between metal and its support have been regarded as a valid approach to enhance the catalytic performance; however, the extent to which exploration of electronic state regulation affects catalytic performance of alcohol oxidation reactions (AOR) has been rarely reported. In this paper, PdAg nanoparticles loaded on a N-doped carbon substrate with controlled nitrogen content (PdAg@NxC, x representing the nitrogen contents) was synthesized through a seeded synthesis strategy for alkaline AOR. Results show that the electronic state of PdAg nanoparticles was significantly modified after nitrogen doping in the carbon support. Experimental and theoretical results indicate that with increasing nitrogen content, the degree of electronic state regulation becomes increasingly significant. Density functional theory (DFT) calculations suggest that the increased degree of SMSI promotes OH* adsorption on the PdAg surface and weakens the binding between catalyst and CO*. As a result, the PdAg@N15.3C with the highest N content exhibits excellent AOR performance, achieving a MA/SA of 10.8 A mgPd−1/13.2 mA cm−2 and 3.8 A mgPd−1/4.7 mA cm−2 on the EOR and MOR, respectively. Moreover, due to the changes in the adsorption energy of key intermediates on PdAg nanoparticles, the onset oxidation potential of PdAg@N15.3C shows a negative shift of 180 mV compared to PdAg@C as revealed by CO stripping analysis, signifying an increase in the CO tolerance. Our study demonstrates the influence of the SMSI effect between the active center and the support on the catalytic performance for AOR and presents a pathway to achieve high AOR performance through SMSI engineering. [ABSTRACT FROM AUTHOR]

Cocatalysts are usually applied in the photocatalytic water splitting process to accelerate the kinetics of the hydrogen evolution reaction (HER). Specifically, the transition metal nitride (Mo2N) featuring a unique local surface plasmon resonance (LSPR) effect has exhibited great potential to function as a HER cocatalyst. However, the low metallicity of Mo2N hampers its ability to improve charge separation. To address this issue, transition metal atom doping (Co and Cu) engineering was used to modulate the electronic structure of Mo2N nanosheets to achieve a higher electrical conductivity and a lower hydrogen adsorption free energy (‖ΔGH*‖), thereby favoring the HER kinetics. Density functional theory (DFT) calculations and experimental results showed that Co-doping and Cu-doping mainly take place at Mo sites in the crystal structure of Mo2N to form stable structures of Co doped Mo2N (Co–Mo2N) and Cu doped Mo2N (Cu–Mo2N). Compared with pristine Mo2N, both Cu–Mo2N and Co–Mo2N demonstrated a much improved cocatalytic effect over g-C3N4 in promoting charge separation, accelerating HER kinetics and enhancing light absorption. The Co–Mo2N with the highest conductivity and lowest ‖ΔGH*‖ illustrated the best cocatalytic effect, and the H2 production performance (367.8 μmol g−1 h−1) of Co–Mo2N/g-C3N4 achieved was 10 and 5 times higher than those of Mo2N/g-C3N4 and Cu–Mo2N/g-C3N4. This paper provides significant guidance in the design and development of efficient cocatalysts for the HER application. [ABSTRACT FROM AUTHOR]

Iron impurities are believed to act as deep acceptors that can compensate for the n-type conductivity in as-grown Ga2O3, but several scientific issues, such as the site occupation of the Fe heteroatom and the complexes of Fe-doped β-Ga2O3 with native defects, are still lacking. In this paper, based on first-principle density functional theory calculations with the generalized gradient approximation approach, the controversy regarding the preferential Fe incorporation on the Ga site in the β-Ga2O3 crystal has been addressed, and our result demonstrates that Fe dopant is energetically favored on the octahedrally coordinated Ga site. The structural stabilities are confirmed by the formation energy calculations, the phonon dispersion relationships, and the strain-dependent analyses. The thermodynamic transition level Fe3+/Fe2+ is located at 0.52 eV below the conduction band minimum, which is consistent with Ingebrigtsen's theoretical conclusion, but slightly smaller than some experimental values between 0.78 eV and 1.2 eV. In order to provide direct guidance for material synthesis and property design in Fe-doped β-Ga2O3, the defect formation energies, charge transitional levels, and optical properties of the defective complexes with different kinds of native defects are investigated. Our results show that VGa and Oi can be easily formed for the Fe-doped β-Ga2O3 crystals under O-rich conditions, where the +3 charge state FeGaGai and −2 charge state FeGaOi are energetically favorable when the Fermi level approaches the valence and conduction band edges, respectively. Optical absorption shows that the complexes of FeGaGai and FeGaVGa can significantly enhance the optical absorption in the visible-infrared region, while the energy-loss function in the β-Ga2O3 material is almost negligible after the extra introduction of various intrinsic defects. [ABSTRACT FROM AUTHOR]

In order to study the influence of cationic vacancy structure on the oxygen evolution reaction (OER) activity of catalysts. A series of cationic vacancy NiO catalysts (d-M x -NiO) with different vacancy structure were prepared by alkali-etching the doping amphoteric oxide element in this paper. Due to diverse intrinsic characteristic of doping amphoteric oxide element, the electronic configuration of cationic vacancy in d-M x -NiO is changed after alkali-etching. Density functional theory (DFT) calculations reveal that the d band center of Ni element is increased gradually with the increasing valence state of doping vacancy element, which is beneficial to optimize the adsorption energy for the OER intermediate products. Among the d-M x -NiO catalysts, d-Al 0.2 -NiO catalyst possesses the highest d band center and oxidation state of Ni, resulting in the superior OER performance with only 285 mV overpotential to achieve the current density of 10 mA cm−2. Additionally, d-Al 0.2 -NiO also demonstrates admirable stability after 100 h OER test with a ∼99% faradaic efficiency. The current finding would offer a valuable insights to design and fabricate the cationic vacancy OER catalysts with high efficiency. [Display omitted] • NiO with different cationic vacancy structure are prepared by three steps. • The electronic configuration of Ni site can be regulated by cationic vacancy. • Oxidation state of Ni is increased with increasing valence state of vacancy element. • The d-Al 0.2 -NiO catalyst only requires 285 mV overpotential at 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Searching for highly efficient bifunctional oxygen evolution reaction/oxygen reduction reaction (OER/ORR) electrocatalysts for sustainable and renewable clean energy is vital. However, these electrocatalyst designs remain cost-prohibitive for both experimental and computational studies. This paper systematically investigates 5d transition metal (5d TM) doped into graphitic carbon nitride (g-C 3 N 3) as potential bifunctional OER/ORR electrocatalysts by considering the defect charge states through the defect chemistry study. Our formation energies results show that 33 kinds of 5d TM doped g-C 3 N 3 have better stabilities in the different charge states. Among them, Ir N ×@C 54 N 53 (Ir occupation N), Ir N •@C 54 N 53 , Pt N ×@C 54 N 53 (Pt occupation N), and Ir i •@C 54 N 54 (Ir interstitial sites) exhibit lower overpotentials. They are great candidates for bifunctional OER/ORR electrocatalysts. This is because adjusting the charge states of 5d-TM@g-C 3 N 3 can tune the interaction strength of the oxygenated intermediates. Furthermore, machine learning shows that the charge transfer of TM atoms (Q e) and total magnetic moment (μ B0) are the two most essential descriptors for OER and ORR overpotential, respectively. The charged defect adjusting of the bifunctional OER/ORR activity would develop the potential electrocatalysts for energy conversion applications. [Display omitted] • Obtained 33 kinds of 5d TM-doped g-C 3 N 3 have better stabilities in the different charge states. • Ir N × @ C 54 N 53 , Ir N • @ C 54 N 53 , Pt N × @ C 54 N 53 and Ir int • @ C 54 N 54 meet the requirements of bifunctional ORR/OER electrocatalysts. • Control of the charge states can optimize the bifunctional OER/ORR activity of 5d transition metal-doped g-C 3 N 3. • The TM atoms' charge transfer and magnetic moment are the most effective descriptors for OER and ORR's overpotentials. [ABSTRACT FROM AUTHOR]

Biomass provides a promising source of carbon for obtaining environment-friendly carbon materials, but obtaining heteroatom-doped carbon materials (HDCMs) from biomass directly by a green method still remains challenging. This study successfully synthesized nitrogen and phosphorus co-doped porous carbon materials (Y-NPC) by the simple in situ pyrolysis of renewable yeast mixed with water from 800 to 950 °C. Various characterization methods show that nitrogen and phosphorus are doped into the carbon skeleton and mainly exist in the forms of graphite-N, pyridine-N, C–P, P–N, and P–O states. The catalyst Y-NPC-900 °C with a 3D hierarchical porous structure and high P–N content exhibited superior nitro hydrogenation performance and reaction stability using molecular hydrogen and hydrazine hydrate as hydrogen sources under mild conditions. Density functional theory (DFT) calculations and experiments attributed the exceptional catalytic performance to hydrogen activation and the good adsorption ability of substrates over N, P co-doped carbon (NPC). Therefore, this research proposes an eco-friendly and simple synthesis strategy for in situ N, P co-doping metal-free carbon catalysts derived from biomass, showing the significance of N, P co-doping and single N- or P-monodoping in the charge distribution of carbon materials. [ABSTRACT FROM AUTHOR]

Context: The electronic and magnetic properties of non-metallic (NM) elements doping defective graphene-like ZnO (g-ZnO) monolayer including O vacancy (VO) and Zn vacancy (VZn) are studied. The results show that VO-g-ZnO is a semiconductor and VZn-g-ZnO is a magnetic semiconductor. B, C, N, Si, P, 2S, and 2Si doping VO-g-ZnO systems present half-metal and magnetic semiconductors, and the magnetism mainly originates from the spin polarization of doping atoms. For single or double NM elements doping VZn-g-ZnO, 2P doping system presents a semiconductor, while other systems present ferromagnetic metal, half-metal, and magnetic semiconductor. The magnetism of single NM elements doping VZn-g-ZnO mainly comes from the spin polarization of O atoms near the defect point. For double NM elements doping VZn-g-ZnO, spin splitting occurs mainly in p orbitals of O atoms, dopant atoms, and d orbitals of Zn atoms. NM elements doping defect g-ZnO can effectively regulate the electronic and magnetic properties of the system. Methods: The software package VASP 5.4.1 (Vienna ab initio Simulation Package) is used for calculations in this paper. The local density approximation (LDA) is adopted as an exchange and correlation function to perform the structural optimization and analysis of electronic structure and magnetic properties. [ABSTRACT FROM AUTHOR]

Noncontact temperature measurement using thermochromic materials is vital in the field of temperature indication, but the related mechanisms behind thermochromic behavior are diverse and high complexity, and the color‐temperature correspondence is poorly explored. This paper systematically studied the thermochromic mechanisms and color‐temperature correspondence in the cobalt‐doped LaCrO3 coatings via experiment and density functional theory study. The coatings appear reversible thermochromism from green to black with temperature and composition, functions from room temperature to 700°C. This thermochromism is attributed to the lattice expansion and bandgap reduction as the temperature increase, and a model of temperature effect bandgap was proposed. Meanwhile, the coating temperature can be inferred from the color change because the CIE chromaticity coordinate of the coating varies linearly with temperature, and the mean relative error of thermochromic measurements is 8.28%. Furthermore, the cobalt doped introduces impurity energy levels and enhances the interaction between photons and carriers, which reduce the bandgap and increase the absorption in the visible spectrum resulting in darker colors. This work provides a stable and efficient high‐temperature thermochromic coating that has a wide thermochromic temperature range and clear color‐temperature correspondence, which shows broad application prospects in the field of thermal indication at high temperatures. [ABSTRACT FROM AUTHOR]

The doping of different elements will make the Fe2O3 catalyst show different catalytic characteristics and improve the activity of the Fe2O3 catalyst in selective catalytic reduction (SCR), mainly by increasing the types of reactive oxygen species and the specific surface area of the catalyst. In this paper, density functional theory (DFT) was used to reveal the reaction path and adsorption behaviour of the Mg‐doped γ‐Fe2O3 catalyst. The results show that the doping of Mg ions can contribute electrons and lead to electron migration on the catalyst surface, which changes the acidity of some sites on the catalyst surface. The adsorption energy of NH3 is related to the binding sites of N atoms on the catalyst surface, and different adsorption sites will be enhanced or weakened due to Mg doping. NH2 reacts with NO to form N2 and H2O, so the dehydrogenation of NH3 to the NH2 radical is a key step in SCR. With doping, this process becomes more likely to occur. In addition, the activation energy barrier of NH2 formation in the aerobic environment is lower than that in the anaerobic condition, which contributes to NH3 dehydrogenation. Therefore, doping Mg on the surface of γ‐Fe2O3 catalyst can improve the catalytic activity of NO removal. [ABSTRACT FROM AUTHOR]

This paper investigates the general trends in the structural, electronic, and optical properties of anatase TiO2 photocatalysts co-doped with transition metals and sulfur. We attempt to rationalize co-dopant selection by employing molecular dynamics and density functional theory calculations. The structural properties of the first-row transition metal co-dopants were determined. TM-TiO2 and TM/S-TiO2 were structurally stable, with minimal changes in their lattice parameters, cell volume, density, and XRD profiles relative to pristine TiO2. However, only Fe and Mn among the first-row transition metals are thermodynamically favorable, i.e., their substitutional energies are lower relative to pristine TiO2. Intermediate energy levels (IELs) are formed during the co-doping of transition metals and sulfur on TiO2. In particular, Fe and Co form two IELs between the VBM and CBM, resulting in improved optical properties, especially in the visible-light region, which are mainly attributed to the unsaturated nonbonding transition metal d orbitals and the half-filled Ti–O bonding orbitals. On the other hand, Cu and Ni form three IELs close to each other due to the M–O anti-bond orbitals, half-filled p orbitals of S, and the Ti–S anti-bonding orbitals. These IELs in co-doped systems can serve as "stepping stones" for photogenerated electrons, facilitating easier charge mobility. Among the investigated co-doped systems, Fe/S-TiO2 was shown to be the most promising for photocatalytic applications. [ABSTRACT FROM AUTHOR]

Correct identification of local configurations of dopants and point defects in random alloys poses a challenge to both computational modeling and experimental characterization methods. In this paper, we propose and implement a computationally efficient approach to address this problem. Combining special quasirandom structures, virtual crystal approximation, and real-space lattice static Green's functions, we are able to calculate, at moderate computational cost, the local phonon density of states (LPDOSs) of impurities in a random alloy crystal for system sizes, surpassing the capabilities of a conventional, cubic-scaling, density functional theory. We validate this method by showing that our LPDOS predictions of substitutional silicon in GaAs and InAs are in excellent agreement with the experimental data. For the case study, we investigate a variety of local configurations of Si and Se substitutional dopants and cation vacancies in quasirandom In 0.5 Ga 0.5 As alloys. In all cases, the impurity LPDOS in a random alloy exhibits qualitatively different signatures from those in the pure binary compounds GaAs and InAs. Specifically, they are characterized by a wide continuous band (rather than narrow discrete peaks) of vibrational modes at frequencies typically higher than the bulk modes, a sign of coupling between localized vibrations of the impurity and those of its random neighboring host atoms. The accuracy and computational cost of this approach open a way to the simulation of impurities in random structures on a large scale and the prediction of vibrational signatures of alloys with defects. [ABSTRACT FROM AUTHOR]

Heteroatom doping, especially with elements of lower electronegativity and smaller atomic radius, can effectively modulate the electronic structure and surface properties of electron materials, facilitating the electrochemical performance of supercapacitors. Herein, we have designed boron-doped NiCoP nanoarrays grown on carbon cloth (B-NCP-CC) for supercapacitor cathode materials using a simple process method combining hydrothermal, calcined phosphating and boronation processes. The introduction of boron, with lower electronegativity (2.04) and smaller atomic radius (0.85 Å) than phosphorus (2.19 and 1.00 Å), induces electron redistribution and shortens the Ni/Co–B bonds, enhancing their redox activity and charge transfer kinetics. The boron doping greatly enables the B-NiCoP-CC-18 (NiCoP-CC borated for 18 h) cathode material to provide a high capacity of 801 C g−1. The assembled B-NiCoP-CC-18‖‖AC hybrid supercapacitor achieves a high energy density of 73.22 W h kg−1 at a power density of 963.8 W kg−1 and retains 90% capacity after 5000 cycles, significantly improving the stability of nickel-based materials. Besides, density functional theory (DFT) calculations further elucidate that the introduction of boron increases the d-band centers of Ni and Co in NiCoP, promoting the conductivity and enhancing the electrochemical properties. [ABSTRACT FROM AUTHOR]

Electrocatalytic nitrogen reduction reaction (NRR) is a promising technology for ammonia synthesis under environmental conditions due to its simplicity of operation, high energy conversion, and environmental friendliness. While development of an efficient and stable electrocatalyst is one of the remaining key challenges. In this paper, the electrocatalytic performance of single Ru atoms anchored in Bn-doped graphyne (RuBn@GY) is systematically investigated using density functional theory (DFT) calculations. The results show that RuB@GY is a highly efficient NRR electrocatalyst with a distal and alternating mechanism considered to be the most active catalytic pathway, with a limiting potential of only − 0.53 V. Overall, our study facilitates the NRR reaction by controlling the number and position of the doped B atoms to reduce the limiting potential, and this work provides theoretical guidance for the further development of highly active and stable single-atom catalysts (SACs). Electrocatalytic nitrogen reduction reaction (NRR) is a promising technology for ammonia synthesis under environmental conditions due to its simplicity of operation, high energy conversion, and environmental friendliness. [ABSTRACT FROM AUTHOR]

The catalysts for oxygen reduction reaction (ORR) are of great significance to the development of electrochemical energy systems. In this paper, the ORR catalytic performance of Mn–Ni dual-metal doped N-coordinated graphene is studied by density functional theory (DFT). The results show that the catalysts with dual-metal active sites are more stable than that with single metal site, and all catalysts show certain catalytic activity. The reaction pathway analyses of catalysts with two different adsorption configurations of O 2 show that when O 2 is adsorbed on two metal sites, OOH will automatically split into OH and O. When O 2 is adsorbed on Mn site alone, the other site does not participate in the adsorption of oxygen-containing intermediates. The thermodynamic calculation results show that the catalytic performance is mainly influenced by the adsorption strength of O, which is controlled by the number of active sites involved in the adsorption, bond length and the number of transferred electrons at the active sites. The G-MnNiN 6 -3 shows the best catalytic performance with an overpotential of 0.453 V and a reaction energy barrier of 0.19 eV. The results of this study highlight the potential application of Mn–Ni dual-metal doped N-coordinated graphene as a highly efficient non-precious catalyst. • The ORR catalytic performance of Mn–Ni dual-metal doped N-coordinated graphene is studied for the first time. • The adsorption of O 2 can be classified into single adsorption and co-adsorption on bimetallic catalyst. • The catalytic performance is most affected by the adsorption strength of O. • The best catalyst shows the overpotential of 0.453 V and a reaction energy barrier of 0.19 eV. [ABSTRACT FROM AUTHOR]

Black phosphorene (BP) is a metal-free two-dimensional photocatalyst with potential for visible-light-driven photocatalytic H2 evolution. However, its inert basal plane toward the HER hinders its practical application. To overcome this problem, we design a novel nonprecious metal–nonmetal co-doping method of BP to activate its inert basal plane and improve photocatalytic HER performance. Through density functional theory (DFT) calculations, we systematically investigate the photocatalytic performance of nonprecious metal and nonmetal co-doped BPs. Our results show that V–N co-doped BP exhibits excellent thermodynamic stability, suitable band structure, improved carrier separation, superior adsorption and dissociation energies and enhanced visible-light absorption coefficient. Importantly, V–N co-doping successfully activates the inert basal plane of BP, allowing it to drive the HER under illumination (ΔGH = −0.12 eV). This study highlights the potential of nonprecious metal–nonmetal co-doping to enhance the photocatalytic activity of BP, providing invaluable insights for advancing the field of co-doped BP in photocatalysis. [ABSTRACT FROM AUTHOR]

Hydrogen production by urea electrolysis is a green, energy conservation and environment protection method. Compared with traditional water electrolysis for hydrogen production, it not only saves costs and energy consumption, but also can treat urea wastewater to purify the environment. In this paper, the sea urchin-like nanoneedles (M (M = Cr, Mo and W)–FeCo 2 P/NF) arrays with different doping elements M (M = Cr, Mo and W) were prepared by hydrothermal method and moderate temperature phosphating method. It is proved that the doping of different elements in the same group cooperates to adjust the electronic structure of Co 2 P, thereby increasing the electrochemical active area and improving the active site. What is noteworthy is that Mo–FeCo 2 P/NF material only needs potential of 1.305 V and overpotential of 232 mV to drive 50 mA cm−2 for urea oxidation reaction (UOR) and hydrogen evolution reaction (HER). The Mo–FeCo 2 P/NF (±) electrolyser can drive a current density of 10 mA cm−2 at a potential of 1.471 V, and is stable for at least 12 h in urea electrolysis. The density functional theory (DFT) demonstrates that Mo–FeCo 2 P/NF electrode has a moderate Gibbs free energy (G H∗) of H adsorption. This work put forward a new strategy for improving the activity and stability of transition metal phosphides by doping strategy for urea electrolysis. The Mo–FeCo 2 P/NF (±) electrolyser cell for only 1.471 V to provide current density of 10 mA cm−2, which is one of the best electrochemistry performances reported up to now. [Display omitted] • Mo, Fe co-doped Co 2 P electrodes was synthesized for the first time through hydrothermal processes. • This Mo–FeCo 2 P nanoarrays exhibits enhanced activity of the urea splitting (cell voltage of 1.471 V @10 mA cm−2). • DFT show that the Mo–FeCo 2 P material exhibits the minimum Gibbs free energy. [ABSTRACT FROM AUTHOR]

HfO2 can assume different crystalline structures, such as monoclinic, orthorhombic, and cubic polymorphs, each one characterized by unical properties. The peculiarities of this material are also strongly related to the presence of doping elements in the unit cell. Thus, the present paper has the main purpose of studying and comparing twelve different systems characterized by diverse polymorphs and doping percentages. In particular, three different crystalline structures were considered: the monoclinic P21/c, the orthorhombic Pca21, and the cubic Fm 3 ¯ m phases of HfO2. Each one has been studied by using Y as a doping agent with three different contents: 0% Y:HfO2, 8% Y:HfO2, 12% Y:HfO2, and 16% Y:HfO2. For all the systems, density functional theory (DFT) methods based on PBE/GGA, and on the HSE hybrid functionals were used to optimize the geometry as well as to study their optical properties. Depending on the polymorphs, Y affects the formation energy in different ways and causes changes in the optical properties. When the percentage of Y did not exceed 12%, a stabilization of the cubic phase fraction and an increase of the dielectric constant was observed. Additionally, the calculated optical bandgap energies and the refractive index are examined to provide an overview of the systems and are compared with experimental data. The bandgaps obtained are in perfect agreement with the experimental values and show a slight increase as the doping percentage grows, while only minor differences are found between the three polymorphs in terms of both refractive index and optical band gap. The adopted first principles study generates a reasonable prediction of the physical-chemical properties of all the systems, thus identifying the effects of doping phenomena. [ABSTRACT FROM AUTHOR]

Triethylamine (TEA) as an excellent solvent, polymer inhibitor and preservative often appears in various places in industrial production, but its harm can not be underestimated. For the detection of TEA, molybdenum trioxide (MoO 3) is a great gas-sensitive material, but its response and recovery time are long. In addressing improvements to MoO 3 , the paper introduced a method involving the introduction of the rare earth metal La and further pinpointed an optimal doping concentration strategy. In this paper, three-dimensional (3D) microspheres of La-doped MoO 3 with different doping concentrations were synthesized using a facile hydrothermal method. Among these, the sensor based on 1 wt% La-doped MoO 3 exhibits the highest gas-sensing response to TEA, with a response value of approximately 30–20 ppm TEA when the temperature is 240 ℃, accompanied by shortened response and recovery times of 10 and 29 s, respectively. Moreover, this doping level demonstrates excellent selectivity, reproducibility and long-term stability. The enhancement of gas-sensing performance is elucidated through the electron depletion layer theory and the increase in oxygen vacancies. Additionally, first-principles density functional theory (DFT) calculation was employed to deeply analyze the adsorption behavior of the MoO 3 towards TEA before and after doping. This study provides valuable insights into the development of high-performance TEA sensors. [Display omitted] • The triethylamine (TEA) sensor based on molybdenum trioxide (MoO 3) microspheres modified via La doping is reported. • The La-doped MoO 3 sensor has the advantages of excellent selectivity, reproducibility and long-term stability. • The adsorption energies of the five adsorption sites in three cases were calculated using DFT calculation. [ABSTRACT FROM AUTHOR]

The slow kinetics of the oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) in air cathodes severely limit the development of reversible zinc–air batteries. Thus, bifunctional oxygen catalysts with excellent electrocatalytic activity and durability for both the oxygen reduction and oxygen evolution reactions (ORR/OER) are keys to achieving long-term rechargeable zinc–air batteries. However, it remains challenging to further improve the performance by adding more active sites. To address this, a series of nitrogen-doped carbon (CN) with NiCo alloys has been synthesized by pyrolyzing a simple bimetal zeolitic-imidazolate framework (ZIF) and then evenly loaded with metallic Ru nanoparticles, resulting in Ru–NiCo/NC samples. Benefiting from the large pore volume and high activities, the Ru–NiCo/NC electrocatalysts exhibit higher ORR (E1/2 = 0.84 V) and OER performance with an overpotential of 342 mV at 10 mA cm−2, along with superior cycle stability. More significantly, when employed in rechargeable zinc–air batteries, Ru–NiCo/NC catalysts demonstrate a high power density of 132.3 mW cm−2, significantly outperforming Pt and Ru-based zinc–air batteries. Additionally, DFT (density functional theory) results indicate that the addition of Ru leads to a downshift of the d-band center from the Fermi level, which benefits the reduction of energy barriers and enhances the desorption of O-containing intermediates. This work provides a feasible strategy for developing efficient and high-performance bifunctional electrocatalysts. [ABSTRACT FROM AUTHOR]

As a pseudocapacitor electrode material, molybdenum disulfide (MoS2) usually shows inferior capacity, rate capability and cyclability. Structural regulation and heteroatom doping are the available methods to ameliorate the electrochemical properties of MoS2. Herein, phosphorus doped molybdenum disulfide regulated by sodium chloride (SP-MoS2) is successfully synthesized using phosphomolybdate acid as a molybdenum source and an in situ dopant and sodium chloride (NaCl) as a structural regulator. Under the structural regulation of NaCl, the SP-MoS2 nanosheets exhibit an interweaved architecture with a large interlayer spacing of 0.68 nm. Owing to the in situ P doping and large specific surface area (21.0 m2 g−1), the SP-MoS2 electrode possesses a maximum capacity of 564.8 F g−1 at 1 A g−1 and retains 56.3% of the original capacity at 20 A g−1. Density functional theory (DFT) calculations indicate that SP-MoS2 displays a high K+ average adsorption energy of −3.636 eV. In addition, the fabricated SP-MoS2//AC asymmetric supercapacitor device displays an energy density of 22.8 W h kg−1 at 759 W kg−1. [ABSTRACT FROM AUTHOR]

The reasonable allocation and control of CO2 concentration in a greenhouse are very important for the optimal growth of crops. In this study, based on density functional theory (DFT), an MoS2–GeSe monolayer was proposed to unravel the issues of the lower selectivity, poorer sensitivity and non-recyclability of traditional nanomaterial gas sensors. The incorporation of MoS2 units greatly enhanced the sensitivity of the pure GeSe monolayer to CO2 and the high binding energy also demonstrated the thermal stability of the doped structures. The ideal adsorption energy, charge transfer and recovery time ensured that the MoS2–GeSe monolayer had a good adsorption and desorption ability. This paper aimed to solve the matter of recycling sensors within agriculture. This research could provide the theoretical basis for the establishment of a potentially new generation of gas sensors for the monitoring of crop growth. [ABSTRACT FROM AUTHOR]

Monolayer BSi has received much attention due to its potential applications in the field of energy storage and superconductivity. However, the mechanical properties of monolayer BSi have not been fully elucidated yet. In this paper, the morphology, elastic constants and Young's moduli of raw and C, N, P, and S doped monolayer BSi have been investigated by the first principle density functional theory (DFT) calculation. The monolayer BSi exhibits an anisotropic mechanical performance. The results indicate that the C, N, P and S doping affect the value of Young's modulus of BSi, as well as the modulus distribution. [ABSTRACT FROM AUTHOR]

In this work, we present the results obtained using a CO2 laser source at 10.6 µm wavelength for the study of the non-melt annealing of phosphorus doped germanium in the millisecond regime. Main objective of this paper is the demonstration of electrically active n+-p junctions in germanium by implanting phosphorus in p-type substrate while trying to maintain minimal dopant diffusion, which is a critical issue for scaling germanium devices. In addition to the phosphorus diffusion studies, we also explore the presence of nitrogen introduced in the substrate together with phosphorus and we conclude that it can further reduce dopant movement at the expense of lower activation level. The observation is confirmed by both electrical and SIMS measurements. Moreover, density functional theory calculations show that nitrogen-phosphorus co-doping of germanium creates stable N-P complexes that, indeed, are consistent with the deactivation and diffusion suppression of phosphorus. [ABSTRACT FROM AUTHOR]

In the quest for active and inexpensive (photo)electrocatalysts, atomistic simulations of the oxygen evolution reaction (OER) are essential for understanding the catalytic process of water splitting at solid surfaces. In this paper, the enhancement of the OER by first‐row transition‐metal (TM) doping of the abundant semiconductor ZnO was studied using density functional theory (DFT) calculations on a substantial number of possible structures and bonding geometries. The calculated overpotential for undoped ZnO was 1.0 V. For TM dopants in the 3d series from Mn to Ni, the overpotentials decreased from 0.9 V for Mn and 0.6 V for Fe down to 0.4 V for Co, and rose again to 0.5 V for Ni and 0.8 V for Cu. The overpotentials were analyzed in terms of the binding to the surface of the species involved in the four reaction steps of the OER. The Gibbs free energies associated with the adsorption of these intermediate species increased in the series from Mn to Zn, but the difference between OH and OOH adsorption (the species involved in the first, respectively the third reaction step) was always in the range 3.0–3.3 eV, despite a considerable variation in possible bonding geometries. The bonding of the O intermediate species (involved in the second reaction step), which is optimal for Co, and to a somewhat lesser extend for Ni, then ultimately determined the overpotential. These results implied that both Co and Ni are promising dopants for increasing the activity of ZnO‐based anodes for the OER. [ABSTRACT FROM AUTHOR]

Applicability of electron holography to deep submicron Si devices with epitaxial layers is limited due to lack of the mean inner potential data and effects of the sample tilt. The mean inner potential V0=12.75V of the intrinsic epitaxial SiGe was measured by electron holography in devices with Ge content CGe=18%. Nanobeam electron diffraction analysis performed on the same device structure showed that SiGe is strain-free in [220] direction. Our results showed good correlation with simulations of the mean inner potential of the strain-free SiGe using density function theory. A new method is proposed in this paper to correct electron holography data for the overlap of potentials of Si and the epitaxial layer, which is caused by the sample tilt. The method was applied to the analysis of the dopant diffusion in p-Field-effect Transistor devices with the identical gate length L=30 nm, which had alternative SiGe geometry in the source and drain regions and was subjected to different thermal processing. Results have helped to understand electrical data acquired from the same devices in terms of dopant diffusion. [ABSTRACT FROM AUTHOR]

Developing earth-abundant and active electrocatalysts for the oxygen evolution reaction (OER) as replacements for conventional noble metal catalysts is of scientific and technological importance for achieving cost-effective and efficient conversion and storage of renewable energy. However, most of the promising candidates thus far are exclusively metal-based catalysts, which are disadvantaged by relatively restricted electron mobility, corrosion susceptibility, and detrimental environmental influences. Herein, hierarchically porous nitrogen (N) and phosphorus (P) codoped carbon nanofibers directly grown on conductive carbon paper are prepared through an electrochemically induced polymerization process in the presence of aniline monomer and phosphonic acid. The resultant material exhibits robust stability (little activity attenuation after 12 h continuous operation) and high activity with low overpotential (310 mV at 10 mA cm−2) toward electrocatalytic oxygen production, with performance comparable to that of the precious iridium oxide (IrO2) benchmark. Experimental measurements reveal that dual doping of N and P can result in an increased active surface area and abundant active sites in comparison with the single doped and pristine carbon counterparts, and density functional theory calculations indicate that N and P dopants can coactivate the adjacent C atoms, inducing synergistically enhanced activity toward OER. [ABSTRACT FROM AUTHOR]

Supported Pt/CeO2 catalysts have been widely used in carbon monoxide (CO) oxidation; however, the high oxygen vacancy formation energy (Evac) in the process leads to the poor performance of these catalysts. Herein, we explored different element (Pr, Cu, or N) doped CeO2 supports using Ce-based metal–organic frameworks (MOFs) as precursors via calcination treatment. The obtained CeO2 supports were used to load Pt nanoparticles. These catalysts were systematically characterized by various techniques, and they showed superior catalytic activity for CO oxidation compared to undoped catalysts which could be attributed to the formation of Ce3+, and high amounts of Oads/(Oads + Olat) and Ptδ+/Pttotal. Moreover, density functional theory calculations with on-site Coulomb interaction correction (DFT+U) were performed to provide atomic-scale insights into the reaction process by the Mars–van Krevelen (M–vK) mechanism, which revealed that the element-doped catalysts could simultaneously reduce the adsorption energies of CO and lower reaction energy barriers in the *OOCO associative pathway. [ABSTRACT FROM AUTHOR]

The structural and electronic properties of several nitrogen-doped fullerenes, C60−2nN2n (n = 1–12), have been studied using density functional theory (DFT) at the M06L/6-311+G(d)//M06L/6-31G(d) level. The electronic features studied using a molecular electrostatic potential (MESP) topology analysis revealed that increasing the N-doping leads to a large improvement in the electron density of the carbon cage. As a result, the N-doped fullerenes showed a stronger interaction with CO2 molecules than C60. Also, the formation of large clusters of CO2 around the N-doped C60 is modeled which revealed that the interaction energy per CO2 is better than the interaction of a single CO2 with the same system. The improved interaction of CO2 in the cluster is attributed to the positive cooperative interaction arising between the adsorbed CO2 molecules. The study also examined the MESP features and the CO2 binding affinity of the anionic modification of the N-doped C60 by attaching a CN− unit on a carbon center. Compared to the N-doped C60, the highly electron-rich anion (C60−2nN2nCN)− showed improved affinity to CO2. The superior electronic features and CO2 binding energy data of N-fullerenes and N-cyanofullerides suggest that they are potent CO2 capturing agents. [ABSTRACT FROM AUTHOR]

Bi3+/Eu3+ doped Cs3GdGe3O9 luminescent materials were prepared by a solid-state reaction. The energy band and density of states of Cs3GdGe3O9 were calculated by density functional theory. The Cs3GdGe3O9 host presents a broadband emission peaking at 520 nm. Systemic measurement and analysis of luminescence properties were performed to confirm the energy transfer in Cs3GdGe3O9:Bi3+,Eu3+. The multicolor modulated emission from blue (0.1678, 0.1568) to red (0.5931, 0.3251) can be achieved by varying the doping ratio of bismuth to europium. A white light-emitting diode (WLED) was produced by combining the Cs3GdGe3O9:0.05Bi3+,0.1Eu3+ phosphor, a commercial green phosphor, and a 310 nm ultraviolet chip. The color rendering index of the WLED driven by 20 mA bias current is 89.6 with the CIE coordinates of (0.3520, 0.3626). The results reveal that the Cs3GdGe3O9:Bi3+,Eu3+ phosphor is a potential material that can be used in multicolor tunable luminescence and WLEDs. [ABSTRACT FROM AUTHOR]

Cocatalysts are usually applied in the photocatalytic water splitting process to accelerate the kinetics of the hydrogen evolution reaction (HER). Specifically, the transition metal nitride (Mo2N) featuring a unique local surface plasmon resonance (LSPR) effect has exhibited great potential to function as a HER cocatalyst. However, the low metallicity of Mo2N hampers its ability to improve charge separation. To address this issue, transition metal atom doping (Co and Cu) engineering was used to modulate the electronic structure of Mo2N nanosheets to achieve a higher electrical conductivity and a lower hydrogen adsorption free energy (‖ΔGH*‖), thereby favoring the HER kinetics. Density functional theory (DFT) calculations and experimental results showed that Co-doping and Cu-doping mainly take place at Mo sites in the crystal structure of Mo2N to form stable structures of Co doped Mo2N (Co–Mo2N) and Cu doped Mo2N (Cu–Mo2N). Compared with pristine Mo2N, both Cu–Mo2N and Co–Mo2N demonstrated a much improved cocatalytic effect over g-C3N4 in promoting charge separation, accelerating HER kinetics and enhancing light absorption. The Co–Mo2N with the highest conductivity and lowest ‖ΔGH*‖ illustrated the best cocatalytic effect, and the H2 production performance (367.8 μmol g−1 h−1) of Co–Mo2N/g-C3N4 achieved was 10 and 5 times higher than those of Mo2N/g-C3N4 and Cu–Mo2N/g-C3N4. This paper provides significant guidance in the design and development of efficient cocatalysts for the HER application. [ABSTRACT FROM AUTHOR]

Electrical conductivity in high Al-content AlGaN has been severely limited, presumably due to a DX transition forming an acceptor state and subsequent self-compensation, which imposed an upper limit on the achievable free carrier concentration. To elucidate this idea, this paper examines Ge doping as a function of Al-content in AlGaN and finds a different behavior: for Al compositions below 40%, Ge behaved as a shallow donor with an ionization energy below 20 meV, while for Al compositions above 40%, above DX transition, it emerged as a deep donor. The ionization energy of this deep state increased with increasing Al content and reached 150 meV for 60% AlGaN. Around the DX transition, a continuous change from the shallow to deep donor was observed. In contrast to the density functional theory predictions, acceptor-type states corresponding to a DX-type transition were not observed. This finding may have profound technological consequences for the development of AlGaN- and AlN-based devices as it offers a feasible pathway to high n-conductivity in these compounds. [ABSTRACT FROM AUTHOR]

Two new organo-europium complexes (OEuCs) [Eu(tfac)3(TB-Im)] (Eu1) [Eu(hfac)3(TB-Im)] (Eu2) incorporating fluorinated (hexafluoroacetylacetone; Hhfaa) or hemi-fluorinated (trifluoroacetylacetone; Htfac) β-diketones together with the large bite angle N^N ligand (2-(4-thiazolyl)benzimidazole; TB-Im) have been synthesized and characterized. The structure of the complexes has been established by single crystal X-ray diffraction (SC-XRD) analysis and shows that the coordination sphere is composed of a EuO6N2 core (octacoordinated). Continuous shape measures (CShMs) revealed that the geometry around Eu(III) is trigonal dodecahedral with approximate D2d-symmetry. Efficient red emission is observed for both the complexes in solution with a fairly large photoluminescence quantum yield (PLQY (Q LEu) = 39.00–47.00%). Furthermore, by utilizing the experimental photoluminescence (PL) data and theoretical modelling employing density functional theory (DFT) in conjunction with LUMPAC, energy transfer (ET) and back energy transfer rates were calculated, and an ET mechanism for the sensitized PL is proposed and discussed in detail. Finally, the complexes were used as an emitting layer (EML) to fabricate 20 organic light emitting diodes (OLEDs) by varying the doping concentration. Interestingly, both the complex-based OLEDs at 4 wt% doping concentration display white electroluminescence (EL) with the brightness (B) = 100.5–364.1 cd m−2 at very low turn-on voltage (Vturn-on) = 3.9–4.6 V. The overall electroluminescence performance of Eu1 and Eu2 is higher than that of the reported europium based single component white-OLEDs. [ABSTRACT FROM AUTHOR]

This paper presents simulation predictions of electric field gradients (EFGs) and binding energies for two phases of ZrO 2 , cubic and tetragonal, when doped with small concentrations of Cd, Y, Y + Nb, and Y + Ta. The creation of oxygen vacancies in bulk is elucidated through ab-initio calculations. The focus is on EFGs as a function of the concentration of free oxygen vacancies with high accuracy. EFGs decrease as the oxygen vacancy trapping probability increases, dependent on vacancy concentration. The crucial factors are point defects. Radiation induced defects, which are traps of charge carriers are discussed. Trivalent Y3+ ions induce an increase in the concentration of oxygen vacancies in ZrO 2 , while Cd, Y + Ta, and Y + Nb dopants induce a decrease in the concentration of oxygen vacancies. A convenient polynomial dependence of the energy on inverse super-cell size, where wave-function overlap and electrostatic interactions bring about more complex dependencies on super-cell access, is presented here. We demonstrate that this complexity can be resolved using Chebyshev polynomials, which may include electron-phonon coupling. • Simulation of electric field gradients and binding energies for ZrO 2 , cubic and tetragonal, doped with dopants. • Creation of oxygen vacancies in bulk is elucidated by ab-initio calculations. • EFG is a function of the concentration of free oxygen vacancies and is with high accuracy determined. • Polynomial dependence on inverse super-cell size, complex dependence, nonlinear properties, scaling are resolved. • Complexity can be solved by the Chebyshev polynomials. [ABSTRACT FROM AUTHOR]

[Display omitted] • BCN/PMS/Vis system completely degraded 4-Chlorophenol in 60 min. • Revealed the mechanism of carbon doping affecting the photocatalytic effect of BCN. • Carbon doping induces peroxymonosulfate to lose electrons for 1O 2 production. • Non-free radical pathway played a dominant role in pollutant removal. In order to improve the photocatalytic activity of pristine carbon nitride while maintaining its metal-free property to achieve the activation of peroxymonosulfate (PMS), a series of carbon-doped g-C 3 N 4 (BCN) with different carbon contents were synthesized in this paper by adding benzotriazole to urea. The catalyst obtained by this approach significantly promoted PMS activation and enhanced the degradation efficiency of 4-chlorophenol (4-CP). Experiments and theoretical calculations showed that the introduction of carbon not only narrowed the band gap, but also accelerated the separation of photoinduced electron-hole pairs, which greatly improved the photocatalytic activity of g-C 3 N 4. In the degradation of pollutants, free radicals and non-free radicals acted simultaneously, with non-free radicals playing a dominant role. This study explained the origin of 1O 2 by Density functional theory (DFT) calculations, visible light excited photocatalysts to form holes, while carbon introduction decreased the valence-electron density around the area, inducing electron transfer from PMS toward g-C 3 N 4 directed to generate 1O 2. The 1O 2 -dominated degradation process improved the application of the catalysts in complex aqueous matrices. In addition, we proposed 4-CP degradation pathways, and the toxicity of intermediates derived from 4-CP degradation process reduced. [ABSTRACT FROM AUTHOR]

Despite the pivotal role of stannum doping in achieving ultrahigh piezoelectric performance in barium titanate-based ceramics, the fundamental mechanisms underlying this enhancement remain elusive. Here, we introduce a single variable nonstoichiometric stannum strategy in lead-free barium titanate-based ceramics with giant piezoelectricity, revealing that stannum doping contributes intrinsically and extrinsically to enhance piezoelectricity. Density functional theory calculations elucidate the intrinsic enhancement of polarization arising from lattice distortion and increased space for titanium-oxygen bonds induced by optimal stannum doping, which is corroborated by Rayleigh analysis. A phase transition from ferroelectric multiphase coexistence to paraelectric phase is observed, alongside a rapid miniaturized and eventually disappeared domains with increasing stannum doping. This evolution in phase structure and domain configuration induces a nearly vanishing polarization anisotropy and low domain wall energy, facilitating easy polarization rotation and domain wall motion, thereby significantly contributing to the extrinsic piezoelectric response. Consequently, the origins of ultrahigh performance can be attributed to the synergistic effect of stannum-induced intrinsic and extrinsic contributions in barium titanate-based ceramics. This study provides fundamental insights into the role of doping elements and offers guidance for the design of high-performance piezoelectrics. The mechanisms of the enhancement of stannum doping in achieving high piezoelectric performance in barium titanate-based ferroelectric ceramics remain elusive. Here, the authors introduce a single variable nonstoichiometric stannum strategy to reveal the intrinsic and extrinsic contributions for enhancing piezoelectricity after stannum doping. [ABSTRACT FROM AUTHOR]

In this paper, the hydrogen storage performance of Sc (Ti, Li)-modified Ψ -graphene (Ψ -g) is investigated by density functional theory (DFT). Sc and Ti can be stably adsorbed on Ψ -g with the binding energies of 4.78 eV and 4.83 eV, respectively. Li atoms can also be stably absorbed on B-doped Ψ -g with the binding energy of 2.51 eV. In addition, Sc and Ti atoms attached on Ψ -g can adsorb up to ten and eight hydrogen molecules, and the hydrogen gravimetric storage capacity reaches 7.93 wt.% and 6.20 wt.%, respectively. Li atoms attached on B-doped Ψ -g can adsorb up to eight hydrogen molecules with the hydrogen gravimetric storage capacity 9.32 wt.%, all meeting DOE standards. On the whole, Bader charge analysis shows that the charge is transferred from C atoms to H atoms, which is more conducive to hydrogen adsorption. All the researches prove that the Sc, Ti-decorated Ψ -g and Li-decorated B-doped Ψ -g are potential hydrogen storage materials. [ABSTRACT FROM AUTHOR]

In this paper, the heterofullerenes made of the smallest fullerene, C20were investigated by quantum chemistry calculations based on density functional theory. The geometrical structures, energies, electronic properties, and the aromaticities of the C19X (X = B, N, O, Al, Si, P, S, Ga, Ge, As, and Se) cages were studied systemically and compared with those of the pristine C20cage. It is found that the doped cages with different heteroatoms exhibit various structural, electronic, and aromatic properties. Several doping behaviors of the C19X cages are different from those of the C59X cages. These results imply the possibility to modulate the physical properties of heterofullerenes by tuning the sizes of the carbon cages as well as the substitution elements. [ABSTRACT FROM PUBLISHER]

In this study, we investigate the energetics of small aluminum clusters doped with a carbon atom using several computational methods, including diffusion quantum Monte Carlo, Hartree–Fock (HF), and density functional theory. We calculate the lowest energy structure, total ground-state energy, electron population distribution, binding energy, and dissociation energy as a function of the cluster size of the carbon-doped aluminum clusters compared with the undoped ones. The obtained results show that carbon doping enhances the stability of the clusters mainly due to the electrostatic and exchange interactions from the HF contribution gain. The calculations also indicate that the dissociation energy required to remove the doped carbon atom is much larger than that required to remove an aluminum atom from the doped clusters. In general, our results are consistent with available theoretical and experimental data. [ABSTRACT FROM AUTHOR]

2,2′-Bipyridine based bisphosphine [C5H3N{N(H)CH2PPh2}]2 (1) and its bischalcogenide derivatives [C5H3N{N(H)CH2P(E)Ph2}]2 (2, E = O; 3, E = S; 4, E = Se) were synthesized, and further reacted with BF3·Et2O/Et3N to form doubly B ← N fused compounds [C5H3N(BF2){NCH2P(E)Ph2}]2 (5, E = O; 6, E = S; 7, E = Se) in excellent yields. The influence of the P＝E bonds on the electronic properties of the doubly B ← N fused systems and their structural features were investigated in detail, supported by extensive experimental and computational studies. Compound 6 exhibited a very high quantum yield of φ = 0.56 in CH2Cl2, whereas compound 7 showed a least quantum yield of φ = 0.003 in acetonitrile. Density functional theory (DFT) calculations demonstrated that the LUMO/HOMO of compounds 5–7 mostly delocalized over the entire π-conjugated frameworks. The involvement of P＝E bonds in the HOMO energy level of these compounds follows the order: P＝O < P＝S < P＝Se. Time-correlated single photon counting (TCSPC) experiments of compounds 5–7 revealed the singlet lifetime of 4.26 ns for 6, followed by 4.03 ns for 5 and a lowest value of 2.18 ns (τ1) and 0.47 ns (τ2) with a double decay profile for 7. Our findings provide important strategies for the design of highly effective B ← N bridged compounds and tuning their photophysical properties by oxidizing phosphorus with different chalcogens. Compounds 5 and 6 have been employed as green emitters (λem = 515 nm) in fluorescent organic light-emitting diodes (OLEDs). For compound 5, doped into the poly(9-vinylcarbazole) (PVK) matrix with 5 wt% doping concentration, nearly 90 Cd m−2 luminance with 0.022% external quantum efficiency (EQE) was achieved. The best performance was observed for compound 6 doped into PVK by 1 wt% having a maximum luminance of 350 Cd m−2 and a similar EQE value. [ABSTRACT FROM AUTHOR]

The absorption edge shifted to long wavelength direction and short wavelength direction of two opposite experimental conclusions have been reported, when the band-gap and absorption spectra of -doped anatase 2 were studied. In order to solve this contradiction, the electronic structure and the optical property of heavy doped anatase 2 have been studied by the first-principles plane-wave ultrasoft pseudopotential method based on the density functional theory with +U method modification. The calculated results indicate that the higher the -doping is, the higher the total energy is, the worse the stability is, the higher the formation energy is, the more difficult the doping is, the wider the optical band-gap is, the more obvious the absorption edge shifting to short wavelength direction is, the lower the absorptivity and the reflectivity is, which is in agreement with the experimental results. The reasonable interpretation of the contradiction has been reported in this paper, too. [ABSTRACT FROM AUTHOR]

Lung cancer has received considerable attention in recent years due to its high mortality. The difficulty in awareness of such disease can be attributed to its strong insidiousness during the early stage. Therefore, the prognosis of lung cancer becomes significant so as to nip this disease in the bud. In this paper, the Rh-doped CNT-based biosensors were introduced to realise the diagnosis of lung cancer through detecting the exhaled gas of possible patients. The adsorption property and sensing mechanism of Rh-CNT towards two kinds of mainly typical gases of lung cancer, namely, C6H6 and C6H7N, were analysed based on density functional theory, aiming at evaluating the potential application of such material to be gas sensors. The results indicated that the Rh-CNT not only has good adsorption towards such two gases but also obvious conductivity increase when interacted with any of them, while presents insensitivity upon the common exhaled gas, CO2. We suggest the Rh-CNT be prepared as biosensors applied in the field of lung cancer pre-diagnosis that can be used in our daily life without pain and complex clinical examination. [ABSTRACT FROM AUTHOR]

This paper described a comprehensive DFT + U investigation on the general trends in structural stability, electronic and optical absorption properties, photocatalytic activity of BiOCl doped with 3 d transition metals (TMs = Sc, V, Cr, Ti, Fe, Co, Ni, Cu, Zn). We find that it is rather difficult for Sc, V, Ti, Ni atoms to substitute Bi into BiOCl crystal lattice in experiments due to their positive formation energies, but the negative formation energies for Cr-, Mn-, Fe-, Co-, Ni-, Cu-, Zn-doped BiOCl systems exhibit the thermodynamic structure stability. Most of TMs doping could narrow the band gap of BiOCl and lead to the changes in conduction band minimum and valance band maximum as well as the formation of several impurity energy levels within the forbidden band of BiOCl, achieving the photoactivity improvement and simultaneously maintaining the stronger redox potential. With 3 d TMs doping, the optical absorption intensity of BiOCl around 350 nm increased and exhibited a redshift to the different extents, in good agreement with reported experimental data. Our theoretical calculations should provide meaningful guidance for the experimentalists to design and develop more thermodynamically stable and highly effective visible light response photocatalysts. [ABSTRACT FROM AUTHOR]

In this paper, first principles calculations based on density functional theory were used to study the electronic properties and adsorption behavior of modified rutile surfaces with neutral element dopants (Si, Ge, Sn). The results showed that Sn doped surface has the smallest work function (7.07 eV) and Ge doped surface has the lowest conduction band edge (1.28 eV). Furthermore, the adsorption behavior of H2O and Arg‐Gly‐Asp (RGD) molecules on modified rutile surfaces was calculated to estimate the biocompatibility of modified dental implant surfaces. For the purpose of simulating the real solution environment, the free energy of solvation for adsorbates, calculated by Gaussian 09 program code, was taken into account. The results of the adsorption calculations of H2O indicate that Sn doped surface has a more negative adsorption energy (−3.15 eV) and a higher charge transfer (−0.1) than any other modified surface, which is consistent with its low work function. The results of the adsorption calculations of Arg‐Gly‐Asp demonstrate that Ge doped surface also has a shorter distance (1.95 Å) between Ti atom and O atom in RGD, which is similar with the partial density of states results. All of the results show that the electronic structure of an implant surface has a significant influence on its bioactivity and is also useful for the design of modification methods on dental implant surfaces. [ABSTRACT FROM AUTHOR]

The present paper reports the effect of B- and BN-doped $$\hbox {C}_{60}$$ as catalysts for lowering the dehydrogenation energy in $$\hbox {MXH}_{4}$$ clusters (M = Na and Li, X = Al and B) using density functional calculations. $$\hbox {MXH}_{4}$$ interacts strongly with B-doped $$\hbox {C}_{60}$$ and weakly with BN-doped $$\hbox {C}_{60}$$ in comparison with pure $$\hbox {C}_{60}$$ with binding energy 0.56-0.80 and 0.05-0.34 eV, respectively. The hydrogen release energy $$(E_{\mathrm{HRE}})$$ of $$\hbox {MXH}_{4}$$ decreases sharply in the range of 38-49% when adsorbed on B-doped $$\hbox {C}_{60}$$ ; however, with BN-doped $$\hbox {C}_{60}$$ the decrease in the $$E_{\mathrm{HRE}}$$ varies in the range of 6-20% as compared with pure $$\hbox {MXH}_{4}$$ clusters. The hydrogen release energy of second hydrogen atom in $$\hbox {MXH}_{4}$$ decreases sharply in the range of 1.7-41% for BN-doped $$\hbox {C}_{60}$$ and decreases in the range of 0.2-11.3% for B-doped $$\hbox {C}_{60}$$ as compared with pure $$\hbox {MXH}_{4}$$ clusters. The results can be explained on the basis of charge transfer within $$\hbox {MXH}_{4}$$ cluster and with the doped $$\hbox {C}_{60}$$ . [ABSTRACT FROM AUTHOR]

Using the principles of density functional theory (DFT) and nonequilibrium Green's function (NEGF), We thoroughly researched carbon-doped zigzag boron nitride nanoribbons (ZBNNRs) to understand their electronic behavior and transport properties. Intriguingly, we discovered that careful doping can transform carbon-doped ZBNNRs into a spintronic nanodevice with distinct transport features. Our model showed a giant magnetoresistance (GMR) up to a whopping 10 5 under mild bias conditions. Plus, we spotted a spin rectifier having a significant rectification ratio (RR) of 10 4 . Our calculated transmission spectra have nicely explained why there's a GMR up to 10 5 for spin-up current at biases of - 1.2 V, - 1.1 V, and - 1.0 V, and also accounted for a GMR up to 10 3 –10 5 for spin-down current at biases of 1.0 V, 1.1 V, and 1.2 V. Similarly, the transmission spectra elucidate that at biases of 1.0 V, 1.1 V, and 1.2 V for spin-up, and at biases of 1.1 V and 1.2 V for spin-down in APMO, the RRs reach 10 4 . Our research shines a light on a promising route to push forward the high-performance spintronics technology of ZBNNRs using carbon atom doping. These insights hint that our models could be game-changers in the sphere of nanoscale spintronic devices. [ABSTRACT FROM AUTHOR]

The structural, electronic, magnetic, and optical properties of Co-doped 10–20-atom silver clusters are investigated by GGA/PBE via the density functional theory. The Ag–Co clusters form core–shell structures with a Co atom in the center. Co atom doping modulates electronic properties like energy gap, molecular softness, global hardness, electronegativity, and electrophilicity index. For the optical spectra of the Ag–Co clusters, the energy of their spectra overall exhibits little change with increasing numbers of atoms; the strongest peaks are roughly distributed at 3.5 eV, and the intensity of their spectra overall is strengthened. Raman and vibrational spectra reflect structural changes with Co atom addition. The addition of the Co atom alters magnetic moments of specific Ag–Co clusters, while others remain unchanged. [ABSTRACT FROM AUTHOR]

Adsorption and activation of C–H bonds by photocatalysts are crucial for the efficient conversion of C–H bonds to produce high-value chemicals. Nevertheless, the delivery of surface-active oxygen species for C–H bond oxygenation inevitably needs to overcome obstacles due to the separated active centers, which suppresses the catalytic efficiency. Herein, Ni dopants are introduced into a monolayer Bi2WO6 to create cascaded active units consisting of unsaturated W atoms and Bi/O frustrated Lewis pairs. Experimental characterizations and density functional theory calculations reveal that these special sites can establish an efficient and controllable C–H bond oxidation process. The activated oxygen species on unsaturated W are readily transferred to the Bi/O sites for C–H bond oxygenation. The catalyst with a Ni mass fraction of 1.8% exhibits excellent toluene conversion rates and high selectivity towards benzaldehyde. This study presents a fascinating strategy for toluene oxidation through the design of efficient cascaded active units. By introducing Ni dopants into monolayer Bi2WO6, Bi/O frustrated Lewis pairs, unsaturated W atoms, and Ni active units are formed. The authors show that these units facilitate oxygen species transfer and enhance photocatalytic toluene oxidation. [ABSTRACT FROM AUTHOR]