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Exploring new materials and methods to achieve high utilization of sulfur with lean electrolyte is still a common concern in lithium‐sulfur batteries. Here, high‐density oxygen doping chemistry is introduced for making highly conducting, chemically stable sulfides with a much higher affinity to lithium polysulfides. It is found that doping large amounts of oxygen into NiCo2S4 is feasible and can make it outperform the pristine oxides and natively oxidized sulfides. Taking the advantages of high conductivity, chemical stability, the introduced large Li–O interactions, and activated Co (Ni) facets for catalyzing Sn2–, the NiCo2(O–S)4 is able to accelerate the Li2S‐S8 redox kinetics. Specifically, lithium‐sulfur batteries using free‐standing NiCo2(O–S)4 paper and interlayer exhibit the highest capacity of 8.68 mAh cm–2 at 1.0 mA cm–2 even with a sulfur loading of 8.75 mg cm–2 and lean electrolyte of 3.8 µL g–1. The high‐density oxygen doping chemistry can be also applied to other metal compounds, suggesting a potential way for developing more powerful catalysts towards high performance of Li–S batteries. [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]

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]

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]

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]

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]

The doping control analyses at the XXXII Olympic Games (July 23 to August 8, 2021) and the XVI Paralympic Games (August 24 to September 5, 2021) held in Tokyo, Japan, after a year of delay due to the COVID‐19 pandemic are summarized in this paper. A new satellite facility at the existing World Anti‐Doping Agency (WADA)‐accredited Tokyo laboratory was established and fully operated by 278 staff, including 33 Tokyo laboratory staff, 49 international experts, and 196 Japanese temporary staff. The numbers of urine samples were 5081 (Olympics) and 1519 (Paralympics), and the numbers of blood samples were 1103 (Olympics) and 500 (Paralympics). The laboratory could prepare for analysis in advance using a paperless chain‐of‐custody system, allowing for faster turnaround time reporting. For the first time, a new polymerase chain reaction method for detecting erythropoietin (EPO) gene doping was used. The laboratory also analyzed blood samples for detecting steroid esters following the spotting of collected venous EDTA blood onto dried blood spot cards. Moreover, full‐scan data acquisition using high‐resolution mass spectrometers was performed for all urine samples, allowing for detecting traces of doping substances, which are not currently analyzed in the subsequent data processing. The presence of some prohibited substances was confirmed, resulting in 8 atypical findings (ATFs) and 11 adverse analytical findings (AAFs), including homologous blood transfusion (2 cases) and recombinant EPO in the blood (1 case), at the Olympics, whereas 2 ATFs and 10 AAFs were reported at the Paralympics. [ABSTRACT FROM AUTHOR]

In this paper, N, Nb composite doped lithium iron phosphate structure was constructed, and its thermodynamic stability, intercalation voltages, volume change rate, electronic structure properties, and mechanical properties were systematically investigated using the first principles. The results of formation energy demonstrate that the N and Nb composite doping system meets the thermodynamic stability requirements and can exist consistently. In the process of de‐lithium, the volume change rate of the anion‐cation hybrid doping system is significantly decreased, and the intercalation voltage is increased, which indicates that the doping makes the cycling performance and energy density of the material improved. A radical shift in the material's electronic structure after doping is conducive to the enhanced conductivity of lithium iron phosphate. Besides, studies on the elastic properties of materials demonstrated that both N and Nb doping inhibited the generation of microcracks and diminished the occurrence of shear deformation. [ABSTRACT FROM AUTHOR]

GaAs crystals are important III–V compound semiconductor materials and the bandgap and quantum efficiency can be optimized by doping. However, the doping may bring some problems to the crystal growth. In this paper, Si‐doped GaAs crystals are grown by the modified vertical Bridgman method and the influence of Si doping on dislocations and mechanical properties are discussed. It is found that a proper amount of Si doping significantly reduces the dislocation density of GaAs crystals. The mechanical properties of (100), (110), (111), and (511) planes are measured, and the results show that the mechanical properties of Si‐doped GaAs crystals have obvious anisotropy. The (111) plane has the strongest mechanical properties among them. The Vickers hardness, fracture toughness, nanoindentation hardness, and elastic modulus of the (111) plane are 6.05 GPa, 0.69 MPa m1/2, 10.82 GPa, 138.7 GPa, respectively. Moreover, Si doping can improve the mechanical properties of GaAs crystals. [ABSTRACT FROM AUTHOR]

PbSe has attracted wide attention owing to its fascinating physical and chemical properties. It has important technical significance for infrared detectors. However, due to the inherent bandgap, low carrier mobility, and dielectric constant of PbSe, it is a significant challenge to realize fast response and mid‐infrared (MID) photodetection. Chemical doping is an efficient method to regulate the band structure and carrier mobility of materials. Nevertheless, the doped film detector cannot satisfy the demands of high‐performance photodetectors. In this paper, different composition ratios powders are synthesized by a solid‐state method. The PbSe0.5Te0.5 alloy film displays narrower bandgap, higher carrier mobility, excellent photo‐response, and broadband detection capacity. By utilizing the above superiority of PbSe0.5Te0.5 and fast charge transfer in MoSe2, a PbSe0.5Te0.5/MoSe2 p‐n heterostructure device is successfully fabricated that has significant rectifying effect (103) and extremely low dark current density (720 µA cm−2). The photodetector has a maximum responsivity (R) and specific detectivity (D*) of 17.5 A W−1 and 3.08 × 1013 Jones at 780 nm. In addition, the detector displays superior photodetection performance with broadband photodetection (405–5000 nm), high switch ratios (Ion/Ioff = 105), and fast response speed. The above outstanding properties indicate that the PbSe0.5Te0.5/MoSe2 heterostructure provides a promising and efficient strategy for achieving a miniaturized, broadband, and high‐performance photodetector. [ABSTRACT FROM AUTHOR]

High current carrying capacity and high conductivity are two important indicators for materials used in microscale electronics and inverters. However, it is challenging to obtain high conductivity and high current carrying capacity at the same time since high conductivity requires a weakly bonded system to provide free electrons, while high current carrying capacity requires a strongly bonded system. In this paper, CuI@SWCNT networks by filling the single‐walled carbon nanotubes (SWCNTs) with CuI is ingeniously prepared. CuI@SWCNT shows good stability due to the confinement protection of SWCNTs. Through the host‐guest hybridization, CuI@SWCNT networks exhibit a current carrying capacity of 2.04 × 107 A cm−2 and a conductivity of 31.67 kS m−1. Their current carrying capacity and conductivity are significantly improved compared with SWCNT. The Kelvin probe force microscopy measurements show a drop of surface potential energy after SWCNT filled with CuI, indicating that the CuI guest molecules regulate the position of the Fermi level of SWCNTs, increasing carrier concentration, achieving high conductivity and high current carrying capacity. This study offers ideas and solutions for the regulation of high‐performance carbon tube networks, which hold great promise for future applications in carbon‐based electronic devices. [ABSTRACT FROM AUTHOR]

Over the last two decades, many studies have contributed to improving our understanding of the brittle failure mechanisms of boron carbide and provided a road map for inhibiting the underlying mechanisms and improving the mechanical response of boron carbide. This paper provides a review of the design and processing approaches utilized to address the amorphization and transgranular fracture of boron carbide, which are mainly based on what we have found through 9 years of work in the field of boron carbides as armor ceramics. [ABSTRACT FROM AUTHOR]

Boron carbide is an excellent armor material due to its light weight and ultrahigh hardness. However, high‐rate mechanical behavior can be degraded by stress‐induced amorphization. In this paper, we review the progressive advances in the understanding of amorphization in three successive generations of boron carbide: stoichiometric (undoped), B‐rich, and B/Si codoped boron carbides. For each generation of boron carbide, the crystal structure and microstructure are first discussed. Then, we outline the experimental observations of amorphization made by Raman spectroscopy and transmission electron microscopy. The susceptibility of amorphization in each generation of boron carbide will be compared and the fundamental mechanisms that explain the reduction in amorphization for B‐rich and B/Si codoped boron carbides elucidated. Comments on future research directions to further broaden and deepen the understanding of stress‐induced amorphization of boron carbide are also provided. [ABSTRACT FROM AUTHOR]

Carbonaceous transition metal catalysts have become one of the most promising materials to replace expensive Pt‐based catalysts because of their high oxygen reduction reaction (ORR) activity and stability. In this paper, three metal‐containing nanoparticles, namely FeCoNi, were encapsulated into carbonaceous matrixes by simple stirring and calcination. The morphology of as‐obtained FeCoNi particles was controlled and investigated by adjusting the amount of melamine as carbon (and nitrogen) source. FeCoNi@NC/CNTs‐6 showed the best ORR activity among all of the catalysts. The half‐wave potential of the FeCoNi@NC/CNTs‐6 is 0.83 V vs. RHE, and its limiting current density is up to 5.16 mA cm−2. It was found that the unique 3D carbon‐based matrix may be the main reason for this enhanced ORR activity. Additionally, higher content of pyridine N and Fe(Co/Ni)Nx group in FeCoNi@NC/CNTs‐6 catalyst may be another reason. Finally, FeCoNi@NC/CNTs‐6 was also used as a cathode to assemble the zinc‐air battery. The results showed that it had better battery performance than the reference Pt/C catalyst. These results could provide theoretical and practical support for the enlarged applicability of similar catalysts. [ABSTRACT FROM AUTHOR]

This paper proposes the fabrication of a new type of electrorheological (ER) fluid with ecoresorbable features as well as excellent electroresponsive performance. The proposed ER fluid consists of biocompatible Mg‐doped silica/titania hollow nanoparticles (ST HNPs) suspended in vegetable oils (canola, grapeseed, olive, and soy). The effects of biodegradable plant‐derived carrier liquids on the ER performance are analyzed. The polarizability and wettability of the fabricated ER fluids are studied. The high polarizability of the nanoparticles contributes to the highly electroresponsive performance by inducing electrostatic interactions between the nanoparticles under electric fields; this enables the formation of a rigid and strong fibril structure. A suitable wettability, which represents the favorable interaction between the oil and the nanoparticles, allows the nanoparticles to disperse evenly in the oil and prevents their aggregation, thereby making the formation of a rigid and strong fibrillar structure under the electric field easier. [ABSTRACT FROM AUTHOR]

In this paper, N, Nb composite doped lithium iron phosphate structure was constructed, and its thermodynamic stability, intercalation voltages, volume change rate, electronic structure properties, and mechanical properties were systematically investigated using the first principles. The results of formation energy demonstrate that the N and Nb composite doping system meets the thermodynamic stability requirements and can exist consistently. In the process of de‐lithium, the volume change rate of the anion‐cation hybrid doping system is significantly decreased, and the intercalation voltage is increased, which indicates that the doping makes the cycling performance and energy density of the material improved. A radical shift in the material's electronic structure after doping is conducive to the enhanced conductivity of lithium iron phosphate. Besides, studies on the elastic properties of materials demonstrated that both N and Nb doping inhibited the generation of microcracks and diminished the occurrence of shear deformation. [ABSTRACT FROM AUTHOR]

Rational design of cost‐effective, high performance and stable hydrogen evolution reaction (HER) electrocatalysts in both acidic and alkaline media holds the key to the future hydrogen‐based economy. Herein, we introduce an effective approach of simultaneous non‐metal (S) and metal (Fe or Mn) doping of MoP to achieve excellent HER performance at different pH. The catalysts show remarkable overpotentials at −10 mA cm−2 of only 65 and 68 mV in 0.5 M H2SO4, and 50 and 51 mV in 1.0 M KOH, respectively, as well as much higher turnover frequencies compared to undoped MoP. Furthermore, the catalysts exhibit outstanding long‐term stability at a fixed current of −10 mA cm−2 for 40 h. The effects of both dopants, such as electronic structure modification and enhancement of the intrinsic activity, increase of the electrochemically active surface area, and formation of coordinatively unsaturated edge sites, act cooperatively to accelerate the HER at both pH media. Additionally, the presence of oxophilic Mn and Fe at the surface results in Mn or Fe oxide/hydroxide species that promote the dissociation of water molecules in alkaline electrolyte. This work introduces a facile and effective design principle that could pave the way towards engineering highly active HER catalysts for a wide pH range. [ABSTRACT FROM AUTHOR]

In this study, color tunable phosphors (Mn2+‐doped Zn2GeO4) were successfully synthesized by a facile microwave hydrothermal process with H2O as solvent. Crystal field modulation and band gap doping by Mn2+ substitution for Zn2+ realizes color tunable Mn2+ emission from 424 to 535 nm. Mn2+‐doping on the phase and size transition of Zn2GeO4 nanocrystals was discussed, and a possible Zn2GeO4 : xMn crystal growth mechanism is discussed. Photoluminescence (PL) spectra indicate that the d‐d transition of manganese ions (4T1→6A1) corresponds to a strong green emission of Zn2GeO4 : xMn phosphors. [ABSTRACT FROM AUTHOR]

Researchers have achieved precise control of the size of quantum dots by using the quantum confinement effect. Rb+ and Cs+ with similar ionic radii have become a new mechanism for researchers to regulate the emission wavelength of quantum dots. However, there are few studies on the performance of codoped quantum dots with ion at present. By adding a saturated solution of RbCl into an organic solution of CsPbBr3, quantum dots doped with Rb+ and Cl− were prepared. The prepared quantum dots realized adjustable emission spectrum (457‐510 nm), stable lattice structure, and good stability under ultraviolet light irradiation. Therefore, double ion doping is a new method to prepare short‐wavelength of quantum dots. [ABSTRACT FROM AUTHOR]

Here, the authors report a practical method for preparing nitrogen‐doped carbon materials using an orthogonal array design. The material with the highest specific capacitance value of 262 F·g−1 at a current density of 1 A·g−1 was obtained under the conditions (KOH as activation agent, activation temperature of 600°C, activation time of 3 h, respectively). Its high electrochemical properties are attributed to its high surface area and additional pseudo‐capacitance. After 5000 cycles, the specific capacitance remained 92.8%, with good cycle stability. Textural characterization of the carbon materials was performed using N2 adsorption/desorption and scanning electron microscopy. [ABSTRACT FROM AUTHOR]

Various concentrations of samarium‐grafted‐carbon nitride (Sm‐g‐C3N4) doped‐bismuth oxobromide (BiOBr) quantum dots (QDs) are prepared by the co‐precipitation method. Elemental evaluation, morphological, optical, and functional group assessment are studied employing characterization techniques. Based on the XRD pattern analysis, it is determined that BiOBr exhibits a tetragonal crystal structure. The electronic spectroscopy revealed an absorption peak for BiOBr at 315 nm and the bandgap energy (Eg) decreasing from 3.9 to 3.8 eV with the insertion of Sm‐g‐C3N4. The presence of vibrational modes related to BiOBr at 550 cm−1 is confirmed through FTIR spectra. TEM revealed that pure BiOBr possessed non‐uniform QDS, and agglomeration increased with the addition of Sm‐g‐C3N4. The catalytic performance of Sm‐g‐C3N4 into BiOBr (6 mL) in a neutral medium toward rhodamine B exhibited excellent results (99.66%). The bactericidal activity is evaluated against multi‐drug resistance (MDR) Escherichia coli once the surface area is increased by dopant and the measured inhibition zone is assessed to be 3.65 mm. Molecular docking results supported the in vitro bactericidal potential of Sm‐g‐C3N4 and Sm‐g‐C3N4 doped‐BiOBr as DNA gyraseE. coli inhibitors. This study shows that the novel Sm‐g‐C3N4 doped‐BiOBr is a better catalyst that increases specific semiconductor's catalytic activity (CA). [ABSTRACT FROM AUTHOR]

The electrochemical N2 reduction reaction (ENRR), driven by renewable electricity and run under ambient conditions, offers a promising sustainable avenue for carbon‐neutral NH3 production. Yet, to efficiently bind and activate the inert N2 remains challenge. Herein, effective and stable electrochemical NH3 synthesis on Sm(OH)3 via enhanced adsorption of hydrogen and dinitrogen by dual integration of sulfur dopants and oxygen vacancies (VO) is reported. The resulting S‐doped lanthanide electrocatalyst attains both a good NH3 yield rate, exceeding 21 μgNH3 h−1 mgcat.−1, and an NH3 faradaic efficiency of over 29% at −0.3 V (vs reversible hydrogen electrode) in an H‐type cell using a neutral electrolyte, figures of merit that are largely maintained after 2 days of consecutive polarization. Density functional theory calculations show that the adsorption energy barrier of N2 on S‐Sm(OH)3(VO) is greatly lowered by the introduction of VO. In addition, the S sites improve the adsorption of hydrogen produced via the Volmer reaction, which is conducive to the formation of the *N–NH intermediate (i.e., the potential determining step, PDS) on adjacent Sm sites, and thereby significantly promotes the reaction kinetics of ENRR. The PDS free energy for the catalyst is comparable with the values at the peak of the ENRR volcano plots of leading transition metal catalyst surfaces. [ABSTRACT FROM AUTHOR]

Active thermal radiation control of an object requires adaptive and flexible strategies to cope with emissivity engineering and its temperature dependence. On the other hand, the concept of digital coding allows a high degree of freedom in manipulating the interacting physical quantities based on local discretized features. Learning from this idea, this study put forward the manipulation of spatial infrared emission based on tungsten (W)‐doped VO2 films toward thermal coding. Here, 1‐bit coding worksheets created by low‐emissivity, that is, code '0′, and high‐emissivity, that is, code '1′, shift with materials metal‐insulator phase transition to encode emissive information in the temperature domain. It is shown experimentally that this concept has marked implications on thermal radiation control at Mid‐infrared, among which are as follows: digital anti‐counterfeiting by in‐plane spatial coding of a group of VO2 thin films with various W‐doping density and infrared camouflage by out‐of‐plane spatial coding of them. With a W‐doping gradient of 0%, 0.8%, and 1.7%, the three‐phase transition points in the temperature domain, that is, 72, 63, and 45 °C, give a remarkable modulation range of 27 °C. These phenomena pave the way for new classes of emissivity engineering for more accurate, flexible, and adaptive thermal radiation control. [ABSTRACT FROM AUTHOR]

We report a new strategy in which a thiolate‐protected Ag25 nanocluster can be doped with open d‐shell group 8 (Ru, Os) and 9 (Ir) metals by forming metal hydride (RuH2, OsH2, IrH) superatoms with a closed d‐shell. Structural analyses using various experimental and theoretical methods revealed that the Ag25 nanoclusters were co‐doped with the open d‐shell metal and hydride species to produce superatom‐in‐superatom nanoclusters, establishing a novel superatom doping phenomenon for open d‐shell metals. The synthesized superatom‐in‐superatom nanoclusters exhibited dopant‐dependent photoluminescence (PL) properties. Comparative PL lifetime studies of the Ag25 nanoclusters doped with 8–10 group metals revealed that both radiative and nonradiative processes were significantly dependent on the dopant. The former is strongly correlated with the electron affinity of the metal dopant, whereas the latter is governed predominantly by the kernel structure changed upon the doping of the metal hydride(s). [ABSTRACT FROM AUTHOR]

The compatibility of impurity doping and the suppression of residual stress are crucial for fabricating a semi‐insulating GaN (SI‐GaN) substrate. Herein, a new method to fabricate several SI‐GaN substrates, including a dual‐layer SI‐GaN substrate comprising upper ≈100 μm‐thick GaN doped with Fe, C, or Mn and a lower ≈300 μm‐thick unintentionally doped GaN, using hydride vapor‐phase epitaxy is proposed. As a result, substrates doped with Fe, C, or Mn are successfully produced without cracks and pits. Resistivities around a doping concentration of ≈1018 cm−3 are up to 6.6 × 108, >1012, and >1012 Ω cm at room temperature, respectively. The residual stress of the dual‐layer SI‐GaN film is also evaluated. [ABSTRACT FROM AUTHOR]

The frequent detection of anabolic androgenic steroids (AAS) indicates their popularity among rule‐breaking athletes. The so called long‐term metabolites play a crucial role in their detection, and non‐hydrolysed sulphated metabolites have gained renewed interest, as research has demonstrated their extended detection time compared to the more conventional markers (e.g., for metenolone and mesterolone). Their potential has been investigated using liquid and gas chromatography–mass spectrometry (LC‐ and GC‐MS). However, due to their complementary nature, chances are that the most promising metabolite on one technique does not necessarily exhibit the same behaviour on the other and vice versa. Therefore, a comparison was carried out where as a trial model, metenolone, mesterolone and 17α‐methyltestosterone were selected and the most likely long‐term sulphated metabolites identified on four mass spectrometric instruments. Additionally, using a modified sample preparation procedure, comparison between conventional and non‐hydrolysed sulphated metabolites between different GC‐MS instruments was also included. When focusing on each individual marker, no cases were observed where a single metabolite provided a superior detection time on all instruments. Furthermore, for each AAS, there were incidences where a metabolite provided the best detection time on one instrument but could only be detected for a shorter period or not at all on other instruments. This demonstrates that metabolite detection windows and hence their added‐value as target substance are unique and dependent on the analytical technique and not only on their pharmacokinetic behaviour. Consequently, in each case, a metabolite versus instrument evaluation is needed to maximise the probabilities of detecting doping offences. [ABSTRACT FROM AUTHOR]

Molecular p‐dopants designed to undergo electron transfer with organic semiconductors are typically planar molecules with high electron affinity. However, their planarity can promote the formation of ground‐state charge transfer complexes with the semiconductor host and results in fractional instead of integer charge transfer, which is highly detrimental to doping efficiency. Here, we show this process can be readily overcome by targeted dopant design exploiting steric hindrance. To this end, we synthesize and characterize the remarkably stable p‐dopant 2,2′,2′′‐(cyclopropane‐1,2,3‐triylidene)tris(2‐(perfluorophenyl)acetonitrile) comprising pendant functional groups that sterically shield its central core while retaining high electron affinity. Finally, we demonstrate it outperforms a planar dopant of identical electron affinity and increases the thin film conductivity by up to an order of magnitude. We believe exploiting steric hindrance represents a promising design strategy towards molecular dopants of enhanced doping efficiency. [ABSTRACT FROM AUTHOR]

Lithium manganese‐rich layered oxides are promising cathode materials for lithium‐ion batteries due to their high discharge capacity, but they suffer from capacity fading and poor rate performance. Herein we report on the physicochemical and electrochemical properties of Li1.15Mn0.7Ni0.2Co0.1O2 synthesized via a sol gel method, and study the effect of copper doping on the resulting materials. Electrochemical testing at 1 C revealed 1 % Cu doping enhanced capacity retention (from 58 % to 78 %) but also decreased capacity, while in contrast 10 % Cu doping increased capacity by 21 %. Thorough characterization (including x‐ray diffraction, scanning electron microscopy, inductively coupled plasma‐optical emission spectroscopy, and electrochemical analyses such as voltage vs. capacity and dQ/dV plots) was employed to understand these results, which may be attributed to the competition of two different phenomena depending on the copper content. Consequently, this work highlights the importance of targeting bespoke stoichiometries depending on the desired electrochemical characteristics – an important point for the future design of materials for fast charging and high power applications. [ABSTRACT FROM AUTHOR]

The light extraction efficiency (LEE) of GaN‐based light‐emitting diodes (LEDs) was limited by intense total internal reflection and the photothermal effect. In order to solve this problem, a method to synergistically control the LEE of GaN‐based LEDs by ​​combining the complex‐period photonic crystals (PhCs) with M (M = Al, In) material doping is proposed. The forbidden band width of two‐dimensional (2D) PhC array, three‐dimensional (3D) LED model, M doping, and electromagnetic field distribution are investigated respectively. By doping the M, the LED emission wavelength range is regulated to achieve the dual‐band emission. Furthermore, a triangular complex‐period photonic structure is introduced to establish stacked or etched PhCs models. By combining the plane wave expansion and finite difference time domain algorithm, the structural parameters of PhCs and M concentration dependent LEE are investigated, and the electromagnetic field distribution is explored also. The results show that the optimal LEEs can be achieved are 19.08% and 13.96% for blue light and ultraviolet, respectively, which are larger than that of traditional flat‐panel LED (4%). This work provides theoretical results and technical support for the design of LEDs with high luminous efficiency. [ABSTRACT FROM AUTHOR]

Cuprous oxide (Cu2O) has a narrow band gap of 2.1–2.3 eV, which facilitates the absorption of visible light and the photocatalytic removal of pollutants from water. However, the catalytic efficiency of Cu2O has been affected by the rapidly compounding carriers in the photocatalytic process. In order to achieve adequate separation of the photogenerated carriers, a straightforward liquid‐phase reduction technique was used in this study to successfully obtain praseodymium‐doped cuprous oxide Pr : Cu2O (0, 1, 3, and 5 mol %). Praseodymium ions were successfully doped into the Cu2O lattice interstitial, as demonstrated by XRD and SEM studies, and the doped praseodymium ions decreased the crystallite size. The FT‐IR peak also confirmed the existence of Cu2O at 631 cm−1. With the increase of Pr doping to 3 %, the band gap gradually decreased to 2.12 eV. Experiments on the degradation of methyl orange (MO) under visible light irradiation showed that 3 % Pr : Cu2O photocatalyst showed the best photocatalytic performance. The Pr doping reduced the recombination of photogenerated electron‐hole pairs and enhanced the photocatalytic activity of Cu2O, according to the analysis results of PL, EIS and transient photocurrent response. Combining these results with active radical capture experiments, the functioning mechanism of the Pr : Cu2O photocatalyst was examined. [ABSTRACT FROM AUTHOR]

Melanins are a class of conjugated biopolymers with varying compositions and functions, which have a variety of potential medical and technical applications. Here, this work examines the conjugated polymers derived from a variety of phenolic monomers (catechol (CAT), levodopa (DOPA), and homogentisic acid (HGA)), using a selection of different analytical chemistry techniques to compare their properties with a view to understanding structure–function relations. The polymers display measurable conductivity, with electronic properties tuned by the functional groups pendant on the polymer backbones (which served as dopants) suggesting their potential for application in electronic devices. [ABSTRACT FROM AUTHOR]

Luminescent solar concentrators (LSCs) are capable of absorbing solar light over a large area, which subsequently converts light into luminescence at a red‐shifted wavelength and then redirects it to a smaller target to increase the per‐unit yield of photovoltaic devices. Among various LSC materials, perovskite nanocrystals (NCs) have attracted great attention due to their adjustable band gap, multi‐exciton effect, and good stability. In this review, a brief introduction of LSCs, including their advances and principles, is given, followed by a summary of perovskite‐NCs‐based LSCs. The selected examples for component optimization of inorganic perovskite NCs are outlined after an introduction to the structure and properties of perovskite NCs. The absorption and/or emission peaks of all‐inorganic and inorganic–organic hybrid perovskite NCs can be efficiently regulated, which not only increases the Stokes shift but also improves the stability. Excellent performance and operability show a bright application prospect of perovskite NCs in the field of LSC applications. [ABSTRACT FROM AUTHOR]

The new zinc borate Zn3B4O9 was synthesized at high‐pressure/high‐temperature conditions of 10 GPa and 1173 K in a Walker‐type multianvil pressure device. It crystallizes in the space group P1‾ ${\bar{1}}$ (no. 2) with a=5.5028(2) Å, b=6.7150(3) Å, c=7.8887(3) Å, α=83.99(1)°, β=73.38(1)°, γ=74.75(1)°, V=269.35(2) Å3, and two formula units (Z=2) per unit cell. The structure was confirmed via single‐crystal X‐ray diffraction. Zn3B4O9 can be synthesized phase pure, which is shown with a Rietveld refinement. IR‐spectroscopic data of a powder sample were collected. [ABSTRACT FROM AUTHOR]

Exploring efficient cocatalysts capable of accelerating surface catalytic reaction is of great significance for the development of solar‐driven hydrogen production. Herein, on the basis of NiFe hydroxide, we developed a series of Pt doped NiFe‐based cocatalysts to promote the photocatalytic hydrogen production of graphitic carbon nitride (g‐C3N4). We find that the Pt doping can trigger phase reconstruction of NiFe hydroxide and lead to the formation of NiFe bicarbonate, which displays higher catalytic activity toward hydrogen evolution reaction (HER). The Pt doped NiFe bicarbonate modified g‐C3N4 shows excellent photocatalytic activity with H2 evolution rate up to 100 μmol/h, which is more than 300 times that of pristine g‐C3N4. The experimental and calculation results demonstrate that the greatly improved photocatalytic HER activity of g‐C3N4 is not only due to the efficient carrier separation, but also attributed to the accelerated HER kinetics. Our work may provide guidance for designing novel and superior photocatalysts. [ABSTRACT FROM AUTHOR]

The diffusion of magnesium in monocrystalline dislocation‐free Czochralski silicon (Cz–Si) with an oxygen concentration of (3–4) × 1017 cm−3 is studied. Initial silicon wafers are doped with Mg by using the sandwich technique. The impurity diffusion profiles are investigated in n‐Si samples by the differential conductivity method. The diffusivity of electrically active magnesium in the temperature range of 1,100–1,250 °C is two to three orders of magnitude lower than the values observed at doping high‐purity silicon crystals grown by the float‐zone method (Fz–Si). The diffusion in Cz–Si is retarded through the trapping of diffusing Mg atoms by oxygen‐related traps. The observed high value of the activation energy of Mg diffusion in investigated samples (4.1 eV) is due—along with the migration energy of interstitial magnesium in the crystal lattice (1.83 eV) —to the significant binding energy of Mg atoms with traps (2.27 eV). A study of the temperature dependence of the Hall effect in bulk‐doped samples reveals two types of deep double donors: interstitial Mg atoms and MgO complexes. [ABSTRACT FROM AUTHOR]

β‐tricalcium phosphate (β‐TCP, β‐Ca3(PO4)2) is an attractive biomaterial for bone repair applications. However, its sintering and mechanical properties are limited by a problematic phase transition to α‐TCP. Cationic doping of β‐TCP is able to postpone the formation of α‐TCP allowing higher sintering temperatures and better mechanical properties. The co‐doping of β‐TCP with Mg2+ and Sr2+ has already been studied in detail, but the addition of antibacterial cations (Ag+ and Cu2+) on the Mg–Sr β‐TCP co‐doped composition remains unexplored. Thus, two co‐doped β‐TCP compositions were realized by aqueous precipitation technique without any secondary phase and compared with undoped β‐TCP: Mg–Sr (2.0–2.0 mol%) and Mg–Sr–Ag–Cu (2.0–2.0–0.1–0.1 mol%). Differential thermal analysis and dilatometry analyses showed a slight decrease of the β‐TCP → α‐TCP phase transition temperature for the Mg–Sr–Ag–Cu (2.0–2.0–0.1–0.1% mol) composition as compared to the Mg–Sr (2.0–2.0 mol%). However, both exhibited much higher transition temperatures than undoped β‐TCP. The addition of Ag+ and Cu2+ slightly reduces the grain size after sintering compared to the Mg–Sr (2.0–2.0 mol%) and the undoped compositions. The co‐doped compositions also exhibited improved mechanical properties, specifically a higher Vickers hardness and elastic modulus. Finally, cell proliferation assays showed that the presence of dopants, even Ag+ and Cu2+, does not affect the survival and proliferation of cells. Thus, the use of Mg2+, Sr2+, Ag+, and Cu2+ co‐doped β‐TCP could be very promising for biomedical applications due to the improvements of these dopants on the thermal stability and mechanical and biological properties. [ABSTRACT FROM AUTHOR]

Mx‐MoO3‐α‐NaFe2(MoO4)3‐α‐FeMoO4 (M = Al, Co, Ni, and Er) nanomaterials were fabricated by the hydrothermal method in the present study. XRPD, FESEM, TEM, BET‐BJH, UV‐Vis, and VSM analyses were used to characterize and study the physical attributes of the as‐synthesized samples. Rietveld analysis data illustrated that the products were a mixture of α‐NaFe2(MoO4)3, α‐FeMoO4, MoO3, and Fe2O3 crystal phases. UV‐Vis spectra indicated that the obtained samples had a small direct band gap energy amount at about 1.3–1.5 eV. VSM analysis confirmed that the as‐fabricated samples had magnetic properties. However, most ferromagnetic behaviors were observed by doping Ni into the host crystal system. Catalytic synthesis of some 5‐aryl‐1H‐tetrazole analogs was performed under heat, microwave, and ultrasonic conditions. Reaction time, temperature, and solvent type parameters were studied to find the optimum conditions. High efficiency was obtained when ethyl alcohol was used as the reaction mixture solvent. [ABSTRACT FROM AUTHOR]

Anti‐doping organisations are mandated to provide a comprehensive anti‐doping programme, which aims to detect, deter and prevent doping in sport. Direct detection of prohibited substances and methods by collection of biological samples from athletes makes up about half of the global anti‐doping budgets but has in the last decade been under critical scrutiny for its lack of efficiency. To ensure optimum detection and deterrence of testing and prevention efforts, a better understanding of doping practices and comparison of different doping test strategies are needed. This study evaluates 17 years of doping test statistics and Anti‐Doping Rule Violations (ADRVs) from the perspectives of a national anti‐doping organisation. A total of 48 709 samples (2865 ± 220 annually) were collected by Anti‐Doping Norway in the period 2003–2019, which resulted in total 216 ADRVs (12.7 ± 3.7 annually), providing an average sample‐to‐ADRV rate of 0.44% when including urine, blood and ABP samples. Most athletes who committed ADRVs were men participating in ball and team or strength sports at a national or recreational level. Few ADRVs were recorded among elite athletes and in most high‐risk sports, despite these groups being subjected to the highest number of doping tests. The number of annual ADRVs did not correlate with the corresponding number of collected doping samples. However, systematic use of intelligence in the test planning process was associated with an increase in ADRVs. Anti‐doping organisations would benefit from improving their target testing capability and to take an intelligence‐led approach in planning doping tests. [ABSTRACT FROM AUTHOR]

A bioanalytical method for detecting the ultra‐long‐acting beta2‐agonist (U‐LABA) inhaled vilanterol and its metabolites, GSK932009 and GW630200, in urine was developed to potentially monitor permitted therapeutic versus prohibited supratherapeutic use in sport. The World Anti‐Doping Agency (WADA) has established urinary concentration thresholds for the beta2‐agonists salbutamol and formoterol. Therapeutic use of vilanterol (25 μg once daily) was recently permitted by WADA; however, there is no established decision limit for adverse analytical findings due to insufficient urine concentration data. In this study, we validated an assay to detect vilanterol in urine collected from four healthy male and female athletes 0–72 h who received inhaled corticosteroid fluticasone furoate/U‐LABA vilanterol (800/100 μg) combination, four times the normal therapeutic dose. After administration, subjects performed 1 h of bike ergometer exercise. The experiment was conducted again after repeat dosing for 1 week. Our method utilised liquid chromatography with tandem mass spectrometry and was validated over urine concentrations of 5–5000 (vilanterol) and 50–50,000 pg/ml (GSK932009 and GW630200). Plasma samples were analysed for vilanterol, using a previously validated assay. The peak concentration values for urine vilanterol, GSK932009 and GW630200 were 9.5, 10.4 and 0.17 ng/ml, for single dosing, and 18.6, 19.5 and 0.20 ng/ml, for repeat dosing. Urine samples from four volunteers using the final validated method are reported, demonstrating this assay has sensitivity to detect vilanterol or GSK932009 in urine for ≥72 h post single or repeat dosing with 800/100 μg fluticasone furoate/vilanterol, whereas GW630200 was quantifiable ≤4 h post dose. [ABSTRACT FROM AUTHOR]

The effect of substitution of Cr in 2H‐CrSe2 by Fe and Co on its electronic, optical, and magnetic properties is studied by first‐principles density functional theory. Spin‐polarized semiconducting state is realized in CrSe2 by substitutional doping of Fe and Co, while a semimetallic state is obtained by Fe doping and the magnetic moment after Fe doping is 4.52 μB. On Co substitution, it is observed that the system presents metallic properties, with relatively low light absorption and reflectance, and good transparency. The magnetic moment after Co doping is 2.71 μB. The absorption coefficient of CrSe2 to visible light increases with the doping of Fe and Co, and the peak value is redshifted, which is conducive to the further application of CrSe2 in the field of optoelectronics. [ABSTRACT FROM AUTHOR]

The discovery of superconductivity in doped infinite‐layer nickelate thin films has brought increased attention to the behavior of the doped perovskite phase. Despite this interest, the majority of existing studies pertain to hole‐doped perovskite rare‐earth nickelate thin films, while most electron‐doping studies have been performed on bulk materials so far. To tackle this imbalance, a detailed study that addresses doping of NdNiO3 thin films using A‐site substitution is presented, using Pb as a dopant and taking advantage of its valence‐skipping nature. Through a combination of complementary techniques including X‐ray diffraction, transport measurements, X‐ray absorption spectroscopy, electron energy‐loss spectroscopy and scanning transmission electron microscopy, the valence of Pb in the Nd1−xPbxNiO3 structure is confirmed to be 4+, and the behavior of the doped thin films is found to be controlled by a competition between carrier injection and structural distortions, which respectively reduce and increase the metal‐to‐insulator transition temperature. This work provides a systematic study of electron doping in NdNiO3, demonstrating that A‐site substitution with Pb is an appropriate method for such doping in perovskite rare‐earth nickelate systems. [ABSTRACT FROM AUTHOR]

The benefits of covalent grafting of fluorine atoms onto carbonaceous materials are described for the design of new electrocatalysts for low‐temperature fuel cells. In order to obtain the best results, the fluorination conditions must be carefully chosen according to the physicochemical properties of the starting materials (specific surface area, pore size distribution, crystallinity, and doping). By describing the main fluorination routes, the article aims to help in the choice of efficient treatment conditions. The effects of fluorination on the performance of the platinum group metal (PGM)‐based catalyst and the non‐PGM‐based electrocatalyst are discussed. Finally, future research prospects and technical challenges of fluorination for fuel cells are proposed. [ABSTRACT FROM AUTHOR]

Supramolecular polymerization of π‐conjugated amphiphiles in water is an attractive approach to create functional nanostructures. Here, we report on the synthesis, optoelectronic and electrochemical properties, aqueous supramolecular polymerization, and conductivity of polycyclic aromatic dicarboximide amphiphiles. The chemical structure of the model perylene monoimide amphiphile was modified with heterocycles, essentially substituting one fused benzene ring with thiophene, pyridine or pyrrole rings. All the heterocycle‐containing monomers investigated underwent supramolecular polymerization in water. Large changes to the monomeric molecular dipole moments led to nanostructures with low electrical conductivity due to diminished interactions. Although the substitution of benzene with thiophene did not notably change the monomer dipole moment, it led to crystalline nanoribbons with 20‐fold higher electrical conductivity, due to enhanced dispersion interactions as a result of the presence of sulfur atoms. [ABSTRACT FROM AUTHOR]

Scintillators are essential for high‐energy radiation detection in a variety of potential applications. However, due to complex fabrication processes and nanocrystal homogeneity, conventional scintillators are challenging to meet the need for cost‐effective, environmentally friendly, and flexible X‐ray detection. Here, monodisperse nanocrystals (NCs) with small grain size and colloidal stability are obtained by adjusting the doping concentration of Zn2+ ions and controlling the morphology uniformity of Cs3Cu2I5 NCs. The photoluminescence quantum yield (PLQY) for the optimal doping concentration is as high as 92.8%, which is a 28.5% improvement compared to nondoped NCs. Density functional theory calculations reveal that the Zn2+ dopant inclines to occupy Cu sites and the I‐rich condition suppresses the formation of I vacancy, enriching the excited electron density at the band‐edge to enhance the self‐trapped exciton emission. Moreover, high luminescence performance and flexible X‐ray scintillator films are prepared using Zn2+‐doped Cs3Cu2I5 NCs, with a spatial resolution of up to 15.7 lp mm–1. This work provides an effective strategy for the development of environmentally friendly, low‐cost, and efficient blue‐emitting 0D all‐inorganic metal halides, as well as shows their great potential for high‐performance flexible lead‐free and low‐toxicity X‐ray detector applications. [ABSTRACT FROM AUTHOR]

In this work, first‐principles calculations were used to study the structural, elastic and thermodynamic properties of Mg17Al12 and M‐doped Mg17Al12 (Mg16Al12M, M = Ga, In, Ge, Sn, Pb) compounds. The calculated results show that Mg16Al12M compounds have negative defect formation energies, the calculated phonon dispersions have no imaginary frequencies, and their single‐crystal elastic constants satisfy the mechanical stability criterion. Thus, Mg16Al12M compounds are thermodynamically, dynamically and mechanically stable. The calculated GH/BH, Poisson's ratio v and Cauchy pressure values indicate that Mg17Al12 and Mg16Al12M are ductile, the ductility of the doped system is greater than that of Mg17Al12. Mg17Al12 and Mg16Al12M have elastic anisotropy, and the order of anisotropy is Mg16Al12Sn > Mg16Al12Ga > Mg16Al12In > Mg17Al12 > Mg16Al12Ge > Mg16Al12Pb. Finally, the minimum thermal conductivities based on Clarke's and Cahill's models were discussed, and the results show the heat transfer rates of Mg17Al12 and Mg16Al12M along the [111] direction are faster than those along other directions. [ABSTRACT FROM AUTHOR]

Na–CO2 batteries are important devices for immobilizing CO2 and storing renewable energy. However, the Na–CO2 batteries with liquid electrolytes have the issues of electrolyte volatilization and poor cyclability. Herein, a composite solid‐state electrolyte consisting of Ca‐doped Na3Zr2Si2PO12 and polyvinylidene fluoride‐co‐hexafluoropropylene (PVDF‐HFP) is synthesized. The solid composite electrolyte Na3.2Zr1.9Ca0.1Si2PO12–PVDF‐HFP shows a high ionic conductivity of 1.32 × 10−4 S cm−1 at room temperature and a broad electrochemical window up to 5.15 V, as well as excellent durability. The assembled solid‐state Na–CO2 battery with this composite electrolyte delivers a high discharge‐specific capacity up to 3320 mA h g−1 and excellent cycling stability. [ABSTRACT FROM AUTHOR]

Covalent adaptable networks (CANs) are reprocessable polymers whose structural arrangement is based on the recombination of dynamic covalent bonds. Composite materials prepared by incorporating magnetic particles into CANs attract much attention due to their remote and precise control, fast response speed, high biological safety and strong penetration of magnetic stimuli. These properties often involve magnetothermal effect and direct magnetic‐field guidance. Besides, some of them can also respond to light, electricity or pH values. Thus, they are favorable for soft actuators since various functions are achieved such as magnetic‐assisted self‐healing (heating or at ambient temperature), welding (on land or under water), shape‐morphing, and so on. Although magnetic CANs just start to be studied in recent two years, their advances are promised to expand the practical applications in both cutting‐edge academic and engineering fields. This review aims to summarize recent progress in magnetic‐responsive CANs, including their design, synthesis and application. [ABSTRACT FROM AUTHOR]

The influence of N/F substitution and site‐exchange of Li and Fe ions on properties of Li2FeSiO4 are investigated by first‐principles calculation, including the structural parameters, mechanical, electrochemical, and magnetic properties of Li2FeSiO4. The calculated results show that site‐exchange of Li and Fe ions occurs during the removal of lithium ions for Li2FeSiO3.5R0.5 (R = O, N, and F), and the cell volume changes greatly. It is found that substitution of O with F can decrease the cell volume change and improve the cyclic stability of Li2FeSiO4. Furthermore, the theoretical average deintercalation voltages can be effectively reduced by N and F doping. The densities of states and magnetic moment show that substitution of O with N and F can improve the conductivity of Li2FeSiO4, and F doping is conducive to the extraction of more Li+ from Li2FeSiO4 system. [ABSTRACT FROM AUTHOR]

The Pt‐Sn/Al2O3 catalyst has been successfully commercialized for propane dehydrogenation, but it is still highly desirable to further improve its catalytic performance for maximizing the utilization efficiency of noble metal Pt. Herein, this work demonstrates that doping Nb and Ta into Pt‐Sn/Al2O3 has great impacts on its structure, and significantly improved catalytic performances are achieved in Pt‐Sn‐X/Al2O3(X=Nb and Ta). It is found that the incorporation of Nb and Ta into Pt‐Sn/Al2O3 can promote the dispersion of Pt‐Sn particles, which results in Pt‐Sn clusters being highly dispersed at the surface of Al2O3. Moreover, the presence of Nb and Ta makes the SnOx species less reducible, and thus the Pt‐Sn particles become more stable at high temperature. Systematic exploration allows to obtain the optimized Pt‐Sn‐Nb5.0/Al2O3 and Pt‐Sn‐Ta1.0/Al2O3, and these two catalysts exhibit high initial propane conversion (above 43.8 % and 50.4 %) with propylene selectivity of above 98 %. Most importantly, they show excellent regeneration in propane dehydrogenation, and their catalytic performance can be completely restored by a simple calcination. [ABSTRACT FROM AUTHOR]

Performance enhancement drugs build muscle mass and increase stamina in athletes, making them a potential candidate for abuse in sports competitions. World Anti‐Doping Agency is an international organization responsible for developing standard guidelines, listing agents prohibited for usage in all athletic events, and taking stringent actions for any discrepancies. Sophisticated analytical instruments and statistical tools are regularly used for the chemical fingerprinting of doping agents in different biological matrices. There is an ever‐increasing demand for developing novel and sensitive mass spectrometry methods for detecting new substances of abuse. This review focuses on applying hyphenated chromatographic techniques, emphasizing advanced mass spectrometric methods to analyze different classes of prohibited substances listed by the World Anti‐Doping Agency. [ABSTRACT FROM AUTHOR]