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Along with the developing of flexible electronics, there is a strong interest in high performance flexible energy storage materials. As natural carbohydrate polymer, cellulose fibers have potential applications in the area due to their biodegradability and flexibility. However, their conductive and electrochemical properties are impossible to meet the demands of practical applications. In this study, cellulose fibers were combined with polyaniline to develop novel paper-based supercapacitor electrode material. Cellulose fibers were firstly coordinated to Cu(II) and subsequently involved in polymerization of polyaniline. Not only the mass loading of polyaniline was significantly increased, but also an impressive area specific capacitance (2767 mF/cm2 at 1 mA/cm2) was achieved. The developed strategy is efficient, environmentally friendly, and has implications for the development of cellulosic paper-based advanced functional materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Sport doping is not a recent phenomenon. Athletes have used many forms of performance enhancements going back to antiquity. Within the sport philosophy literature, sport doping is entangled in a multitude of ethical discourses, some denouncing, and some supporting, doping in sport. Our aim is to use a systematic approach to classify ethical discourses put forward by scholars focused on doping. To take stock of these ethical discourses, and to advance the sport philosophy literature on doping, this paper provides an empirical account of the types of arguments used in the peer-reviewed sport philosophy literature. This empirical account is intended to provide a map of the ethical discourses in circulation, to highlight the most common arguments, and to show where other types of arguments are absent or less well developed. To map the ethical discourses, the authors use an ethical discourse typology from a university-based ethical reasoning program. [ABSTRACT FROM AUTHOR]

In this paper, the effect of C, N and O atom doping of intrinsic MoSe2 on the adsorption capacity of Ni is investigated based on first-principle research methods. The aim is to analyze whether intrinsic MoSe2 can be doped and modified to improve its adsorption capacity of Ni so that it can be used as a new type of adsorbent material. By calculating and analyzing the energy band structure, density of states, differential charge and optical properties of each system, the conclusions are as follows: the O-doped MoSe2 system has the best adsorption capacity for Ni, and the adsorption capacities of the three systems are in the following order: O>N>C. The bandgap value of intrinsic MoSe2 adsorbed Ni-atom decreases, while the Fermi energy level of the C-doped MoSe2 adsorbed Ni-atom system is located in the valence band, which shows p-type doping. The differential charge of the system was analyzed and the charge transfer of the adsorbed system was increased by C, N and O atom doping, and the O-doped system had the strongest adsorption capacity for Ni. It was shown that the charge distribution between the system and the adsorbed Ni-atom changed considerably after atomic doping, and the bonds between the Ni-atom and the dopant atoms of the C-, N- and O-doped adsorption system were strongly ionic. Optical analysis reveals that C, N and O atom doping improves the charge binding ability of Ni-adsorbed MoSe2 material, which gives it a higher polarization rate and faster electric field response. The absorption of ultraviolet light is greatly enhanced, which can improve the efficiency of solar cells and convert solar energy into electricity more effectively. Overall, the Ni adsorption capacity of atomically doped MoSe2 is improved, indicating that doping can be an effective means to improve the adsorption of Ni-atom by intrinsic MoSe2. It is hoped that the research results in this paper can provide some theoretical guidance for the application of MoSe2 in optoelectronic devices. [ABSTRACT FROM AUTHOR]

In this paper, the effect of doping and nanostructuring on the electrostatic potential across the electrochemical interface between a transition metal oxide and a water electrolyte is investigated by means of the Poisson–Boltzmann model. For spherical nanoparticles and nanorods, compact expressions for the limiting potentials at which the space charge layer includes the whole semiconductor are reported. We provide a quantitative analysis of the distribution of the potential drop between the solid and the liquid and show that the relative importance changes with doping. It is usually assumed that high doping improves charge dynamics in the semiconductor but reduces the width of the space charge layer. However, nanostructuring counterbalances the latter negative effect; we show quantitatively that in highly doped nanoparticles the space charge layer can occupy a similar volume fraction as in low-doped microparticles. Moreover, as shown by some recent experiments, under conditions of high doping the electric fields in the Helmholtz layer can be as high as 100 mV/Å, comparable to electric fields inducing freezing in water. This work provides a systematic quantitative framework for understanding the effects of doping and nanostructuring on electrochemical interfaces, and suggests that it is necessary to better characterize the interface at the atomistic level. [ABSTRACT FROM AUTHOR]

Context: In this paper, we systematically studied the effects of non-metallic element (B, C, N, O, F) doping and biaxial stretching on the photoelectric properties of ZrS2/ZrSe2 heterostructures by using the first-principles calculation method based on density functional theory. The results show that the p-type doping is realized by B, C, and N atom doping, and the n-type doping is realized by O and F atom doping. The doping of B and C atoms produces impurity energy levels in the band gap, which affects the conductivity of the heterostructure. The band gap of N and O atom–doped heterostructures increases under tensile strain, but it is still a direct band gap. The analysis of the optical properties of the heterostructures shows that the doping of non-metallic atoms can adjust the optical absorption rate and reflectivity of the heterostructures. Under the action of tensile strain, the optical properties of the doped heterostructures have changed significantly in the low-energy region. This article provides a theoretical basis for the future application of ZrS2/ZrSe2 heterostructures. Method: This paper uses the first-principles calculation method based on density functional theory. The PBE exchange-correlation functional based on generalized gradient approximation (GGA) is selected for the specific calculation, and the crystal structure is geometrically optimized by the ultrasoft pseudopotential method. It is verified that when the cutoff energy of the ZrS2/ZrSe2 heterostructure is 500 eV, the K-point grid is selected to be 10 × 10 × 2 with the lowest energy, so the cutoff energy is selected to be 500 eV. The K-point grid is selected to be 10 × 10 × 2. The convergence limits for structural optimization are as follows: the maximum force between atoms is 0.01 eV/Å, the convergence threshold of the maximum energy change is set to 10−9 eV/atom, and the convergence threshold of the maximum displacement is 0.001 Å. In order to avoid the influence of atomic periodic motion between different atomic layers, a vacuum layer of 20 Å is added in the vertical direction. Considering the interaction of vdW between the interfaces, the DFT-D2 method is used to verify. The optical properties were calculated by the random phase approximation method, and the K-point grid was selected as 12 × 12 × 2. [ABSTRACT FROM AUTHOR]

The thermal stability of the γ-Fe2O3@SiO2 nanocomposites and super low friction of the γ-Fe2O3@SiO2 nanocomposite coatings in ambient air at high temperature are investigated in this paper. X-ray diffraction, scanning electron microcopy, transmission scanning electron microcopy, high-temperature tribometer, thermogravimetric analysis and differential scanning calorimetry were used to investigate the microstructure, surface morphology and high-temperature tribological properties of the γ-Fe2O3@SiO2 nanocomposite coatings, respectively. The results show that the γ-Fe2O3@SiO2 nanocomposite with the core–shell structure has excellent thermal stability because the SiO2 shell inhibits the phase transition of the γ-Fe2O3 phase to the α-Fe2O3 phase in the nanocomposites. The temperature of the phase transition in γ-Fe2O3 can be increased from 460 to 829 °C. The γ-Fe2O3@SiO2 nanocomposite coatings exhibit super low friction (0.05) at 500 °C. A high-temperature super low friction mechanism is attributed to γ-Fe2O3 and the tribochemical reactions during sliding. [ABSTRACT FROM AUTHOR]

A novel class of nanomaterials known as carbon quantum dots (CQDs) has drawn significant attention because of numerous benefits, particularly its small size (between 1 and 10 nm) and great water solubility, fluorescence, ease of synthesis, and low toxicity among others. There are still many crucial questions that need to be answered, such as how to prepare high-quality CQDs with an appropriate yield using a simpler and easier approach. Most of the articles reviewed have discussed the production of CQDs intended for applications in imaging and sensing. Nevertheless, there is a scarcity of research focusing on producing undecorated and doped CQDs. In this review paper, the various methods for synthesizing CQDs by using various carbon sources have been summarized. Additionally, In this paper, we discuss the primary characterization techniques and the applications of CQDs in various fields. The fundamental objective of this paper is to analyze various synthesis methods used over different periods to address the challenges that one might encounter during the synthesis of CQDs. [ABSTRACT FROM AUTHOR]

Context: The effect of X (X = O, Se, N, P, F, Cl) doping on the adsorption of Zn atoms by WS2 was investigated based on first principles. The electronic structure and optical properties of the adsorbed system after atomic doping were calculated. It is found that the Zn atom adsorbed on the W top (Tw) site has the most stable structure. When an S atom is replaced with an X atom based on the adsorption system, where the adsorption energy decreases after doping of O, P, F, and Cl atoms compared to the undoped system, it means that each system is more stable after doping of these atoms; charge transfer shows that the adsorption system after P-atom doping the system around the Zn atom loses electrons while S-atom gains electrons, which indicates that P-atom doping is favorable for the adsorption of Zn by WS2, N, P-atom is introduced as p-type doping and F, Cl-atom is introduced undoped by n-type doping, and the band gap of the doped system is less than that of the undoped one. With the introduction of different dopant atoms, certain impurity energy levels are introduced into the adsorption system. The prohibited bandwidth around the Fermi energy level reduces the density of states, causing the doped system's density of states to shift to lower energies, among which the shifts of N, P, F, and Cl are more pronounced. The P-doped adsorption system shows a new peak near the energy of − 11 eV. In addition, the study of optical properties showed that the peak reflections of both doped and non-doped systems adsorbing Zn atoms appeared in the ultraviolet region; the absorbance coefficient of the doped system is moved in the lower energy direction and red-shifted after atom doping; in addition, the absorption coefficients and reflectance of the P, Se doped systems are enhanced in the wavelength range of 200–300 nm compared with that before doping, the dielectric function and CBM and VBM positions were also calculated further indicating the potential of Se-doped systems in improving photocatalytic efficiency. Methods: In this paper, the structure optimization of X (X = O, Se, N, P, F, Cl) doping on WS2 adsorbed Zn atom model is performed based on the CASTEP module in Materials-Studio software under the first principles using GGA and PBE generalized function. The corresponding binding energies, bond lengths, bond angles, charge densities, energy band structures, densities of states, and optical properties were also analyzed. The Monkhorst–Pack particular K-point sampling method is used in the calculations; the K-point grid is 6 × 6 × 1, and the cutoff energy for the plane wave expansion is 500 eV. After geometric optimization, the iterative accuracy converges to a value of less than 1 × 10−5 eV/atom for the total energy of each atom and less than 0.03 eV/Å for all atomic forces. The thickness of the vacuum layer was set to 20 Å to avoid the effect of interlayer interaction forces. In this paper, 27 atoms were used to form a 3 × 3 × 1 supercellular tungsten disulfide system consisting of 18 S atoms and 9 W atoms. [ABSTRACT FROM AUTHOR]

Electrolysis of water for production of hydrogen has become one of the most fascinating methods to relieve the energy crisis and environmental pollution. In this paper, a series of M-NiS/Mo 2 S 3 (M = Co, Fe, Ce and Bi) materials was in situ grown on Ni foam through a two-step hydrothermal process, and the synthesized Co–NiS/Mo 2 S 3 material present excellent hydrogen evolution reaction (HER) properties. Under an alkaline condition of 1 M KOH, Co–NiS/Mo 2 S 3 requires only overpotential of 142 mV to achieve a current density of 10 mA cm−2, and using Co–NiS/Mo 2 S 3 as both cathode and anode, only the potential of 1.574 V is required to drive a current density of 50 mA cm−2, with a relatively good durability over 15 h. Density functional theory (DFT) analysis show that the ΔG H* of Co–NiS is closer to 0 and its density of states near the Fermi energy level is higher, suggesting that Co–NiS improves the electrical conductivity of Co–NiS/Mo 2 S 3 and plays a significant catalytic action. This work proposes novel insights for the future exploration of novel sulfur-based composite electrocatalysts with excellent HER performance. In this paper, a series of M-NiS/Mo 2 S 3 (M = Co, Fe, Ce and Bi) materials was in situ grown on Ni foam by a two-step hydrothermal method, and the synthesized Co–NiS/Mo 2 S 3 material present excellent hydrogen evolution reaction (HER) properties. [Display omitted] • M-NiS/Mo 2 S 3 (M = Co, Fe, Ce and Bi) materials were successfully synthesized by hydrothermal processes. • Co–NiS/Mo 2 S 3 electrode shows excellent catalysis in the cathode reaction of water and water electrolysis. • Co–NiS/Mo 2 S 3 requires only overpotential of 142 mV to achieve a current density of 10 mA cm−2. [ABSTRACT FROM AUTHOR]

Fe/N-doped carbon (Fe-NC) is an excellent base-metal catalyst for use in an electrocatalytic oxygen reduction reaction (ORR) with high activity. In this paper, graphite phase carbon nitride (g-C3N4) was first obtained from the pyrolyzing of melamine, and then different proportions of FeCl3 were separately doped into g-C3N4 to further prepare the Fe-NC catalyst. The Fe-NC catalyst was applied in an ORR reaction, and the results show that the Fe-NC catalyst doped with 0.5 mmol FeCl3 possesses exceptional electrocatalytic performance, with an onset potential of 0.96 V and a half-wave potential of 0.81 V, which approaches that of a Pt/C catalyst. Meanwhile, the Fe-NC catalyst displays high stability and methanol resistance. The results supply a new way to prepare efficient ORR electrocatalysts. [ABSTRACT FROM AUTHOR]

In this paper, using a scanning electron microscope (SEM) and atomic analysis, the location map of microcomposites formed on the surface of n-Si, p-Si, n-Si and p-Si samples was studied. Force microscope (AFM) research devices. The atomic fractions of inclusions of carbon, oxygen and lutetium formed on the surface of the samples were studied. Also, using the ASM device, the sizes, relief and topographic appearance of defects formed on the surface of the samples were determined. In silicon samples doped with Lu, a decrease in the size of surface defects and the formation of nano-sized structures were found, which makes it possible to obtain materials with a more perfect crystal structure. Using a ZEISS GeminiSEM 300 scanning electron microscope, the structural structure, chemical composition and images of their arrangement of n-Si, p-Si, n-Si and p-Si samples were obtained. In this case, the electron accelerating voltage was 20 kV, and the pressure in the sample chamber was (10-3 mmHg). Research results show that the structural structure of microand nanocomposites formed in silicon mainly depends on the diffusion time and cooling rate of the samples after diffusion annealing. [ABSTRACT FROM AUTHOR]

GeFe2O4 (GFO) is a germanium mineral whose spinel crystal structure determines its interesting functional properties. Recently, it was proposed for application as an anode for Sodium and Lithium-Ion Batteries (SIBs and LIBs) thanks to its combined conversion and alloying electrochemical mechanism. However, its entire potential is limited by the poor electronic conductivity and volumetric expansion during cycling. In the present paper, pure and Sn or Mg doped GFO samples obtained from mechano-chemical solid-state synthesis and properly carbon coated were structurally and electrochemically characterized and proposed, for the first time, as anodes for SIBs. The spinel cubic structure of pure GFO is maintained in doped samples. The expected redox processes, involving Fe and Ge ions, are evidenced in the electrochemical tests. The Sn doping demonstrated a beneficial effect on the long-term cycling (providing 150 mAh/g at 0.2 C after 120 cycles) and on the capacity values (346 mAh/g at 0.2 C with respect to 300 mAh/g of the pure one), while the Mg substitution was less effective. [ABSTRACT FROM AUTHOR]

Photocatalysis is considered as the promising energy conversion way to resolve the issues of energy crisis and environmental pollution. As the key point of the photocatalysis, the photocatalyst determines the final conversion efficiency from solar, therefore, the composition and photoelectronic nature of which deserve to be valued. Halogen often affects immensely the intrinsic electron configuration of the matrix because of electrophilic property, and thus its topic has attracted lots of attention for photocatalytic application. In this review, halogencontained organic porous semiconductors are discussed in detailed. Firstly, the role of halogens in photocatalysis based on organic porous semiconductors are categorized. Then, the way to introduce the halogens into organic porous semiconductors and their applications in photocatalysis are reviewed. At last, the outlooks are given at the end of this paper. This review would bring new insights into the non-metal doping engineering for improving the photocatalytic performance of organic semiconductors. [ABSTRACT FROM AUTHOR]

To enable the application to next-generation devices of semiconductor nanowires (NWs), it is important to control their formation and tune their functionality by doping and the use of heterojunctions. In this paper, we introduce formation and the characterization methods of nanowires, focusing on our research results. We describe a top-down method of controlling the size and alignment of nanowires that shows advantages over bottom-up growth methods. The latter technique causes damage to the nanowire surfaces, requiring defect removal after the NW formation process. We show various methods of evaluating the bonding state and electrical activity of impurities in NWs. If an impurity is doped in a NW, mobility decreases due to the scattering that it causes. As a strategy for solving this problem, we describe research into core–shell nanowires, in which Si and Ge heterojunctions are formed in the diameter direction inside the NW. This structure can separate the impurity-doped region from the carrier transport region, promising as a channel for the new ultimate high-mobility transistor. [ABSTRACT FROM AUTHOR]

Context: To lessen the impact of the dangerous metal Cr, this paper applies the first principles to investigate the adsorption behavior and photoelectric properties of GaS on Cr. The effects of doped GaS on Cr adsorption behavior are investigated with four GaS systems, which are pure, boron (B)-doped, nitrogen (N)-doped, and oxygen (O)-doped, in order to maximize the characteristics of GaS for use in novel sectors, to obtain understanding of the impact of doping on the electronic structure and optical properties of GaS adsorption of Cr, as well as to promote the development of the material. Four GaS adsorbed Cr systems, pure, B-doped, N-doped, and O-doped, are optimized, and the optimized results show that the stable adsorption position of Cr on both pure and doped GaS is the top position of Ga atoms, whereas doped elements B, N, and O can promote the adsorption of Cr on GaS, and the order of the strength of this promotion is B > N > O. Method: In this paper, molecular simulation calculations and analyses using the CASTEP module in the software Materials Studio are performed to simulate the structure optimization of GaS-adsorbed Cr materials doped with B, N, and O atoms by using the generalized gradient approximation (GGA) plane-wave pseudopotential approach [1] and the Perdew-Burke-Ernzerhof (PBE) generalized function [2]. From the convergence test, it is reasonable to set the K-point network to 4 × 4 × 1 and the truncation energy to 500 eV [3]. In this paper, a 3 × 3 × 1 supercell structure with 18 S atoms and 18 Ga atoms is selected. The convergence value of the iterative accuracy is 1.0e − 5 eV/atom, and all the atomic forces are less than 0.02 eV/Å. A vacuum layer of 16 Å is also set in the C direction to avoid interlayer interactions of GaS. First, we optimize the geometry of the model and then analyze the nature of the adsorption energy and electronic structure corresponding to the model. [ABSTRACT FROM AUTHOR]

The 2H-MoS2 incorporated with N-doped carbon (2H-MoS2/NC) with high discharge capacity has attracted more research focus as an anode material for K-ion batteries (PIBs). However, large longitudinal lattice deformation at 2H-MoS2/NC heterointerfaces caused by interfacial intercalation of K ions negatively impacts the structural stability, which limits its cycling performance. In this paper, interfacial engineering has been applied to optimize the structural stability of 2H-MoS2/NC. By using first-principle simulation, the evolutions of longitudinal lattice deformation, K adsorption/diffusion performance/behaviour, interfacial strength, and electronic property with the interfacial interlayer spacing have been systematically explored. The results show that with the increase of interlayer spacing from 5.0 to 7.0 Å, the lattice deformation, interfacial strength, and K adsorption kinetics first decrease sharply with interlayer spacing in the range of 5.0–6.5 Å, and then they drop minorly at 6.5–7.0 Å. The K interfacial diffusion capability can be improved due to the decreased charge accumulation at interface that leads to weakened K–S bonding with a rising interlayer spacing. Based on variation of structural stability and K storage performance, an optimal interlayer spacing of 6.75 Å is confirmed. These findings can provide a solid theoretical basis and guidance for the experimental preparation of high-performance 2H-MoS2/NC electrode materials and further cultivate new concepts for the optimal design of two-dimensional composite electrode materials. [ABSTRACT FROM AUTHOR]

Understanding the adsorption interactions between carbon materials and sulfur compounds has far‐reaching impacts, in addition to their well‐known important role in energy storage and conversion, such as lithium‐ion batteries. In this paper, properties of intrinsic B or Si single‐atom doped, and B–Si codoped graphene (GR) and graphdiyne (GDY) were investigated by using density functional theory‐based calculations, in which the optimal doping configurations were explored for potential applications in adsorbing sulfur compounds. Results showed that both B or Si single‐atom doping and B–Si codoping could substantially enhance the electron transport properties of GR and GDY, improving their surface activity. Notably, B and Si atoms displayed synergistic effects for the codoped configurations, where B–Si codoped GR/GDY exhibited much better performance in the adsorption of sulfur‐containing chemicals than single‐atom doped systems. In addition, results demonstrated that, after B–Si codoping, the adsorption energy and charge transfer amounts of GDY with sulfur compounds were much larger than those of GR, indicating that B–Si codoped GDY might be a favorable material for more effectively interacting with sulfur reagents. [ABSTRACT FROM AUTHOR]

In this study, we have investigated numerous influential factors such as length, diameter, impurity introduction, and vacancy defects on the thermal conductivity of carbon nanotubes (CNTs). These investigations were conducted through molecular dynamics simulations using the large-scale atomic/molecular massively parallel simulator (LAMMPS). It is observed that longer CNTs tend to exhibit heightened thermal conductivity, a consequence of the increased support for phonon vibration modes that facilitate efficient thermal transport. Furthermore, CNTs with larger diameters display superior thermal characteristics owing to reduced phonon scattering effects. The introduction of boron doping reduces CNTs thermal conductivity by approximately 3% with the inclusion of 6% boron atoms, whereas nitrogen doping increases it by a similar margin. These doping effects hold great potential for optimizing the performance of MEMS and NEMS devices. This duality in doping offers a versatile means to fine-tune the thermal conductivity of CNTs, enabling effective heat management in micro/nanodevices. By strategically modulating thermal conductivity, we can optimize the heat transfer properties of CNT-based materials and devices. This optimization is of utmost importance in ensuring efficient heat dissipation and averting thermal-induced issues, such as overheating, performance degradation, or failure. Additionally, this paper explores how vacancy defects impact the thermal conductivity of CNTs. By varying the vacancy concentration from 1 to 6%, a decrease in thermal conductivity of approximately 2% to 4% was observed in both SWCNTs and DWCNTs. These results emphasize the pivotal role of defects in perturbing the efficient phonon transport mechanisms in CNTs and suggest the potential for customizing CNTs with specific defect concentrations to enhance their suitability for thermoelectric devices and thermal insulation materials. [ABSTRACT FROM AUTHOR]

GeFe2O4 (GFO), with its intriguing intercalation mechanism based on alloying–conversion reactions, was recently proposed as an anode material for sodium ion batteries (SIBs). However, drawbacks related to excessive volume expansion during intercalation/deintercalation and poor electronic conductivity enormously hinder its practical application in batteries. In this regard, some experimental strategies such as cation substitutions and proper architectures/carbon coatings can be adopted. In this paper, pure and Mn-doped GFO samples were prepared by hydrothermal synthesis. The doped samples maintained the spinel cubic structure and the morphology of pure GFO. The electrochemical tests of the samples, performed after proper carbon coating, showed the expected redox processes involving both Ge and Fe ions. The Mn doping had a positive effect on the capacity values at a low current density (about 350 mAh/g at C/5 for the Mn 5% doping in comparison to 300 mAh/g for the pure sample). Concerning the cycling stability, the doped samples were able to provide 129 mAh/g (Mn 10%) and 150 mAh/g (Mn 5%) at C/10 after 60 cycles. [ABSTRACT FROM AUTHOR]

Negatively charged nitrogen-vacancy (NV−) centres formed in diamond crystals are point defects that have potential applications in various quantum devices such as highly sensitive magnetic sensors. To improve the sensitivity of magnetic sensors using NV− centres, it is essential to precisely control the nitrogen concentration in the crystals. In this paper, we demonstrated that nitrogen concentration in diamond can be controlled with high precision for the following two representative growth methods. One is the high-pressure/high-temperature (HPHT) synthesis method and the other is the chemical vapour deposition (CVD) method. The nitrogen concentration of HPHT-grown diamond decreased semi-logarithmically with increasing contents of titanium or aluminium as nitrogen getter materials. The nitrogen concentration of CVD-grown diamond increased linearly with increasing the flow rate ratio of nitrogen to carbon. NV− centres were formed by controlling the total fluence of electron beams so that approximately 20% of the nitrogen became NV− centres. The coherence time of electron spin of NV− centres obtained by the Hahn-echo pulse sequence T2 of these diamond crystals was inversely proportional to the nitrogen concentration. A comparison of T2 of the NV− centres for HPHT-synthesized and CVD-grown diamonds showed no significant difference between them. This article is part of the Theo Murphy meeting issue 'Diamond for quantum applications'. [ABSTRACT FROM AUTHOR]

The evolution trend of wireless communication systems tends to ultra-high data rate, ultra-low latency, and high bandwidth systems. It is foreseen that 6G wireless communication systems will be developed in the range of 100–300 GHz (upper mmWave band) and 300–3000 GHz (terahertz band). In such frequencies, the performance of junctionless field effective transistors is limited due to the reduction of carrier mobility in the device channel. In this paper, for the first time, a shell doped device is proposed to improve RF merit parameters and high-frequency noise performance of GaN junctionless double surrounding nanotube FET device with dual material outer gate (SD-GaN-JNFET). Simulation results show that the doping engineering in the proposed device reduces scattering caused by phonon and doping and increases electron mobility significantly. Parameters gmmax and ƒT of the SD-GaN-JNFET device in channel length of 15 nm are 666 μS and 8.47 THz, respectively, and NFmin<0.025 dB is satisfied in the frequency range of 0-500 GHz. The effect of shell doped area on the linearity performance is evaluated. Moreover, the device shows excellent reliability in terms of trap charges. A non-quasi-static small signal model is developed for the device and incorporated into a low noise amplifier (LNA) design. The LNA with S21 = 22.10 dB and NF = 0.032 dB in central band frequency (140 GHz) was attained. This article opens up an opportunity to achieve high-performance LNA for D-Band 6G applications with the reliable SD-GaN-JNFET device. [ABSTRACT FROM AUTHOR]

In this paper, tetrahedral amorphous carbon (ta-C) coatings containing Al were deposited by a hybrid technique of sputtering and arc evaporation. The influence of Al incorporation in the structure and properties of the ta-C coatings were studied as a function of the Al concentration. It is found that Al tends to form a Al-O-C bond when the Al concentration is small. An Al-C bond was detected when the Al concentration is high. Al can facilitate the graphitization of the ta-C coatings and the graphite cluster size as well as the sp2/sp3 ratio of the coatings increase as the Al concentration increases. The decline of the sp3 fraction causes the drop in the hardness of the coatings. The incorporation of Al can effectively decrease the residual stress of the ta-C coatings. During friction tests, Al can facilitate the formation of the sp2-rich graphitic tribo-layer and decrease the friction coefficient. Nevertheless, the decline of the hardness due to the Al incorporation will result in the increase in the wear rate of the coating. It is believed that the ta-C coating with a proper concentration of Al appears to achieve a good comprehensive performance with high hardness, low residual stress, and a low friction coefficient and wear rate. [ABSTRACT FROM AUTHOR]

In this paper, we report the modelling of quantum capacitance in both single-layer and bilayer graphene devices to investigate the temperature dependence. The model includes the existence of electron and hole puddles due to local fluctuations of the potential, which is taken into account with the possibility of finite lifetimes of electronic states to calculate the quantum capacitance using the Gaussian distribution. The results indicate that the simulations are in agreement with the experimental measurements, which proves the accuracy of the proposed model. On the other hand, temperature dependence around the charge neutrality point has been reported for both single and bilayer graphene. [ABSTRACT FROM AUTHOR]

The urgent development of economically practical and sustainable electrocatalysts to accelerate the hydrogen evolution reaction (HER) is critical for solving the pressing issues related to carbon dioxide emissions. Because of their platinum-like catalytic efficiency, excellent stability, and multidimensional structure of their crystal phases, molybdenum phosphides have emerged as extremely promising HER electrocatalysts. In this account, we begin with a meticulous explication of the hydrogen-generating process by water electrolysis, followed by an examination of the criteria used to assess HER catalytic activity. Also, the role of the phosphorus component and synthetic routes of molybdenum phosphides is presented in HER applications. Moreover, in recent years, various strategies designed to enhance the HER performance of molybdenum phosphides have been introduced, encompassing state-of-the-art techniques such as the fabrication of heterostructures, hetero-atom doping, hybrid structures involving carbon materials, and defect engineering. Furthermore, the theoretical studies based on density functional theory (DFT) are mentioned for HER. The paper concludes by emphasizing the current challenges and auspicious prospects in advancing electrocatalysts for hydrogen production, with a dedicated focus on catalysts based on molybdenum phosphides. • Outstanding features of molybdenum phosphides were presented. • Various methods were introduced in the fabrication of molybdenum phosphides. • Enhancement strategies in HER efficiency of molybdenum phosphides were discussed. • Current challenges and possible solutions on molybdenum phosphides-based HER electrocatalyst were provided. • DFT works of molybdenum phosphides on HER were presented. [ABSTRACT FROM AUTHOR]

Dried blood spot (DBS) analysis has been an inherent part of sports drug testing through the technological advancements of the past decade. Trimetazidine, a non‐threshold banned substance, is excreted into urine after a dose of the permitted drug lomerizine. Therefore, a lomerizine‐specific metabolite (M6) is analyzed to confirm the origin of trimetazidine in traditional urine analysis. Application studies were conducted to develop an analytical method for trimetazidine applicable to DBS. These studies comprise (1) the effect of different sampling sites on the detection of trimetazidine, (2) the determination of the appropriate trimetazidine level required for DBS analysis, and (3) differentiating between trimetazidine and lomerizine use. A high‐resolution mass spectrometric method for detecting trimetazidine in DBS was validated. After oral administration of trimetazidine (n = 7), venous and capillary blood (fingertip and upper arm) were spotted on cellulose paper. Trimetazidine could be identified in DBS in all subjects up to 60 h after administration. The limit of detection was 0.05 ng/ml, and the limit of identification was 0.06 ng/ml, suggesting the minimum required performance level of 0.2 ng/ml. In the fingertip capillary blood, biases of 9.7% (vs. upper arm) and 13.0% (vs. vein) were observed in the trimetazidine intensity; however, there were no concerns in the qualitative analysis. After administering lomerizine (n = 10), the intact lomerizine has a strong peak intensity in blood compared to trimetazidine. Contrary to urine analysis, the M6 was less detectable in blood. Laboratories should confirm intact lomerizine whenever trimetazidine is identified in DBS. [ABSTRACT FROM AUTHOR]

As a typical penta two-dimensional material and proposed to be potentially synthesized, in this paper we built a two-probe photodetector based on the penta-BP5 monolayer, and further studied linear and elliptical photogalvanic effects in this device. It was found that produced photocurrents in the BP5 photodetectors mainly show sine relation on double times of the polarized or elliptical angle for the incident light, and the relation can be modulated by the photon energy and polarized angle. Interestingly, due to high asymmetry of the BP5 monolayer, the pristine BP5 photodetector generates very high photocurrents, which are even larger than those including vacancy- and substitution-doping, and this result further proved that asymmetry plays a decisive role in the generation of robust photogalvanic effects, instead of introducing impurities to enhance this effect. Furthermore, the linear photogalvanic effect is stronger than the elliptical photogalvanic effect, and the BP5 photodetectors for the pristine, vacancy- and substitution-doping cases have relatively high extinction ratios showing these BP5 photodetectors are all polarization-sensitive. In conclude, these results manifest great potential applications of the penta-BP5 photodetectors on high performance optoelectronics and nanoelectronic devices. [ABSTRACT FROM AUTHOR]

Biomass‐derived carbon material has drawn significant attention recently due to its wide availability, environmentally free, and effective performance of the resulting porous carbons for supercapacitor (SC) applications. Carbon electrode material derived from biomass is used for energy storage (ES) because it has distinct qualities in porosity, a large specific surface area, and excellent conductivity. Furthermore, these materials' homogeneous, flawless biological structures can be used as models to create electrode materials with accurate geometries. The ES devices, known as SCs, also known as ultra‐capacitors, serve as a link between a capacitor and a battery. Due to their charge storage, SCs can produce a much higher density than batteries. Several factors, including the electrode's potential window, the electrode materials characteristics, and the electrolyte choice, have a major effect on SC performance. Therefore, all efforts have been made to develop SC electrode materials. This paper explains the different types of SCs and how they work. The various available biomass resources, as well as the methods for producing them, are outlined. In addition, the different types of electrode materials, activation methods, heteroatom functionalization, and electrolyte types are all thoroughly examined. The application and research advancement of biomass‐derived carbon used in SCs over the past 3 years are highlighted. Furthermore, this research outlines the benefits of SCs for the environment and the economy, as well as present challenges and future recommendations for advancing biomass‐derived carbon applications. This article aims to give an in‐depth knowledge of carbon‐based biomass materials that are used in SCs. [ABSTRACT FROM AUTHOR]

Context: The electronic properties and optical properties of Cr-doped monolayer WS2 under uniaxial compressive deformation have been investigated based on density functional theory. In terms of electronic structure properties, both intrinsic and doped system bandgaps decrease with the increase of compression deformation, and the values of the bandgap under the same compression deformation after Cr doping are reduced compared with the corresponding intrinsic states. When the compressive deformation reaches 10%, both the intrinsic and doped system band gaps are close to zero. New electronic states and impurity energy levels appear in the WS2 system when doped with Cr atoms. For the optical properties, the calculation and analysis of the dielectric function under each deformation regime of monolayer WS2 show that the compression deformation affects the dielectric function, and when the compression deformation is 10%, the un-doped and Cr-doped regimes show a decrease in ε1(ω) compared to the compression deformation of 8%. For each deformation system, the peak reflections occur in the ultraviolet region. Near the position where the second peak of the absorption spectrum appears, it can be seen that the ability of each system to absorb light gradually decreases with the increase of the amount of deformation and appears to be red-shifted to varying degrees. Methods: This study follows the initial principles of the density functional theory framework and is based on the CASTEP module of Materials-Studio software GGA and PBE generalizations are used to perform computations such as geometry optimization of the model. We have calculated the energy band structure of monolayer WS2 with intrinsic and compressive deformations of 2% and 4% using PBE and HSE06, respectively. The band gap values calculated using PBE are 1.802 eV, 1.663 eV, and 1.353 eV, respectively, and the band gap values calculated with HSE06 are 2.267 eV, 2.034 eV, 1.751 eV. The results show that the bandgap values calculated by HSE06 are significantly higher than those calculated by PBE, but the bandgap variations calculated by the two methods have the same trend, and the shape characteristics of the energy band structure are also the same. However, it is worth noting that the computation time required for the HSE06 calculation is much longer than that of the PBE, which is far beyond the capability of our computer hardware, and the purpose of this paper is to investigate the change rule of the effect of deformation on the bandgap value, so to save the computational resources, the next calculations are all calculated using the PBE. The Monkhorst–Pack special K-point sampling method is used in the calculations. The cutoff energy for the plane wave expansion is 400 eV, and the K-point grid is assumed to be 5 × 5 × 1. Following geometric optimization, the iterative precision converges to a value of less than 0.03 eV/Å for all atomic forces and at least 1 × 10−5 eV/atom for the total energy of each atom. The vacuum layer's thickness was selected at 20 Å to mitigate the impact of the interlayer contact force. [ABSTRACT FROM AUTHOR]

Context: The electronic properties and optical properties of Cr-doped monolayer WS2 under uniaxial compressive deformation have been investigated based on density functional theory. In terms of electronic structure properties, both intrinsic and doped system bandgaps decrease with the increase of compression deformation, and the values of the bandgap under the same compression deformation after Cr doping are reduced compared with the corresponding intrinsic states. When the compressive deformation reaches 10%, both the intrinsic and doped system band gaps are close to zero. New electronic states and impurity energy levels appear in the WS2 system when doped with Cr atoms. For the optical properties, the calculation and analysis of the dielectric function under each deformation regime of monolayer WS2 show that the compression deformation affects the dielectric function, and when the compression deformation is 10%, the un-doped and Cr-doped regimes show a decrease in ε1(ω) compared to the compression deformation of 8%. For each deformation system, the peak reflections occur in the ultraviolet region. Near the position where the second peak of the absorption spectrum appears, it can be seen that the ability of each system to absorb light gradually decreases with the increase of the amount of deformation and appears to be red-shifted to varying degrees. Methods: This study follows the initial principles of the density functional theory framework and is based on the CASTEP module of Materials-Studio software GGA and PBE generalizations are used to perform computations such as geometry optimization of the model. We have calculated the energy band structure of monolayer WS2 with intrinsic and compressive deformations of 2% and 4% using PBE and HSE06, respectively. The band gap values calculated using PBE are 1.802 eV, 1.663 eV, and 1.353 eV, respectively, and the band gap values calculated with HSE06 are 2.267 eV, 2.034 eV, 1.751 eV. The results show that the bandgap values calculated by HSE06 are significantly higher than those calculated by PBE, but the bandgap variations calculated by the two methods have the same trend, and the shape characteristics of the energy band structure are also the same. However, it is worth noting that the computation time required for the HSE06 calculation is much longer than that of the PBE, which is far beyond the capability of our computer hardware, and the purpose of this paper is to investigate the change rule of the effect of deformation on the bandgap value, so to save the computational resources, the next calculations are all calculated using the PBE. The Monkhorst–Pack special K-point sampling method is used in the calculations. The cutoff energy for the plane wave expansion is 400 eV, and the K-point grid is assumed to be 5 × 5 × 1. Following geometric optimization, the iterative precision converges to a value of less than 0.03 eV/Å for all atomic forces and at least 1 × 10−5 eV/atom for the total energy of each atom. The vacuum layer's thickness was selected at 20 Å to mitigate the impact of the interlayer contact force. [ABSTRACT FROM AUTHOR]

In this paper, (1- x)(Bi 0.5 Na 0.5)TiO 3 - x BaTiO 3 (x = 0, 0.06, 0.08, and 0.10) ceramic coatings were prepared by supersonic plasma spraying. Phase structure, microstructure, dielectric, ferroelectric, and piezoelectric properties of the (Bi 0.5 Na 0.5)TiO 3 ceramic coatings doped with BaTiO 3 were all thoroughly examined. According to the findings, all of the (1- x)(Bi 0.5 Na 0.5)TiO 3 - x BaTiO 3 ceramic coatings have a typical perovskite structure and form a morphotropic phase boundary (MPB) with rhombohedral and tetragonal phases coexisting in the x = 0.06–0.10 range. The coating's overall surface is uniformly flat, with a surface roughness (Sa) of less than 10 μm and a line roughness (Ra) of less than 2 μm. The coating has a homogeneous cross section, a well-integrated interface, a few pores and cracks, and a porosity of less than 6 %. With no obvious valence changes of the other elements, the results of XPS indicate a certain degree of breakdown during the spraying process, when Ti4+ changes to generate oxygen vacancy defects of Ti3+. The best electrical conductivity of the 0.92BNT-0.08BT coating has been found at x = 0.08, where the dielectric constant is 255 (0.02), the remnant polarization (P r) is 22.21 μC/cm2, the coercive field (E c) is 29.17 kV/cm, and the piezoelectric coefficient (d 33) is 35.1 pC/N. The (1- x)(Bi 0.5 Na 0.5)TiO 3 - x BaTiO 3 ceramic coating application space and range at high temperature are expanded when the temperature (T m) close to the maximum dielectric constant increases significantly reaching 431.2 °C. [ABSTRACT FROM AUTHOR]

DPC in Scanning Transmission Electron Microscopy (STEM) is a valuable method for mapping the electric fields in semiconductor materials. However, optimising the experimental conditions can be challenging. In this paper, we test and compare critical experimental parameters, including the convergence angle, camera length, acceleration voltage, sample configuration, and orientation using a four‐quadrant segmented detector and a Si specimen containing layers of different As concentrations. The DPC measurements show a roughly linear correlation with the estimated electric fields, until the field gets close to the detection limitation, which is ∼0.5 mV/nm with a sample thickness of ∼145 nm. These results can help inform which technique to use for different user cases: When the electric field at a planar junction is above ∼0.5 mV/nm, DPC with a segmented detector is practical for electric field mapping. With a planar junction, the DPC signal‐to‐noise ratio can be increased by increasing the specimen thickness. However, for semiconductor devices with electric fields smaller than ∼0.5 mV/nm, or for devices containing curved junctions, DPC is unreliable and techniques with higher sensitivity will need to be explored, such as 4D STEM using a pixelated detector. [ABSTRACT FROM AUTHOR]

[Display omitted] The 2H-MoS 2 /nitrogen-doped carbon (2H-MoS 2 /NC) composite is a promising anode material for potassium-ion batteries (PIBs). Various transition metal doping has been adopted to optimize the poor intrinsic electronic conductivity and lack of active sites in the intralayer of 2H-MoS 2. However, its optimization mechanisms have not been well probed. In this paper, using Cobalt (Co) as an example, we aim to investigate the influence of transition metal doping on the electronic and mechanical properties and electrochemical performance of 2H-MoS 2 /NC via first-principles calculation. Co doping is found to be effective in improving the electronic conductivity and the areas of active sites on different positions (C surface, interface, and MoS 2 surface) of 2H-MoS 2 /NC. The increased active sites can optimize K adsorption and diffusion capability/processes, where general smaller K adsorption energies and diffusion energy barriers are found after Co doping. This helps improve the rate performance. Especially, the pyridinic N (pyN), pyrrolic N (prN), and graphitic N (grN) are first unveiled to respectively work best in K kinetic adsorption, diffusion, and interfacial stability. These findings are instructive to experimental design of high rate 2H-MoS 2 /NC electrode materials. The roles of different N types provide new ideas for optimal design of other functional composite materials. [ABSTRACT FROM AUTHOR]

Context: In this paper, the structural stability, electronic structure, and optical properties of monolayer MoSe2 doped with C, O, Si, S, and Te atoms, respectively, under defective conditions are investigated based on first principles. It is found that the system is more structurally stable when defecting a single Se atom as compared to defecting a single Mo or two Se atoms. The electronic structure analysis of the system reveals that intrinsic MoSe2 is a direct bandgap semiconductor. The bandgap value of the system decreases with a single Se atom defect and introduces two new impurity energy levels in the conduction band. The defective systems doped with C and Si atoms all exhibit P-type doping. The total density of states of intrinsic MoSe2 is mainly contributed by the Mo-d and Se-p orbitals, and new density of state peaks appears near the conduction band after the defects of Se atoms. The total density of states of the defective system doped by each atom is mainly contributed by Mo-d, Se-p, and the result of the p orbital contribution of each dopant atom. By analyzing the dielectric function of each system, it is found that the intrinsic MoSe2 has the lowest static permittivity and the C-doped defect system has the highest static permittivity, which reaches 21.42. The C- and Si-doped defect systems are the first to start absorbing the light, and the intrinsic MoSe2 absorbs the light later, with its absorption edge starting at 1.25 eV. In the visible range, the reflection peaks of the systems move toward the high-energy region and the blue-shift phenomenon occurs. It is hoped that applying modification means to modulate the physical properties of the two-dimensional materials will provide some theoretical basis for broadening the application of monolayer MoSe2 in the field of optoelectronic devices. Methods: This study utilizes the first principle computational software package MS8.0 (Materials studio8.0) under density functional theory (DFT). The exchange–correlation potential (GGA-PBE) is described by the Perdew-Burke-Ernzerhof correlation function in CASTEP, and the potential function adopts the ultrasoft pseudopotential in the inverse space formulation. The plane wave truncation energy Ecut is set to 400 eV, the K-point is taken as 5 × 5 × 1, and the force convergence criterion is 0.05 eV/Å. The convergence accuracy of the total energy of the system is less than 1.0 × 10−5 eV/atom, the tolerance shift is less than 0.002 Å, and the stress deviation is less than 0.1 GPa. The vacuum layer is taken as 15 Å, which is intended to minimize the interlayer force. The vacuum layer was set to 15 Å to avoid the effect of layer-to-layer interaction forces in the crystal cell. [ABSTRACT FROM AUTHOR]

Context: In this paper, the structural stability, electronic structure, and optical properties of monolayer MoSe2 doped with C, O, Si, S, and Te atoms, respectively, under defective conditions are investigated based on first principles. It is found that the system is more structurally stable when defecting a single Se atom as compared to defecting a single Mo or two Se atoms. The electronic structure analysis of the system reveals that intrinsic MoSe2 is a direct bandgap semiconductor. The bandgap value of the system decreases with a single Se atom defect and introduces two new impurity energy levels in the conduction band. The defective systems doped with C and Si atoms all exhibit P-type doping. The total density of states of intrinsic MoSe2 is mainly contributed by the Mo-d and Se-p orbitals, and new density of state peaks appears near the conduction band after the defects of Se atoms. The total density of states of the defective system doped by each atom is mainly contributed by Mo-d, Se-p, and the result of the p orbital contribution of each dopant atom. By analyzing the dielectric function of each system, it is found that the intrinsic MoSe2 has the lowest static permittivity and the C-doped defect system has the highest static permittivity, which reaches 21.42. The C- and Si-doped defect systems are the first to start absorbing the light, and the intrinsic MoSe2 absorbs the light later, with its absorption edge starting at 1.25 eV. In the visible range, the reflection peaks of the systems move toward the high-energy region and the blue-shift phenomenon occurs. It is hoped that applying modification means to modulate the physical properties of the two-dimensional materials will provide some theoretical basis for broadening the application of monolayer MoSe2 in the field of optoelectronic devices. Methods: This study utilizes the first principle computational software package MS8.0 (Materials studio8.0) under density functional theory (DFT). The exchange–correlation potential (GGA-PBE) is described by the Perdew-Burke-Ernzerhof correlation function in CASTEP, and the potential function adopts the ultrasoft pseudopotential in the inverse space formulation. The plane wave truncation energy Ecut is set to 400 eV, the K-point is taken as 5 × 5 × 1, and the force convergence criterion is 0.05 eV/Å. The convergence accuracy of the total energy of the system is less than 1.0 × 10−5 eV/atom, the tolerance shift is less than 0.002 Å, and the stress deviation is less than 0.1 GPa. The vacuum layer is taken as 15 Å, which is intended to minimize the interlayer force. The vacuum layer was set to 15 Å to avoid the effect of layer-to-layer interaction forces in the crystal cell. [ABSTRACT FROM AUTHOR]

Catalysis is an integral part of numerous chemical industries. Noble metals like platinum (Pt) are known for having high catalytic activity and stability for various catalytic reactions such as methane reforming, water gas shift reaction, electrocatalytic reactions etc. However, due to the limited resources and high cost of platinum, the catalysts with low Pt content are desirable. To overcome this issue, the substitutionally doped Pt catalysts are gaining significant interest. In the present review, the synthesis methods, characterization techniques, and utility of Pt-doped catalysis is discussed. Various synthesis methods (impregnation, solution combustion, sol-gel, hydrothermal) and characterization techniques are discussed briefly in the review. The effects of Pt-doped catalysts on various reactions such as methane reforming, water-gas shift reactions, CO oxidation reactions, electrocatalytic reactions, and photocatalytic reactions are discussed here. The comparison of the activity of supported and doped catalysts is also presented to understand the effects of substitutional doping better. • Paper presents synthesis and utilization of Platinum doped catalysts (ionic catalysts). • Doped Pt (ionic Pt) catalysts are extensively used in energy-conversion reactions. • Platinum in Pt4+ and Pt2+ ionic forms contribute to enhancement of catalytic activity and stability. • Generation of oxygen vacancies and lattice distortion due to metal substitution improves the catalytic activity. [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]

Given the prevalent use of inhaled beta2‐agonists in sports, there is an ongoing debate as to whether they enhance athletic performance. Over the last decades, inhaled beta2‐agonists have been claimed not to enhance performance with little consideration of dose or exercise modality. In contrast, orally administered beta2‐agonists are perceived as being performance enhancing, predominantly on muscle strength and sprint ability, but can also induce muscle hypertrophy and slow‐to‐fast fiber phenotypic switching. But because inhaled beta2‐agonists are more efficient to achieve high systemic concentrations than oral delivery relative to dose, it follows that the inhaled route has the potential to enhance performance too. The question is at which inhaled doses such effects occur. While supratherapeutic doses of inhaled beta2‐agonists enhance muscle strength and short intense exercise performance, effects at low therapeutic doses are less apparent. However, even high therapeutic inhaled doses of commonly used beta2‐agonists have been shown to induce muscle hypertrophy and to enhance sprint performance. This is concerning from an anti‐doping perspective. In this paper, we raise awareness of the circumstances under which inhaled beta2‐agonists can constitute a performance‐enhancing benefit. [ABSTRACT FROM AUTHOR]

Sport has always played an important role in society, bringing joy, excitement and a sense of community as well as national pride. Over the centuries, sport has evolved from simple local competitions to global events watched by millions of people, gaining ever greater socio-political and economic importance. In the paper "Management and prevention of abuses in sports" we make a brief presentation of the types of abuses existing in sports and the solutions that can be used to eliminate these harmful actions, including a survey conducted on this topic. [ABSTRACT FROM AUTHOR]