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Metallurgical solid wastes, such as metallurgical dust and mud containing iron, are formed during metallurgical sintering. They are composed of complex components and are harmful to the environment. Alongwith the current metallurgical sintering process, NOx emission control is the top priority of pollution control in the steel industry. This paper proposes a new idea of preparing doped low-temperature catalysts using metallurgical dust and mud containing iron. Herein, the metallurgical iron-containing mud was modified by acid leaching, and the products were doped with Ce and Mn by the precipitation method to prepare a new type of catalyst. The prepared Mn–Ce-doped mud-based catalyst (Mn0.05Ce0.1/ADM, the ADM represents the dust and mud from acidolysis) was characterized via X-ray diffraction, nitrogen adsorption/desorption isotherm method, scanning electron microscopy, X-ray photoelectron spectroscopy, temperature-programmed desorption of ammonia, and temperature-programmed reduction of hydrogen. The results showed that Mn0.05Ce0.1/ADM achieveda NOx removal rate of >90% within a wide temperature range from 170 ℃ to 430 ℃. Moreover, itshowed excellent SO2 and H2O resistance. A microstructural analysis revealed that the strong interaction between Fe–Ce–Mn could improve the surface acidity of the catalyst, thus increasing Lewis acid sites. Further, the active components of Mn0.05Ce0.1/ADM prepared by Ce and Mn exhibited good dispersion and an excellent mesoporous structure. In particular, Mn doping could inhibit the crystallization degree on the catalyst surface, improve the dispersed state of the active components in Mn0.05Ce0.1/ADM, and help improve the catalyst SCR (Selective Catalytic Reduction) activity. Combined with theanalysis of the factors influencing the catalyst, the results showed that the Ce–Mn doped catalyst increased the Fe3+ concentration while sacrificing a certain amount of Ce3+ and high-valent Mn+, achieving the most balanced denitration activity. Mn0.05Ce0.1/ADM formed more NO active centers by increasing the Lewis acid content to promote the generation of nitrate species and NO2. Moreover, Mn doping enhanced the Fe–Ce synergy, which makes active species (Mn–Ce–Fe) easier reduction. In particular, the increase in surface oxygen mobility could significantly improve the low-temperature activity of the catalyst. The water and sulfur resistance tests of the three catalysts (Ce0.1/ADM、Mn0.05/ADM、Mn0.05Ce0.1/ADM) showed that Mn0.05Ce0.1/ADM benefited from the excellent water and sulfur resistance of Fe and Ce. The results showed that doping Ce into ADM inhibited the adsorption of H2O molecules on the active component β-MnO2 and also the reaction of SO2 molecules with the component. The results reported herein can provide theoretical references for the high-value-added utilization of metallurgical solid wastes.

The rapid development of lithium-ion batteries (LIBs) has been a great driving force for the progress of human society. The continuous development of electric vehicles, power grids, electronic products and other industries all have an increasing demand for high energy density batteries. The primary factor limiting the development of LIBs that have high energy and low cost is the cathode material. In the existing cathode materials, the Lithium-rich (Li-rich) cathodes compensate for capacity by redox reactions involving anions and cations, which have become the ideal cathode materials for the future LIBs due to their ultra-high specific capacity and energy density. However, the problems such as structural deterioration and lattice oxygen evolution during the cycle of Li-rich cathodes have seriously hindered the commercialization of Li-rich cathodes. Therefore, this paper has discussed the factors leading to the degradation of the electrochemical performance of Li-rich cathodes from the aspects of electron energy state and microstructure. Meanwhile, it also discussed the latest development in the modification and analysis of Li-rich cathodes including multifunctional surfaces, gradient doping and high entropy doping matters, in order to provide useful insights into the future preparation and modification of these cathodes. [ABSTRACT FROM AUTHOR]

Vanadium oxides, being a potential cathode material for lithium ion batteries (LIBs), are extensively interested from scientists owing to their greater advantages in terms of theoretical specific capacity, energy density, and cost. However, the specific capacity of vanadium oxides decays irreversibly during cycling process for reasons including its structural stability and poor electrical conductivity. As a consequence, the electrochemical performance of V 2 O 5 ·4VO 2 electrode materials，in this paper, is further enhanced via metal ion doping. Herein, Al-doped 3D flower-like V 2 O 5 ·4VO 2 microspheres are successfully prepared via a green and simple hydrothermal synthesis with Al(NO 3) 3 ·9 H 2 O as the aluminum source. It is revealed that when the Al doping amount is n(Al3+)/n(V5+)= 5.00%, the prepared 3D flower-like V 2 O 5 ·4VO 2 microsphere exhibits high specific capacity (the specific capacity is up to 385.1 mAh/g at a current density of 0.1 A/g), outstanding rate performance (presenting a high capacity of 264.1 mAh/g at 1 A/g current density), and excellent cycling stability (90.7% capacity retention after 120 cycles at 1 A/g current density). As a result, Al-doped 3D flower-like V 2 O 5 ·4VO 2 microspheres hold enormous commercialization potential as cathode materials for LIBs. • The 3D flower-like V 2 O 5 ·4VO 2 microspheres with Al-doped cathode is synthesized by a green hydrothermal method. • The appropriate amount of Al doping causes a larger number of reactive sites as well as a greater specific surface area. • The prepared 3D flower-like V 2 O 5 ·4VO 2 microspheres with Al-doped cathode exhibits Superior cycling and rate performance (264.1 mAh/g at 1 A/g). [ABSTRACT FROM AUTHOR]

Quantum capacitance (C Q) is one of the key parameters that determine the energy density of supercapacitors. In this paper, density functional theory (DFT) was used to explore the effects of different types of B and N doping, and the adsorption of transition metal atoms Au (Ag, Cu, Ti, Mn) on the structural stability, C Q and surface storage charge of graphyne (GY). We found that the C Q of GY can be adjusted by changing the type of adsorbed transition metal and the concentration of doped B and N atoms, improving the defect that the C Q of GY tends to zero at a negative potential. The C Q and surface storage charges of GY monotonically increase with increasing N and B doping concentrations under positive and negative bias voltages, respectively. The adsorption of Ti atoms at the most stable position increases the C Q of GY to 66.1 μF/cm2 (0.22 V), improved C Q at low potential. The research results provide an effective and simple new idea for the design of high energy density GY supercapacitors. • The modulated graphdyne improves the quantum capacitance of negative potential. • The charge accumulation of B/N-doped GY is proportional to the doping concentration. • Ti-doping structure shows the highest quantum capacitance of 66.1 μF/cm2. • Doping and Adsorption can enhance the quantum capacitance of graphdyne electrode materials. [ABSTRACT FROM AUTHOR]

The direct bandgap nonmagnetic semiconductor two-dimensional SiC has attracted extensive research attention recently due to its unique physical and chemical properties. The synthesis of materials is inevitably affected by atmospheric elements. In this paper, the effects of adsorption and doping of atmospheric elements (H, C, N, and O) on the structure, electronic, and magnetic properties of SiC were studied based on first-principles calculations. It was found that O-doped SiC is unstable. O-adsorbed SiC and C-doped SiC exhibit non-magnetic semiconductor properties with reduced bandgap. In contrast, a semi-metallic state emerges in H- and N-adsorbed, as well as H- and N-doped SiC. In addition, C-adsorbed SiC displays a magnetic semiconductor state, which may have significant potential for application in spintronics due to the high Curie temperature of 441 K. These findings demonstrate that the electronic and magnetic properties of SiC could be effectively tuned by doping or adsorbing atoms of atmospheric elements. [ABSTRACT FROM AUTHOR]

Due to the rapidly growing energy demand and the development of electric vehicles and energy storage systems, research on high-capacity batteries is actively conducted. Among them, the Li-ion battery with a Ni-rich cathode has recently come under the spotlight due to its high capacity. However, the Ni-rich cathode suffers from problems such as electrode and interface stability, structural stability and gas emissions, among others. These issues result in poor cycling efficiency and increase the risk of battery combustion, requiring a solution. With the recent development of computational methods, they are applied to Li-ion batteries, including, but not limited to battery modeling and lithium diffusion. The calculation method has a complementary relationship with the experiments. Before conducting the experiment, the calculation method can be used to check whether the dopant and coating materials are feasible with the Ni-rich cathode, as well as the mechanism of performance improvement according to the strategy. Additionally, experimental results can be compared with calculation methods to increase the reliability of the calculations. Therefore, we summarized the current problems of Ni-rich cathodes such as phase transitions and cation mixing currently facing Ni-rich cathodes, as well as the reduction of electrochemical performance and stability problems caused by the generation of Residual Li, Cracks, and gas. Furthermore, experiments and computing methods for performance improvement using various strategies such as doping, coating, washing, and single crystalline cathodes to solve this problem were summarized. The experiments and calculation results summarized in this paper can enable accelerated discovery of Ni-rich cathode materials in the future and can provide insights into exploring the mechanisms of various phenomena. • A Study on the Problems in NCM for Utilizing High Capacity High-Ni NCM. • Calculation-based Li-ion battery modeling. • Integrate experiment and calculation for reliable NCM problem-solving. [ABSTRACT FROM AUTHOR]

A high-efficiency nickel-doped porous biochar (PCNi3) has been successfully synthesized from chestnut shell waste via a two-step chemical activation treatment with H3PO4. The influences of microstructure, surface morphology, elemental composition, surface functional groups, specific surface area, porosity, pore-size distribution, and chemical properties of the surface state on the removal of Cr (VI) from water were thoroughly investigated by using XRD, FESEM, FTIR, Raman, BET, and XPS testing methods, N2 adsorption, and XPS testing techniques respectively. The results indicate that the treatment of H3PO4 activation and nickel doping can effectively improve microstructure characteristics, thus promoting Cr (VI) adsorption capacity. The effects of initial solution pH, solution concentration, time, and temperature on remediation are revealed. The Cr (VI) uptake experiments imply that the adsorption curves of PCNi3 fit well with the Freundlich model, the pseudo-second-order kinetic model, and the Elovich model. The adsorption process of PCNi3 can be regarded as a spontaneous endothermic reaction limited by diffusion among particles and porosity. The adsorption mechanisms of PCNi3 are ion exchange, complexation, electrostatic adsorption, and coprecipitation with the assistance of surface active sites, porosity, Ni0 particles, and Ni7P3. With these advantages, PCNi3 reveals an extraordinary Cr (VI) removal capacity and a strong ability to reduce Cr (VI) to Cr (III). [ABSTRACT FROM AUTHOR]

Highlights: Surface energy and surface Pourbaix diagram reveal that ZrO2 ( 1 ¯ 11 ) is the most thermodynamically stable facet and is preferentially occupied by HO* at the equilibrium potential of oxygen evolution reaction (OER). Microkinetic modeling analyzed the OER activity of 40 single-metal doped ZrO2 and identified 16 metals exhibit improved catalytic activity, with Rh and Fe dopants showing the remarkable improvement. Thermodynamic free energy diagrams, density of states analysis, and ab initio molecular dynamics simulations further confirm that Fe–ZrO2 and Rh–ZrO2 are highly promising catalysts for OER, showcasing low ΔG for the rate-determining step, high conductivity, and exceptional stability. The design of cost-effective electrocatalysts is an open challenging for oxygen evolution reaction (OER) due to the "stable-or-active" dilemma. Zirconium dioxide (ZrO2), a versatile and low-cost material that can be stable under OER operating conditions, exhibits inherently poor OER activity from experimental observations. Herein, we doped a series of metal elements to regulate the ZrO2 catalytic activity in OER via spin-polarized density functional theory calculations with van der Waals interactions. Microkinetic modeling as a function of the OER activity descriptor (GO*-GHO*) displays that 16 metal dopants enable to enhance OER activities over a thermodynamically stable ZrO2 surface, among which Fe and Rh (in the form of single-atom dopant) reach the volcano peak (i.e. the optimal activity of OER under the potential of interest), indicating excellent OER performance. Free energy diagram calculations, density of states, and ab initio molecular dynamics simulations further showed that Fe and Rh are the effective dopants for ZrO2, leading to low OER overpotential, high conductivity, and good stability. Considering cost-effectiveness, single-atom Fe doped ZrO2 emerged as the most promising catalyst for OER. This finding offers a valuable perspective and reference for experimental researchers to design cost-effective catalysts for the industrial-scale OER production. [ABSTRACT FROM AUTHOR]

The electronic, optoelectronic, linear and nonlinear optical (NLO) properties of some corannulenes of formula C5n2H5n (with n = [2,4]), doped with boron–nitride units at the rim position, have been studied using density functional theory (DFT) and time-dependent DFT (TD-DFT) calculations. This work aims to substitute B–N units at the rim position in some corannulene structures in order to propose new materials for electronic, optoelectronic and nonlinear optical applications. According to the investigations carried out, the analysis of the cohesive energies of the studied corannulene derivatives indicates that they are energetically stable materials. Based on the |HOMO–LUMO| energy gap values, we find that corannulenes doped with B–N units at the rim position exhibit the same semiconducting nature as the parent structure from which they derive. Moreover, the value of first-order hyperpolarizability (β0) of structures containing B–N isoelectronic units at the rim position in corannulenes is higher than that of the urea molecule considered as a reference molecule commonly used in nonlinear optics (NLO). We hope that the present work will also pave the way for the design of high-performance nonlinear optical materials based on boron–nitride-doped corannulene at the rim position. TD/B3LYP-D3/6–31 + G(d) calculations revealed that among the proposed derivatives, the compounds C35B5N5H15 and C70B5N5H20 exhibit high photo-current response in the visible range. This gives these new materials good performances for optoelectronic applications. Although all the studied properties of the doped structures with B–N units at the rim position are not better than those at the spoke position reported in the literature, these proposed systems have good capabilities to be used as suitable organic semiconductors in the photovoltaic field. [ABSTRACT FROM AUTHOR]

The work presents the study results of the determination of the resistance of neodymium zirconate doped with MgO and Y2O5 to radiation damage stemming from irradiation with heavy ions akin to nuclear fuel fission fragments. The attraction towards this type of ceramics stems from its potential to raise the operational temperatures within the core of next-generation nuclear reactors. This is owed to its superior thermal conductivity when compared to zirconium dioxide, coupled with the heightened strength parameters that signify the ceramics' resistance against external factors. The main results of this study are to determine the influence of the formation of substitution or interstitial phases when adding magnesium and yttrium oxides to the composition, on increasing the stability of the strength and thermophysical parameters of neodymium zirconate to the radiation defects accumulation in the damaged surface layer. During the studies, it was found that the formation of impurity phases in the form of MgO inclusions (when it is added to the composition) and a substitution phase of the Y2Zr2O7 type (with the addition of Y2O5) results in an elevation in the hardness and crack resistance stability of neodymium zirconate ceramics, which indicates the positive effect of doping linked to the formation of additional interphase boundaries that prevent strain embrittlement of the damaged layer under high-dose irradiation. During determination of the thermophysical parameters of the studied neodymium zirconate ceramics, it was observed that the formation of interphase boundaries during doping not only enhances thermal conductivity but also mitigates the decline in the thermal conductivity coefficient during irradiation for two-phase ceramics in comparison with undoped neodymium zirconate ceramics. [ABSTRACT FROM AUTHOR]

In this work, Zinc oxide (ZnO) nanoparticles in pure, doped and concurrently co-doped with magnesium and copper were synthesized via simple co-precipitation method. The optical properties and morphology of the products were studied. Results from ultraviolet–visible (UV–Vis) spectroscopy showed absorption at 378 nm which proved the formation of pure ZnO and further blue and red shifts occurred in UV absorbance depending on the type of the dopant and its concentration. UV–Vis data also showed a good tailoring of the band gap from 2.87 to 3.56 eV depending upon the dopant. X-ray diffraction studies confirmed the formation of ZnO in all samples with a wurtzite hexagonal structure. The results from field emission scanning electron microscopy confirmed the average size of all particles to be 60 nm with a flake-shaped form. Fourier-transform infrared spectra further verified the presence of different functional groups and formation of ZnO in all samples. This study confirmed that ZnO accompanied by some impurities is a great option for optoelectronic applications such as UV photo-absorbers in the UVA range. [ABSTRACT FROM AUTHOR]

Y2O3 and SiO2 co-doped ZrO2 powders with various additions of SiO2 substitution Y2O3 have been prepared by co-precipitation method. The microstructure, phase and chemical composition, phase transformation process, and phase stability after repeated calcination at 1300 °C of these powders have been investigated. The main phase of all powders is t′-ZrO2. There is no phase transformation when the powders are heated from room temperature to 1400 °C. Increasing the ratio (1:4 to 4:1) of SiO2 substitution Y2O3 will reduce the tetragonality of the powder at 1300 °C. The amorphous SiO2 will inhibit the growth of grains to a certain extent during the calcination process. The increase of the substitution ratio of SiO2for Y2O3will lead to the m-ZrO2more stable and the t′-ZrO2more unstable. The relationship among the SiO2 substitution Y2O3 addition, phase composition, and high-temperature phase stability of the powders has been discussed. Highlight: The main phase of the Y2O3 and SiO2 co-doped ZrO2 powder is t′-ZrO2. Increasing the ratio of SiO2 substitution Y2O3 will reduce the tetragonality of the powder at 1300 °C. The amorphous SiO2 will inhibit the growth of grains to a certain extent during the calcination process. The increase of the substitution ratio of SiO2 for Y2O3 will lead to the m-ZrO2 more stable and the t′-ZrO2 more unstable. [ABSTRACT FROM AUTHOR]

Bimetallic nanoclusters have attracted great interest due to their ability to enhance the catalytic properties of nanoclusters through synergetic effects that emerge from the combination of the metal nanocluster with different transition metal (TM) species. However, their indefinite composition and broad distribution hinder the insightful understanding of the interaction between these invasive metals in bimetallic doped nanoalloys. In this study, we report a density functional theory calculation with the PBEsol exchange-correlation functional for 16-atom TiN−1TM (TM = Ni, Ir, Pd) nanoalloys, which provides new insights into the synergetic effect of these invasive metals. The probe into the effect of these metal impurities revealed that the replacement of a Ti atom with Ni, Ir and Pd enhances the relative stability of the nanoalloys, and the maximum stability for a lower bimetallic composition is reached for Ti4Ir, Ti5Pd and Ti7Ni. The most stable nanoalloy is reached for the Ti12Ir cluster in comparison with the Ti12Pd and Ti12Ni clusters and pure Ti13 monoatomic nanocluster. This stability trend is as revealed well by both the binding energy and the dissociation energy. The average HOMO-LUMO gap for the bigger clusters revealed that the valence electrons in the HOMO can absorb lower energy, which is indicatory of a higher reactivity and lower stability. The quantum confinement is higher for the smaller clusters, which illustrates a higher stability and lower reactivity for those systems. [ABSTRACT FROM AUTHOR]

Thin films of pure NiO and doped with Zn are prepared by varying dopant concentration using spray pyrolysis. This paper presents the characteristics of thin films, including their structure, morphology, chemical composition, optical properties, and gas-sensing abilities. By adding 2 wt% Zn to pure NiO matrix, the film's structural, morphological, and ability to sense ammonia gas were notably changed. The Zn-doped NiO thin films were effective ammonia gas sensors with reliable performance at room temperature, making them suitable for real-time detection and monitoring of ammonia vapours. Gas-sensing studies suggest that the Zn-doped NiO thin film gas sensor can simultaneously improve stability, reproducibility, and sensitivity. Additionally, the NiO thin film of the p-type has a higher binding affinity for NH3 gas than other test gases. The 2 wt% Zn-doped NiO thin film exhibited an excellent response of 53.2 with response and recovery times of 24 and 30 s towards 25 ppm of NH3 at room temperature.