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This diagram depicts the generation process of the core–shell structure Prussian blue material in this paper:Under the influence of introduced H+ ions, Fe(CN) 6 4- decomposes to yield Fe2+, benefiting from the excellent chelating properties of IDHA to protect the generated Fe2+ from oxidation. As the MnHCF surface, is rich in nucleation sites, the ions chelated after nucleation transfer to the MnHCF surface. Upon dissociation under the influence of H+, heterogeneous nucleation occurs on the surface. [Display omitted] In recent years, core–shell structured Prussian Blue Analogues (PBAs) have been considered as highly promising cathode materials for sodium-ion batteries. Reducing production costs and simplifying the preparation method for core–shell PBAs have also become crucial considerations. This paper presents a novel approach for the first time: by acid-treating the as-synthesized solution from a simple coprecipitation reaction, a high-crystallinity, sodium-rich Mn2+-doped iron hexacyanoferrate (Fe/MnHCF) shell material is self-grown on the surface of manganese hexacyanoferrate (MnHCF). This method significantly improves the electrochemical properties of the MnHCF material. The core–shell structured PBA exhibits excellent cycling performance (with a capacity retention of 95.5 % for 400 cycles at 1 A/g) and high rate performance (134.2mAh/g@10 mA/g, 95.2mAh/g@1 A/g). In this article, we explore the growth mechanism of the high-sodium content, high-crystallinity shell structure and introduce a green chelating agent that is better suited for the crystallization of Mn and Fe-type PBA systems. Our study demonstrates that Mn2+ doping enhances the conductivity of the shell material. Meanwhile, the heterojunction structure of MnHCF@Fe/MnHCF conducive to charge separation and migration. This straightforward synthesis strategy offers a novel approach for fabricating high-performance core–shell structured Prussian Blue Analogue materials. [ABSTRACT FROM AUTHOR]

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Transition metal sulfides (TMSs) have been regarded as greatly promising electrode materials for supercapacitors because of abundant redox electroactive sites and outstanding conductivity. Herein, we report a self-supported hierarchical Mn doped Co9S8@Co(OH)2 nanosheet arrays on nickel foam (NF) substrate by a one-step metal–organic-framework (MOF) engaged approach and a subsequent sulfurization process. Experimental results reveal that the introduction of manganese endows improved electric conductivity, enlarged electrochemical specific surface area, adjusted electronic structure of Co9S8@Co(OH)2 and enhanced interfacial activities as well as facilitated reaction kinetics of electrodes. The optimal Mn doped Co9S8@Co(OH)2 electrode exhibits an ultrahigh specific capacitance of 3745 F g−1 at 1 A g−1 (5.618 F cm−2 at 1.5 mA cm−2) and sustains 1710 F g−1 at 30 A g−1 (2.565 F cm−2 at 45 mA cm−2), surpassing most reported values on TMSs. Moreover, a battery-type asymmetric supercapacitor (ASC) device is constructed, which delivers high energy density of 50.2 Wh kg−1 at power density of 800 W kg−1, and outstanding long-term cycling stability (94% capacitance retention after 8000 cycles). The encouraging results might offer an effective strategy to optimize the TMSs for energy-storage devices.

In this special work, two types of material, which are undoped and Mn doped TiO2 thin films, have been produced by spin coating technique, and then their structural, morphological and optical properties have been measured at different Mn doping rates. Four different doping ratios, undoped, 1, 3 and 5% Mn doped TiO2 have been both experimentally and theoretically investigated and some significant enhancements have been reported. The results of X-ray diffraction (XRD) such as dislocation density, strain, and crystallite size have indicated that undoped, 1, 3 and 5% Mn doped TiO2 thin films had the phase of anatase at 450 °C. It has been observed that the peak intensity of 3% Mn doped TiO2 films has decreased compared to undoped and 1% Mn doped TiO2 while the peak intensity has increased for 5% Mn doped TiO2. The refractive indices and dielectric coefficients of the undoped and Mn doped TiO2 thin films have also been calculated. The undoped and Mn doped TiO2/p-Si heterojunction diodes has exhibited photosensitive behaviour in the illuminated environment. 1% Mn doped TiO2/p-Si heterojunction diode indicated the highest photocurrent. The electrical parameters of all diodes have been calculated and compared to the conventional J–V and Norde methods. Additionally, 1% Mn doped TiO2/p-Si heterojunction diode has been modelled by using the SCAPS-1D program, and Jph values have also been calculated based on the shallow donor density (ND). The experimental and theoretical Jph values of this diode were found to be compatible with each other. [ABSTRACT FROM AUTHOR]

Antibiotic pollution has posed a serious threat to water environments. To cope with this issue, layered double hydroxides (LDHs) have been employed and exhibited effective removability. However, most of LDHs adsorb antibiotics for water decontamination, which is difficult to degrade the pollutants and usually takes a quite long treatment time. In this work, Mn doped NiAl‐LDHs electrode was synthesized for antibiotic degradation with target pollutant tetracycline (TC). The removal efficiency of TC was then investigated by conducting electro‐oxidation with Mn doped NiAl‐LDHs anode. Specifically, some Mn doped NiAl‐LDHs nanoflowers were shed from NF substrate during the oxidation process, thus forming a 3D‐like electrode device and facilitating TC removal. Meanwhile, due to particle electrode‐like architecture and electro‐oxidation of the composite electrode, high concentration of TC can be removed quickly in a short time, and the removal efficiency can reach 92.6% in 5 min. [ABSTRACT FROM AUTHOR]

Overuse of antibiotics has led to ecological hazards such as the emergence of resistance genes and super bacteria, necessitating the development of water pollution control technology. Indium zinc sulfide (ZnIn2S4, ZIS) is a promising material for environmental applications due to its narrow band gap and excellent light absorption ability. This study investigates Mn‐doped ZIS photocatalysts to enhance their photocatalytic oxidation efficiency. Structural morphology, electrochemical testing, and active species testing confirm that Mn‐doping optimizes the energy band structure of ZIS and increases the concentration of active free radicals, improving the efficiency of charge separation. Mn‐doping also causes lattice distortion, leading to trapping centers to enhance charge separation efficiency. The optimal ZIS‐4% oxidation degradation rate of levofloxacin was 2.5 times higher than that of pristine ZIS, with degradation rates reaching almost 100% in 30 minutes. This study provides a novel approach to designing Mn‐doped photocatalysts for antibiotic pollution control. [ABSTRACT FROM AUTHOR]

The structure, electronic and magnetic properties of the MgO bulk of (1x2x2) and (1x1x1) atoms for the B4 wurtzite phase, doped by Manganese Mn have been studied. Accordingly, the Mn atom location in the far and near spots was taken into account, as well as recognizing the magnetic interaction between both spots. Such initiative was provided thanks to the use of the density function theorem (DFT). As for the energy gap of the semiconductor MgO, it was calculated by the linearly increasing planar method, and by the local density approximation (LDA), not to mention the generalized gradient approximation (CGA). It is found that the calculated results agree well with other theoretical and experimental findings. Whereas, the energy gap and the total magnetic torque have been recorded for the Mn doped MgO in the (1x2x2) super Celle. Therefore, our given results have shown that the use of the classification-generalized approximation could enable us to provide more precise results of the d orbital composites, and they also added new properties to the new compound. [ABSTRACT FROM AUTHOR]

The dilute magnetic semiconductor (DMS) materials have important application prospects in the field of electronic science and technology. Ca 2 Ge is a new environmentally friendly semiconductor material. The structure characteristics indicate that the dilute magnetic properties can be achieved by doping, in the theory. There are C I , C II , C III , O I , O II and O III six doped types by Mn doping. For the C I , C II and O III , Ca 2 Ge is a semiconductor with a band gap of 0.21 eV, 0.21 eV and 0.065 eV, respectively; For the O II , Ca 2 Ge turns into a semi-metallic; For the C III and O I , Ca 2 Ge turns into a metal. Ca 2 Ge trans into ferromagnetism with Mn doped, the molecular magnetic moments of C I , C II , C III , O I , O II and O III are 5 μ B , 5 μ B , 1 μ B , 5 μ B , 5 μ B and 7 μ B , respectively. The results of the projected density of states (PDOS) indicated that the magnetism mainly comes from the Mn 3 d orbital spin, the orbital population shows that the spin of Mn atom affects the spin of Ca atom and the spin of Ge atom, the magnetic moment that is excited by Mn atom doping. [ABSTRACT FROM AUTHOR]

Monitoring hydroxyl radical (·OH) in living cells remains a big challenge on account of its high reactivity and short half-life. In this work, we designed a fluorescent probe based on manganese-doped silicon quantum dots (Mn-SiQDs) for detecting and imaging of ·OH with good water solubility. The manganese was doped in its ethylene diamine tetra-acetic acid (EDTA) complex form and effectively improved the metal ion tolerance of fluorescence of SiQDs. And m-dihydroxybenzene was used as the reductant to extend the emission of SiQDs to the green region at 515 nm when the excitation wavelength was 424 nm. Basing on the fluorescence quenching of Mn-SiQDs, a linear response of ·OH was observed in the range 0.8–50 μM with a limit of detection (LOD) of 88.4 nM, which is lower than those reported with SiQDs. The interference from other ROS or RNS has been assessed and no impact was found. In fully aqueous systems, the Mn-SiQDs have been applied to monitor and image the endogenous ·OH in HeLa cells. Our work provided a new strategy for designing SiQDs with good biocompatibility, high selectivity and long monitoring wavelength. Synthesis of green-emitting silicon quantum dots with N-[3 -(trimethoxysilyl) propyl] ethylenediamine (DAMO), Ethylenediamine tetraacetic acid disodium salt dehydrate (EDTA-2Na·2H2O), manganese acetate tetrahydrate (Mn(CH3COO)2·4H20) and m-dihydroxybenzene. The green fluorescence of the silicon quantum dots can be selectively quenched by hydroxyl radicals. [ABSTRACT FROM AUTHOR]

• Co-doping with alkaline-earth (AE2+) elements enhances the photoluminescence properties of Mn2+-doped CsPbCl 3 nanocrystals. • Introduction of small AE2+ ions into the doping process induces lattice contraction in Mn2+-doped CsPbCl 3 nanocrystals, leading to improved photoluminescence quantum yield and photostability. • The co-doping of Sr2+ ions with Mn2+ in CsPbCl 3 nanocrystals demonstrates a remarkable enhancement in luminescence and light-emitting diode performance. Doping Mn2+ into CsPbCl 3 nanocrystals (NCs) has garnered significant attention for its potential to create tailored optical properties in optoelectronic applications. However, this approach still faces challenges, including low photoluminescence quantum yield (PL QY), suboptimal Mn2+ doping efficiency, and inadequate stability. Herein, we delve into the specific realm of Mn2+ doping in CsPbCl 3 NCs and delve into the effects of co-doping these NCs with alkaline earth (AE2+) metal ions. Through a comprehensive characterization of the co-doped NCs, we systematically unravel bonding characteristics, and luminescence behaviors induced by AE2+ co-doping. The outcomes underscore the notable enhancement in luminescence performance and stability achieved through AE2+ co-doping, particularly with Sr2+. The utilization of smaller AE2+ results in lattice contraction, leading to improved PL QY and heightened photostability. This work offers valuable insights into tailoring the performance of transition metal-doped semiconductor NCs for advanced optoelectronic devices, establishing a foundation for subsequent optimization and diverse applications. The enhancement in luminescence performance and stability of Mn2+ doped CsPbCl 3 nanocrystals achieved through alkaline-earth (AE2+) metal ions co-doping. [Display omitted] [ABSTRACT FROM AUTHOR]

Graphical abstract Abstract A novel Mn-doped Fe 2 O 3 modified g-C 3 N 4 nanosheets composite has been prepared for overall water splitting. Structure characterizations reveal that the Mn are successfully doped in the Fe 2 O 3 nanoparticle and a close interface between g-C 3 N 4 and Mn-doped Fe 2 O 3 is obtained. The optimized FMC-10 photocatalyst has a H 2 evolution of 51 μmol h−1. The improved photocatalytic performance can be ascribed to the synergy effect of both Mn-doped Fe 2 O 3 and g-C 3 N 4. Doping Fe 2 O 3 with Mn promotes photo-induced charges and increases the charge transfer for the improved conductivity of the bulk Fe 2 O 3 , while favorable contacting with g-C 3 N 4 enhances the charge separation ability. [ABSTRACT FROM AUTHOR]

NiCrO (NCO) spinel composites with different Mn/Ni atomic ratios (Mn/Ni = 0.05, 0.10, 0.15, and 0.20) were synthesized via solid state reaction method. Phase compositions and microstructure of samples were characterized by X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The TG-DSC curves showed that the appropriate baking temperature for Mn-doped NCO spinel preparation was approximately 1 320 °C. X-ray diffraction patterns exhibited the formation of NCO spinel with Fd-3m space group. Valence state of the Mn ions was determined from 2 p and 3 s X-ray photoelectron spectra. Manganese ions were mostly in divalent and trivalent states, and the ratio of Mn/Mn was 0.78-0.98. Fourier transform infrared spectroscopy (FTIR) was used to analyze the spectral emissivity of Mn doped NCO spinel. It was revealed that the infrared emissivity of Mn-doped NCO spinel in 1.8-5 μm could be significantly enhanced with increasing content of Mn, reaching as high as 0.9398. Mn-doped NCO spinel showed excellent radiation performance and good prospect in high emissivity applications in the temperature range of 800-1 200 °C. [ABSTRACT FROM AUTHOR]

Mn-doped TiO 2 grown on reduced graphene oxide(rGO) was synthesized by one-pot hydrothermal method and the photocatalytic removal of Cr by the material was investigated under sunlight. The materials were characterized by a combination of scanning electron microscopy, transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, Brunauer-Emmett-Teller method, UV–vis diffuse reflectance spectra, photoluminescence spectra, electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy. Cr(total) removal efficiency of the material is 97.32% in 30 min and 99.02% in 60 min under sunlight irradiation, as the initial concentration of Cr(VI) is 20 mg/L. The high photocatalytic activity under visible light is considered mainly due to the Mn-doping, and rGO plays an important role in the synergetic effect of adsorption and photocatalysis to sustain the high efficient removal of Cr(VI) and Cr(III). Cr(VI) adsorbed on the surface of rGO is reduced to Cr(III) by photo electrons which are transported through rGO, and the reaction product Cr(III) continues to be adsorbed. The process contributes to the release of abundant photocatalytic sites of Mn-TiO 2 and improves photocatalytic efficiency. The excellent adsorption and photocatalytic effect with the explanation of the synergetic mechanism are very useful not only for fundamental research but also for the potential practical applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Mn doped Co 3 O 4 spinel catalysts like spherical were successfully prepared. • Excellent catalytic performance for toluene oxidation over Mn 0.4 Co 0.6 O x. • Improving the formation of surface Co2+, Mn4+and lattice oxygen. • Enhancing mobility of surface oxygen due to formation of surface Mn-O-Co bonds. • Role of surface absorbed oxygen and surface lattice oxygen in toluene combustion. Catalytic combustion is considered as the most promising technology for removing VOCs over composite metal oxide catalysts. Herein, Mn doped Co 3 O 4 spinel catalysts (Mn a Co 1-a O x) like spherical were successfully prepared via solvothermal method, and applied for catalytic toluene combustion. The physical and chemical properties of catalysts were analyzed by various characterization techniques such as XRD, N 2 physical-adsorption, SEM, TEM, H 2 -TPR, O 2 -TPD, XPS and in-situ DRIFTS. Among these catalysts, Mn 0.4 Co 0.6 O x shows optimal catalytic activity (T 50 = 206 °C; T 90 = 215 °C) and stability, and it can still maintain good activity even in presence of H 2 O. The amounts of the surface Co2+, Mn4+and lattice oxygen are improved based on the interaction between Co and Mn ions (Mn3+ + Co3+ → Mn4+ + Co2+), leading to far stronger oxidation ability of catalyst. The formation of the surface Mn-O-Co bonds on spinel catalysts Mn a Co 1-a O x improves the mobility of surface oxygen. In addition, the catalytic combustion of toluene over these catalysts follows the Mars-van Krevelen mechanism and the surface lattice oxygen plays a crucial role in the cycle of oxygen species based on in-situ DRIFTS results. [ABSTRACT FROM AUTHOR]

In this study, manganese [Mn]-doped zinc oxide [ZnO] nanoparticles are prepared by microwave irradiation method using zinc acetate and manganese acetate as precursors. The optical properties of the samples were investigated by UV-Vis-NIR, photoluminescence (PL) and Fourier transform infrared spectroscopy. Optical absorption analysis of the samples exhibits a red shift in the absorption band edge with increasing dopant concentration, and corresponding defects in ZnO are responsible for broad bands in the visible part of the photoluminescence (PL) spectrum. The room-temperature photoluminescence shows that the intensity of near band energy (NBE) emission depends strongly on the content of Mn in ZnO. We have also discussed in the paper the types of transitions and possible assignments of the PL bands. The chemical groups of the samples were confirmed by FTIR spectra. [ABSTRACT FROM AUTHOR]

NaYF:Yb/Er upconversion nanoparticles doped with Mn were synthesized by hydrothermal method. The upconversion photoluminescence measured by 975 nm continuous wave laser indicates that the as-synthesized samples generated green and red color emission with various intensity ratio ranging from 3.25 to 548.35, which is highly correlative to the dopant concentration of Mn. However, there is no red emission enhancement observed in Cu-doped NaYF:Yb/Er nanoparticles. [ABSTRACT FROM AUTHOR]

Manganese doped aluminum nitride (AlN:Mn) nanowires were fabricated by direct nitridation of Al and Mn mixed powders. The as-synthesized AlN:Mn nanowires were characterized by X-ray diffraction, Raman, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, scanning and transmission electron microscopy. The measurements reveal the successful incorporation of Mn2+ ions into AlN nanowires. The magnetic and optical properties of the AlN:Mn nanowires were studied using vibrating sample magnetometer and photoluminescence spectroscopy. The AlN:Mn nanowires exhibit room temperature ferromagnetic behavior and a red emission band centered at 597 nm corresponding to the 4T 1 (4G)-6A 1 (6S) transition of Mn2+. The abnormal thermal quenching behavior and long afterglow feature are investigated through the temperature dependent emission and the afterglow spectrum. The thermoluminescence curve shows that AlN:Mn nanowires have the plentiful traps, which leads to the abnormal thermal quenching behavior and persistent luminescence. Multifunctional AlN:Mn nanowires with magnetic and luminescence properties are expected to be used in spintronic and optoelectronic nanodevices. • Mn doped AlN nanowires were fabricated using modified arc discharge method. • Mn doped AlN nanowires exhibit ferromagnetism at room temperature. • Mn doped AlN nanowires exhibit an intensive red emission. • Mn doped AlN nanowires exhibit abnormal thermal quenching behavior and persistent luminescence. [ABSTRACT FROM AUTHOR]

• Cu-Zn-Ga-Se and Cu-Mn-Zn-Ga-Se QDs were obtained via one-pot method. • Cu-Zn-Ga-Se QDs originated from the diffusion of Cu+ into Zn-Ga-Se nanoparticles. • Incorporating Mn led to white emission well-tuned by incremental ZnSe deposition. • These results reveal the potential to fabricate better color rendering WLEDs. Single-phased and white-emissive quantum dots (QDs) with a broadband spectrum are highly desirable as color converter for white light-emitting diodes (WLEDs) and have been less researched up till now. In this work, a series of copper gallium selenium based multicomponent QDs including quaternary Cu-Zn-Ga-Se (CZGSe) and quinary Cu-Mn-Zn-Ga-Se (CMZGSe) QDs were synthesized. From the perspective of thermodynamics and kinetics, the comparison between PL spectra under increasing temperatures via one-pot and hot-injection methods indicated that the formation of CZGSe cores originated from the diffusion of Cu+ into Zn-Ga-Se nanoparticles. For wider spectra distribution, the incorporation of Mn2+ gave rise to Mn d-d emission around 590 nm. Together with Cu-related emission about 500 nm and intrinsic emission around 430 nm, white emission of CMZGSe QDs could be realized well-tuned by incremental ZnSe deposition, whose chromaticity coordinates shifted along with the Planckian locus. These results about multicomponent alloyed QDs enrich mechanistic insight for the formation kinetics and reveal the potential to fabricate better color rendering WLEDs. [ABSTRACT FROM AUTHOR]

Energy storage devices based on the two-dimensional transition metal dichalcogenides (TMDs) have great interest due to their fascinating physical and chemical properties. In this study, Mn incorporated MoS 2 nanosheets are self-assembled into nanoflowers via a simple one-step hydrothermal process. The nanoflowers retain the feature of the high specific surface area of the nanosheets and the intercalation of Mn atoms up to a certain amount increases the porosity of MoS 2 , thus enhancing active sites for reaction. The presence of an intermediate oxidation state of Mn (Mn3+), which also plays an important role in increasing capacitance, is highest in low doped sample resulting in superior capacitance performance compared to bare and high Mn content samples. So the supercapacitor electrode made of low Mn incorporated MoS 2 nanoflowers exhibits maximum specific capacitance (430 F g−1), energy density 48.9 W h kg−1 and power density 5.0 kW kg−1 with excellent capacitance retention up to 5000 cycles at 10 A g−1, when used as a supercapacitor electrode. Further, the performance of the electrode material has been examined by lightning four LED bulbs in series showing longer discharge time. Our findings open new areas to explore Mn doping with TMDs as next-generation energy devices systematically. Image 1 [ABSTRACT FROM AUTHOR]

Manganese-doped zinc oxide (Mn:ZnO) nanofibers were synthesized using the electrospinning process. Structural, chemical, morphological and optical properties of the nanofibers were characterized and compared with undoped ZnO nanofibers. To investigate photocatalytic activity of nanofibers under the both UV and visible light, methylene blue (MB) was used as a representative dye pollutant. It was found that substitutional incorporation of Mn2+ and Mn4+ ions in ZnO resulted in the generation of additional energy levels within the band gap of ZnO. Furthermore, higher manganese incorporation resulted in smaller-sized Mn:ZnO nanoparticles with highly concave-convex structures, and consequently, an increase in surface area. Substitutional incorporation of the dopant ions and the resulting morphological variations provide better photocatalytic efficiency due to formation of a greater number of charge carriers and the corresponding delay in the recombination process. Among the studied dopant content, 0.5 at.% Mn:ZnO fibers was determined as the optimal composition and the degradation of MB can reach about ~100% after 90 min. UV light and ~35% after 100 min visible light illumination. The doped fibers displayed high stability and durability in the degradation tests, even after ten cycles. Mn:ZnO nanofibers are thus good candidate materials for photocatalytic applications with superior efficiencies and highly reusable properties. [ABSTRACT FROM AUTHOR]