Dopant Incorporation Research Articles

Spraying-Deposited Transparent p-Type Sn-Doped CuI Film and Its Ultrahigh-Speed Self-Powered Photodetector.

The exploitation of simply processed p-type semiconductors and photodetectors with promising optoelectrical properties remains challenging yet essential for current and future advanced optoelectronic applications. Transparent p-type CuI and Sn-doped CuI (Cu-Sn-I) films and their self-powered photodetectors have been successfully fabricated by the spraying method. It is found that the incorporation of Sn dopants enhances the optical, electrical, and photoelectric properties of CuI thin films as well as their corresponding self-powered heterojunction photodetectors. This improvement of the optoelectrical properties of the Cu-Sn-I film and its photodetector can be attributed to the adjustment of the acceptor defect level and increased hole concentration resulting from Sn doping. The Cu-Sn-I/n-Si photodetector exhibits a responsivity of 10.7 mA/W, a detectivity of 6.79 × 1011 Jones, and a response time of 77 μs/30 μs (0 V bias). The response time exhibits the fastest rise and decay times compared with the other CuI-based self-powered UV photodetectors in recent years, showcasing promising applications in the realm of transparent electronics moving forward. This study also presents an effective strategy for enhancing the electrical properties of p-type semiconductors and devices through effective doping.

III–V heterostructure tunnel field-effect transistor operation at different temperature regimes

Tunnel field-effect transistors (TFETs) are a potential alternative to MOSFETs for low-temperature electronics. We provide an in-depth experimental characterization of TFETs analyzing the fundamental physical behavior at different temperature regimes. TFET characteristics from 13 to 300 K both in forward and reverse bias are discussed by employing a variation in InAs/InGaAsSb/GaSb heterojunction vertical nanowire devices. Evaluation of the TFET Negative Differential Resistance (NDR) characteristics at different temperatures is established as a technique to probe the dopant incorporation. It is observed that the temperature dependence of the Fermi degeneracy and Fermi-Dirac distribution largely influences the transistor performance at each operating temperature. Our investigation reveals that the TFETs demonstrate lower subthreshold swing than the physical limit of MOSFETs above 125 K. For low-temperature applications, the devices can be operated down to a low operating bias of 0.1 V, while for high temperature, a larger bias of 0.3 V is preferred.

Enhancement of luminescence and thermal stability in Eu3+-doped K3Y(BO2)6 with Li+ and Na+ co-doping

Eu3+-doped and Li+/Na+ co-doped K3Y(BO2)6 (KYBO) phosphors were synthesized through a microwave-assisted sol–gel method, and their structural and photoluminescent (PL) characteristics were examined. X-ray diffraction (XRD) and Rietveld refinement confirm effective dopant incorporation and preservation of the crystalline structure. Fourier Transform Infrared (FTIR) spectroscopy indicates the maintenance of the borate structure, confirming the structural integrity of the phosphors upon doping. The addition of Li+ and Na+ co-dopants notably enhances luminescent efficiency and thermal stability, making these phosphors promising candidates for solid-state lighting (SSL) applications. PL analysis reveals strong red emission peaks at 612 nm, attributed to the 5Do → 7F2 transition of Eu3+ ions. The study indicates that electric dipole-quadrupole interactions are the primary mechanism for energy migration, with a critical distance of approximately 22.68 Å. This mechanism contributes to concentration quenching at higher doping levels. High temperature PL measurements indicated an activation energy of 0.1389 eV for thermal quenching in the Li+ co-doped sample. Additionally, the Na+ co-doped sample exhibited an abnormal thermal stability behavior, with an even higher activation energy of 0.2536 eV. This suggests that Na+ co-doping significantly enhances the thermal resilience of the phosphor, making it more suitable for high-power light-emitting applications that operate under extreme conditions. CIE chromaticity diagrams highlight the potential for optimizing Eu3+ doping levels, combined with Li+ and Na+ co-doping, to improve luminescent performance and thermal stability for advanced SSL applications.

Unveiling the influence of dopants on structural, defect chemistry, morphological and optical characteristics of NiO nanostructures

Abstract In this paper, undoped and doped (Fe, Co and Fe-Co) nickel oxide (NiO) nanostructures have been synthesized using co-precipitation method. Prepared samples were characterized for the structural, compositional, morphological and optical properties using x-ray diffraction, scanning electron microscopy (SEM), Energy dispersive spectrocopy (EDS), UV-visible spectroscopy and photoluminescence spectroscopy. Structural analysis confirmed the single cubic phase formation of undoped and doped samples. Defect chemistry showed that Fe-Co co-doped NiO possesses a lower density of defects than other samples. SEM results revealed the agglomeration of particles. EDS results confirmed the presence of Ni, O, Fe and Co in the respective undoped and doped samples. Optical analysis revealed the band edge shifts with the incorporation of dopants in the NiO crystal lattice confirmed the variation of band gap energy. Emission peaks were observed in the UV and visible regions. The Incorporation of dopants in the crystal lattice causes variation of emission centers. Surface oxygen vacancies and imperfections significantly impact the emission characteristics of NiO. Variable spectral response of NiO with dopant incorporation has potential for optoelectronic applications.

Zirconium-doped lead dioxide anodes prepared by sol-gel method for ampicillin removal from simulated pharmaceutical polluted wastewater.

New anodes consisting of zirconium-doped PbO2 coating, growth on titanium dioxide interlayer, were deposited on titanium substrates using spin coating method and have been tested for the removal of ampicillin, a β-lactam antibiotic, from water. Morphological, structural, and electrochemical properties of the prepared coatings were characterized by scanning electron microscopy (SEM), atomic force microscope (AFM), X-ray diffraction (XRD), and electrochemical impendence spectroscopy (EIS). Results showed that the incorporation of zirconium dopant had a noticeable modification in the morphology of anodes. An increase in the surface roughness and the specific active area were observed with Ti/TiO2/PbO2- 10% Zr electrode compared to other anodes. The electrochemical measurements indicated that the anode doped with 10% Zr showed a more protective coating performance than the undoped and 20% Zr-doped PbO2 electrodes. The experiments on ampicillin degradation revealed that doped lead dioxide anodes have excellent electrocatalytic activity. The major byproduct generated during anodic oxidation treatment has been identified as ampicilloic acid by liquid chromatography-mass spectroscopy (LC-MS) analysis. Results demonstrated that Ti/TiO2/PbO2- 10% Zr anode presents the best removal rate of ampicillin with a minimum intermediate amount, which leads to conclude that 10% is the optimum percentage of zirconium dopant for antibiotic wastewater treatment.

Production and characterization of Zn- and Cu-doped Y2O3-Al2O3-SiO2 (YAS) glass microspheres.

Y2O3-Al2O3-SiO2 (YAS) glass microspheres are currently used in radioembolization treatment. However, abscess formation can occur following this treatment. This study aims to endow YAS glass microspheres with antibacterial properties to address the abscesses forming in patients after radioembolization treatment. In this study, undoped YAS glass microspheres and those doped with antibacterial agents zinc (Zn) and/or copper (Cu) were successfully fabricated using a sol-gel derived method. After heat treatment, the microspheres exhibited an amorphous structure. Additionally, the incorporation of Zn and/or Cu dopants did not alter the patterns observed in the X-ray diffraction analysis. Fourier transform infrared spectroscopy analysis detected Si-O-Si, Al-O-Al, and Y-O band vibrations within the structure. The presence of Zn and Cu dopants was confirmed through X-ray photoelectron spectroscopy analysis. Scanning electron microscopy revealed that all samples possessed a regular microsphere morphology, with average particle sizes ranging from 6 to 50 μm. These average particle sizes were further confirmed using a mastersizer. The antibacterial agent-doped YAS glass microspheres show promise in combating infections that occur following radioembolization treatment.

Enhancing dye-sensitized solar cells efficiency through organic dyes-sensitized holmium-doped TiO2/SnO2 nanocomposites blended with P3HT

The pursuit of sustainable energy solutions has spurred innovation in photovoltaic technology, with dye-sensitized solar cells (DSSCs) emerging as promising contenders. This study presents a novel approach leveraging holmium-doped TiO2/SnO2 nanocomposites sensitized with organic dyes, Arsenazo-III, carminic acid, and dithizone, blended with poly (3-hexylthiophene) (P3HT). Through meticulous characterization and analysis, key parameters including short-circuit current density (Jsc), open-circuit voltage (Voc), fill factor (FF), and overall percent efficiency (%) were scrutinized to evaluate photovoltaic performance comprehensively. Absorption spectra analysis facilitated the calculation of band gaps, revealing a significant reduction from 3.10 eV in pure Titania (TiO2) nanoparticles to 2.72 eV upon doping with Holmium and coupling with SnO2. Notably, Arsenazo-III dye-sensitized holmium-doped TiO2/SnO2 nanocomposites exhibited highest power conversion efficiency, achieving a promising efficiency of 2.10 %, which marked a significant improvement over the reference device (0.82 %). This improvement is attributed to the synergistic effects of holmium dopant incorporation and SnO2 interaction, enhancing light responsiveness. The findings not only validate the efficacy of nanohybrid assemblies but also contribute valuable insights to solar cell technology advancement.

A Comparative Study of Congo Red Textile Dye Photodegradation Using ZnO Al and ZnO Al+Mn Nanoparticles

Photodegradation of Congo Red textile dye was successfully carried out using ZnO Al and ZnO Al+Mn nanoparticles synthesized using the bottom-up coprecipitation method. Powder X-ray diffraction provides information that Al and Mn doping successfully inserted in the host crystal structure while maintaining the Hexagonal Wurtzite crystal structure. However, a shift in the diffraction peak caused by the lattice distance changes with the addition of doping. FE-SEM EDS provides information that both nanoparticles are nonuniform sphere-like due to the addition of dopping, and each dopping is detected through EDS spectra. There is a decrease in the gap energy in each sample. ZnO Al nanoparticles have a gap energy of 3.29 eV, and ZnO Al+Mn nanoparticles have a gap energy of 3.28 eV. However, the decrease in the gap energy is not directly related to the percentage and kinetic rate of Congo Red photodegradation. Adding 5 mg of ZnO Al Nanoparticles powder could degrade Congo Red up to 97.9 % within 120 min using UV A radiation or 0.03504/min. At the same time, adding ZnO Al+Mn Nanoparticles powder with the same parameters could only degrade 67.6 % or 0.00759/min. HIGHLIGHTS Energy Bandgap Modification of ZnO Nanoparticles The incorporation of Al single dopants and Al, Mn co-dopants into ZnO nanoparticles synthesized via a bottom-up coprecipitation method significantly alters the energy bandgap. Al single doping resulted in a bandgap of 3.29 eV, while Al, Mn double doping yielded a bandgap of 3.28 eV. Enhanced Photocatalytic Activity of Al-Doped ZnO Al-doped ZnO nanoparticles exhibited superior photocatalytic activity toward the degradation of Congo Red textile dye. With a photodegradation rate constant of 0.03504 min⁻¹, these nanoparticles achieved 97.9 % degradation of Congo Red within 120 minutes. Comparative Photocatalytic Performance of Al, Mn Co-Doped ZnO While Al, Mn co-doped ZnO nanoparticles were synthesized using the same method, their photocatalytic performance for Congo Red degradation was notably lower than that of Al-doped ZnO. The calculated photodegradation rate constant was 0.00759 min⁻¹, resulting in 67.6 % degradation within the same timeframe. GRAPHICAL ABSTRACT

Optical properties analysis of gelatin-based prepared Co, Ni, and Mn-doped ZnO nanoparticles in infrared and UV–vis region using Kramers-Kronig methods

This study investigates the structural, optical, and morphological properties of ZnO nanoparticles doped with Ni, Mn, and Co (Zn0.97A0.03O where A = Ni, Mn, and Co, designated as ZN, ZM, and ZC, respectively). X-ray diffraction (XRD) analysis confirms the successful incorporation of dopants into the ZnO lattice without altering its wurtzite structure. Field emission scanning electron microscopy (FESEM) images reveal that doping results in larger and more uniformly distributed particles. Energy-dispersive X-ray spectroscopy (EDX) verifies the presence of Ni, Mn, and Co in the respective samples. Fourier transform infrared (FTIR) spectroscopy indicates an increase in average phonon energies due to doping, as evidenced by the shift in the Zn-O vibration peak. Ultraviolet–visible (UV–vis) spectroscopy shows that doping causes a blue shift in the absorbance peak and increases the optical band gap from 3.17 eV for pure ZnO to 3.22 eV for Co-doped ZnO. Transmission electron microscopy (TEM) and corresponding EDX results further confirm the presence of dopants and illustrate that doped ZnO nanoparticles are larger than pure ZnO particles. These findings provide valuable insights into the impact of doping on ZnO nanoparticles, potentially enhancing their suitability for various technological applications.

Exploring different dopant materials in conjunction with iron oxide and analyzing their characterization and magnetic properties

The comparative studies of pure and different doping materials of α-XFe2O3 (X = Co, Mn, Ni and Zn) nanoparticles in Structural, Morphological, Optical, and magnetic behavior were analyzed in this article. The synthesis of α-XFe2O3 nanoparticles through the Sol-gel method for magnetic properties with various doping materials such as Co, Mn, Ni, and Zn. The structural, morphological, optical, and magnetic properties were carefully examined, revealing enhanced characteristics. XRD studies confirmed the successful incorporation of dopants into the crystal structure of α-Fe2O3, while Morphological analysis through SEM images indicated superparamagnetic properties in Co and Zn doped samples, and ferrite behavior in Mn and Ni doped samples. UV Spectra analysis showed optical transitional changes related to magnetic behavior, and the dielectric effect was attributed to the presence of multiple domains within the sample. The study effectively demonstrated the unique magnetic properties of pure and α-XFe2O3 nanoparticles, highlighting the importance of different doping materials in influencing their characteristics.

Characteristics of NixCoxMgxCuxZn1-4xO nanomaterials: Their structural and magnetic properties and functional attributes

The current study evaluates the photocatalytic, structural, morphological, optical, and magnetic characteristics of the NixCoxMgxCuxZn1-4xO nanomaterials (x = 0.000–0.010). The NixCoxMgxCuxZn1-4xO nanomaterials were synthesized using the temperature-assisted co-precipitation technique. The characteristics of the NixCoxMgxCuxZn1-4xO nanomaterials were investigated using X-ray diffraction (XRD), Field emission scanning electron microscopy (FE-SEM), Fourier transform infrared spectroscopy (FTIR), UV–Vis spectroscopy, and Vibrating sample magnetometer (VSM). XRD analysis revealed dopant incorporation into the ZnO crystal structure, affecting lattice parameters. Magnetic behavior transitioned from diamagnetic to a combination of diamagnetic and ferromagnetic with increasing dopant levels. The optical band gap decreased as dopant concentration increased. Notably, the nanomaterial with x = 0.001 exhibited optimal photocatalytic performance, degrading 98.9 % of Rhodamine B within 20 min under UV light. This nanomaterial also showed efficacy against Methyl Orange and Congo Red, with hydroxyl radicals playing a crucial role in pollutant removal. These findings provide the exceptional reusability and stability of the NixCoxMgxCuxZn1-4xO nanomaterials (x = 0.001)

Boosting oxygen reduction performance by copper-iron co-doped on ZIF-derived N-doped carbon nanotubes

Developing high-efficiency non-noble metal catalysts for the oxygen reduction reaction (ORR) is paramount for sustainable energy conversion. In this study, we proposed a Cu, Fe co-doped zeolite imidazole framework (ZIF)-derived nitrogen-doped carbon nanotubes catalyst (Cu–Fe@CNTs/NC) obtained by hydrothermal method and pyrolysis. The electrochemical results showed that Cu–Fe@CNTs/NC exhibited favorable oxygen reduction performance and good stability under alkaline electrolyte. The incorporation of Cu and Fe bimetallic dopants promoted the carbon nanotubes growth on ZIF nanosheets, and the collaborative action of Cu and Fe enhanced its ORR catalytic activity. These findings provide an innovative way to prepare high active non-platinum ORR catalysts.

Copper restructured transition metal/metal oxide heterostructure with a hierarchical nanostructure for accelerated water dissociation kinetics and alkaline hydrogen evolution

The slow kinetics of water dissociation on electrocatalysts lacking platinum hinders the advancement of cost-effective hydrogen production via alkaline water electrolysis. Herein, a hierarchically peach-flower-shaped electrocatalyst consisting of copper-restructured cobalt–nickel/cobalt–nickel oxide heterostructure anchored on copper nanowires (Cu-CoNiO/CoNi@Cu NWs) is developed for efficient hydrogen evolution reaction (HER). Benefiting from the optimized electronic configuration and geometric structure, this Cu-CoNiO/CoNi@Cu NWs catalyst performs an outstanding alkaline HER activity of 29 mV at 10 mA cm−2 and 98 mV at 100 mA cm−2, which is comparable with the state-of-the-art Pt/C catalyst (26 mV at 10 mA cm−2 and 117 mV at 100 mA cm−2). Our findings rank among the topmost catalytic efficiencies when compared to all previously reported non-noble metal catalysts and numerous noble metal catalysts. The combined experimental exploration and theoretical studies reveal that the incorporation of Cu dopant into CoNiO/CoNi heterostructure enhances electron transfer from metal atoms to O atom, leading to the formation of the polarized electric field to accelerate water dissociation and H evolution, eventually facilitating the overall alkaline HER process. The boosted electron exchange and mass transportation deriving from the introduction of Cu NWs and hierarchically peach-flower-shaped nanostructure further reinforce the HER activity of the Cu-CoNiO/CoNi catalyst.

Antibacterial activity and structural properties of gelatin-based sol-gel synthesized Cu-doped ZnO nanoparticles; promising material for biomedical applications

This study investigates the antibacterial activity and spectral characteristics of Cu-doped ZnO nanoparticles synthesized via the gelatin-based sol-gel method, focusing on their potential biomedical applications. Zn₁₋ₓCuₓO nanoparticles (x = 0.0, 0.01, 0.03, and 0.05) were fabricated using this method. The incorporation of copper dopants into the ZnO matrix significantly influences both the crystalline structure and spectral properties of the nanoparticles. X-ray diffraction analysis confirms the presence of a wurtzite structure without any pyrochlore phase. The broadening of spectral features indicates modifications in lattice parameters and elastic constants. XRD results reveal that adding Cu to the ZnO lattice causes a decrease in crystallite size from 32 to 18 nm. Transmission electron microscopy shows spherical-shaped ZnO nanoparticles with sizes ranging from 30 to 40 nm. Moreover, Cu-doped ZnO nanoparticles exhibit considerable inhibition against bacterial growth. Adding Cu enhances the antibacterial activity of ZnO nanoparticles, suggesting their potential in biomedical applications. Overall, these findings highlight the promising prospects of sol-gel synthesized Cu-doped ZnO nanoparticles in the biomedical field.

Up-Conversion Emissions from HfO2: Er3+, Yb3+ Nanoparticles Synthesized by the Hydrothermal Method.

Up-conversion emission from HfO2 nanoparticles, as a host lattice, doped with Er3+ and Yb3+ ions and codoped with alkaline cations Li+ and Na+ obtained. The HfO2 nanoparticles, about 80 nm in diameter, were synthesized by the hydrothermal method at 200 °C for 1.3 h, and an additional heat treatment at 1000 °C was necessary to ensure the dopants incorporation into the host lattice. These nanoparticles were studied by means of XRD, Raman Spectroscopy, SEM, EDS, PL, CL, and up-conversion luminescence. First, the doping was performed with Er3+ ions in different percentages. The photoluminescence and cathodoluminescence studies showed an inefficient emission, and only at 7 at % Er3+ ions, the sample presented emissions at 522, 545, and 656 nm corresponding to the transitions of the Er3+ ions. So, codoping was carried out, and HfO2: Er3+/Yb3+ generated an efficient conversion process. The atom percentage of Yb3+ ions was fixed (7 at % Yb3+), and the Er3+ content was varied, showing the highest emission intensity at 3 at % Er3+ ions. Subsequently, the up-conversion emission intensity was optimized by varying the percentage of Yb3+ ions and keeping the Er3+ ion content fixed (3 at %). Adding cations such as Na+ and Li+ in different percentages, a notable improvement of the up-conversion emission intensities in the HfO2: Er3+/Yb3+ nanoparticles was obtained. The up-conversion emission bands observed were located at ∼523 and 544 nm, corresponding to the electronic transitions 2H11/2 → 4I15/2 and 4S3/2 → 4I15/2, respectively. While the bands at ∼652 and 673 nm correspond to the transition 4F9/2 → 4I15/2, respectively. The excitation of these materials with infrared radiation (980 nm) produced noticeable emission bands in the red spectral range, whereas excitation with accelerated electrons (CL) generated prominent bands in the green region.

Giant chiral amplification of chiral 2D perovskites via dynamic crystal reconstruction.

Chiral hybrid perovskites show promise for advanced spin-resolved optoelectronics due to their excellent polarization-sensitive properties. However, chiral perovskites developed to date rely solely on the interaction between chiral organic ligand cations exhibiting point chirality and an inorganic framework, leading to a poorly ordered short-range chiral system. Here, we report a powerful method to overcome this limitation using dynamic long-range organization of chiral perovskites guided by the incorporation of chiral dopants, which induces strong interactions between chiral dopants and chiral cations. The additional interplay of chiral cations with chiral dopants reorganizes the morphological and crystallographic properties of chiral perovskites, notably enhancing the asymmetric behavior of chiral 2D perovskites by more than 10-fold, along with the highest dissymmetry factor of photocurrent (gPh) of ~1.16 reported to date. Our findings present a pioneering approach to efficiently amplify the chiroptical response in chiral perovskites, opening avenues for exploring their potential in cutting-edge optoelectronic applications.

Investigating the dielectric and ferromagnetic behaviour of Ni and Co dual doped ZnO for diluted magnetic semiconductor

Herein, Ni/Co co-doped ZnO nanoparticles (NPs) were successfully prepared via chemical co-precipitation process. The structural, purity and crystallite size of as-prepared particles were confirmed by using x-ray diffraction (XRD). The results revealed the hexagonal wurtzite structure of ZnO without any impurity phase of as-prepared samples. The crystallite size decreased from 34.9 to 9.6 nm, whereas lattice strain reduced to 0.00086. The change in crystallite size, lattice parameters, strains and dislocation density further indicates the successful incorporation of dopants in ZnO host lattice. The dielectric properties, ac conductivity, and magnetic behaviour were steadily examined. The dielectric constant has been found to be 1070 with 5wt% at low frequency and become constant at higher frequency. It was revealed that dopant additions lead to attain high dielectric constant and low loss possibly attributed to interface polarization, and dipole polarization due to oxygen vacancy defects. M-H measurement observed that ferromagnetism at room temperature pure and doped ZnO samples. The ferromagnetic behaviour of pure ZnO NPs with Ms = 0.17 emu g−1, Mr = 0.11 emu g−1 and Hc = 67 which was increased to Ms = 0.85 emu g−1 and Mr = 0.65 emu/g for 5wt% Co. This improvement with increasing Co concentration indicates that oxygen defects may stabilize the ferromagnetic order. These interesting features encouraging to use this material for ultrahigh dielectric materials and spintronics.

Investigating Cu-Site Doped Cu-Sb-S Nanoparticles Using Photoelectron and Electron Paramagnetic Resonance Spectroscopy.

Tetrahedrite (Cu12Sb4S13) and famatinite (Cu3SbS4) are good candidates for green energy applications because they possess promising thermoelectric and photovoltaic properties as well as contain earth-abundant and nontoxic constituents. Herein, X-ray photoelectron spectroscopy (XPS), ultraviolet photoelectron spectroscopy (UPS), and electron paramagnetic resonance spectroscopy (EPR) methods examined inherent electronic properties and interatomic magnetic interactions of Cu-site doped tetrahedrite and famatinite nanomaterials. An energy-efficient modified polyol method was utilized for the synthesis of tetrahedrite and famatinite nanoparticles doped on the Cu-site with Zn, Fe, Ni, Mn, and Co. This is the first parallel study of tetrahedrite and famatinite nanomaterials with XPS, UPS, and EPR methods alongside a systematic analysis of dopant-dependent effects on the electronic structure and magnetic interactions for each material. XPS showed that the Cu and Sb species in tetrahedrite and famatinite possess different oxidation states, while UPS characterization reveals larger dopant-dependent shifts in the work function for tetrahedrite nanoparticles (4.21 to 4.79 eV) than for famatinite nanoparticles (4.57 to 4.77 eV). Finally, all famatinite nanoparticles display an EPR signal, indicating trace amounts of paramagnetic Cu(II) present below the detection limit of XPS. For tetrahedrite, EPR signatures were observed only for the Zn-doped and Mn-doped nanoparticles, suggesting signal broadening from Cu-Cu spin exchange or spin-lattice relaxation. This study demonstrates the complementary nature of XPS and EPR techniques for studying the oxidation states of metals in solid-state nanomaterials. Comparing the electronic and magnetic properties of tetrahedrite and famatinite while studying the impact of dopant incorporation will guide future endeavors in designing sustainable, high-performance materials for renewable energy applications.

A new insight on surface chemistry and redox species of transition metal (Fe, Mn) doped CeO2-SnO2/Al2O3 nanocomposites for automobile emission control

The ceria-tin/alumina mixed metal oxides (Ce/Sn =1) with different proportions of Fe & Mn dopants were synthesized and investigated in detailed approach for diesel emission reduction. The dopants created structural defects enhancing the oxygen ion mobility for exhaust treatment. The existence of surface-active oxygen sites and oxygen ion vacancy sites generated for charge compensation due to reduction of Ce4+, Sn4+ and dopants incorporation evidenced from XPS analysis. The Mn doped sample holds better physicochemical properties than Fe doped sample. The Mn doped sample with higher surface area of about 101.32 m2 g−1 exhibits greater active sites for better catalytic activity. The redox couples in the Mn-doped sample Ce4+/Ce3+, Sn4+/Sn2+, and Mn3+/Mn2+ helps in oxygen regeneration to contribute to exhaust treatment by oxygen ion conduction from bulk to the surface. This sample exhibited the 92 % of NOx reduction and proved to be a dynamic candidate for diesel emission reduction.

High-performance Li-ion battery cathode: Mn-doped LiFePO4 via solution combustion synthesis method

The main drawbacks of LiFePO4, namely low electronic conductivity and slow lithium ion diffusion, are overcome by doping through solution combustion synthesis. This study focuses on altering the properties of LiFePO4 cathode material by introducing manganese (Mn) into the Fe site. Using solution combustion synthesis, we successfully created Mn-doped LiFe1-xMnxPO4 samples (where x = 0.04, 0.08, and 0.12) as it provides highly pure and crystalline material with homogeneous incorporation of dopants. Through various analyses including X-ray diffraction (XRD), RAMAN spectroscopy, scanning electron microscopy (SEM), transmission electron microscopy (TEM), EDAX, X-ray photoelectron spectroscopy (XPS), BET surface area measurement, charge/discharge tests (CD), stability assessments, and rate performance evaluations, we uncovered insights into the structure, morphology, elemental composition, surface area, and electrochemical properties of the synthesized materials. Notably, the LiFe0.92Mn0.08PO4 sample exhibited an average capacity of 166.34 mAh/g over 100 cycles at a 0.1C rate, slightly below its theoretical capacity of 170 mAh/g.