Mn Doping Research Articles

Effect of Mn dopant on physiochemical properties of V2O5 and their photocatalytic application toward mineralization of malachite green (MG) dye

The doping method is considered a proficient technique for enhancing the photocatalytic performance of nanostructures. Herein, doping of Mn into the V2O5 (VO) nanostructure increased their photodegradation capacity toward malachite green dye (MG). Different physical strategy to investigate the physiochemical behavior of the undoped and Mn doped V2O5. Using an aqueous malachite green (MG) solution and xenon light illumination, the degradation capabilities of the manufactured pristine and Mn doped V2O5 were studied. The pristine V2O5 and Mn doped V2O5 nanoarray display a photocatalytic efficiency of 94.79 % for MG compared to the pure V2O5 (75.52 %). Consistently, doping of Mn into V2O5 was shown to affect the photodegradation of malachite green significantly. Our finding suggests that Mn doped V2O5 nanomaterials act as potential photocatalysts to degrade the MG dye and can act as an environmental cleaner to resolve the other related issues.

Enhanced adsorption and visible-light photocatalytic degradation of CIP by CdS QDs‐Decorated Mn-doped NH2-UiO-66

CdS Quantum dots (QDs) interspersed on the surface of Mn-UiO-66-NH2 (hereafter abbreviated as CdS QDs@Mn-UiO-66-NH2) Z-scheme heterojunction composites were synthesized by solvothermal method for the removal of ciprofloxacin (CIP) under visible light irradiation. The influences of the doping content of Mn and the initial concentrations of CIP on the adsorption capacity and photocatalytic performance were investigated in detail. Compared to the pristine CdS and Mn-UiO-66-NH2, the fabricated CdS QDs@Mn-UiO-66-NH2 composites exhibited enhanced adsorption and photocatalytic capabilities, especially for the CMU-5 with 10 % Mn doping showing around 52.5 % adsorption removal efficiency and about 92 % photocatalytic removal efficiency for CIP (30 mg/L). Various technologies such as XPS, TG and UV–vis DRS have confirmed that the superior catalytic performance of CMU-5 is ascribed to the d-d transitions improving the utilization of visible light after the coordination of the transition metal and the presence of a heterojunction with a tight interfacial structure enhancing the charge transfer. The possible intermediates in the photodegradation process of CIP were detected using gas chromatography-mass spectrometry (GC-MS).

Study of the Optical and Structural Properties of Metal-Doped Titanium Dioxide Electrode Prepared by the Sol-Gel Method for Dye-Sensitized Solar Cells

This study presents a strategy to increase the efficiency of dye-sensitized solar cells (DSSCs) by doping titanium dioxide (TiO2) with different magnesium (Mn) concentrations (1, 3, 5, 7, and 9%) generated by the sol-gel process and effectively employed as a photo-anode (the working electrode) for DSSCs. The Doctor Blade method coated the indium-doped tin oxide (ITO) glass with a thin film layer. X-ray diffraction (XRD) was used to evaluate the characteristics of undoped and manganese-doped TiO2, and the results demonstrate that all of the thin films are anatase. The samples were examined using XRD to assess grain size before and after Mn doping. The spectrum of UV-Vis absorption changes; accordingly, as doping increases, the energy gap decreases. The smallest energy gap's value (2.4 eV) is 7% manganese doping. AFM pictures show the average roughness and root mean square of the weight percentage of films doped with 5%. Field effect scanning electron microscope (FE-SEM) studies show that the particle size of thin films gets smaller as more Mn is added, which happens at least as much as 7% Mn doping. The optimal thickness for TiO2 paste over conductive glass is 15 μm, and the cell's power conversion efficiency increased to 0.604074% with an Imax of 4.965 mA, a Vmax of 0.488 V, and a fill factor (FF) of 68.45954%.

Microwave absorption properties of spinel-structured magnesium zinc aluminate nanocomposites through Mn doping: characterization and performance analysis of (Mg–Zn)1−xMnxAl2O4 (x = 0.05, 0.1, 0.15, and 0.2)

Microwave absorption properties of spinel-structured magnesium zinc aluminate nanocomposites through Mn doping: characterization and performance analysis of (Mg–Zn)1−xMnxAl2O4 (x = 0.05, 0.1, 0.15, and 0.2)

Impact of doping and hydrostatic pressure on structural, electronic, optical, and mechanical properties of novel double halide perovskite Cs2LiGaBr6

The emergence of lead-free halide double perovskites exhibiting bandgaps within the visible spectrum represents a substantial advancement in engineering environmentally benign perovskite solar cells. In this work, we investigated the structural, optical, electronic, and mechanical properties of Cs-based lead-free Cs2LiGaBr6 double halide perovskites with Mn and Cr doping under hydrostatic pressure ranging from 2 to 80 GPa using density functional theory (DFT). The introduction of dopants consistently alters the lattice parameters because of the mismatch in atomic radii, whereas increasing the pressure leads to a reduction in these constants. All the studied Cs2LiGaBr6 compounds exhibited direct band gaps, which increased slightly with doping. This is attributed to the modulation of electronic states by dopant-related defect levels. The bandgap variation under pressure is primarily attributed to changes in the quantum confinement effects induced by compressive strain. Analysis of the density of states and optical properties revealed enhanced absorption in the visible spectrum for the doped compositions, and in the UV spectrum under pressure. The study of mechanical stability confirms the ductile nature of both the doped and pristine compounds under pressure, underscoring their suitability for thin film production. This study contributes to the understanding of sustainable alternatives for perovskite optoelectronic applications, emphasizing Cs2LiGaBr6's potential under diverse conditions and dopant influences.

Role of Mn Doping in Improving the Hydrophobic Property of ZnO Coating on Aluminum Substrate

Role of Mn Doping in Improving the Hydrophobic Property of ZnO Coating on Aluminum Substrate

Influence of trace Mn doping on the high-speed shear performance of lead-free alloy/copper solder joints: Experimental and first principles investigation

This study aims to investigate the mechanical properties changes and the underlying reasons caused by Mn addition to the Cu6Sn5 intermetallic compounds (IMC). For this purpose, 0.07 wt.% Mn doped SnAgCu (SAC)305/Cu joint were prepared to observe its shear performance at a high speed of 1000 mm/s after aging at 170 °C for 750 h. The mechanical properties of Mn-doped samples exhibited a smaller decline after aging, in comparison to the undoped samples. Notably, the fracture location transitioned from the interior of the SAC joint to joint interface after doping. Nanoindentation experiments demonstrated a significant increase in the modulus and hardness of the Mn doped Cu3Sn and Cu6Sn5 phases. To gain a deeper understanding of the underlying mechanisms driving the changes in IMC properties, first principles calculations were employed. The introduction of Mn resulted in a strengthened bonding due to the hybridization of Mn and Sn atoms in the high-energy regions, leading to the formation of charge-enriched areas and improved mechanical properties of the IMC. The results obtained from both computational and experimental approaches exhibit similar trends in these changes. Moreover, the integration of computational and experimental methods provides a guidance for advancing IMC research and enhancing our understanding of their behavior.

Enhancing electronic, magnetic, and elastic properties of SmFe2 by Mn substitution at Fe sites: A first-principle computational study

In this comprehensive theoretical investigation, we present the effects of manganese (Mn) substitution for iron (Fe) in samarium iron (SmFe2) on its electronic, magnetic, elastic, and magnetostriction properties, utilizing state-of-the-art Density Functional Theory (DFT) within the Generalized Gradient Approximation (GGA) complemented by the Full Potential Linearized Augmented Plane Wave (FP-LAPW) method. Our investigations are further enriched by Monte Carlo simulations framed within the Ising model, providing a comprehensive understanding of the material's behavior under Mn doping. Our findings reveal a significant shift in magnetic anisotropy from the [100] direction in pristine SmFe2 to the [111] direction following Mn substitution. This transition enhances the material's magnetic favorability and introduces new electronic states at the Fermi level, increasing the number of states available for conduction and enhancing its metallic behavior. Consequently, this transition results in altered elastic constants and magnetostriction values, highlighting a delicate interplay between the material's structural and magnetic properties that warrants further exploration. By developing a Hamiltonian model, we delve into the intricate coupling among magnetic atoms within SmFe2, offering insights into the underlying mechanisms governing the observed phenomena. Monte Carlo simulations further corroborate the robust ferromagnetic ordering of SmFe2, evidenced by a high critical temperature (Tc = 651.3 K).

Degradable tumor-specific H2S nanogenerators for disrupting tumor metabolic symbiosis and activating anti-tumor immune responses

The design of highly efficacious nanotherapeutic agents that target tumors and degrade in specific response is of great relevance and developmental promise. We have designed a tumor-specific decomposable H2S nanogenerator for the purpose of safely and effectively disrupting tumor metabolic symbiosis and activating anti-tumor immune responses. Dendritic mesoporous organosilica doped with Mn2+ (DMOM) was used as a H2S donor that could be specifically degraded in response to glutathione (GSH), and then α-Cyano-4-hydroxycinnamic acid (CHC, a monocarboxylate transporter protein inhibitor) was loaded on the pores and surface of the organosilica through a condensation reaction, and further modified with hyaluronic acid (HA). The H2S nanogenerator could target the tumor site and undergo continuous self-degradation, releasing doped Mn2+ and loaded CHC while depleting GSH and generating large amounts of H2S, which could ultimately destroy lactate metabolic symbiosis, induce multiple acidosis in tumor cells, reduce intracellular adenosine triphosphate (ATP) and enhance chemodynamic therapy. More importantly, both the H2S produced and the inhibition of lactate efflux could have an immunomodulatory effect and exert a positive influence on the activation of the immune system. Therefore, the tumor-specific degradable H2S nanogenerator with diverse therapeutic functions introduced in this work is expected to provide a new idea and a new paradigm for efficient anti-tumor therapy.

Effect of manganese (Mn) doping on the structural, dielectric, ferroelectric, and ferromagnetic properties of ceria (CeO2)

The Ce1-xMnxO2 ceramics were prepared using a solid-state route, with Mn doping concentrations of (x = 0.00, 0.03, 0.08, 0.13, and 0.18). Examination of X-ray diffraction patterns confirms the effective insertion of Mn into the CeO2 lattice, resulting in discernible changes in oxygen vacancy concentration and lattice expansion. X-ray photoelectron spectroscopy (XPS) analysis confirmed the presence of Ce3+, Ce4+, Mn3+, and Mn2+ oxidation states. The Photoluminescence (PL) spectra reveal the existence of oxygen vacancies, as manifested by the appearance of peaks within the energy range spanning from 3.1 eV to 2.71 eV. Raman spectra reveal a symmetric vibration around 466.81 cm-1 in all samples. The surface morphology of the samples exhibited subtle changes in grain size upon the introduction of Mn into CeO2. The dielectric behavior, investigated across a range of frequencies with varying Mn doping concentrations, exhibits an increased dielectric constant in Mn-doped CeO2, particularly with a smaller dielectric loss at lower frequencies. The ferroelectric response revealed a maximum recoverable energy density of 0.56 mJ/cm2 with an efficiency of 47.86% for CeO2. The room temperature magnetic response of the samples improved as Mn concentration increased, which is well explained by the Bound Magnetic Polarons (BMPs) and exchange interactions model. Overall, the studies show the effect of structural, electrical, and magnetic properties after doping with Mn, opening avenues for diverse applications of these ceramics.

Efficient Life-Cycle Management: Recyclable self-support MnCuOxS1-x wastewater treatment catalyst for electrosynthesis of benzoic acid to accelerate hydrogen production

Integrating recyclability and reusability into catalyst design can effectively mitigate environmental impact. In this investigation, a three-dimensional Mn-doped Cu2OxS1-x catalyst was incorporated into Cu foam. Following its application in wastewater treatment, the reclaimed catalyst demonstrates robust electrocatalytic prowess in benzyl alcohol oxidation. It efficiently degrades 93.5 % of tetracycline within a 30-minute timeframe in neutral wastewater conditions. Notably, alterations in its morphology and valence state have bolstered its electrocatalytic performance. During the electrosynthesis of benzoic acid, it showcases a diminished starting voltage (1.27 V) while retaining an impressive Faraday efficiency of 97.4 % even at a high voltage of 1.70 V. Density Functional Theory (DFT) analyses shed light on the integration of the catalyst onto Cu foam, facilitating electron transfer from the Cu substrate to the surface catalyst. Furthermore, it is readily recoverable and enhances the adsorption of electrophilic H2O2, thereby augmenting wastewater treatment efficacy. In the context of benzoic acid electrosynthesis, DFT investigations demonstrate that Mn doping significantly enhances the adsorption of OH* and benzyl alcohol in electrocatalysis, thereby enhancing their conversion to benzoic acid. This method of catalyst design, integrating recycling and reuse strategies, has reduced material and energy consumption during catalyst preparation and provided a pathway for the development of advanced catalysts with a focus on sustainability.

Acceleration mechanisms of Fe and Mn doping on CO2 separation of CaCO3 in calcium looping thermochemical heat storage

The doping strategy with dark metallic oxide has proven effective in improving optical absorptions and heat storage performances of calcium-based materials for the direct solar-driven thermochemical energy storage system, but the microscopic mechanisms of accelerated decomposition of CaCO3 during heat storage process are still unclear. Carbide slag as an industrial waste with low cost and high CaO content is considered as a potential calcium-based precursor for large-scale thermochemical energy storage. Herein, the novel Fe-doped and Mn-doped calcium-based materials were synthesized from carbide slag and their optical absorption properties and heat storage performances were determined in the experiment. The optimum decomposition temperatures of CaCO3 during heat storage process decreased 10.5 °C and 18.6 °C due to Fe doping and Mn doping, respectively. The acceleration mechanisms by Fe doping and Mn doping for enhancing the CO2 separation of CaCO3 in the calcination stage of the heat storage process were investigated by density functional theory (DFT) calculations. The structural parameters, partial density of states, electron differential densities and energy barriers during CO32– dissociation in heat storage process on the doped CaCO3 and undoped CaCO3 surfaces were compared to clarify the effects of Fe doping and Mn doping on the CaCO3 decomposition. The energy barriers of Fe-doped material and Mn-doped material are 1.68 eV and 1.42 eV, respectively, which are 29.4% and 40.3% lower than that of undoped material. This work helps to understand the microscopic mechanisms of accelerated CaCO3 decomposition by Fe and Mn during heat storage process.

La-Co-Mn perovskite (LCMO) for NO and Hg0 oxidation: Experimental and DFT investigations of adsorption processes

To achieve superior catalytic performance, the development of plausible regulation of pure perovskite structure is necessary, which has become a hot research topic. In this study, manganese (Mn) ions were employed to dope cobalt (Co) ions at the B-site of LaCoO3, yielding a series of LaCo1-xMnxO3 (x = 0.1–0.5) perovskite (LCMO). The oxidation activity of NO and Hg0 was conducted, evaluating the effect of Mn-doping. The results indicated a minor change in NO oxidation activity and a significant enhancement in Hg0 oxidation, reaching above 92% at 100°C–300°C for LCMO. Structural characterization revealed a gradual transition in the phase structure of LCMO from the R-3C diamond phase to the Pm-3m cubic phase with increasing Mn doping. Furthermore, electronegativity properties of LCMO evolved with Co ions at the B-site exhibiting a preference for generating Co2+ over the more active Co3+. Finally, DFT calculations were conducted to analyze the adsorption energies of NO and Hg0 at different active sites on the surfaces of LaCoO3 (110) and Mn-LaCoO3 (110). The results indicated that Mn doping increased the active site amounts and strengthened the adsorption energy of Hg0 on the Mn-LaCoO3 (110) surface. However, the adsorption energy of NO remained largely unchanged, validating the oxidation results. This study offered insights for selecting B-site ions to adjust the perovskite structure of excellent performance, facilitating its industrial application.

Studies of optoelectrical properties of Mn-doped ZnO nanostructure for supercapacitor and photodetector applications

The transition metal Manganese (Mn)-doped Zinc Oxide (ZnO) nanoparticles were synthesized using the sol-gel method. The nanomaterials ZnO and Zn1-xMnxO (x=0–0.15) formation, their crystal structure, and morphological properties were confirmed by X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) analysis of the materials. All the studied materials show hexagonal wurtzite structure with the particle size in nanometres. The optical properties of transition metal Mn-doped ZnO nanomaterials were explored by the absorption and transmission spectra. The band gap of the nanomaterials decreases with the increase of Mn doping concentration from 3.01 to 3.26 eV. The mobility and electrical conductivity of the Mn-doped ZnO thin films show a decreasing trend with the increase of Mn doping concentration in ZnO. The Mn-doped materials were investigated for supercapacitor and photodiode applications. The Zn0.90Mn0.10O nanomaterials show the maximum specific capacitance, power and energy density of ∼ 220 F/g, 2202 W/kg and 1.15 Wh/kg, respectively. The electrochemical properties confirm that the doping of ZnO opens a new window for its application in energy storage devices. The ZnO and Mn-doped ZnO were used as an electron transport layer in perovskite MAPbI3 photodiodes. Under the Illumination of blue (465 nm) light, the highest detectivity of undoped ZnO perovskite photodiode is ∼4.5×1010 Jones and doped ZnO perovskite photodiode is 0.7×1010 Jones, respectively. The low mobility of charges and unfavorable energy level alignment of Mn-doped ZnO with MAPbI3 thin films is the reason for the decrease in photo detectivity. Our studies demonstrate that the Mn-doped ZnO nanomaterials and their thin films have avenues for potential application in energy storage devices and photodiodes of perovskite MAPbI3.

Enhancing the Red Fluorescence of Carbon Dots: The Role of Mn Doping and Precursor Concentration Control

Enhancing the Red Fluorescence of Carbon Dots: The Role of Mn Doping and Precursor Concentration Control

Synthesis and characterization of Y and Mn -doped ZnO nanoparticles: Structural, optical, morphological, and gas sensing investigations

ZnO and Mn-doped Zn0.92Y0.08-xMnxO (x = 0, 0.01, 0.02, 0.04, 0.06) nanoparticles were synthesized hydrothermally and thoroughly characterized structurally, morphologically, and optically. X-ray diffraction (XRD) confirmed their crystalline wurtzite structure, with dopant concentration affecting lattice parameters, causing expansion or contraction. X-ray photoelectron spectroscopy (XPS) confirmed Mn and Y integration into the ZnO matrix. Scanning electron microscopy (SEM) showed morphological shifts from rods to flowers with increased Mn doping concentration. UV–visible absorption revealed optical band changes due to doping. Fourier transform infrared spectroscopy (FTIR) identified Zn–O, Y–O, and Mn–O bonds. Photoluminescence (PL) indicated intensity shifts with doping, suggesting dopant influence on defect-related emissions. Doped ZnO nanoparticles displayed superior hydrogen gas sensing, especially x = 0.04 at 250 °C, attributed to smaller size and structural changes.

Mn derived growth of CsPbBr3 nanoplatelets for stable and bright orange emission

Abstract Mn-doped perovskites have been extensively studied in optics, magnetism, and electronics due to their orange emission. However, successful Mn doping required a high Mn/Pb feed ratio. In this paper, Mn-doped CsPbBr3 nanoplatelets (NPLs) with bright orange emission were prepared by a two-step slow thermal injection synthesis. The slow injection of precursors effectively slow-down the crystal growth kinetic process and controls the growth of undoped CsPbBr3 NPLs. This process also significantly improves Mn doping efficiency. Mn doping induced the generation of numerous precursor clusters during the growth of CsPbBr3 NPLs, and the formation of these clusters was crucial for enhancing the doping efficiency. The maximum amount of Mn precursor in CsPb0.83Mn0.17Br3 was 50% of Pb precursors. The photoluminescence quantum yields (PLQYs) of CsPb0.94Mn0.06Br3 NPLs reached up to 80.6%, which was 3.1 times of that of CsPbBr3 NPLs. The PL properties of Mn-doped CsPbBr3 NPLs were significantly enhanced compared with pure CsPbBr3 NPLs. The growth process and luminescence mechanism of Mn-doped CsPbBr3 NPLs were discussed. High PLQYs and efficient Mn doping supplied an ideal approach for the preparation of various CsPbX3 (X = Cl, Br, and I) NCs for commercial applications.

Bridging OER Electrocatalysis and Tumor Therapy: Utilizing Piezoelectric‐Hole‐Induced OER Electrocatalysis for Direct Oxygen Generation to Address Hypoxia

AbstractIn addressing the challenge of hypoxia within the tumor microenvironment (TME), a significant obstacle to effective cancer therapy, this research introduces a pioneering nanozyme engineered to utilize water and oxygen as reactants. Utilizing ultrasonic piezoelectricity, this nanozyme converts these substrates into oxygen (O2) and reactive oxygen species, thereby amplifying oxidative stress without relying on endogenous H2O2. This approach involves the strategic engineering of porous ZnSnOv:Mn nanosheets (named MZSO NSs), which are distinguished by oxygen‐rich vacancies and enhanced piezoelectric properties. This breakthrough represents the initial attempt to merge catalytic activities akin to catalase (CAT) with the electrocatalytic oxygen evolution reaction (OER), confirmed through both enzymatic reactions and electrochemical voltammetric analysis. The predominant mechanism of ultrasound‐augmented oxygen generation in MZSO is identified as piezoelectric hole‐induced OER. Supporting theoretical analyses clarify the synergistic impact of oxygen vacancies and Mn doping on the dynamics of carriers and the OER process, leading to a notable increase in catalytic efficiency. These findings highlight the potential of piezoelectric‐enhanced OER electrocatalysts to alleviate hypoxia in the TME, providing novel insights into the development of piezoelectric acoustic sensitizers for the treatment of cancer.

Triple-function Mn regulation of NiFe (oxy)hydroxide for oxygen evolution reaction

Transition metal (oxy)hydroxides are potential oxygen evolution reaction (OER) electrocatalysts; however, simultaneously modulating multiple factors to enhance their performance is a grand challenge. Here, we report an incorporating heteroatom strategy via one-step hydrothermal approach to adjust more than one factor of Mn-doped NiFe (oxy)hydroxide (Mn-NiFeOOH/LDH) heterojunction. Mn doping regulates heterojunction morphology (reducing nanoparticles and becoming thinner and denser nanosheets), Ni/Fe ratio and valence states (Ni2+, Ni3+, and Ni3+Δ) of Ni ions. The former could effectively increase surface active sites, and the latter two reduce the content of Fe in the Mnx-NiFeOOH/LDH heterojunction, enabling more Ni2+ convert to Ni3+/3+Δ that have higher intrinsic OER activity. As a result, the first-rank Mn-NiFeOOH/LDH with ultra-low overpotential of 185 mV@20 mA cm−2 and 296 mV@500 mA cm−2, and the improved OER performance are outdo to those of commercial RuO2 catalyst for OER. Moreover, the Mn-NiFeOOH/LDH affords the earliest initial potential (1.392 V vs. RHE), corresponds to a recorded low overpotential (162 mV). Based on the density functional theory (DFT), Mn dopants can alter intermediate adsorption energy and effectively decrease *OOH’s energy barrier. This research exhibits a feasible strategy to design low cost electrocatalysts and provide new possibilities for future industrialization.

Mn-doped nickel-copper phosphides as oxygen evolution reaction electrocatalyst in alkaline seawater solution

Compared with traditional water electrolysis, electrolysis of seawater has larger resources and a brighter future. However, seawater contains more elements that have greater corrosive effects on electrodes; especially chloride ions (seawater contains more chloride ions) have the greatest impact. The existence of the corrosion problem creates greater difficulties in electrolyzing seawater, further limiting the efficiency of the electrocatalyst for electrolysis of seawater. In this paper, we report a Mn-doped Ni2P/Cu3P as an environmentally friendly monofunctional electrode for seawater electrolysis, which was made by a simple hydrothermal phosphatization operation method. The experimental results show that Mn-doped Ni2P/Cu3P presents overpotential of only 161 mV for oxygen evolution reaction (OER) at iR compensation of 90 and a current density of 10 mA cm−2. It has a small Tafel slope (25.15 mV dec−1) and a large capacitance (9.58 mF cm−2 on 1 × 1 nickel foam), which exceeds most reported oxygen evolution activities of non-precious metal-based electrocatalysts for electrolysis of alkaline seawater. The performance of Ni2P/Cu3P was probably significantly enhanced due to Mn doping by some characterization means. Through Density functional theory (DFT) analysis, it is known that the doping of Mn gives a large enhancement in the adsorption energy of water when Ni2P/Cu3P is electrolyzed with seawater. This paper provides train of thought for the exploration of excellent electrocatalysts for electrolysis of alkaline seawater.