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In the chemical mechanical polishing (CMP) process for SiC substrates, enhancing the chemical oxidation rate can markedly improve processing efficiency. This study uses graphene oxide (GO) as a carrier material to prepare a novel Mn-based slurry, MnO 2 /GO/Al 2 O 3 , through chemical precipitation and ultrasonic impregnation methods. Chemical composition and morphological analyses revealed that MnO 2 and GO are linked with Mn-O bonds, with GO significantly enhancing the dispersion of MnO 2 and Al 2 O 3 particles. The slurry's effectiveness in planarizing SiC substrates within a potassium permanganate system was systematically evaluated. CMP tests demonstrated that, compared to using Al 2 O 3 alone, MnO 2 /GO/Al 2 O 3 substantially increased the material removal rate (MRR) for SiC, achieving up to 1020 nm/h, while reducing the surface roughness (Sa) of the polished substrate to 0.664 nm. Electrochemical corrosion tests further showed that the inclusion of MnO 2 and GO significantly accelerated the slurry's corrosion rate on SiC. Additionally, the physical property characterization of the polishing slurry indicated that the improvement in MRR is primarily attributed to its enhanced chemical oxidation capability. XPS analysis confirmed the formation of Mn–O–Si compounds between MnO 2 /GO/Al 2 O 3 and SiC. Based on these findings, a polishing mechanism for MnO 2 /GO/Al 2 O 3 is proposed. [ABSTRACT FROM AUTHOR]

Monolithic catalysts with excellent O 3 catalytic decomposition performance were prepared by in situ loading of Co-doped KMn 8 O 16 on the surface of nickel foam. The triple-layer structure with Co-doped KMn 8 O 16 /Ni 6 MnO 8 /Ni foam was grown spontaneously on the surface of nickel foam by tuning the molar ratio of KMnO 4 to Co(NO 3) 2 ·6H 2 O precursors. Importantly, the formed Ni 6 MnO 8 structure between KMn 8 O 16 and nickel foam during in situ synthesis process effectively protected nickel foam from further etching, which significantly enhanced the reaction stability of catalyst. The optimum amount of Co doping in KMn 8 O 16 was available when the molar ratio of Mn to Co species in the precursor solution was 2:1. And the Mn2Co1 catalyst had abundant oxygen vacancies and excellent hydrophobicity, thus creating outstanding O 3 decomposition activity. The O 3 conversion under dry conditions and relative humidity of 65%, 90% over a period of 5 hr was 100%, 94% and 80% with the space velocity of 28,000 hr−1, respectively. The in situ constructed Co-doped KMn 8 O 16 /Ni foam catalyst showed the advantages of low price and gradual applicability of the preparation process, which provided an opportunity for the design of monolithic catalyst for O 3 catalytic decomposition. [Display omitted] [ABSTRACT FROM AUTHOR]

• Bamboo-like B-MnO 2 ⋅Co 3 O 4 (S) is prepared via the repeated hydrothermal route. • The B-MnO 2 ⋅Co 3 O 4 (S) catalyst exhibits an outstanding toluene oxidation activity (T 50% = 276 °C). • Co3+ and Mn3+ species are the active sites for toluene oxidation. • B-MnO 2 ⋅Co 3 O 4 (S) shows good H 2 O, CO 2 , and SO 2 resistance in toluene oxidation. The manganese-cobalt mixed oxide nanorods were fabricated using a hydrothermal method with different metal precursors (KMnO 4 and MnSO 4 ·H 2 O for MnO x and Co(NO 3) 2 ⋅6H 2 O and CoCl 2 ⋅6H 2 O for Co 3 O 4). Bamboo-like MnO 2 ⋅Co 3 O 4 (B-MnO 2 ⋅Co 3 O 4 (S)) was derived from repeated hydrothermal treatments with Co 3 O 4 @MnO 2 and MnSO 4 ⋅H 2 O, whereas Co 3 O 4 @MnO 2 nanorods were derived from hydrothermal treatment with Co 3 O 4 nanorods and KMnO 4. The study shows that manganese oxide was tetragonal, while the cobalt oxide was found to be cubic in the crystalline arrangement. Mn surface ions were present in multiple oxidation states (e.g., Mn4+ and Mn3+) and surface oxygen deficiencies. The content of adsorbed oxygen species and reducibility at low temperature declined in the sequence of B-MnO 2 ⋅Co 3 O 4 (S) > Co 3 O 4 @MnO 2 > MnO 2 > Co 3 O 4 , matching the changing trend in activity. Among all the samples, B-MnO 2 ⋅Co 3 O 4 (S) showed the preeminent catalytic performance for the oxidation of toluene (T 10% = 187°C, T 50% = 276°C, and T 90% = 339°C). In addition, the B-MnO 2 ⋅Co 3 O 4 (S) sample also exhibited good H 2 O-, CO 2 -, and SO 2 -resistant performance. The good catalytic performance of B-MnO 2 ⋅Co 3 O 4 (S) is due to the high concentration of adsorbed oxygen species and good reducibility at low temperature. Toluene oxidation over B-MnO 2 ⋅Co 3 O 4 (S) proceeds through the adsorption of O 2 and toluene to form O*, OH*, and H 2 C(C 6 H 5)* species, which then react to produce benzyl alcohol, benzoic acid, and benzaldehyde, ultimately converting to CO 2 and H 2 O. The findings suggest that B-MnO 2 ⋅Co 3 O 4 (S) has promising potential for use as an effective catalyst in practical applications. [Display omitted] [ABSTRACT FROM AUTHOR]

• The start-up of filters for NH 4 + and Mn2+ removal by catalytic oxidation was studied. • Different combinations of oxidants and reductants were introduced during the start-up period. • Comparison of catalytic oxidation activity of MnOx follows: Mn7+→MnO x ˃Mn7+→MnO x ←Mn2+ ˃ Mn2+→MnO x. • Potassium permanganate was more conducive to the formation of active species. A pilot-scale filtration system was adopted to prepare filter media with catalytic activity to remove manganese (Mn2+) and ammonium (NH 4 +-N). Three different combinations of oxidants (KMnO 4 and K 2 FeO 4) and reductants (MnSO 4 and FeCl 2) were used during the start-up period. Filter R3 started up by KMnO 4 and FeCl 2 (Mn7+→MnO x) exhibited excellent catalytic property, and the NH 4 +-N and Mn2+ removal efficiency reached over 80% on the 10th and 35th days, respectively. Filter R1 started up by K 2 FeO 4 and MnSO 4 (MnO x ←Mn2+) exhibited the worst catalytic property. Filter R2 started up by KMnO 4 and MnSO 4 (Mn7+→MnO x ←Mn2+) were in between. According to Zeta potential results, the Mn-based oxides (MnO x) formed by Mn7+→MnO x performed the highest pH IEP and pH PZC. The higher the pH IEP and pH PZC , the more unfavorable the cation adsorption. However, it was inconsistent with its excellent Mn2+ and NH 4 +-N removal abilities, implying that catalytic oxidation played a key role. Combined with XRD and XPS analysis, the results showed that the MnO x produced by the reduction of KMnO 4 showed early formation of buserite crystals, high degree of amorphous, high content of Mn3+ and lattice oxygen with the higher activity to form defects. The above results showed that MnO x produced by the reduction of KMnO 4 was more conducive to the formation of active species for catalytic oxidation of NH 4 +-N and Mn2+ removal. This study provides new insights on the formation mechanisms of the active MnO x that could catalytic oxidation of NH 4 +-N and Mn2+. [Display omitted] [ABSTRACT FROM AUTHOR]

To overcome the limitation of SPEEK/PBI membrane, BN was introduced to the membrane in different percentages. Firstly, boron nitride was functionalized by introducing hydroxyl group using KMNO 4 , H 2 O 2 , as oxidation agents. At the same time SPEEK was prepared by sulfonating PEEK at 80 °C using sulfonic acid. Further, a SPEEK/PBI/BN blend was prepared by dissolving SPEEK/BN in DMCs and then mixed with PBI heated solution. The percentage of the BN were 10%, 15 and 20%. The prepared membranes were characterized, however, SPEEK/PBI/BN-10% showed the optimum physicochemical properties; in which the degree of sulfonating, ion exchange capacity, water uptake, tensile stress, ionic conductivity, and thermal stability were 80.53%, 2.18 meq.g−1, 6.13%,8.61 MPa, 245 mS/cm, and 316.6 °C. The results show that the addition of BN influenced the characteristics of the membrane remarkably in a positive way as the protonic conductivity increased remarkably from 170 mS/cm to 245 mS/cm. Moreover, there was a huge enhancement in the thermal stability and the ionic conductivity. • Among all the available nonperflurinated materials for electrolyte membranes, SPEEK and PBI seem to be the best option. • SPEEK membrane was modified with PBI and BN to enhance its thermomechanical and its protonic conductivity. • SPEEK/PBI/BN-10 showed the greatest properties, in which the ion exchange capacity was found 2.18meq.g−1. • On the other hand, Tensile stress, Water uptake, and Maximum temperature were 8.61 MPa, 316.6 °C, and 6.13% respectively. • The protonic conductivity enhanced remarkably from 170 mS/cm to 245 mS/cm. [ABSTRACT FROM AUTHOR]

Large-scale electrochemical and photochemical hydrogen production methods from water splitting are limited by the water-oxidation reaction (WOR). This study investigates the influence of calcination temperatures on the WOR efficiency of layered Mn oxides, which are known for their stability and high catalytic activity. The Mn oxides were synthesized via thermal decomposition of KMnO 4 and characterized using various techniques including scanning electron microscopy, high-resolution transmission electron microscopy, X-ray diffraction, thermal gravimetric analysis, and Raman spectroscopy. The results indicate that even after calcination at high temperatures (≥400 °C), layered Mn oxides remain effective catalysts for WOR. Notably, the calcined sample at 800 °C in cerium (IV) ammonium nitrate at concentrations of 0.30 M shows maximum turnover frequency and turnover number of 6.7 × 10−6/s and 8.6 × 10−3 mol (O 2)/mol (Mn) (for 1300 s), respectively. The effect of calcination temperature on layered Mn oxides toward water-oxidation reaction in the presence cerium (IV) ammonium nitrate (CAN) is investigated. [Display omitted] • Synthesis of layered Mn oxides was achieved by thermally decomposing KMnO 4 at varying temperatures. • Characterization of the synthesized layered Mn oxides was performed using different analytical methods. • The catalytic activity of layered Mn oxides remains even after calcination at high temperatures. [ABSTRACT FROM AUTHOR]

Biochar-based nanomaterials are an efficient and economical adsorption material, often used to adsorb and remove heavy metals in sewage. In this study, eucalyptus biochar nanomaterials were produced by pyrolysis as a carbon precursor and modified with potassium penetrant (KBC) to improve its adsorption performance for Cd removal. Various characterization techniques have been used to fully characterize and analyze the physical and chemical properties of KBC. The adsorption kinetics, thermodynamics and adsorption isotherms of KBC on Cd(II) ions and the effects of various reaction parameters (pH, adsorbent dosage, adsorption time, temperature and initial concentration) on the adsorption capacity and removal rate were evaluated. The results show that the best adsorption capacity of KBC for Cd(II) is 31.050 mg/g, under the best conditions (pH = 5, dosage = 0.08 g, time = 6 h, temperature 25°C and initial concentration = 50 mg/g·L). The adsorption process follows the pseudo-second-order kinetic model and the isothermal Langmuir adsorption model. This model is based on a single layer adsorbed on a uniform surface and absorbs heat spontaneously under physical and chemical action. The adsorption mechanism of Cd(II) is mainly through complexation, oxidation and cation-π-electron interaction to adsorb oxygen-containing and manganese-containing KBC groups. Potassium permanganate surface-modified eucalyptus biochar proved to be an effective method to deal with heavy metal pollution. [ABSTRACT FROM AUTHOR]

To enhance the Cd(II) adsorption capacity on sludge biochar (SBC), potassium permanganate modified sludge biochar (MSBC) was prepared. Additionally, the removal performance and adsorption behavior of Cd(II) on biochar were investigated by initial pH, coexisting ions, dosage, adsorption kinetics and adsorption isotherms. The Cd(II) adsorption behavior of SBC and MSBC was consistent with the pseudo-second-order kinetic model and the Langmuir model. The coexisting ion concentration of NaCl had almost no effect on the Cd(II) adsorption of SBC and MSBC. The maximum Cd(II) adsorption capacities of SBC and MSBC were 55.81 and 108.69 mg/g at the optimum conditions of 25°C, 1 g/L dosage and pH 5.0, respectively. After four replicate experiments, the removal efficiency of Cd(II) by SBC and MSBC was 64.05% and 90.34%, respectively. Complexation of Cd(II) with O-containing groups, Cd(II)-p interactions, co-precipitation and electrostatic interaction were the main mechanisms for the Cd(II) removal from aqueous solutions by SBC and MSBC. The KMnO4-modification effectively enhanced the number of O-containing groups in the biochar and enhanced the complexation of Cd(II) by MSBC, which was the main reason for the increased Cd(II) adsorption capacity of MSBC. The results showed that KMnO4-modification could effectively increase the Cd(II) adsorption by sludge biochar. [ABSTRACT FROM AUTHOR]

In order to study the adsorption effect of peanut shell on dye in industrial wastewater, the dye Rhodamine B was used as the research object and the peanut shell was modified. After modification, the best adsorption effect is potassium permanganate modified materials. The factors affecting the adsorption of Rhodamine B on peanut shell, such as pH value, initial concentration of dye, amount of adsorbent, contact time, adsorption temperature and ionic strength, were investigated. The best adsorption conditions of peanut shell for Rhodamine B were obtained. The adsorption thermodynamic equation, adsorption kinetic equation and the sorption isotherms were determined. The results showed that the adsorption process satisfied Freundlich isothermal adsorption equation and the adsorption process was spontaneous and exothermic. The adsorption of Rhodamine B on peanut shell accorded with the pseudo-second-order adsorption kinetics. [ABSTRACT FROM AUTHOR]

At present, the most widely used aluminum adjuvants have poor ability to induce effective Th1 type immune responses. Existing evidence suggests that manganese is a potential metal adjuvant by activating cyclic guanosine phospho-adenosine synthase (cGAS)-interferon gene stimulator protein (STING) signaling pathway to enhance humoral and cellular immune response. Hence, the effective modulation of metal components is expected to be a new strategy to improve the efficiency of vaccine immunization. Here, we constructed a manganese and aluminum dual-adjuvant antigen co-delivery system (MnO 2 -Al-OVA) to enhance the immune responses of subunit vaccines. Namely, the aluminum hydroxide was first fused on the surface of the pre-prepared MnO 2 nanoparticles, which were synthesized by a simple redox reaction with potassium permanganate (KMnO 4) and oleic acid (OA). The engineered MnO 2 -Al-OVA could remarkably promote cellular internalization and maturation of dendritic cells. After subcutaneous vaccination, MnO 2 -Al-OVA rapidly migrated into the lymph nodes (LNs) and efficiently activate the cGAS-STING pathway, greatly induced humoral and cellular immune responses. Of note, our findings underscore the importance of coordination manganese adjuvants in vaccine design by promoting the activation of the cGAS-STING-IFN-I pathway. With a good safety profile and facile preparation process, this dual-adjuvant antigen co-delivery nanovaccine has great potential for clinical translation prospects. A sketch of the preparation of a manganese and aluminum dual adjuvant antigen delivery system (MnO 2 -Al-OVA) and its use for targeting lymph nodes (LN) and effective induction of antitumor immune response. [Display omitted] [ABSTRACT FROM AUTHOR]

The sluggish kinetics of oxygen-evolution reaction (OER) through water-oxidation reaction results in high overpotentials for water splitting. Among different compounds, carbon-based material/Mn oxide composites were reported as OER catalysts. Fullerene soot (FS), which contains a mixture of fullerenes and carbon blacks, is low-cost compared to fullerenes and is commercially available. Herein, the Mn oxide/fullerene soot (MnO x /FS) composite was investigated as an OER catalyst under neutral conditions. The composite was prepared through the reaction of KMnO 4 and FS as a facile, easy, and low-cost procedure. In this method, amorphous Mn oxide is formed directly on FS. The material was characterized by a number of methods. Then, the OER catalytic activity of MnO x /FS was studied in a LiClO 4 solution (pH ≈ 6.3). Compared to pristine FS, the OER activity of MnO x /FS is 2.5 times higher at 2.25 V vs. RHE. The Tafel slopes for OER are 450 and 240 mV per decade for FS and the reported composite, respectively. [Display omitted] A simple strategy to synthesize Mn oxide/fullerene soot as a catalyst for the oxygen-evolution reaction through water-oxidation reaction under neutral conditions is reported. • An Mn oxide/fullerene soot (FS) composite was prepared through the reaction of KMnO 4 and FS. • The composite was introduced as a promising catalyst for water-oxidation reaction. • In the composite, fullerene soot acts as conductive support, and MnO x acts as a catalyst. [ABSTRACT FROM AUTHOR]

Defect engineering exerts a crucial impact on polarization loss and thereby enhances electromagnetic (EM) wave absorption ability. The EM loss mechanism beneath of morphology conversion is usually vaguely considered as the synergism of multiple mechanisms. Morphology induced defects and its dominated polarization loss mechanisms are little focus on. In this work, MnO 2 /Carbon foam (MCF) composites with tunable morphology were prepared via facile hydrothermal and annealing process. Morphological conversion of MnO 2 and its induced defects were achieved by KMnO 4 concentration, which contributes to the reduction of conductive loss, optimization of impedance matching, increase of polarization loss and multiple scattering. Therefore, the minimum reflection loss of MCF composite harvests −65.18 dB at 3.19 mm and the broad effective absorption bandwidth covers the entire X band. Despite multiple dissipation mechanisms, the excellent performance is dominated by morphology modulated defects in MCF composites. Besides, the optimal MCF composite displays a high compressive strength of 14.647 MPa. According to the results of computer simulation technology, the MCF composite can attenuate EM energy in the actual condition. This work is expected to offer an inspired understanding of morphology modulated defects toward high-performance of EM wave absorption materials. [Display omitted] • MnO 2 /CF with diversed morphologies and defects were rely on the content of KMnO 4. • Morphological evolution changed carbon defect, oxygen vacancy and lattice defects. • Effective absorption bandwidth of 4.2 GHz and reflection loss of −65.18 dB were achieved. • Defect deduced polarization loss can effectively enhance MA performance. • The RCS contribution of MnO 2 /CF composites in far field was calculated by CST. [ABSTRACT FROM AUTHOR]

A new method for loading MnO 2 quantum dots (MnO 2 QDs) onto hierarchical carbon nanowires derived from MOF-5 (CNM) has been proposed. CNM is obtained by calcining MOF-5 as a sacrificial template, and MnO 2 QDs are uniformly distributed on CNM through the reduction of KMnO 4. The resulting composites, when used as anodes for lithium-ion batteries (LIBs), demonstrate excellent reversible capacity, rate performance, and cycle stability. Specifically, the 1-MnO₂/CNM composite electrode exhibits a high reversible capacity of 983 mAh g⁻1 at a current density of 0.2 A g⁻1, and an average reversible capacity of 530 mAh g⁻1 at a high rate of 1 A g⁻1. Moreover, the 1-MnO₂/CNM composite shows remarkable long-term cycle stability, retaining more than 90 % of its capacity after 500 cycles. • The specific cubic externally attached carbon nanowire structure was formed. • MnO 2 quantum dots were modified on carbon nanowires derived from MOF-5 (CNM). • Lithium-ion battery anode materials show high reversible specific capacity. [ABSTRACT FROM AUTHOR]

[Display omitted] • A porous biochar (CCB) was derived from pyrolysis of KMnO 4 -activated waste corncob. • MOF-5/CCB composite was synthesized hydrothermally by in situ growth of Zn-MOF-5 on CCB. • MOF-5/CCB exhibited an exceptional NH 3 adsorption capacity of 6.88 mmol/g at 298.15 K and 1 bar. • The NH 3 capture on MOF-5/CCB was ascribed to a combined physical–chemical adsorption process. Ammonia (NH 3) is an odor gas pollutant which has serious harm to the environment and human health. The development of advanced adsorbents to remove NH 3 is of great significance. Herein, a new adsorbent for NH 3 adsorption with high efficiency was prepared by in-situ growth of Zn-MOF-5 on the KMnO 4 -activated waste corncob-derived porous biochar (KCB). The optimized M 0.6 K 0.1 CB-400 sample was obtained by optimizing the mass ratio of KMnO 4 to corncob at 0.1, activation temperature at 400 °C, and the dosage ratio of Zn-MOF-5 to porous biochar at 0.6. The M 0.6 K 0.1 CB-400 demonstrated an excellent NH 3 adsorption capacity of 6.88 mmol/g at 298.15 K and 1 bar, exhibiting a fast adsorption kinetics with 94 % of the equilibrium adsorption capacity reached in just 10 min. The M 0.6 K 0.1 CB-400 composite demonstrated good regeneration functionality by maintaining a NH 3 removal capacity of 3.44 mmol/g after 6 regeneration cycles. Based on the thermodynamic and kinetic analyses, along with characterization of the chemical composition and physical structure of the NH 3 -adsorbed samples, the adsorption process of MKCB on NH 3 was proven to involve a combination of physical and chemical adsorption. This study introduces a novel method for synthesizing MOF-modified biochar as a highly efficient NH 3 adsorbent, offering new insights into the underlying mechanisms of gas purification. [ABSTRACT FROM AUTHOR]

MnO 2 nanosheets modified CoP/P-C core/shell nanotubes with vertically aligned channels for promoting supercapacitor performances. [Display omitted] • MnO 2 nanosheets modified CoP/P-C core/shell nanotube arrays are successfully prepared. • The CoP/P-C/MnO 2 @CC electrode shows the specific capacity of 742 F g−1 at 1 A g−1. • The electrochemical performance of CoP/P-C@CC can be efficiently enhanced by the growth of MnO 2 nanosheets. • The CoP/P-C/MnO 2 @CC//AC supercapacitor delivers a high energy density of 93.12 Wh kg−1 at power density of 800 W kg−1. Research into electrode materials that are low-cost, possess high capacity, and exhibit long cycle life is pivotal for the advancement of supercapacitor technology. Herein, a CoP/P-C/MnO 2 @CC composite is synthesized by solution impregnation and high temperature phosphating. The unique combination of nanotubes and MnO 2 nanosheets reduces ion and electron transmission distance and significantly increases active sites. The CoP/P-C/MnO 2 @CC electrode demonstrates a specific capacitance of 742.0 F g−1 at 1 A g−1, a substantial improvement over the counterpart prior to KMnO 4 immersion (459.4 F g−1). Furthermore, an asymmetric supercapacitor based on the CoP/P-C/MnO 2 @CC electrode was assembled, achieving a high energy density of 93.12 Wh kg−1 at a power density of 800 W kg−1. Meanwhile, the device maintains 77.3 % of its original capacity after 8000 cycles, demonstrating good cycle stability. This study not only presents an attractive electrode material with unique structure, but also provides a referential methodology for developing superior electrodes. [ABSTRACT FROM AUTHOR]

[Display omitted] • Manganese ferrites were synthetized by a variant of the Schikorr reaction. • KMnO 4 was used as oxidant agent and as a source of divalent manganese. • The lattice parameter of the samples vs. manganese content obeys the Vegard's law. • A good analytical correlation exists between XRFS and FAAS techniques. • The catalytic activity of ferrites is function of Mn content and particle size. The main goal of present work was to show a new method of synthesis, of manganese ferrite (Mn x Fe 3-x O 4 , x = 0.085 to x = 0.379) with variable composition of Fe(II), Fe(III) and Mn(II) ions by coprecipitation, with the application of KMnO 4 and KNO 3 as oxidizing agents, followed by the characterization and research of the catalytic properties of the prepared samples. The chemical analysis by Flame Atomic Absorption Spectroscopy (FAAS), X-Ray Fluorescence Spectroscopy (XRFS) and potentiometric titration, allows to calculate the elemental and ionic composition of the prepared ferrites. The use of KMnO 4 enables not only the oxidation of iron(II) to iron(III) but also a source of manganese(II). The Mn substitution in Mn x Fe 3-x O 4 ferrite as well as higher gel dispersion, cause the exponential increase of the catalytic activity, which is more significant in smaller particles. [ABSTRACT FROM AUTHOR]

Phenolic compounds usually produce coupling phenols during the upstream oxidation treatment of water, but the disinfection by-products (DBPs) of coupling phenols in the subsequent disinfection process have been overlooked. Herein, we demonstrated the generation and higher toxicity of these DBPs. In Songhua River water, 0.355 ng/L 4-(4-bromophenoxy)phenol and 122.67 ng/L phenol were detected. Pre-oxidation with K 2 FeO 4 and KMnO 4 resulted in the formation of 0.68 ng/L and 0.506 ng/L 4-(4-iodophenoxy)phenol in subsequent disinfection, respectively, which were 2–3 times that without pre-oxidation. Coupling of phenolic compounds during pre-oxidation and then halogenated during chlorination was shown to be the main pathway for the generation of coupling phenolic DBPs. The maximum rate constants for the reactions of hypochlorous acid with phenol and its coupling products (4-phenoxyphenol, 2,2′-biphenol, and [1,1′-biphenyl]−2,4′-diol) were 115.61 M−1s−1, 65.85 M−1s−1, 143.13 M−1s−1, and 212.52 M−1s−1, respectively, with 2,2′-biphenol and [1,1′-biphenyl]−2,4′-diol breaking through lower energy barriers and releasing more energy than phenol. This indicated coupling phenols have a higher potential to form DBPs. Additionally, coupling phenolic DBPs (4-(4-chlorophenoxy)phenol, 4-(4-bromophenoxy)phenol, and 4-(4-iodophenoxy)phenol) was 1–3 orders of magnitude more toxic than their precursors (4-phenoxyphenol, 2,2′-biphenol, [1,1′-biphenyl]−2,4′-diol, and phenol) and uncoupled DBPs (4-iodophenol). Therefore, the formation and hazards of coupling phenolic DBPs require more attention. [Display omitted] • Phenols in water would generate coupling phenols in chemical oxidation process. • Coupling phenols would generate DBPs in chlorination disinfection. • The potential of coupling phenols forming DBPs is higher than that of uncoupled. • The toxicity of coupling phenolic DBPs was higher than that of uncoupled. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hollow MnO 2 microcuboids outperform 1% Pt/Al 2 O 3 in benzene oxidation catalysis. • Oxygen vacancies in hollow MnO 2 boost benzene oxidation efficiency. • Hollow structure's capillary action concentrates reactants, enhancing catalysis. • Hollow MnO 2 ′s remarkable stability makes it promising for real-world use. Tackling the urgent need for efficient catalytic abatement of harmful volatile organic compounds (VOCs), this study presents the controlled synthesis of hollow MnO 2 microcuboids with hierarchical structures for enhanced benzene oxidation catalysis. The hollow MnO 2 catalysts, obtained via a redox reaction between MnCO 3 precursors and KMnO 4 followed by selective acid etching, exhibit significantly higher surface area, oxygen defects, and Mn3+ concentration compared to solid MnO 2. Comprehensive characterization techniques reveal the structure–activity relationships governing the superior catalytic performance, which rivals that of a 1 % Pt/Al 2 O 3 reference catalyst. The unique hollow morphology, comprising thin shell walls built from interconnected nanorods, substantially enhances active site accessibility and lowers the activation energy barrier. A key feature of the hollow structure is its ability to concentrate reactants within the confined internal void through capillary action, a phenomenon that enriches reactant concentrations and further promotes catalytic activity. In-situ DRIFTS analyses provide mechanistic insights into surface species transformations during benzene oxidation. Notably, the hollow MnO 2 catalyst demonstrates impressive long-term stability and high activity in the presence of water vapor, highlighting its potential for practical industrial VOC abatement applications. [ABSTRACT FROM AUTHOR]

[Display omitted] • Preparation of PET/Cu composite foils without graft modification or magnetron sputtering. • Pretreatment of PET substrates significantly impact microstructure and properties. • The texture affects the adhesion of PET/Cu composite foils. • Bonding of PET/Cu composite foils meets the ASTM 5B standard. PET/Cu composite foils are expected to have widespread applications due to their lightweight, good bendability and excellent electrical conductivity. However, efficiently and stably preparing copper cladding layers on the surface of PET film with good bonding to the substrate remains a challenge. In this study, by optimizing the process route and adopting a synergistic method involving electroless plating and electroplating, PET/Cu composite foils with excellent conductivity and robust bonding can be successfully prepared. The experimental results indicate that the optimal performance of PET/Cu composite foils is achieved when the PET substrate is roughened with KMnO 4 /H+ solution, activated with salt-based colloidal palladium, subsequently treated with a weak alkaline electroless nickel plating solution for 5 min, and plated copper at a current density of 0.4 A·dm−2. The adhesion strength of the PET/Cu composite foils meets the ASTM 5B standard and the electrical conductivity reaches up to 4.17 × 107 S/m. The method proposed in this study offers an efficient and concise approach for preparing high-quality PET/Cu composite foils that hold great potential for diverse applications in flexible copper clad laminates. [ABSTRACT FROM AUTHOR]

[Display omitted] • O 3 pre-oxidation accelerated the start-up and ripening of MnO x filter. • Deep removal of manganese was achieved with O 3 addition. • Oxidation of adsorbed Mn2+ promoted the formation of vernadite with high activity. • Mn(III)-rich nanosheets with low crystallinity dominated Mn removal. Manganese (Mn) is a common contaminant with a strict limit value in drinking water, which is traditionally removed by virtue of manganese oxides (MnO x) filter, in which the performance and stability depend on its ripening. Herein ozone (O 3) is employed as a pre-oxidant to ripen MnO x filter for the removal of Mn from drinking water, with KMnO 4 as a control. The O 3 pre-oxidation (OPO) assisted filter presents more excellent performance in Mn removal during the whole start-up period and achieves a significant shortening of the start-up time from 74 days to 41 days as well as ripening time from 108 days to 80 days compared with the KMnO 4 pre-oxidation (KPO) filter. The O 3 facilitates the generation of active vernadite via the direct oxidation of manganese ions (Mn2+) and promotes the evolution of deposited MnO x by assembling Mn2+ from water during the 120-day reactions. The vernadite nanosheets with low crystallinity (16.23–30.35 %) and abundant Mn(III) species (44.19–48.48 %) in deposited MnO x formed by OPO act as the active components to promote the adsorption and subsequent oxidation of Mn2+, thus enhancing Mn removal from water. The OPO costs less than KPO in completing the start-up of MnO x filter and avoids the chemicals pollution. This work establishes a novel strategy to accelerate the start-up and ripening of MnO x filter for efficient removal of Mn from drinking water. [ABSTRACT FROM AUTHOR]

Designing and constructing stable and high-performance catalysts for room-temperature ozone decomposition under humid conditions remains a significant challenge. Herein, we report manganese oxide (MnO x) rich in surface hydroxyl groups (-OH), synthesized through a facile three-step process combining solid-state grinding, heat treatment, and hydrothermal activation using potassium permanganate and ascorbic acid as precursors. The as-prepared catalyst (MnO x -A) demonstrated remarkable stability with 100 % ozone conversion maintained for 240 min under ≤ 50 % relative humidity (RH). Notably, it achieved 90 % ozone conversion after 240 min even under 90 % RH, surpassing its performance (79 % conversion) at 70 % RH. Through comprehensive characterization and density functional theory calculations, we revealed that the abundant surface -OH groups effectively mitigate the water-induced deactivation of MnO x during room-temperature catalytic ozone decomposition under humid conditions. Furthermore, we established a correlation between the catalytic activity of -OH groups and the manganese valence state. These findings provide valuable insights for the rational design of highly efficient and stable catalysts for practical ozone elimination applications. [Display omitted] • A MnO x with abundant surface OH was synthesized. • Surface OH can improve the performance of MnO x catalysts for O 3 decomposition under humid conditions • DFT calculations further confirmed that low-valent Mn facilitates OH activity. • New insights into the design of MnO x for effective O 3 decomposition were proposed. [ABSTRACT FROM AUTHOR]

The incorporation of manganese acetylacetonate as a secondary manganese source in an appropriate molar ratio significantly enhances the specific surface area of the catalyst. This expanded surface area facilitates the adsorption of gases integral to the reaction process. Furthermore, adding manganese acetylacetonate increased the content of Mn4+ and chemisorbed oxygen (O α) in the catalyst, thereby amplifying its reduction capabilities. This enhancement results in superior denitrification performance at lower temperatures. Additionally, the integration of manganese acetylacetonate generates more acidic sites on the catalyst, facilitating ammonia adsorption and activation. This not only improves the efficiency of the catalyst but also fortifies its resistance to sulfur poisoning, marking a positive advancement in catalytic performance. [Display omitted] • 90 % NO conversion can be kept for more than 6 h at 140 °C and 100 ppm SO 2. • Mixed manganese resources significantly increased the specific surface area. • Mixed manganese resources can significantly avoid the formation of SO 3. • Manganese acetylacetonate increased the surface acidity and reduction capacity. It remains a big challenge to enhance the SO 2 resistance of catalyst in low-temperature NH 3 -SCR reduction. In this work, a series of MnO x -a%Mn (a = 0, 1, 3, 5, 10) catalysts were prepared by introducing manganese acetylacetonate during the reaction between lactic acid and KMnO 4 , based on the molar ratio of manganese acetylacetonate to KMnO 4. Notably, MnO x -5 %Mn exhibited more than 95 % NO conversion and 100 % N 2 selectivity at 80–240 °C. Moreover, the catalyst demonstrated excellent sulfur resistance by sustaining over 90 % NO conversion at 140 °C at the presence of 100 ppm SO 2 for more than 6 h. Furthermore, XPS characterization indicated that adding manganese acetylacetonate enhanced electron transfer efficiency and improved the reduction capacity of the catalyst due to the interconversion between Mn3+ and Mn4+, which improved electron transfer efficiency. The enhanced reduction capacity of the catalyst promoted the formation of oxygen vacancies and surface-adsorbed oxygen species (O α), avoiding over-oxidation of NH 3. The results elucidated that manganese acetylacetonate could optimize the overall performance by modulating the synergistic effect between the oxidizing ability and surface acidity of the catalyst. Therefore, the MnO x -5 %Mn catalyst possessed a broad operational temperature window (40–240 °C) and SO 2 resistance in the NH 3 -SCR reaction, indicating its potential for practical application. [ABSTRACT FROM AUTHOR]

• Organic pollutants were oxidized into gases by acidic KMnO 4. • Gas pressure meter was served as a portable detector. • Heating and ultraviolet irradiation were used for assisting catalytic gas generation. • A portable analytical system was fabricated for COD Mn on-site and rapid analysis. Permanganate index (COD Mn) is one of the important indicators of surface water quality measurement. Herein, a portable analytical system was developed for on-site and rapid analysis of COD Mn , organic substances in water were oxidized and transformed into gases, so that COD Mn concentration was converted into a change of gas pressure signal, the pressure signal change was further detected by a gas pressure meter. Heating method and ultraviolet (UV) irradiation method were used as assisting technologies for oxidization of organic substances by acidic KMnO 4 , a linear range of 2–150 mg l -1 and a detectable limit of 2 mg l -1 were obtained. Those methods were further applied to the detection of COD Mn in various water samples (lake waters and domestic sewage) and certified reference water samples (BWZ 6974–2016C and BWZ 7617–2016), with recoveries of 89–111 %. Among them, a portable analytical system based on UV irradiation gas pressure meter was further established and used for the analysis of COD Mn in field. It is a promising analytical system/device for COD Mn monitoring in field, offering advantages of low-cost, easy-operation, portability and rapidness. [Display omitted] [ABSTRACT FROM AUTHOR]

• PTC-dual oxidation promoted benzene removal by 78 % compared to sole-oxidant systems. • MnO 4 −transfer ratio was positively related to NAPL solubility and hydrophilicity. • Colloidal MnO 2 formed from KMnO 4 reduction was the most effective activator of PMS. • SO 4 •−, O 2 •- and 1O 2 were first observed in NAPL phase in the double-oxidant system. • Adding oxidants in sequence achieved trichloroethene and benzene removal over 75 %. Structural differences among non-aqueous phase liquids (NAPLs) result in varying oxidation rates, limiting mass transfer between NAPLs and oxidants and seriously impairing the effectiveness of remediation via traditional in-situ chemical oxidation. To tackle this challenge, a novel approach is proposed for remediating multi-NAPL-polluted groundwater that leverages phase transfer catalysis (PTC) to enhance heterogeneous mass transfer by transferring oxidants from groundwater to NAPLs. Meanwhile, "oxidation- in-situ activation" is achieved through bifunctional oxidation using permanganate and peroxymonosulfate (PP). The proposed approach is referred to PTC-PP in this study. Herein, trichloroethene (TCE) and benzene serve as a representative multi-NAPL system. Experimental results indicated that PP significantly improved degradation efficiency of benzene in multi-NAPL system by at least 60.8 % compared to single-oxidant systems, and further enhancement (17.6 %) was achieved when PP was combined with PTC compared to PP alone. Dissolved Mn(II) and MnO 2 generated by MnO 4 − reduction effectively activated peroxymonosulfate in PTC-PP system, with colloidal MnO 2 being the most effective activator. Consequently, SO 4 •−, O 2 •− and 1O 2 were formed in both NAPL and aqueous phases, while •OH was formed in aqueous phase, playing a crucial role in benzene oxidation. In phase transfer process of PTC-PP, the proportion of MnO 4 − transferred to benzene exceeded that to TCE. This finding illustrated that nondirectional phase transfer of oxidants posed a challenge for simultaneous promotion of TCE and benzene degradation. However, TCE and benzene removal efficiencies were both >75.7 % by applying peroxymonosulfate after KMnO 4 addition. These findings lay the theoretical groundwork for PTC-PP application in groundwater remediation. [Display omitted] [ABSTRACT FROM AUTHOR]

• A portable platform for the quantitative detection of colorimetric and fluorescent solutions. • The system is equipped with dual light sources that facilitate both bright-field and fluorescence detection. • The platform maintains detection stability, demonstrating a deviation of 1.93% to 3.41%. The color of liquids is crucial in food safety, pharmaceuticals, cosmetics, and environmental monitoring. Traditional color measurement methods typically require expensive spectrophotometers, limiting their utility in rapid testing and cost-effective applications. This study developed a cost-effective, portable dual-mode colorimetric and fluorescence sensing platform with using the TCS230 sensor and STM32F103ZET6 microcontroller for real-time RGB color detection. Equipped with built-in white and ultraviolet light sources, the platform operates reliably across different environmental conditions, aided by its darkroom design and white balance calibration strategy to minimize ambient light interference. Tests with fluorescent and dye solutions show stability and reliability of the platform. The relationship between color saturation and concentration under different concentrations showed the excellent correlation coefficients above 0.99 for CuSO 4 and KMnO 4 solutions. The measurement deviations of 1.93% to 3.41%, render it an efficient tool for on-site and multiple-mode color testing. [ABSTRACT FROM AUTHOR]

The Li-rich cathode Li 1.2 Mn 0.6 Ni 0.2 O 2 (PLR) has garnered much attention as an attractive candidate for lithium-ion batteries due to its low cost, environmental friendliness, and wide voltage window. However, challenges such as rapid capacity degradation and voltage decay resulting from the release of lattice oxygen remain unresolved. Herein, a spinel phase Li 4 Mn 5 O 12 coating was generated on the surface of Li 1.2 Mn 0.6 Ni 0.2 O 2 cathode (SLR) through KMnO 4 surface modification, aiming to enhance the structure stability and conductivity of PLR. The results demonstrate that the Li 4 Mn 5 O 12 coating effectively inhibits the release of lattice oxygen and accelerates the speed of lithiation and delithiation processes of Li 1.2 Mn 0.6 Ni 0.2 O 2 cathode, thereby significantly enhancing cycling stability over a wide temperature range. Particularly notable is SLR cathode, which shows superior capacity retention of 92.5 % at 1.0 C after 200 cycles at room temperature. Meanwhile, the SLR material retains excellent electrochemical properties even at high temperatures (60°C) with a capacity of 192.9 mAh/g after 100 cycles. This study not only elucidates the mechanism of Li 4 Mn 5 O 12 modification on Li 1.2 Mn 0.6 Ni 0.2 O 2 cathode, but also provides an effective strategy to improve the performance of Li-rich cathode materials. [Display omitted] • A spinel Li 4 Mn 5 O 12 coating was formed on the surface of Li 1.2 Mn 0.6 Ni 0.2 O 2 (PLR). • Li 4 Mn 5 O 12 coating effectively inhibits the initial lattice oxygen loss. • Li 4 Mn 5 O 12 coating accelerates the lithium-ion transport speed in PLR cathode. • SLR realizing excellent cycle stability over a wide temperature range. [ABSTRACT FROM AUTHOR]

4H silicon carbide (4H-SiC) wafers are widely used in high-power, high-temperature, and high-frequency electronics owing to their excellent physical and electrical properties. In the processing of 4H-SiC wafers, chemical-mechanical polishing (CMP) is commonly employed to realize atomic-scale smoothness, damage-free surface, and global planarization. The CMP process is the synergy of wet oxidation and mechanical grinding, whose efficiency significantly relies on the oxidation process. Therefore, understanding the wet oxidation mechanism of Si face and C face of 4H-SiC wafers is critical to high-efficiency double-side CMP. In this work, the anisotropic CMP performance of Si face and C face of 4H-SiC wafers are investigated. It has been found that the material removal rate of the C face is 2–3 times that of the Si face. The thicknesses of the transient oxide layer on the C face and Si face are 8.71 nm and 3.50 nm, respectively. X-ray photoelectron spectroscopy analysis reveals that the oxygen content on the C face is higher than that on the Si face after wet KMnO 4 oxidation. This indicates that the C face of 4H-SiC is easier to oxidize, which results in more oxides that that on the Si face of 4H-SiC. Our work shows that accelerating the oxidation of the Si face of 4H-SiC wafers during the simultaneous double-sided CMP process is crucial for the efficient polishing of 4H-SiC wafers. [ABSTRACT FROM AUTHOR]

• Hierarchical porous structure of GA is optimized via GO oxidation conditions. • H 2 SO 4 content in GO synthesis shows the greatest effect on oxidation degree. • High CO 2 capture is achieved via the highest S micro /S Total and macropores in GA. • High concentration of H 2 SO 4 promotes GA porous structure and CO 2 capture. • High content of KMnO 4 led to fewer macropores and decreased the CO 2 capture. Graphene aerogels as solid porous adsorbents are great candidates for CO 2 adsorption based on their tunable hierarchical pore structure and oxygenated groups on graphene oxide can control the self-assembly and pore structure of graphene aerogels. Modified Hummer's method was used to synthesize graphene oxides by using various levels of H 2 SO 4 , KMnO 4, and H 2 O 2 and 3D graphene aerogels were synthesized via the hydrothermal and freeze-drying method. FTIR, RAMAN, XRD, FE-SEM, and BET analysis were used for characterizations. The effect of graphite oxidation conditions on the hierarchical porous structure of graphene aerogel for CO 2 adsorption was investigated. The graphene aerogel with the high meso and micro surface areas and the highest S m /S T value (micro surface area/total micro and meso surface area) of 33 % and also, the adequate macropores was achieved using high dosage of H 2 SO 4 in the graphene oxidation process led to the highest CO 2 adsorption capacity of 1.72 mmol/g. increasing the H 2 O 2 dosages increased the macropores in the aerogel structure and improved the value of S m /S T leading to an increase in the CO 2 adsorption capacity. The high content of KMnO 4 led to low S m /S T value and fewer macropores and decreased the CO 2 adsorption capacity (1.04 mmol/g). [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • Mn(VII)/S(IV) process was proposed to improve the performance of UF in algae-laden water. • Calcium ions promoted the aggregation of in-situ MnO 2 and algal pollutants. • Mn(VII)/S(IV) system produced active substances that facilitate the removal of algae organics. • The coupling process changed the fouling mechanism and greatly alleviated membrane fouling. Membrane fouling caused by algal-derived foulants severely impedes the widespread application of ultrafiltration (UF). Herein, two sulfites (Na 2 SO 3 and CaSO 3 , S(IV)) were used to activate potassium permanganate (Mn(VII)) as pretreatment to enhance the performance of UF in treating algae-laden water. The results showed that the Mn(VII)/S(IV) system produced MnO 2 with abundant hydroxyl groups, which was advantageous for adsorbing algal pollutants. Compared with Mn(VII)/Na 2 SO 3 , Mn(VII)/CaSO 3 process further increased the aggregation tendency of algal cells, which was due to the Ca2+ bridging effect that promoted the aggregation of MnO 2 and algal foulants. S(IV) can activate Mn(VII) to produce free radical (OH and SO 4 −), and enhance removal of dissolved organic carbon (DOC) and fluorescent organics in coordination with the adsorption of in-situ MnO 2. Moreover, the presence of Ca2+ ensured compliance with residual manganese in the treated water. Extended Derjaguin-Landau-Verwey-Overbeek (XDLVO) theory suggested that the Mn(VII)/S(IV) strategy weakened the attractive forces between pollutants and the membrane. FTIR analysis further confirmed that the combined process reduced the accumulation of protein organics on the membrane surface. As a result, the reversible fouling was reduced by 65.3 % and 92.2 %. The in-situ formed manganese oxide altered the structure of the cake layer and delayed the formation of the cake filtration mechanism. Mn(VII)/CaSO 3 pretreatment produced a looser cake layer, resulting in a shift of the fouling mechanism towards a single standard blocking. In summary, the novel integrated process can ensure the efficient operation of UF in the purification of algae-laden water. [ABSTRACT FROM AUTHOR]

• KMnO 4 reacts with ethanol to form the α-MnO 2 with a cryptomelane structure. • α-MnO 2 demonstrates stable glucose oxidation currents in a neutral medium. • Sensitivity of α-MnO 2 in the glucose oxidation achieves 17.8 μA mM−0.5 cm−2 geo. • Concentration plot shows a linearity in the physiological glucose range (1–30 mM). • α-MnO 2 keeps glucose selectivity in the presence of acetone, urea and lactic acid. A high demand for non-enzymatic glucose sensors and continuous glucose monitoring systems encourages the development of stable and active catalysts for the enzymeless anodic oxidation of glucose in the neutral medium. In regard to this reaction, we analyze the prospects of alpha manganese dioxide with a cryptomelane structure synthesized via an aqueous chemical route. To provide various specific surface area, the hydrated α-MnO 2 oxide is annealed in a wide temperature range from 60 to 700 °C. Furthermore, we investigate the influence of the oxide annealing temperature on the amount of crystal water, chemical composition, morphology, electrochemical recharging behavior, electrocatalytic activity and stability in the glucose oxidation carried out in an isotonic NaCl-based phosphate-buffered saline (pH 7.40). To solidly determine potentials of the irreversible cathodic dissolution of α-MnO 2 as well as O 2 /Cl 2 evolution on α-MnO 2 , a rotating ring-disk electrode is applied. For the most active α-MnO 2 sample with the 100 μg cm−2 geo loading the glucose oxidation current of ca. 40 μA cm−2 geo after 1 h at +0.8 V (SCE) for 7 mM of glucose is achieved. The linear concentration dependence in a physiological glucose range (1–30 mM) with the sensitivity of ca. 17.8 μA mM−0.5 cm−2 geo at 25 °C is observed. Finally, glucose selectivity of α-MnO 2 in relation to fructose, galactose, xylose, ribose, urea, lactic acid, acetone, ascorbic acid and paracetamol is revealed. [Display omitted] [ABSTRACT FROM AUTHOR]

Heavy metal sediment pollution has become an increasingly serious problem associated with industrial development, so extensive studies have been conducted concerning their removal. Biochar has recently shown good potential for in-situ remediation of heavy metal-contaminated sediments. The heavy metal adsorption capacity of inexpensive biochar can be improved by loading it with metal oxides. In this study, manganese-modified biochar (MBC) was prepared by KMnO 4 -modified waste-activated sludge biochar and applied to immobilize Pb and Cd in sediments. Its effects on the sediment microbial community were also investigated. The Results showed that manganese modification of the biochar made it more conducive to the adsorption of heavy metals, owing to its higher specific surface area and graphitization structure, more active sites and oxygen-containing groups, and the presence of Mn 2 O 3 crystal structure on the surface. The maximum adsorption capacities of this material for Pb2+ and Cd2+ in solution were 176.9 mg/g and 44.0 mg/g, respectively. The application of MBC to the remediation of heavy metal-contaminated sediments transformed Pb and Cd in the sediments from exchangeable to residual state. The F4 content of Pb in the sediments increased from 40.52%-42.36% to 49.11%–51.14% after application of 1% MBC, and to 63.94%–64.49% after application of 5% MBC. Correspondingly, the F1 content of Pb in the sediments decreased from 29.09%-30.68% to 17.43%–17.69% after the application of 5% MBC. Furthermore, MBC efficiently enriched the microbial biodiversity and affected the microbial population structure within 60 days. The relative abundance of uncultured f Symbiobacteraceae and Fonticella communities significantly increased after incubation. The results may provide empirical support for the combination of metal oxides and biochar for the remediation of heavy metal-contaminated sediments. [Display omitted] • Manganese-modified biochar enhances heavy metal adsorption in sediments. • Biochar modification increased microbial diversity and changed community structure. • MBC transformed heavy metals in sediments from exchangeable to residual states. • MBC significantly reduced biological toxicity in heavy metal-contaminated sediments. [ABSTRACT FROM AUTHOR]

The presence of potassium permanganate in aquatic environment poses a significant issue that requires resolution. In response, zeolitic imidazolate framework nanoparticles with large pore sizes, extensive surface areas, and high chemical stability in water were synthesized. Subsequently, 8-hydroxyquinoline was incorporated into ZIF-8 (named 8-HQ@ZIF-8) to enhance its capability to decompose potassium permanganate in aquatic environment. The synthesized material underwent thorough characterization using powder X-ray diffraction, Fourier-transform infrared spectroscopy, nitrogen isothermal adsorption-desorption at 77 K, thermogravimetric analysis, and scanning electron microscopy. Electrical conductivity tests revealed that the 8-HQ@ZIF-8 material can decompose potassium permanganate within 5 min and be recycled over five runs. Furthermore, the nanocomposite of 8-HQ and ZIF-8 exhibited greater stability than the original ZIF-8 under strong oxidizing conditions. This suggests that functionalizing with organic ligands can enhance the durability and performance of the material. In addition to its degradability, the 8-HQ@ZIF-8 material, which carries manganese oxide, also displays variable fluorescence properties, making it a potential sensor for detecting residual potassium permanganate in drinking water treatment systems. Therefore, the 8-HQ@ZIF-8 material shows considerable promise for both the treatment and detection of pollutants in aquatic environments. [Display omitted] • Synthesized ZIF-8 nanoparticles with large pores and high chemical stability in water. • Enhanced ZIF-8 with 8-HQ to decompose KMnO₄ effectively in aquatic environments. • 8-HQ@ZIF-8 degrades KMnO₄ within 5 min and is recyclable for 5 cycles. • Improved stability of 8-HQ@ZIF-8 under strong oxidizing conditions compared to ZIF-8. • 8-HQ@ZIF-8's fluorescence properties enable detection of KMnO₄ in water treatment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Pioneered dual-mode PAD for efficient nitrite detection. • Integrated colorimetric and electrochemical detection to enable comprehensive and versatile nitrite monitoring. • Achieved improvements in detection range, precision, and utility for diverse applications including water quality monitoring, food safety assessments, etc. This study introduces a novel, miniaturized analytical platform for a comprehensive range of founded nitrite concentrations on a single, portable device. Nitrites, essential for extending shelf life and enhancing color, are commonly found in both natural and industrial environments. In environmental settings, it is important to detect low nitrite concentrations, industrial applications, such as in the food industry, require handling higher concentrations effectively. This groundbreaking approach combines colorimetry and electrochemical detection for nitrite monitoring in a single portable paper-based device (PAD). Utilizing potassium permanganate (KMnO 4) as a chromogenic agent, the device enables rapid, visual detection and quantification of high nitrite concentrations via smartphone-based color intensity analysis. For sensitive detection of low-level nitrite, it incorporates a cellulose acetate-modified screen-printed electrode (CA/SPCE) with differential pulse voltammetric detection. Under optimal conditions, the proposed dual-detection platform effectively detects nitrite concentrations ranging from 0.05 to 12.5 mM. Specifically, it covers (0.05–0.6 mM using electrochemical detection and 0.5 to 12.5 mM through colorimetric analysis. High nitrite levels produce a faded color in the test zone, while low or undetectable color changes trigger electrochemical analysis for enhanced precision. This PAD platform is portable, cost-effective, and minimizes reagent usage. Importantly, the method's detection limit aligns with the World Health Organization's acceptable daily nitrite intake in drinking water (3 mg L−1, approximately 65 µM), making it a practical tool for nitrite screening. [ABSTRACT FROM AUTHOR]

Potassium permanganate (KMnO 4), as a versatile and safe solid source of MnO 4 -, received substantial attention from researchers as a potential soil oxidant reagent. In this study, we prepared polylactic acid (PLA)-coated KMnO 4 (KMnO 4 @PLA) to control MnO 4 - release. The experimental results indicated that the optimal preparation scheme for KMnO 4 @PLA was a particle size of 1–2 mm, a solid-liquid ratio of 1:3, and a core-shell ratio of 1:3. And the release lifetimes of MnO 4 - from KMnO 4 @PLA in aqueous and quartz sand media were 200 hours and 310 hours, respectively, which were 2400 and 33 times longer than the release lifetimes of raw KMnO 4. The controlled release of MnO 4 - from KMnO 4 @PLA was achieved through the hydrolysis of PLA. And the release process adhered to first-order reaction kinetics and displayed Fickian diffusion characteristics. Moreover, the removal of phenol by KMnO 4 @PLA in aqueous, quartz sand, and soil media were investigated through batch and flow column experiments. Compared with the raw KMnO 4 , the KMnO 4 @PLA exhibited a stronger ability to degrade phenol, due to the mildly acidic nature of the PLA shell. These findings demonstrated that KMnO 4 @PLA has significant advantages for the remediation of organically contaminated soils. • Polylactic acid (PLA)-coated KMnO 4 was prepared by solvent evaporation method. • The release lifetime of MnO 4 - from KMnO 4 in quartz sand medium reached 310 hours. • The lifetime of KMnO 4 were controlled by changing KMnO 4 @PLA sizes. • The release mechanism of MnO 4 - from KMnO 4 @PLA was hydrolysis and swelling of PLA. [ABSTRACT FROM AUTHOR]

Water pollution poses significant health and environmental risks, impacting ecosystems and human health. This study investigates the removal of potassium permanganate (KMnO 4) from water using a magnetic hydrochar composite (HTCNP) synthesized from Calotropis procera (CP) leaves through a single-step hydrothermal carbonization process. This eco-friendly and efficient synthesis method provides an advantageous alternative to traditional multi-step processes. Structural analysis confirmed the composite's porous structure and functional groups that contribute to effective adsorption. Under optimal conditions (pH 7, adsorbent dose of 1 g/L, contact time of 60 minutes, and temperature of 298 K), HTCNP achieved a maximum adsorption capacity of 388.09 mg/g. Adsorption kinetics followed a pseudo-second-order model, and the adsorption behavior aligned with the Freundlich isotherm, indicating multilayer adsorption on a heterogeneous surface. Furthermore, the HTCNP composite demonstrated good reusability over five cycles, maintaining high removal efficiency, and effectively removed KMnO 4 from real wastewater samples. These findings highlight the potential of HTCNP as an efficient, sustainable, and practical adsorbent for water purification applications, contributing to environmental protection and public health improvement. • New method for magnetic hydrochar composite using Calotropis procera leaves. • High adsorption capacity (388.09 mg/g) for potassium permanganate removal. • Adsorption follows pseudo-second-order kinetics, fitting the Freundlich model. • Composite is reusable for five cycles, maintaining high removal efficiency. • Effective in purifying polluted water, contributing to environmental protection. [ABSTRACT FROM AUTHOR]

Membrane fouling seriously impedes the application of membrane technology in water treatment. Although oxidation achieved intensive attention in membrane fouling control, controversy results were observed in many works since oxidation may accelerate fouling and damage membrane under some circumstances and the underlying mechanism still remained unclear in complex water matrices. This study provides a comprehensive review on the recent progress of pre-oxidation and oxidation cleaning in fouling control for membrane (e.g., microfiltration (MF), ultrafiltration (UF), nanofiltration (NF), reverse osmosis (RO), forward osmosis (FO), membrane distillation (MD)). Common oxidation approaches (e.g., chlorine, ozonation, H 2 O 2 , sulfate radical (SO 4 ●–), potassium permanganate (KMnO 4) and Fe(VI) based oxidation) were systematically summarized and compared, along with their positive and negative impact on fouling mitigation. Furthermore, the fouling control performance and underlying mechanism were reviewed according to the recent published literatures. Ultimately, the challenges and future prospects of oxidation technology in membrane fouling control application were also proposed based on the current review. Overall, this review may provide the guidance for developing advanced oxidation strategy in controlling membrane fouling in water treatment and minimizing the potential drawbacks and risks of oxidation as a membrane fouling control strategy. [Display omitted] • Recent advances in oxidation based membrane fouling control are reviewed. • Applications of different oxidation approaches in fouling control are summarized. • The underlying fouling control mechanisms are systematically revealed and compared. • The challenges and future prospects of oxidation are outlined for fouling control. [ABSTRACT FROM AUTHOR]

The overuse of sulfonamide antibiotics (SAs) has placed considerable treatment pressure on wastewater treatment plants. The adsorption-biological coupling reactor we developed have been demonstrated to be effective in the treatment of SAs wastewater. However, the effect of filler modification on reactor performance and the degradation mechanisms of SAs remains inadequately understood. Herein, the amendment of filler with L-arginine and KMnO 4 were investigated. The overall removal efficiency of COD, TP, NH 3 -N, sulfadiazine (SD), and sulfamethoxazole (SMX) in the reactor with L-arginine-modified coke (A-Coke) as filler were (79.29±15.29)%, (84.81±4.13)%, (92.67±11.25)%, (93.45±4.74)% and (93.60±4.13)%, while in the reactor with KMnO 4 -modified coke (K-Coke) as filler, the overall removal efficiency of COD, TP, NH 3 -N, SD and SMX were (90.60±6.68)%, (96.26±2.52)%, (95.14±5.29)%, (92.63±5.78)% and (93.65±6.48)%, respectively. The dominant bacteria in the reactor with A-Coke as filler were Azohydromonas , Propionibacterium , Bdellovibrio , and Sphingomonas , and those in the reactor with K-Coke as filler were Azohydromonas , Lysobacter , Plasticicumulans , and Cupriavidus. The compounds 4-hydroxy-2-aminopyrimidine, 4-hydroxy-2-hydroxy-aminopyrimidine, n-acetamide, 4-benzoquinone, 1,2, 4-trihydroxybenzene, 3-amino-5-methylisoxazole, and TP163 were detected as metabolites of SAs in the reactor filled with A-Coke. In contrast, 4-hydroxy-2-hydroxy-aminopyrimidine, 3-amino-5-methyl isoxazole, and TP163 as metabolites of SAs were detected in the effluent water of the reactor with K-Coke as filler. The results demonstrate that the amendment of L-arginine and KMnO 4 could increase the performance of the adsorption-biological coupling reactor, which has potential application prospects in the treatment of SAs wastewater. [Display omitted] • Adsorption-biological coupling reactor with manganese-modified coke as filler was beneficial for pollutant removal. • Proteobacteria and Actinomycetes dominated the microbial communities in the reactors. • korA and a ccA were high metabolic genes in the L-arginine modified coke. • Manganese increased the abundance of functional genes for nitrogen fixation. [ABSTRACT FROM AUTHOR]

Catalytic combustion is one of effective ways to remove short-chain alkanes. In this study, we elaborately designed a novel catalyst of in situ Co-Mn decorated LaMnO 3 perovskite for ethane catalytic combustion, in which extra Mn and Co species were introduced via acidic KMnO 4 and Co(NO 3) 2 solution precipitation method. The addition of Mn and Co could not only slightly etch LaMnO 3 , thereby increasing specific surface area and redox property, but also generate new active phase CoMn 2 O 4 , thus accelerating reaction. Among all the as-prepared catalysts, CMO/LMO-0.5 exhibited admirable ethane removal efficiency with a T 90 of 365 °C, a reaction rate of 0.46 mmol·g−1·h−1, a TOF value of 0.64 mmol·g−1·h−1, and excellent hydrothermal stability and reusability. Moreover, according to in situ DRIFTS, a possible pathway was proposed. This work can rationalize an alternative approach to develop an active catalyst for short-chain alkanes catalytic combustion or other catalytic systems. [Display omitted] • Co-Mn ions were decorated on LaMnO 3 perovskite via in situ precipitation method. • Specific surface area and redox property shot up after inducting Co and Mn. • CMO/LMO-0.5 catalyst exhibited admirable ethane removal efficiency. • The ability to activate ethane for catalytic combustion is of vital importance. [ABSTRACT FROM AUTHOR]

Talc exhibits excellent floatability and, as a major silicate gangue mineral associated with chalcopyrite, significantly obstructs the purification and smelting of chalcopyrite. This study investigates the reverse flotation separation of chalcopyrite and talc using KMnO 4 as a depressant and DDA (dodecylamine) as a collector within a reverse flotation system. Single mineral flotation experiments show that after adding KMnO 4 , the recovery of chalcopyrite in 38–74 μm is only 6.86 %, whereas the recovery of talc in 45–106 μm and 25–45 μm are 93.47 % and 89.25 %, respectively. Further experiments with artificially mixed ores demonstrate that KMnO 4 effectively achieves the separation of chalcopyrite and talc. The depression mechanism of KMnO 4 on chalcopyrite and talc was analyzed using Zeta potential, contact angle measurement, AFM (atomic force microscopy), FTIR (Fourier transform infrared spectroscopy), XPS (X-ray photoelectron spectroscopy), and DFT (density functional theory) calculations. Mechanistic analysis indicates that in an alkaline environment, chalcopyrite can undergo a redox reaction with KMnO 4 , forming hydrophilic hydroxide species (Cu(OH) 2 , Fe(OH) 3) on the chalcopyrite surface, which depresses chalcopyrite flotation. In contrast, the surface properties of talc are relatively stable and difficult to react with KMnO 4 , which cannot depress the flotation of talc. Therefore, KMnO 4 can be used as an efficient and selective depressant for the reverse flotation separation of chalcopyrite and talc. [Display omitted] • Using KMnO 4 as a depressant in the flotation separation of chalcopyrite and talc. • KMnO 4 selectively depressed the flotation of chalcopyrite rather than that of talc. • An oxidation-reduction reaction occurred between KMnO 4 and chalcopyrite. • Chalcopyrite oxidized by KMnO 4 produces hydrophilic hydroxides on its surface. • DFT shows that KMnO 4 has better adsorption properties on the chalcopyrite surface. [ABSTRACT FROM AUTHOR]

In this study, corn stover biochar (CSBC) and KOH and KMnO4 modified corn stover biochars (HCSBC and MCSBC) were used for oxytetracycline (OTC) removal and the enhancement of the modification was investigated. The modifications of KOH and KMnO4 improved the physical and chemical properties of CSBC (e.g., pore structure, surface morphology, crystal structure, surface functional groups, and distribution and binding state of surface elements), which significantly contributed to the removal of OTC. The removals of OTC by CSBC, HCSBC and MCSBC were multilayer, and their maximum removal amounts were 26.21 mg/g, 48.30 mg/g and 200.4 mg/g, respectively. The removals of OTC by CSBC, HCSBC and MCSBC were a combination of physical and chemical actions, but the chemical action was dominant. The rates of OTC removal by CSBC and HCSBC depended on liquid film diffusion and intraparticle diffusion, while the rate-controlling step of OTC removal by MCSBC was only liquid film diffusion. Meanwhile, the removals of OTC by CSBC, HCSBC and MCSBC were spontaneous and endothermic, and the randomness of the solid-liquid interface was irregularly increased during the process. Furthermore, the mechanisms of OTC removal by CSBC and HCSBC should be the same, and the enhancement of OTC removal by HCSBC may be attributed to the increase of active sites. The increase of active sites and degradation together resulted in that removal capacity of MCSBC was the greatest, and the contribution of degradation should be dominant. Most of the OTCs and their degradation products were attached to HCSBC and MCSBC via hydrogen bonding, π-π interactions and complexation. [Display omitted] • The q max (mg/g) of CSBC, HCSBC and MCSBC were 26.21, 48.30 and 200.4, respectively. • Multilayer surface chemisorption was dominant for OTC removal. • The rate-controlling step for OTC removal by MCSBC was different from HCSBC and CSBC. • The enhanced OTC removal was due to the increase in active sites and degradation. • Chemisorption relied mainly o hydrogen bonding, π-π interaction and complexation. [ABSTRACT FROM AUTHOR]

Amorphous MnO 2 /CuO/ZrO 2 nanocompositeswere synthesized by facile hydrothermal method at 120 °C. The nanomaterialswere prepared from KMnO 4 with Mn, Cu and Zr aqueous salts. The mixed oxide active materials were produced through three different molar ratios. The synthesized nanocomposites demonstrated a phase mixer of tetragonal-MnO 2 , monoclinic-CuO and tetragonal-ZrO 2. The ultrahigh specific capacitance of 1964F/g at a current density of 1A/g was achieved for the nanocomposite MnO 2 /CuO /ZrO 2 synthesized at a mole ratio 1:2:1. Based on the electrochemical performance; the nanomaterial synthesized at higher mole percentage of copper has shown a high-rate capability of 20.93 Wh/kg at constant power discharge of 4013.10 W/kg. These findings interrogated that Manganese Copper, Zirconium mixed nanocomposite is proved to be an excellent electrode material for energy storage devices. [ABSTRACT FROM AUTHOR]

Endotoxins are found in the outer membrane of all gram-negative bacteria and are a primary cause of endotoxemia, organ failure, and significant harm to human health. Limulus reagent as traditional detection method has certain limitations for the rapid and accurate detection of endotoxin due to the high costs associated with the horseshoe crab used in the sensing process. Herein, a fluorometric and colorimetric dual-mode biosensor was prepared for the rapid and sensitive detection of endotoxin. The chitosan-grafted Fe,Cu-doped carbon dots (CDs) was used to reduce KMnO 4 to produce CS@Fe,Cu/CDs-MnO 2 , which demonstrated distinctive characteristics including high catalytic activity as an artificial nanozyme and a fluorescence quantum yield of 76 %. On the one hand, CS@Fe,Cu/CDs-MnO 2 with the peroxidase-like activity and positively charged property can oxidize 3,3-diaminobenzidine tertrahydrochloride (DAB) and H 2 O 2 to yield a brown product (oxDAB). Additionally, it can interact with negatively charged endotoxin through electrostatic forces, which leads to a reduction in its nanozyme catalytic activity. On the other hand, oxDAB can quench the CS@Fe,Cu/CDs-MnO 2 fluorescence via inner-filter effect and static quenching. Therefore, a dual-mode biosensor that utilizes both fluorescence and colorimetric methods is developed with the aid of a smartphone. It was found that the gray value of absorbance increased linearly with endotoxin concentration in the range of 0.125–175 EU/L with a minimum limit of detection (LOD) of 0.058 EU/L, while the gray value of fluorescence intensity also demonstrated a linear increase upon the addition of endotoxin within the range of 0.05–90 EU/L with a LOD of 0.036 EU/L. The sensor is effectively utilized for detecting endotoxin in real injection samples, achieving acceptable recovery rates between 89.0 % and 101.3 %, with a relative standard deviation (RSD) of no more than 4.51 %. This indicates the reliability of the fabricated biosensor. [Display omitted] • Chitosan-grafted CS@Fe,Cu/CDs-MnO 2 with the POD-like activity was synthesized. • Endotoxins could inhibit the POD-like activity of CS@Fe,Cu/CDs-MnO 2. • Selective POD-like-induced fluorescence activity by endotoxin is achieved. • A colorimetric-fluorescence dual-mode sensing platform of endotoxin was established. [ABSTRACT FROM AUTHOR]

Novel Biochars from Hericium erinaceus wastes (both the spent mushroom substrate and mushroom carcasses), were first produced at three temperatures (250 °C, 500 °C & 750 °C), then modified with Fe(NO 3) and KMnO 4 and characterised for physical and chemical parameters. The Biochars were used for the treatment of Phosphates (PO 4 3-) and Cadmium (Cd2+) polluted waters. In all cases, the Fe/Mn modified Biochars provided better adsorption of the pollutants than the pristine. Both the modified substrate (250MS), and mushroom (250MM), demonstrated removal rate of 95 % for a 100 mg/l, and 150 mg/l Phosphate solution, respectively. For Cd, all the Biochars demonstrated strong adsorption for Cd even at very high concentrations of up to 3000 mg/l, with the highest removal rate (100 %) obtained for 750MM at 1000 mg/l of Cd in solution. The main adsorption pathways were identified as increased functional groups (-OH, Fe-O, Mn-O etc.), pollutants precipitation and change in electronegativity/electron transfer rate. Other factors influencing the Biochars' capacity include the amorphous nature and the combined mechanisms of physisorption and chemisorption. To date no studies have investigated Hericium erinaceus (Lion's mane mushrooms) for biochar use. This study therefore revealed the potential of Hericium erinaceus Biochars for remediation of polluted waters, which is very attractive because of the high yield of the Biochars compared to others in literature, and the dual tendency to remove both cations and ions from water samples even at high pollutant concentrations. The wider implications of the findings include reducing environmental waste, and providing clean options for water treatment, which is both sustainable and cost effective. [Display omitted] • Novel Biochars from H. erinaceus demonstrate high yield and efficiency for Cd & Phosphate removal. • The high efficiency is due to the amorphous nature, and a mix of physisorption and chemisorption. • The efficiency of the Biochars is also associated with the high cation exchange capacity • These Biochars from H. erinaceus wastes offer viable clean technology for water treatment. • The Biochars exhibited dual tendency to remove both cations and ions from water samples. [ABSTRACT FROM AUTHOR]

• Novel alkaline ferricyanide leaching was employed for waste PCBs recycling. • Ferricyanide had dual functions of oxidation and leaching. • Ferricyanide was shown regenerable from ferrocyanide with permanganate oxidation. Precious metals leaching using conventional processes presents challenges due to the use of toxic, expensive, and complex leaching systems, such as cyanidation, thio-systems, and halide systems comprising both lixiviant and oxidant. The present study employed a simple leaching system of alkaline ferricyanide solution with dual functions of leaching and oxidization, to extract precious metals from waste printed circuit boards (PCBs). The ferricyanide concentration, pH and temperature were found affecting Au extraction considerably. The selective extraction of Au, Ag and Pd over base metals reached 68.3, 93.0 and 74.0 % (10 g/L ferricyanide, pH 11 and 80℃), respectively. The recovery of precious metals from leachate using carbon adsorption and the regeneration of ferricyanide from barren solutions employing ferri/ferrocyanide redox cycle were shown feasible. Around 91.7 % ferricyanide could be regenerated by oxidising ferrocyanide using potassium permanganate. Finally, conceptual flowsheets were proposed to extract and recover precious metals and to regenerate and reuse the only reagent introduced ferricyanide. The study proved the feasibility of the simple leaching method, paving the way for future development of the new process. [ABSTRACT FROM AUTHOR]