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The development of efficient and cost-effective electrocatalysts is crucial for achieving a green hydrogen economy through electrocatalytic water splitting. Herein, we report an excellent catalyst, one-dimensional NiS2/NiS/Mn2O3 nanofibers prepared by electrospinning, which exhibits outstanding electrochemical performance in an alkaline solution. We explored effective strategies to construct one-dimensional nanostructures and composite oxides to promote the electrocatalytic performance of transition metal dichalcogenides. At a current density of 20 mA cm−2, it requires an overpotential of 333 mV for OER. Furthermore, NiS2/NiS/Mn2O3 nanofibers maintain good durability even after 1000 cycles. The long-term electrochemical stability test of the catalyst NiS2/NiS/Mn2O3 was implemented at 20 mA cm−2 for 12 h. The potential remained at 99.52%. Therefore, this study demonstrates that NiS2/NiS/Mn2O3 can serve as a viable green hydrogen production electrocatalyst. [ABSTRACT FROM AUTHOR]

This work aims to study the effect of Mn 2 O 3 additions on the electrical properties and microstructure characteristics of a SnO 2 -based ceramic varistor system doped additionally with Sb 2 O 5 , Cr 2 O 3 , and CoO. The specimens were prepared using conventional ceramic processing and homogenized by a high-energy ball milling system using the following composition: (98.99-X) % SnO 2 – 0.05% Cr 2 O 3 – 0.05% Sb 2 O 5 – 1.00% CoO – X% Mn 2 O 3 where X = 0.00, 0.05, 0.10, 0.20, 0.50 and 1% mol. Characterization by TG-DSC/DTA, XRD, XPS, and SEM/EDS, and the proposed chemical and defect-formation reactions allowed the conclusion that Mn 2 O 3 additions produce alterations of the microstructure consisting of the in situ formation of the spinel Co 2 MnO 4 secondary phase and modification of the potential barriers in the intergranular regions, where, in addition, oxygen vacancies are formed. With the 0.05 mol % Mn 2 O 3 , the grain size (average in the range of 2–3 μm) drops by 20 %, thus augmenting the grain boundaries. Altogether, this leads to a decrease in the nonlinearity coefficient (α) and an advantageous displacement of the breakdown electric field (E B). The 0.05 mol % Mn 2 O 3 specimen compares favorably with the reference material by surpassing the E B value by a factor of 8. Elucidation of Mn2+ and Co2+ in 1 mol % Mn 2 O 3 specimens by XPS suggests the role of MnO and CoO as intermediate phases, essential for Co 2 MnO 4 formation. The pathway for in situ formation of Co 2 MnO 4 is set forth based on the above characterization techniques in conjunction with proposed chemical and defect-formation reactions. [ABSTRACT FROM AUTHOR]

Antibiotics in wastewater pose a major threat to human health and environmental safety, and the generation of reactive oxygen species by peroxomonosulfate (PMS) activation is an attractive option for the treatment of treating antibiotic wastewater. However, achieving efficient PMS activation remains challenging due to insufficient electron mobility efficiency. Herein, Co-doped Mn2O3 catalyst (Co5-Mn2O3) is prepared by a simple one-step calcination method, and the degradation performance of the Co5-Mn2O3/PMS system is investigated using ofloxacin (OFX) as the target pollutant, and the removal of OFX reaches 95% within 15 min, which is 12.3-fold enhancement compared with the pristine Mn2O3, and the degradation performance of the Co5-Mn2O3/PMS system shows excellent degradation performance for a variety of pollutants (ciprofloxacin, sulfamethoxazole, tetracycline, rhodamine B, and methyl orange), which demonstrates the potential for practical applications. It is confirmed by X-ray photoelectron spectroscopy that Co doping induces the surface reconstruction of the catalyst and electron migration to achieve the formation of Mn4+-O-Co2+ active sites. Trap experiments show that the electron-rich Co site and the electron-deficient Mn site could effectively activate PMS to generate sulfate radicals and singlet oxygen for the efficient removal of ofloxacin. This work provides a structural modulation method of the active site for controlling the catalytic function, which will provide a new perspective for the rational design of Fenton-like catalysts. [ABSTRACT FROM AUTHOR]

Background and Aim: At present, detailed studies are being conducted to confirm the safety of the use of metal-containing ultrafine particles (UFP) in animal feeding, preventing the possibility of negative effects on productive qualities and physiological state, as well as on the environment and final consumer, that is, humans. Thus, the purpose of this research was to study the safety of cobalt- and manganese-containing UFP (UFP Co3O4, Mn2O3 UFP) together with Origanum vulgare (PB) herb extract in a bioluminescence inhibition test, as well as the effect of this composition on ruminal digestion in vitro. Materials and Methods: The safety of the studied samples was determined using a multifunctional microplate analyzer TECAN Infinite F200 (Tecan Austria GmbH, Austria), recording the luminescence value of the bacterial strain Escherichia coli K12 TG11 (Ecolum, JSC NVO Immunotech, Russia). Dry matter (DM) digestibility studies were performed using the in vitro method on an “artificial rumen” model using an ANKOM Daisy II incubator unit (AD II; USA). The number of protozoa in ruminal fluid was counted in a Goryaev chamber. The bacterial mass was assessed by differential centrifugation followed by drying. This method is based on differences in the sedimentation rate of particles that differ in size and density. Results: UFP Co3O4 and Mn2O3 at concentrations above 1.5 × 10-5 and 1.9 × 10-3 mol/L, respectively, have a pronounced bactericidal effect, suppressing more than 50% of the luminescence of E. coli K12 TG1. The combined use of UFP metals and plant extract increases the luminescence of the test object, indicating its safety. The combined use of UFP and PB increases the digestibility of feed DM in vitro and the number of protozoa in 1 mL of ruminal fluid; however, the combination of UFP Mn2O3 + PB (13.8%) yielded the best result, which is recommended for further in vivo research. Conclusion: Origanum vulgare extract reduces the toxicity of UFP Co3O4 and Mn2O3 in vitro, indicating that their combined use is safer.

The hydrothermal method was used to prepare manganese oxide (Mn2O3) nanoparticles. Reduced graphene oxide (rGO) powder was sonicated with Mn2O3 forming a homogeneous Mn2O3-rGO nanocomposite. The prepared nanocomposite was characterized by UV–Vis spectroscopy to unravel origin of absorption photons strongly in the visible region that ensues due to charge transfer, Fourier transform infrared (FTIR) result reveal that the catalytic role of Mn2O3 in graphene reduction in sono-nano composites formation, X-ray diffraction (XRD) result also stand out all of structural parameters enhance slight increase for the position non-ideality (δ dislocation density) of atoms in crystallite size (D) and micro strain (ε).Decreasing the average crystallite size 41.13 nm and 37.2 nm for Mn2O3 and Mn2O3-rGO respectively due to high (600 W) ultra-sonication in presence of rGO-sheets. Field emission scanning electron microscopy (FESEM) show up uniform distribution of Mn2O3 and tightly anchored on the surface of the rGO sheets. These different characterization techniques confirmed the formation of the nanocomposite. Molecular quantum mechanical calculations for interaction investigation mechanism between rGO and Mn2O3, were conducted. Two model molecules were built for Mn2O3 and functionalized rGO, and 8 possible interaction mechanisms between Mn2O3 and functionalized rGO were proposed. Density functional theory (DFT) calculations using B3LYP/LANL2DZ basis set were conducted for the studied model molecules. Electronic properties and reactivity were investigated by calculating molecular electrostatic potential (MESP) mapping for model structures. The most active and plausible structure is the interaction of rGO through the OH group at the terminal with Mn2O3 through the Mn atom. It can be concluded that Mn2O3 activates the rGO surface and increases its detection sensitivity and reactivity. [ABSTRACT FROM AUTHOR]

The conditions of application of thin semiconductor Mn2O3 films on p-InSe crystalline layered semiconductor substrates at a temperature of 623 K by the spray-pyrolysis method to create anisotypic heterojunctions n-Mn2O3/p-InSe were investigated. InSe is a promising material for photoelectronics. The use of the Mn2O3 film, which is transparent in the region of maximum photosensitivity of InSe, makes it possible to effectively exploit the optical properties of InSe in the fabrication of various semiconductor devices. The advantage of using layered semiconductors in the production of heterojunctions is that high-quality interfaces are obtained even with a significant discrepancy in the parameters of the crystal lattices of the starting materials. This significantly expands the choice of heterojunction materials. Electrical and photoelectric parameters of n-Mn2O3/p-InSe heterojunctions were measured and theoretical models describing them were proposed. The graphical dependencies of I-V characteristics, series resistance, height of the potential barrier and photosensitivity are constructed. It was established that these heterojunctions are photosensitive and have rectifying properties. Using the energy parameters of the starting materials, an energy diagram of the heterojunction was constructed, which allows for the analysis of physical processes in the obtained heterojunctions. Based on the temperature dependence of both direct and reverse I-V characteristics, the dynamics of changes in the energy parameters of the heterojunction with temperature, as well as the mechanisms of current flow through the heterojunction, are established. The spectral photosensitivity of the heterojunction was analyzed. [ABSTRACT FROM AUTHOR]

In this work, Mn2O3 synthesized from Mn-MIL-100 was used as an efficient PMS activator for Rhodamine B (RhB) removal in water. The materials were characterized by XRD, FITR, SEM, EDX, and BET analyses. Results showed that the prepared Mn2O3 had better PMS activation efficiency than Mn2+, Mn3O4, MnO2, and commercial Mn2O3. In RhB removal, the highest RhB degradation and COD removal efficiencies reached 98.2% and 72.15%, respectively, after 70 min at the conditions of 10 mgRhB/L, 500 mgPMS/L, 400 mgMn2O3/L, pH 7, and 30 °C. Radical quenching tests showed that the sulfate radicals played a major role in the degradation of RhB. The decomposition of RhB followed pseudo-first-order kinetics (R2 > 0.99) with an activation energy of 34.94 kJ/mol. The effect of anion on RhB decomposition was in the order of SO42−< NO3−< Cl−3−42−32−. RhB degradation efficiency remained at 86.74% after 5 cycles of reuse. These results suggest a potential application of PMS activation by Mn2O3 in the treatment of non—or hard-biodegradable wastewater. [ABSTRACT FROM AUTHOR]

The electrospinning technique is used to synthesize several types of mesoporous manganese oxides, namely Mn2O3, Mn3O4, and hybrid manganese oxides. The as-spun nanofibers are heated at different temperatures from 500 to 1000 °C for 2 h. XRD analysis reveals that the Mn2O3 phase starts to form at 500 °C, whereas at 900 °C, Mn2O3 and Mn3O4 are co-existent and at 1000 °C, Mn3O4 is the sole phase. The mesoporous material's behavior can be seen in all isotherms of the prepared manganese oxide nanofibers. The maximum surface area of 1306.98 m2/g is achieved for the sample calcined at 500 °C, which is one of the highest surface areas recorded for Mn2O3 as compared with the literature. [ABSTRACT FROM AUTHOR]

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Leishmaniasis is a group of diseases caused by infection with Leishmania parasites. The lesions that develop as a result of leishmaniasis can vary depending on the species of the parasite and the type of leishmaniasis. Cutaneous leishmaniasis is the most common form of the disease and it results in skin sores or ulcers. Materials with manganese oxide (Mn2O3) nanoparticles and tellurium oxide (TeO2) nanorods have been shown to have antibacterial, antifungal, and antiparasitic effects. The purpose of this study was to ascertain how Mn2O3 and TeO2 nanoparticles affected Leishmania major-caused wound healing in rats. The albino rats were separated into four groups of five once a lesion appeared on their tails. In the two treatment groups, Mn2O3 and TeO2 nanoparticles were injected every day, once a day, intra-wound in three places, and in the meglumine antimoniate group, the drug was injected intramuscularly for five weeks. The albino rats in the negative control group did not receive any medication. The size of the wounds in the group treated with Mn2O3 nanoparticles did not differ significantly from the control group that did not receive treatment, however the diameter of the wounds in the group treated with TeO2 nanorods did change significantly from the control group that did not receive treatment. It was, however, larger than the group that received meglumine antimoniate treatment. TeO2 nanorods, as opposed to Mn2O3 nanoparticles, had an in vivo anti-Leishmanial potential. [ABSTRACT FROM AUTHOR]

Three kinds of three‐dimensional (3D) Mn2O3 catalysts with different morphologies (cube, fan‐like structure, and sphere) and various exposed crystal planes were prepared by a hydrothermal method for benzene oxidation. The activity results suggested that sample Mn2O3‐Cl with hierarchical cube morphology exhibited a better rate of benzene degradation than the other samples. Mn2O3‐Cl exhibited the lowest complete benzene conversion temperature (T90 = 252°C), which was ~48°C lower than that of the Mn2O3‐S sample. Meanwhile, the Rm and Rs values of Mn2O3‐Cl were 2.71 and 3.21 times, respectively, higher than those of Mn2O3‐S. TEM results suggested that morphology has a significant effect on crystal planes. The activity–morphology relationship over the Mn2O3 samples was investigated by multiple analytical techniques. It can be concluded that the low crystallinity, superior redox ability, abundant low‐valence Mn ions, and Olatt species in the Mn2O3‐Cl catalyst were responsible for its superior catalytic activity. [ABSTRACT FROM AUTHOR]

Currently, efforts to address the energy needs of large-scale power applications have expedited the development of sodium–ion (Na–ion) batteries. Transition-metal oxides, including Mn2O3, are promising for low-cost, eco-friendly energy storage/conversion. Due to its high theoretical capacity, Mn2O3 is worth exploring as an anode material for Na-ion batteries; however, its actual application is constrained by low electrical conductivity and capacity fading. Herein, we attempt to overcome the problems related to Mn2O3 with heteroatom-doped reduced graphene oxide (rGO) aerogels synthesised via the hydrothermal method with a subsequent freeze-drying process. The cubic Mn2O3 particles with an average size of 0.5–1.5 µm are distributed to both sides of heteroatom-doped rGO aerogels layers. Results indicate that heteroatom-doped rGO aerogels may serve as an efficient ion transport channel for electrolyte ion transport in Mn2O3. After 100 cycles, the electrodes retained their capacities of 242, 325, and 277 mAh g−1, for Mn2O3/rGO, Mn2O3/nitrogen-rGO, and Mn2O3/nitrogen, sulphur-rGO aerogels, respectively. Doping Mn2O3 with heteroatom-doped rGO aerogels increased its electrical conductivity and buffered volume change during charge/discharge, resulting in high capacity and stable cycling performance. The synergistic effects of heteroatom doping and the three-dimensional porous structure network of rGO aerogels are responsible for their excellent electrochemical performances. [ABSTRACT FROM AUTHOR]

Due to its high energy density, non-toxic, economical and efficient, manganese oxide stands out as a promising cathode material for employment in aqueous zinc-ion batteries. However, the Jahn-Teller effect of Mn3+ and manganese dissolution impose limitations on the widespread application of aqueous zinc-ion batteries during charging and discharging. Herein, the Co doped Mn 2 O 3 electrode material is introduced. Co atoms in the low valence state replace Mn in the manganese oxide lattice, which effectively regulates the layer spacing of Mn 2 O 3. This modulation maintains the structural stability of the electrode during cycling, prevents structural collapse, and inhibits manganese dissolution and the Jahn-Teller effect. Additionally, Co doping increased oxygen vacancies and improved the conductivity of zinc-ion batteries. The Co-Mn 2 O 3 electrode exhibits a high specific capacity of 478 mAh·g−1 at 0.1 A g−1 current density, with 93 % capacity retention 1000 cycles at 1 A g−1 current density. This study delves into the role of Co doping in suppressing the Jahn-Teller effect, offering new insights for improving manganese oxide as an anode material for zinc-ion batteries. This study introduces a high-capacity Co-doped Mn₂O₃ electrode material. Cobalt atoms replace manganese in the Mn₂O₃ lattice, effectively regulating layer spacing and maintaining structural stability during cycling. Meanwhile, the introduction of cobalt prevents structural collapse, inhibits manganese dissolution, and suppresses the Jahn-Teller effect. Additionally, Co doping increases oxygen vacancies and improves conductivity. [Display omitted] • Co doping in Mn₂O₃ regulates layer spacing, maintaining structural integrity. • Co suppresses Jahn-Teller distortion of Mn³⁺ and prevents Mn dissolution. • Co doping increases oxygen vacancies, boosting electrode conductivity. [ABSTRACT FROM AUTHOR]

The surface acidity and electron transfer performance of manganese oxide catalysts significantly affected its performance of peroxymonosulfate (PMS) activation. In this work, Mn 2 O 3 catalyst was prepared by the precipitation method. The C-hybridization Mn 2 O 3 (Mn 2 O 3 -D) catalyst prepared with disodium oxalate as a precipitant had more Mn3+ and Lewis acid sites on the surface, promoting the binding of PMS on the catalyst surface, which exhibited the best performance in inducing PMS activation to degrade bisphenol A (BPA). Quenching experiments and in situ electron spin resonance (ESR) results indicated that radicals and singlet oxygen were not the main reactive oxygen species (ROSs) in the advanced oxidation process. The chemical probe experiment of phenylmethylsulfone (PMSO) showed that the ≡ Mn-OOSO 3 - metastable intermediate formed by the binding of PMS with Mn sites on the catalyst surface was important active species for contaminants degradation. Contaminants combined with intermediates on the catalyst surface to form the electron transfer channels, which were directly degraded through oxygen-atom-transfer pathway and single-electron-transfer pathway. And the hybridization of C promoted the electron transfer during this process. This work further elucidated the reaction mechanism of PMS activation by manganese oxides, and proposed new ideas for the design of MnO x catalysts for efficient activation of PMS. [Display omitted] • C-hybridization Mn 2 O 3 is synthesized by using sodium oxalate as a precipitant. • More Mn3+ and Lewis acid sites lead better catalytic activity. • Radicals and 1O 2 are not the main causes of contaminants degradation. • ≡Mn-OOSO 3 - directly degrades contaminants through mediated electron-transfer. [ABSTRACT FROM AUTHOR]

This study synthesizes cuboidal-shaped hierarchical Mn 2 O 3 (MNO) particles using a simple hydrothermal technique with Good's buffer piperazine and examines their electrochemical performance. The research explores how varying piperazine concentrations (piperazine concentration x in MNO- x) affect the structure and electrochemical properties of the MNO particles. X-ray diffraction (XRD) confirms the crystalline nature of MNO while scanning electron microscopy reveals that piperazine concentration influences the particles' shape, size, and morphology. The MNO synthesized with 6 mmole piperazine (MNO-6) has the highest surface area of 8.67 m²/g. Electrochemical tests in 1 M and 6 M KOH electrolytes show that MNO-6 achieves the highest specific capacitance, with 440 F/g in 1 M and 952 F/g in 6 M KOH at a 1 mV/s scan rate. At a 1 A g-1 current density, MNO-6 exhibits a specific capacitance of ∼545.8 F/g in 1 M KOH and 809.0 F/g in 6 M KOH, with corresponding energy densities of 27.3 Wh/kg and 40.4 Wh/kg, and power densities of 315.7 W/kg and 365 W/kg, respectively. The superior electrochemical performance is attributed to the high surface area and porous structure of MNO synthesized with piperazine, highlighting its potential for advanced energy storage applications. [Display omitted] [ABSTRACT FROM AUTHOR]

In this paper, the NO-SCO (the selective catalytic oxidation of NO) experiments of single-phase Mn2O3, supported Mn2O3/Al2O3, and the Ce-doped MnxCey/Al catalyst system were carried out. The physical and chemical properties of the catalysts were analyzed by XRD, BET, XPS, SEM, O2-TPD, and H2-TPR. The effects of loading and Ce doping on catalyst activity were studied. The results show that the Mn2O3 catalyst exhibited the best activity at 300 ℃, and the NO conversion rate of Mn2O3 was 78.2%. The relative content of Oα adsorbed on the surface of the Mnx/Al catalyst decreased obviously by loading Mn2O3 on γ-Al2O3, which led to the decrease in catalyst activity. And the temperature window moved to the high-temperature region. After doping Ce, the dispersion of Mn enhanced, and the relative content of oxygen Oα adsorbed on the surface increased. The low-temperature activity and fluidity of oxygen in catalysts were improved. Among them, the Mn0.2Ce0.08/Al catalyst obtained a high specific surface area, good pore structure, large oxygen storage capacity, and excellent surface oxygen species. The corresponding NO conversion rate reached 83.5% at 290 ℃. Then, the effects of operating parameters such as space velocity, NO concentration, and O2 content on the catalytic activity of Mn0.2Ce0.08/Al were discussed. The experimental results show that the NO conversion rate of Mn0.2Ce0.08/Al decreased with increasing NO concentration and space velocity. The O2 content had a positive effect on the catalytic activity of the catalyst. However, the NO conversion rate tended to be stable due to the saturation of oxygen adsorbed on the catalyst. Through cycling experiments, we found that Mn2O3, Mn0.2/Al, and Mn0.2Ce0.08/Al catalysts showed good oxidation stabilities for NO oxidation. The evaluation of the water and sulfur resistance of the catalyst shows that the toxicity of SO2 was reduced by the aqueous atmosphere to a certain extent. Through the structural optimization of the basic model and the calculation of the NO-SCO reaction path, the results show that the NO-SCO reaction on the Mn2O3 (110) face followed the ER mechanism more. For the Mn2O3/Al2O3 (110) surface, the LH-MvK hybrid mechanism can greatly reduce the desorption energy barrier of the reaction intermediates, which is more favorable for the NO-SCO reaction. The catalytic mechanisms of the MnxCey/Al catalysts require further in-depth research. [ABSTRACT FROM AUTHOR]

Mn2O3@Mn(Bi)OCl composite for supercapacitor were successfully synthesized via a facile solid-phase method using Bi(NO3)3 and MnCl2 with molar ratio of 2 : 1 as precursors. The Mn2O3@Mn(Bi)OCl composite were characterized by X-ray diffraction, scanning electron microscopy, thermogravimetry and differential scanning calorimetry and Brunauer–Emmett–Teller surface area measurements, respectively. Cyclic voltammetry and galvanostatic charge/discharge technique were performed for the Mn2O3@Mn(Bi)OCl mix-crystals in 1 M Na2SO4 aqueous solutions; the specific capacitance of Mn2O3@Mn(Bi)OCl was about 203 F g‒1 at the current density of 1 A g–1 with a long life time, owing to the high power density and the large surface area, good conductivity, and high stability of the of Mn2O3@Mn(Bi)OCl composite. [ABSTRACT FROM AUTHOR]

In this article, a flexible self-healing supercapacitor was fabricated by assembling two activated carbon cloth (ACC)/Mn2O3 electrodes and a self-healing physically cross-linked PVA-H2SO4 gel electrolyte. The results show that ACC/Mn2O3 exhibited excellent electrochemical performance (the area specific capacitance at 1 mA/cm2 was 2 264 mF/cm2, and the capacitance retention rate after 10 000 cycles was 93%). The supercapacitors showed excellent flexibility and good self-healing ability, and the capacitance retention rate after 4 cut-healing cycles was about 80.47%.

As well established, the morphology and architecture of electrode materials greatly contribute to the electrochemical properties. Herein, a novel structure of mesoporous coral-like manganese (III) oxide (Mn 2 O 3) is synthesized via a facile solvothermal method coupled with the carbonization under air. When fabricated as anode electrode for lithium-ion batteries (LIBs), the as-prepared Mn 2 O 3 exhibits good electrochemical properties, showing a high discharge capacity of 1090.4 mAh g−1 at 0.1 A g−1, and excellent rate performance of 410.4 mAh g−1 at 2 A g−1. Furthermore, it maintains the reversible discharge capacity of 1045 mAh g−1 at 0.1 A g−1 after 380 cycles, and 755 mAh g−1 at 1 A g−1 after 450 cycles. The durable cycling stability and outstanding rate performance can be attributed to its unique 3D mesoporous structure, which is favorable for increasing active area and shortening Li+ diffusion distance. [ABSTRACT FROM AUTHOR]

Three different morphologies of CeO2 supports (nanoparticle, nanocube, and nanorod) were prepared by hydrothermal technique and further Mn2O3 metal was impregnated on CeO2 supports using wet‐impregnation methods, and their activity for NO reduction using NH3−SCR technique was analysed. The synthesized catalysts and supports were further characterized through scanning electron microscopy (SEM), Energy‐dispersive X‐ray spectroscopy (EDX), X‐ray diffraction (XRD), X‐ray Photoelectron Spectroscopy (XPS), and transmission electron microscopy (TEM), and Brunauer‐Emmett‐Teller (BET). The catalytic performance of Mn2O3/CeO2‐nanoparticle has shown the highest conversion (76 %) compared to the other two catalysts in the temperature range of 50–450 °C. [ABSTRACT FROM AUTHOR]

Mn2O3/Fe2O3/few layer graphene/sulfur composites were prepared by melted salt method, interlayer catalytic exfoliation, annealing and melt diffusion method in sequence for lithium-sulfur batteries cathode. The three-dimensional conductive network formed by highly conductive few layers graphene provides electron transfer channel, thus promoting the high capacity performance of lithium-sulfur batteries. The metal oxides distributed uniformly on the surface of graphene exhibit strong interaction towards polysulfides, which can restrain the dissolution of polysulfides and shuttle effect and promote the cycling performance of lithium-sulfur batteries. As a result, the Mn2O3/Fe2O3/FLG30/S cathode shows high capacity and cycling performance. The cathode delivers an initial discharging capacity of 886.3 mAh·g-1 with a high capacity retention of 88.1% after 100 cycles at rate of 0.1 C.

Introduction Manganese(III) oxide (Mn 2 O 3 ) is a transition metal oxide that has gained significant attention due to its unique properties and potential applications in various fields, including catalysis, energy storage, and sensing. Dopamine, a neurotransmitter in the human brain, plays a crucial role in regulating several physiological processes as its detection is important in areas such as medical diagnostics and neurochemistry. The synthesis of Mn 2 O 3 can be achieved through methods like precipitation, hydrothermal synthesis, or solid-state reactions. Aims The objective of this study is to synthesize Mn 2 O 3 , characterize its structure and morphology, and investigate its electrochemical properties toward dopamine. Materials and methods Materials used included manganese sulfate (MnSO 4 ), potassium permanganate, deionized water, a Teflon steel autoclave, and a hot air oven. For the synthesis of a hierarchical Mn 2 O 3  rodlike shape, MnSO 4 •H 2 O (8 mmol) and potassium permanganate (8 mmol) were firstly dissolved in deionized water (40 mL) by stirring, which was then transferred to a Teflon-lined stainless steel autoclave (50 mL). This autoclave was sealed and maintained at 90℃ for six hours. Finally, the resultant Mn 2 O 3 rods were collected by filtration, washed with distilled water and absolute ethanol for several times, and dried in air at 80℃. Mn 2 O 3  rods were obtained by the calcinations of the as-prepared Mn 2 O 3  rods at different temperatures. When Mn 2 O 3  rods were treated at 600℃ for six hours in air, Mn 2 O 3  rods could be collected. Results The X-ray diffraction (XRD) analysis shows that Mn 2 O 3  is crystalline in structure and it matched with that of the Joint Committee on Powder Diffraction Standards (JCPDS). The field emission scanning electron microscopy (FE-SEM) shows the morphology of Mn 2 O 3 is a particle with the size of 100 nm. Cyclic voltammetry response shows that compared to bare electrode, modified electrode shows the higher current response which indicates the sensing ability of the dopamine molecule. Conclusion  Mn₂O₃ was prepared using a hydrothermal technique, and the formation of nanoparticles (NPs) was verified through XRD, while the morphology was examined using FE-SEM. The Mn 2 O 3 obtained was utilized in the detection of electrochemical dopamine, showing promise in the development of effective dopamine sensors. This study sets the stage for the integration of Mn₂O₃ into microfluidic systems for ongoing dopamine monitoring, presenting novel prospects for healthcare and neurochemical investigations. The exploration of various surface engineering approaches may additionally improve the electrochemical capabilities of Mn₂O₃ for the advancement of sensor technology., Competing Interests: Human subjects: All authors have confirmed that this study did not involve human participants or tissue. Animal subjects: All authors have confirmed that this study did not involve animal subjects or tissue. Conflicts of interest: In compliance with the ICMJE uniform disclosure form, all authors declare the following: Payment/services info: All authors have declared that no financial support was received from any organization for the submitted work. Financial relationships: All authors have declared that they have no financial relationships at present or within the previous three years with any organizations that might have an interest in the submitted work. Other relationships: All authors have declared that there are no other relationships or activities that could appear to have influenced the submitted work., (Copyright © 2024, Suresh et al.)

A simplified sol-gel method that can be scaled up for large-scale production was adopted for the preparation of manganese oxide nanocrystals. Prepared Mn2O3 exhibited micron-sized particles with a nanoporous structure. In the present study, a simple and low-cost strategy has been employed to fabricate nanoporous Mn2O3 with an increased surface area for an electrode/electrolyte interface that improved the conduction of Mn2O3 material. The crystal phase and morphology of the prepared material was investigated by X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDX). The prepared electrode materials were deposited on a nickel foam substrate to investigate the electrochemical properties. The galvanostatic charge/discharge (GCD), cyclic voltammetry (CV), and complex impedance studies confirmed excellent specific capacitance and capacitive behavior of the prepared material. The synthesized Mn2O3/graphene composites exhibited an excellent specific capacitance of 391 F/g at a scan rate of 5 mV/S. Moreover, a specific capacitance of 369 F/g was recorded at a current density of 0.5 A/g using the galvanostatic charge/discharge test. The high porosity of the materials provided a better electrolyte-electrode interface with a larger specific area, thus suggesting its suitability for energy storage applications.

MnCO3 particles were thermally decomposed to obtain Mn2O3 particles. MnCO3 was prepared by co-precipitation method using MnCl2.4H2O and CO(NH2)2 as reactants. Two separate parts of the obtained MnCO3 were calcined at 450 °C and 550 °C. The structural, crystallographic, morphological properties and elemental composition of all the materials were investigated using Fourier transform infrared spectrometry (FTIR), X-ray diffraction analysis (XRD), scanning electron microscopy and energy-dispersive X-rays spectroscopy (EDX). FTIR spectrum of the precursor and calcined products was related to MnCO3 and Mn2O3, respectively. As per XRD study, the precursor and calcined product obtained at 550 °C was crystalline, while the product obtained at 450 °C was amorphous in nature. From topographic study, the particles of MnCO3 and Mn2O3 were of cuboid shape. Elemental analysis of the samples via EDX analysis confirmed that the weight and atomic percentages of the precursor and calcined products are related to MnCO3 and Mn2O3, respectively. Afterward, the calcined products were used for investigation of their humidity sensing behavior at room temperature. The product obtained at 550 °C demonstrated reproducible, highly sensitivity and stable response toward humidity having response and recovery time 3 s and 13 s, respectively. Percent sensitivity of this material increased up to 96% by varying the humidity from 35 to 96%. The sensing mechanism was suggested to be based on protonic model, wherein the generation of H+ ions due to the dissociation of H3O+ ions reduces the sensor resistance and enhances the humidity sensitivity. [ABSTRACT FROM AUTHOR]

MnOx thin films on various types of substrates (glass, quartz, alumina, and Pt/Al2O3/Pt) were prepared by a combination of the sol–gel method and pen plotter printing, using the hydrolytically active heteroligand complex [Mn(C5H7O2)2 –x(C4H9O)x] as the precursor. The effect of synthesis parameters and printing modes on the microstructure, optical and electrophysical properties of the manufactured planar nanomaterials was studied. The electron work function of the MnOx film surface was assessed by Kelvin probe force microscopy (KPFM). Impedance spectroscopy was used to determine the temperature-dependent electrical conductivity of the prepared films in the temperature range 325–500°С. The proposed synthetic method and printing technology show promise for the formation of thin-film manganese oxide nanostructures for supercapacitor electrodes and optical devices. [ABSTRACT FROM AUTHOR]

A great oxygen carrier for chemical looping combustion (CLC) supports the carbon capture activity. In this study, Fe 2 O 3 , NiO, and Mn 2 O 3 are prepared on SiO 2 support for test in CLC under various operating conditions. The best utilization value of 100 % was performed by 20%Fe 2 O 3 /SiO 2 and stability was presented up to 10 redox cycles. 20%Fe 2 O 3 /SiO 2 was used for the following study with the presence of HCl. Combination of HCl and CO in the inlet gas had insignificant changes. Differently, a drastic improvement achieved by combination with H 2. However, the presence of HCl in multiple cycles test led to pore enlargement, surface area reduction, and decline in performance of 20%Fe 2 O 3 /SiO 2. The presence of H 2 O and CO 2 from the exhausted gas after the reaction indicated the efficient and complete reaction of the 20 % Fe 2 O 3 /SiO 2. Besides, analysis of the reaction kinetics with Type I deactivation mode performed a well fitted result. [Display omitted] • 20 % Fe 2 O 3 /SiO 2 reached 100 % conversion of CO and H 2. • 20 % Fe 2 O 3 /SiO 2 presented high stability in cycle test. • HCl addition promoted the performance of 20 % Fe 2 O 3 /SiO 2 under H 2 atmosphere. • Multiple cycle under mixed reducing atmosphere and HCl transformed the pore structure. • Type I deactivation kinetics model presented a well fitted data. [ABSTRACT FROM AUTHOR]

[Display omitted] • h-BN-Mn was successfully synthesized by a facile one-step method. • Free radicals and 1O 2 generated from the redox process of manganese. • Mn(IV) species and electron transfer supplemented to promote degradation. • Mn-N mediated the promotion of stable, long-lived Mn(IV) species. • h-BN-Mn-loaded membranes were capable of managing an expanded water system. The Mn 2 O 3 -loaded hexagonal boron nitride (h-BN-Mn) catalyst for peroxymonosulfate (PMS) activation was successfully synthesized using a one-step calcination process. The h-BN-Mn/PMS system achieved an impressive 97 % levofloxacin removal within a mere 90-minute timeframe. This catalyst, h-BN-Mn, effectively addresses the challenge of elevated manganese leaching rates and exhibits a broad pH degradation spectrum spanning from 3 to 11. Notably, it maintained robust degradation performance over five cycles, showcasing the potential for large-capacity water treatment when integrated with a polyvinylidene fluoride (PVDF) membrane (h-BN-Mn@PVDF), resulting in an 83.8 % removal rate over 6 h. In-depth analysis revealed three distinct degradation pathways. Primarily, the generation of reactive oxygen species (ROS), including singlet oxygen (1O 2), played a pivotal role. This was complemented by direct electron transfer from the contaminant to the catalyst-PMS complex, augmented by contributions from Mn(IV) species derived from the complex. This study not only presents a compelling instance of antibiotic degradation through multi-pathway activated PMS but also sheds light on the remarkable synergistic effects achieved by combining manganese oxide with boron and nitrogen compounds. [ABSTRACT FROM AUTHOR]

Manganese oxide is a promising material due to its low cost, abundant reserves, and environmental friendliness. However, low cycling performance has been restricting the manganese oxide cathode materials on the road to commercialization. In this paper, Mn 2 O 3 microspheres with a porous structure are prepared by hydrothermal process and then compounded with low dimensional and small-scale carbon dots (CDs), and the obtained Mn 2 O 3 /CDs materials are used to assemble aqueous zinc ion batteries. X-ray Diffraction (XRD) and Scanning Electron Microscope (SEM) are used to characterize its structure and morphology, which prove that the composite with CDs do not change the structure of the original material. The morphology of microspheres can increase the surface area of electrolyte-electrode interface, which is beneficial to ion embedding into cathode materials. Compared with pure Mn 2 O 3 , the composite with CDs content of 3% (MC3) has the best electrochemical performance (the discharge specific capacity is 252.7 mAh·g−1 at 0.1 A g−1). Moreover, the reversible capacity of the Mn 2 O 3 /CDs composites is improved due to the inhibition of the dissolution of Mn by the highly conductive CDs. The specific discharge capacity of the Mn 2 O 3 /CDs composites after 300 cycles is 102.8 mAh·g−1, which is 2.3 times higher than that of the pure Mn 2 O 3. • Mn 2 O 3 /CDs porous microspheres prepared by hydrothermal method improves cycling performance. • CDs improves the specific capacity and cycle life of Mn 2 O 3 cathode. • The reaction kinetics of high rate performance of Mn 2 O 3 /CDs is investigated. [ABSTRACT FROM AUTHOR]

In this study, we investigate the influence of calcination temperature on the structural, optical, and electrochemical properties of Mn 3 O 4 nanoparticles synthesized through a chemical co-precipitation route. Field-Emission Scanning Electron Microscopy (FESEM) images depict the formation of highly agglomerated, spherical-shaped particles. At calcination temperatures of 700 °C and 900 °C, the observation reveals the emergence of flat pellets and rod-like structures. The X-ray Diffraction (XRD) patterns confirm the presence of the Mn 3 O 4 phase in M 0 and M 1 samples. However, the sample calcined at 500 °C (M 3) showed a mixed phase of Mn 3 O 4 and Mn 2 O 3. Upon further calcination at 700 and 900 °C, this mixed phase undergoes complete transformation into the Mn 2 O 3 phase. The change in absorption onset and photoluminescence intensity of samples is found with an increase in calcination temperature due to the crystal growth and phase modification. Furthermore, the synthesized samples are employed as electrode materials for supercapacitor applications. The sample calcined at 300 °C (M 1) in three-electrode system demonstrated the specific capacitance (C sp) of 273.3 F/g at 0.5 A/g in an alkaline medium. The asymmetric cell assembled by using M 1 and Hibiscus cannabinus stem-derived carbon material (HBC-900) delivered higher C sp of 205.7 F/g at 0.5 A/g. In addition, asymmetric supercapacitor device exhibited a high energy and power density of 43.1 Wh/kg and 476.2 W/kg with 82.07 % of initial C sp retention over 10,000 cycles at 10 A/g, which makes the sample M 1 as the potential electrode material for supercapacitor application. • Study gives optical & electrochemical properties of Mn 3 O 4 prepared via coprecipitation method. • Calcinated Mn 3 O 4 phase nanomaterials converted into a flat pellets and rod-like structures. • Further, mixed phase of Mn 3 O 4 and Mn 2 O 3 transformed into the Mn 2 O 3 phase. • Nan Mn 3 O 4 showed specific capacitance (C sp) of 273.3 F/g at 0.5 A/g in an alkaline medium. [ABSTRACT FROM AUTHOR]

Manganese oxides have attracted great interest in electrochemical energy storage due to high theoretical specific capacitance and abundant valence states. The multiple valence states in the redox reactions are beneficial for enhancing the electrochemical properties. Herein, three manganese microspheres were prepared by a one‐pot hydrothermal method and subsequent calcination at different temperatures using carbon spheres as templates. The trivalent manganese of Mn2O3 exhibited multiple redox transitions of Mn3+/Mn2+ and Mn4+/Mn3+ during the intercalation/deintercalation of electrolyte ions. The possible redox reactions of Mn2O3 were proposed based on the cyclic voltammetry and differential pulse voltammogram results. Mn2O3 microsphere integrated the advantages of multiple redox couples and unique structure, demonstrating a high specific capacitance and long cycling stability. The symmetric Mn2O3//Mn2O3 device yielded a maximum energy density of 29.3 Wh kg−1 at 250 W kg−1. [ABSTRACT FROM AUTHOR]

Water oxidation is an energy-consuming, four-electron-transfer reaction and is essential for solar fuel production from water. Catalysts based on precious metals such as RuO2 and IrO2 show high efficiency for oxygen evolution reaction. However, these catalysts are less abundant and expensive. To date, earth-abundant water oxidation catalysts still exhibit less activity for water oxidation. Herein, we report the synthesis of high surface area Mn2O3 nanomaterials for an efficient photocatalytic water oxidation catalyst. The synthesis process involves three simple steps. In the first step, CaMnO3 is synthesized by the citrate-gel method. In the second step, CaMnO3 is transformed into freestanding layers of ε-MnO2 by selective removal of Ca2+. In the third step, these layers are converted into irregularly shaped two-dimensional Mn2O3 flakes (AD-Mn2O3) by calcination at 550 °C. These AD-Mn2O3 nanostructures show 4 times higher surface area (127 m2 g–1) when compared to the irregularly shaped Mn2O3 nanoparticles (CG-Mn2O3) synthesized by the citrate-gel method at the same temperature. The AD-Mn2O3 nanostructures show super hydrophilicity with a contact angle of zero degree. This material exhibits excellent photocatalytic water oxidation activity with a turnover frequency of 1.53 × 10–3 s–1, which is twice the activity shown by CG-Mn2O3. This study can help in developing an earth-abundant, cost-effective, efficient catalyst for overall water splitting. [ABSTRACT FROM AUTHOR]

X-ray photoelectron spectroscopy was used to characterize the chemical composition and elemental states of bare and composite Mn2O3 (Mn2O3-Ag, Mn2O3-SnO2) nanomaterials. The target systems were prepared by the initial plasma enhanced-chemical vapor deposition of manganese oxides on alumina substrates, followed by annealing in inert atmospheres and functionalization with Ag and SnO2 by radio frequency-sputtering on the Mn2O3 surface. The survey scans of the fabricated samples, along with detailed spectra of the C 1s, O 1s, Mn 2p, Mn 3s, and, eventually, Ag 3d, Ag MVV, and Sn 3d regions, were collected and analyzed in detail. The obtained results revealed the formation of composite systems characterized by the presence of Mn2O3 free from other manganese oxides and pure SnO2, whereas appreciable Ag oxidation was observed. The O 1s photoelectron peaks could be fitted by means of two components related to lattice oxygen and to hydroxyl groups/oxygen species chemisorbed on surface O defects. The occurrence of the latter could exert a beneficial effect on the system functional behavior in gas sensing and electrocatalytic applications. [ABSTRACT FROM AUTHOR]

The Fe doped Mn2O3 nanoparticles were synthesized by the microwave-assisted method and synthesized samples were further annealed at 5000C and the samples were subjected to analyze structural, optical and magnetic properties. The structural properties of the nanoparticles were characterized by using X-ray diffractometry. XRD pattern revealed that the existence of Mn2O3 with cubic structure and Mn-doped Fe isa rhombohedral lattice structure. FTIR spectroscopy confirmed the formation of Fe-O stretching vibrations. The observed band positioned at 570cm-1 could be due to the stretching vibration of Fe-O bonds. Energy dispersive analysis (EDAX) spectroscopy confirmed the purity, chemical composition of the FeMn2O3 nanoparticles. The structural properties were analyzed by scanning electron microscope (SEM) analysis. [ABSTRACT FROM AUTHOR]

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A series of CuxMn composite oxide catalysts with different Cu/Mn molar ratios (x = 1, 1.5 and 2) was synthesized by the co-precipitation method. The catalytic performance of CuxMn in N2O decomposition has been studied with a continuous flowing microreactor system. The obtained catalysts were characterized by XRD, BET, Raman, FT-IR, ICP-AES and H2-TPR. The catalytic tests show that the CuxMn catalysts exhibit more excellent N2O catalytic decomposition activity compared with the pure CuO and Mn2O3 catalysts, and the Cu1.5Mn shows the highest catalytic activity under the reaction conditions of N2O 0.1%, GHSV 10000 h−1. The characterizations results suggest that bulk CuO and Mn2O3 existed in pure CuO and Mn2O3 catalysts, respectively. In the CuxMn catalysts, with the decreasing of x, the amount of bulk CuO gradually decreases until it disappears, while the amount of newly formed CuMn2O4 gradually increases. However, the amount of small crystal CuO increases first and then decreases, which might be considered as an important active phase that contributes to the excellent catalytic performance of CuxMn in N2O decomposition. [ABSTRACT FROM AUTHOR]

• Green Mn2O3 was used to active PDS for removing E3 from real wastewaters. • Effects of substrates of wastewaters on the removal of E3 by Mn 2 O 3 /PDS system. • Combined DFT, LC-MS analyses and ECOSAR to understand the reaction mechanisms. • The degradation pathway and toxicity of intermediates were predicted. While green synthesized Mn 2 O 3 has been used to activate peroxydisulfate (PDS) to degrade estrogens, effective application in real wastewater is less common due to variation in environmental matrices in wastewater. Here, green synthesized Mn 2 O 3 was used as a Fenton-like catalyst to activate PDS for estriol (E3) degradation in wastewater. The results show that the high concentration of K+ and humic acid in wastewater could inhibit the activation process of the Mn 2 O 3 /PDS system, resulting in low removal efficiency of E3 in wastewater. However, when the concentration of PDS was increased to 15 mM, the removal efficiency of E3 in medical wastewater can reach 100 %, because the high PDS concentration increases the main reactive oxygen species singlet oxygen (1O 2) in medical wastewater. XRD and SEM-EDS analysis indicate that the crystal structure of Mn 2 O 3 is stable, with a consistent rice grain-like morphology before and after reaction. XPS results show no obvious changes in the percentages of Mn(II), Mn(III) and Mn(IV) before and after reaction, indicating that Mn 2 O 3 has good stability when degrading E3 in medical wastewater. Based on density functional theory (DFT) calculations, liquid chromatography-mass spectrometry (LC-MS), and ecological structure–activity relationship (ECOSAR) modeling data analysis, the reactive oxygen species produced by the Mn 2 O 3 /PDS system mainly attack the benzene ring structure of E3, where the toxicity of its intermediate products declines significantly after breaking the benzene ring structure. Overall, this work provides greater understanding of the E3 degradation pathway and the toxicity of its degradation products. [ABSTRACT FROM AUTHOR]

[Display omitted] • Chemical looping OCM is attractive method for conversion of CH 4 to C 2 H 4. • Qualified oxygen carrier catalyst is particularly desirable but remains challenging. • Na 2 WO 4 -doped Mn 2 O 3 -TiO 2 is a promising catalyst for the CL-OCM reaction. • This catalyst works efficiently at 740 °C via MnTiO 3 ↔ TiO 2 + Mn 2 O 3 redox cycle. • Doping of Na 2 WO 4 benefits the *CH 3 transfer and desorption to form ∙CH 3 radicals. Intrinsic safety chemical looping-oxidative coupling of methane (CL-OCM) is an attractive method for direct conversion of methane to ethylene, but well-qualified oxygen carrier catalyst still remains challenging. Herein, we report a promising Na 2 WO 4 -doped Mn 2 O 3 -TiO 2 catalyst toward high-efficiency CL-OCM process. The standout Na 2 WO 4 /2Mn1Ti (Mn 2 O 3 /TiO 2 weight ratio of 2/1) catalyst, with good cycling performance, achieves a high space time yield of 27.8 (or 22.9) g C2-C3 kg cat −1h−1 with 19.5 % (or 15.7 %) CH 4 conversion and 80 % (or 82.7 %) C 2 -C 3 selectivity at 740 (or 720) oC and a low catalyst/CH 4 weight ratio of 13.5. The TiO 2 substantially lowers the CL-OCM reaction temperature, due to the establishment of a low-temperature light-off "Mn 2 O 3 + TiO 2 ↔ MnTiO 3 " redox cycle with CH 4 /O 2. The enabling role of Na 2 WO 4 in modulating the reaction of Mn 2 O 3 with CH 4 into OCM instead of combustion is theoretically unveiled, which in nature benefits the *CH 3 transfer and spontaneous desorption to form ∙CH 3 radicals. [ABSTRACT FROM AUTHOR]

In this study, the Mn 2 O 3 @In 2 O 3 core-shell structures were prepared by a two-step hydrothermal method for TEA detection. Characterization of the morphological composition reveals that Mn 2 O 3 @In 2 O 3 is a microsphere structure with Mn 2 O 3 as the core and In 2 O 3 as the shell. The results of the gas-sensitive performance tests showed that the response of Mn 2 O 3 @In 2 O 3 to 100 ppm TEA was 47 at 180 °C, which was a significant improvement over the original In 2 O 3 , and it had excellent long-term stability and reproducibility. The improved gas-sensitive properties are due to the special structure of the core-shell material and the successful construction of p-n heterojunctions between the interfaces. • Mn 2 O 3 @In 2 O 3 core-shell microspheres were prepared by a two-step thermal method. • The special structure of core-shell effectively enhances the gas sensitive property of TEA. • Mn 2 O 3 @In 2 O 3 core-shell has excellent response and long-term stability to TEA. [ABSTRACT FROM AUTHOR]

The rational synthesis of hybrid catalysts with diverse electrocatalytically active components for robust oxygen reduction reaction (ORR) is highly desirable for the development of sustainable metal-air batteries. By using melamine as nitrogen and hydrogen precursors, herein, melamine pyrolysis-induced functionalized nitrogen doping was adopted for the construction of nitrogen doped manganese oxides (N-MnO x Rs), which consists of manganese oxyhydroxide (MnOOH) rooted in manganese sesquioxide (Mn 2 O 3) rod, as a robust ORR electrocatalyst. Systematic studies have found that a suitable mass ratio of melamine to β-MnO 2 rods is necessary for the formation of electrocatalytically MnOOH and Mn 2 O 3. The representative N-MnO x Rs exhibits the nano structure consisting of interconnected nonorods, nanowires, and nanoparticles, which not only increases the exposure of more active sites but also enhances microstructure stability. Moreover, the nitrogen doping creates high content of oxygen vacancies, which accelerates electron transmission/transfer of N-MnO x Rs. As a result, the optimal N-MnO x Rs exhibits impressive ORR catalytic performance in a homemade ZAB. The N-MnO x Rs driven ZAB (176.6 mW cm-2; 811 mAh g-1) delivers a high peak power density and large discharging capacitance comparable to Pt/C driven one (178.1 mW cm-2; 800 mAh g-1), displaying a promising application potential. This work provides a functionalized nitrogen doping strategy for rational construction of robust hybrid electrocatalysts for energy conversion. • Functional nitrogen doping strategy was adopted for construction of MnOOH rooted in Mn 2 O 3 rod hierarchical electrocatalyst. • The nano hierarchical feature not only increases exposure of active sites but also enhances microstructure stability. • The representative N-MnO x Rs exhibits robust ORR catalytic performance comparable to Pt/C catalyst in a homemade ZAB. [ABSTRACT FROM AUTHOR]

[Display omitted] • Tetracycline is effectively decontaminated by Mn 2 O 3 @ZIF-8 via PS activation. • OH, O 2 −, 1O 2 and reactive MnII (s) -S 2 O 8 2−* are involved tetracycline degradation. • Zn-O-Mn electron transport channel facilitates the electron transfer in PS activation. • MnII (s) on Mn 2 O 3 @ZIF-8 surface is the dominant sites for active species generation. Advanced oxidation processes (AOPs) based on persulfate (PS) activation is an extremely effective method to removal antibiotics in wastewater. In this process, endowing abundant active sites and rapid electron transfer channel over catalyst are two essential factors for high performance towards decontamination. Herein, a novel core–shell catalyst Mn 2 O 3 @ZIF-8 with large specific surface area was prepared to remove antibiotics via PS activation under visible light irradiation. Intriguingly, the removal efficiency of tetracycline (TC) by Mn 2 O 3 @ZIF-8 with optimal compound ratio was 3.2 times that of original Mn 2 O 3. The characterizations and density functional theory calculations proved that a Zn-O-Mn electron transfer channel was constructed in Mn 2 O 3 @ZIF-8 heterostructure, which greatly promoted electron transport and photogenerated electron-hole separation. In addition, the activation of PS and degradation of pollutants by Mn 2 O 3 @ZIF-8 was a highly surface-dependent reaction. The correlation between surface physicochemical properties and pollutant removal was further established to uncover the dominant active sites for PS activation. The quenching experiments and electron paramagnetic resonance (EPR) tests confirmed that PS was mainly activated by surface active MnII (s) and dissociated into reactive oxygen species OH, O 2 −, and 1O 2 , or formed reactive complexes MnII (s) -S 2 O 8 2−* to induce electron transfer and achieve TC oxidation. Besides, Mn 2 O 3 @ZIF-8 exhibited satisfactory removal of multiple pollutants and actual pharmaceutical wastewater as well as effective detoxification due to the coexistence of the above radicals and non-radicals pathways. The study provides novel insights into the design of high efficiency of Mn-based catalysts for antibiotic wastewater purification. [ABSTRACT FROM AUTHOR]