Generation Of Superoxide Ion Research Articles

Generation of superoxide ions in the electrochemical reduction of molecular oxygen in concentrated lithium bis(trifluoromethanesulfonyl)imide aqueous solutions

Electrolytic generation of superoxide ions (O2•-) from the reduction of molecular oxygen (O2) was previously successful only by the formation of a hydrophobic reaction field on an electrode surface. However, in our study, O2•- was generated in concentrated lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) aqueous solutions that can be confirmed electrochemically or spectroscopically. In the concentrated LiTFSI aqueous solution, O2•- was more stable than it is in normal aqueous solutions, but it was not as stable as it is in organic solvents. When other related-concentrated electrolyte solutions are used, the electrolysis of O2•- greatly varies depending on the types of cations and anions used as electrolytes. Thus, a synergistic effect of reducing free water with cations and creating a hydrophobic atmosphere with anions was achieved.

Gold nanoparticles supported on ZnGa2O4 nanosheets as efficient photocatalysts for selective oxidation of methane to ethane under ambient conditions

In this study, we fabricated photocatalysts comprising of ZnGa2O4 nanosheets modified with gold (Au) nanoparticles for the selective oxidative coupling of methane (CH4). Our findings indicate that the C2H6 production rate of ZnGa2O4 with the optimal loading of Au nanoparticles (NPs) reached 1315.3 μmol g–1 h–1, with a selectivity of 53 %. These results were considerably higher than those obtained with pure ZnGa2O4. The presence of Au NPs facilitated the activation of O2 molecules, leading to the generation of superoxide ions (O2–), which were the primary active species responsible for the cleavage of CH4 into methyl radicals (•CH3). Additionally, Au NPs stabilized •CH3 and promoted the coupling of •CH3 into C2H6 while impeding the excessive oxidation of •CH3 into CO2. In conclusion, our study demonstrates that modifying ZnGa2O4 with Au NPs can significantly enhance the yield and selectivity of C2H6 during the photocatalytic oxidative coupling of CH4.

Zinc phthalocyanine sensitized g-C3N4 photocatalyst for exceptional photocatalytic hydrogen evolution and pollutant degradation

Here in this manuscript, the high charge conductivity and exceptionally wide range soalr light absorption of metal phthalocyanines were followed for boosted photocatalysis. Graphitic carbon nitride, g-C3N4 (CN) was thermally prepared from melamine and loaded with appropriate amount of zinc phthalocyanine (ZnPc) to form ZPCN nanocomposites. The fabricated samples were used to liberate hydrogen from water and decompose 2,4-dichlorphenol (2,4-DCP) pollutant under visible-light irradiation. The optimized nanocomposite (0.5ZPCN) purchased highly accelerated photocatalysis and liberated 90 μmol H2 in 1 h in the presence of methanol as sacrificial agent. The same nanocomposite also showed 85% decomposition efficiency for the degradation of 2,4-DCP pollutant. These enhanced catalytic activity of g-C3N4 functionalized with ZnPc are attributed to the exceptional visible light absorption and effective generation of super oxide ions and holes formed after charge transfer between g-C3N4 and ZnPc as confirmed from photoluminescence, fluorescent and electrochemical characterization of the nanophotocatalysts. The charge/radical trapping experiments confirmed that super oxide anions were the main oxidizing agents in the decomposition of 2,4-DCP.

Photocatalytic degradation of methylene blue at nanostructured ZnO thin films

The photocatalytic degradation of the wastewater dye pollutant methylene blue (MB) at ZnO nanostructured porous thin films, deposited by direct current reactive magnetron sputtering on Si substrates, was studied. It was observed that over 4 photocatalytic cycles (0.3 mg · l−1 MB solution, 540 minUV irradiation), the rate constant k of MB degradation decreased by ∼50%, varying in the range (1.54 ÷ 0.78) · 10–9 (mol·l−1·min−1). For a deeper analysis of the photodegradation mechanism, detailed information on the nanostructured ZnO surface morphology and local surface and subsurface chemistry (nonstoichiometry) were obtained by using scanning electron microscopy (SEM) and x-ray photoelectron spectroscopy (XPS) as complementary analytical methods. The SEM studies revealed that at the surface of the nanostructured ZnO thin films a coral reef structure containing polycrystalline coral dendrites is present, and that, after the photocatalytic experiments, the sizes of individual crystallites increased, varying in the range 43 ÷ 76 nm for the longer axis, and in the range 28 ÷ 58 nm for the shorter axis. In turn, the XPS studies showed a slight non-stoichiometry, mainly defined by the relative [O]/[Zn] concentration of ca. 1.4, whereas [C]/[Zn] was ca. 1.2, both before and after the photocatalytic experiments. This phenomenon was directly related to the presence of superficial ZnO lattice oxygen atoms that can participate in the oxidation of the adsorbed MB molecules, as well as to the presence of surface hydroxyl groups acting as hole-acceptors to produce OH· radicals, which can be responsible for the generation of superoxide ions. In addition, after experiments, the XPS measurements revealed the presence of carboxyl and carbonyl functional groups, ascribable to the oxidation by-products formed during the photodegradation of MB.

Electro-assisted catalytic oxidation of flue gas desulfurization-derived magnesium sulfite using cobalt ferrite as catalyst under moderate condition

The catalysts were prepared by supporting cobalt ferrite (CoxFe3−xO4) on the surfaces of sphere mesoporous silica (MCM−41) nanoparticles. The electro-assisted catalytic oxidation of MgSO3 displayed an improved oxidation rate under moderate temperatures. Electric field and CoFe2O4/MCM−41 exhibited a beneficial synergistic effect because the associated MgSO3 oxidation rate is 3.38 times the oxidation rate when only the electric field was present, and 1.83 times the oxidation rate when only the catalyst was present. The cyclic voltammetry results proved that the catalysts reduced the oxidation potential of SO32− in the presence of an electric field, and increased the electron transfer rate in the oxidation. Both the X-ray photoelectron spectroscopy (XPS) characterization and free radical scavenging experiment results indicated that Co2+ served as the initiator in the generation of superoxide ions (O2−·), which was the primary active free radical responsible for the oxidation of SO32−. The electron spin resonance (ESR) spectra showed that the electric field and high current density expedited the production of O2−·. The XPS results convincingly demonstrated that the electric field effectively alleviated the catalyst deterioration, and, as a result, significantly improved the catalyst's recyclability. Lastly, the synergistic mechanism between the electric field and the catalyst in the catalytic oxidation of MgSO3 was explored.

A novel Sillén-structured Bi-based oxybromide: CdBiO2Br ultrathin nanosheets for enhanced photocatalytic activity

: According to the typical Sillén-structured BiOBr, a simple solvothermal method was used to successfully synthesize Sillén-structured bimetallic oxyhalide CdBiO2Br with the existence of 1-hexadecyl-3-methylimidazolium bromide ([C16mim]Br), a kind of reactive ionic liquid. The introduction of the metal cadmium, which can form Sillén-structured bimetallic oxyhalide, made the alternating structure of BiOBr originally [Bi2O2]2+ and bilayer Br- modified to that of [CdBiO2]+ and monolayer Br-. So that the distance between layer and layer is greatly shortened, which facilitates the migration and separation of photogenerated carriers and promotes the generation of more reactive oxygen species. After modification, the band positions of CdBiO2Br materials can make more full use of visible light and more favorable utilization of solar resources. As confirmed by radical trapping analysis and ESR analysis, superoxide radical (·O2 -) and hole (h+) acted the major part during photocatalysis. The possible intermediate products that appeared during the degradation progress were analyzed by LC-MS. Moreover, the generation of superoxide ions was quantitatively analyzed by nitroblue tetrazolium chloride (NBT). In this paper, we present an ultra-thin layered material for visible light catalysis, which enlightens a feasible scheme for the research and development of new layered photocatalytic materials.

Orally Administered Activated Charcoal as a Medical Countermeasure for Acute Radiation Syndrome in Rats

Activated charcoal (AC) can be taken orally as enterosorbent for treatment of pathological states related to exogenous and endogenous intoxications. Synthesized granulated AC with a highly developed active surface (SBET ~2700 m2/g) was used as a medical countermeasure (MCM) to acute radiation sickness (ARS) in rats after total body X-ray irradiation. AC demonstrates positive results in ARS treatment, as expressed in, (i) a decrease in body weight loss, (ii) a protection of bone marrow (BM) cells colony formation capacity, (iii) a reduction of BM chromosomal aberrations and small intestine and spleen tissue damage, (iv) an amelioration of white blood cell count, and (v) a mitigation of superoxide ion generation rate in the liver. AC oral prescription seems to be perspective modality of ARS treatment.

(+)-Catechin potentiates the oxidative response of Acinetobacter baumannii to quinolone-based antibiotics

(+)-Catechin is a versatile compound with its pharmacophore (catechol and resorcinol) responsible for prooxidant and antibacterial activities. In this study, we present that demonstrating the synergistic interaction between (+)-catechin and quinolone-based antibiotics, ciprofloxacin and gemifloxacin is related to reactive oxygen species generation. The minimum inhibitory concentration of (+)-catechin against Acinetobacter baumannii AB5075 were considerably lowered for ΔsodB and ΔkatG mutants. Checkerboard assay shows synergistic interactions between (+)-catechin and quinolones. (+)-Catechin amplified quinolones-induced redox imbalance by increasing superoxide ion generation, NAD+/NADH ratio and ADP/ATP ratio. Conversely, the level of reduced glutathione was significantly lowered. We conclude that (+)-catechin potentiates quinolone-based antibiotics-induced oxidative stress in A. baumannii by increasing ROS generation, energy metabolism and electron transport chain activity with a concomitant decrease in glutathione.

Ferulic acid potentiates the antibacterial activity of quinolone-based antibiotics against Acinetobacter baumannii

Ferulic acid is a cinnamic derivative of phenolic acid and its pharmacophore (catechol) is responsible for antioxidant, prooxidant and antibacterial activities. In this study, we evaluated the influence of ferulic acid on the antibacterial activity of quinolone-based antibiotics against Acinetobacter baumannii. The minimum inhibitory concentration of ferulic acid against Acinetobacter baumannii AB5075 were considerably lowered for ΔsodB and ΔkatG mutants. Checkerboard assay shows synergistic interactions between ferulic acid and quinolones. In a murine sepsis model, ferulic acid potentiated the antibacterial activities of quinolones. Ferulic acid amplified quinolones-induced redox imbalance by increasing superoxide ion generation, NAD+/NADH ratio and ADP/ATP ratio. Conversely, the level of reduced glutathione was significantly lowered. We conclude that ferulic acid potentiates the antibacterial activity of quinolone-based antibiotics against A. baumannii by increasing ROS generation, energy metabolism and electron transport chain activity with a concomitant decrease in glutathione.

Label-free electrochemical sensor to investigate the effect of tocopherol on generation of superoxide ions following UV irradiation

BackgroundGeneration of reactive oxygen species (ROS), triggered by ultraviolet radiation (UVR), is associated with carcinogenesis of the skin. UV irradiation induced superoxide anion (O2•−) is the key ROS involved in the cellular damage. The cytoprotective efficacy of an unknown anti-oxidant compound can be evaluated by analyzing the production of O2•− from treated cells.MethodsIn this study, a glass carbon electrode functionalized with nanotube@DNA-Mn3(PO4)2 composite was applied to quantitative determination of generation of highly unstable O2•− from the melanoma A375 cell line following UVR(UV, UVA and UVB). In addition, the cytoprotective efficacy of anti-oxidant α-tocopherol was evaluated by quantifying the production of O2•−.ResultsThe results showed that, UVR triggers generation of O2•− in melanoma A375 cells, and α-tocopherol is effective in diminishing the production of O2•− following UV irradiation. By comparing the conventional cell-survival assays results, we found that our simple and quick electrochemical sensing method can quantify O2•− generation through the biological activity of an anti-oxidant compound (α-tocopherol).ConclusionOur label-free electrochemical quantification method for ROS (O2•− major) in cells facing UVR stress demonstrates its potential application for high-throughput screening of anti-oxidation compounds.

Singlet-Oxygen Generation in Alkaline Periodate Solution.

A nonphotochemical generation of singlet oxygen ((1)O2) using potassium periodate (KIO4) in alkaline condition (pH > 8) was investigated for selective oxidation of aqueous organic pollutants. The generation of (1)O2 was initiated by the spontaneous reaction between IO4(-) and hydroxyl ions, along with a stoichiometric conversion of IO4(-) to iodate (IO3(-)). The reactivity of in-situ-generated (1)O2 was monitored by using furfuryl alcohol (FFA) as a model substrate. The formation of (1)O2 in the KIO4/KOH system was experimentally confirmed using electron spin resonance (ESR) measurements in corroboration with quenching studies using azide as a selective (1)O2 scavenger. The reaction in the KIO4/KOH solution in both oxic and anoxic conditions initiated the generation of superoxide ion as a precursor of the singlet oxygen (confirmed by using superoxide scavengers), and the presence of molecular oxygen was not required as a precursor of (1)O2. Although hydrogen peroxide had no direct influence on the FFA oxidation process, the presence of natural organic matter, such as humic and fulvic acids, enhanced the oxidation efficiency. Using the oxidation of simple organic diols as model compounds, the enhanced (1)O2 formation is attributed to periodate-mediated oxidation of vicinal hydroxyl groups present in humic and fulvic constituent moieties. The efficient and simple generation of (1)O2 using the KIO4/KOH system without any light irradiation can be employed for the selective oxidation of aqueous organic compounds under neutral and near-alkaline conditions.

Crystal engineering and characterization of a structure-H ionic clathrate hydrate

Ionic hydrates are known to form numerous clathrate structures in which either the cations or anions sit in cages and the counterions are incorporated into the water framework. Due to the inclusion of the ionic species, such ionic clathrate hydrates not only show many peculiar features such as metal ion encagement and superoxide ion generation, but also exhibit notable physicochemical properties such as outstanding ionic conductivity and thermal stability. Thus, the ionic clathrate hydrates are considered for their potential applicability in various fields, including those that involve solid electrolytes, gas sensors, and energy storage. In this study, we report the design, synthesis, and characterization of the first ionic clathrate hydrate of the hexagonal structure-H (Str.H) crystal type. Diethyl-dimethyl-ammonium hydroxide hydrate was synthesized with CH4 and Xe as help gases, and the crystal structure was identified by powder X-ray diffraction analysis. Further confirmation of the formation of Str.H was obtained from Raman spectroscopy and 13C, 129Xe, and 2H solid-state NMR spectroscopy. From 13C NMR and ab initio calculations, it was shown that the quaternary ion occupies the large cage of Str.H with a conformation different from that in solution, due to constraints imposed by the dimensions of the cage. The H deficiency introduced by substitution of OH– for a water molecule appears, from 129Xe NMR, to be disordered over the framework, and, from 2H NMR, to substantially increase the rate of reorientational mobility of the D atoms in the framework, over that observed for a Str.I hydrate and for ice. The Str.H hydrates are commonly more stable than other structures, thus the present findings on the ionic Str.H clathrate hydrate may offer a new approach for improving the stability of ionic clathrate hydrates for their practical application.

Stability of Superoxide Ion in Phosphonium-Based Ionic Liquids

In this work the chemical generation of superoxide ion and determination of its stability in five phosphonium-based ionic liquids has been carried out. The stability of the generated superoxide ion depended on the anion. For the trihexyl(tetradecyl)phosphonium cation, the bis(2,4,4-trimethylpentyl)phosphinate anion (IL 104) has shown a relatively good stability with a rate constant of 3.34 × 10–5 s–1 for the reaction of the superoxide ion. Triisobutyl(methyl)phosphonium tosylate has also shown moderate stability (6.8 × 10–5 s–1). The order of stability, bis(2,4,4-trimethylpentyl)phosphinate > dicyanamide (6.97 × 10–5 s–1) > Br– (7.72 × 10–5 s–1) > Cl– (12.7 × 10–5 s–1), correlates well with the order of their respective ionic volumes. On application of the generated superoxide ion for the oxidation of two organic sulfur compounds, 15% conversion of thiophene was attained in 2 h while dibenzothiophene (DBT) was found to be unreactive to the ion in IL 104. This was attributed to higher electron density on t...

Kinetics of superoxide ion in dimethyl sulfoxide containing ionic liquids

The chemical generation of superoxide ion (O2 •−) by dissolving potassium superoxide was investigated. The chemically generated O2 •− was then used to study the long-term stability of O2 •− in dimethyl sulfoxide (DMSO) containing ionic liquids (ILs) and determine the rate constants based on pseudo 1st- and 2nd-order reactions between the IL and O2 •− generated in DMSO. O2 •− was unstable in DMSO containing [S222][TFSI], [DMIm][MS], [BDMIm][TfO], [EMIm][TFSI], [EMIm][MS], [P14,666][TPTP], [P14,666][TFSI], and all pyridinium-based ILs. In contrast, O2 •− was very stable in DMSO containing [MOPMPip][TFSI], [BMPyrr][DCA], [BMPyrr][TFSI], [BMPyrr][TfO], [HMPyrr][TFSI], [MOEMPip][TPTP], [BMPyrr][TFA], [N112,1O2][TFSI], and [MOEMMor][TFSI]. This shows that these ILs can be used for different applications involving O2 •−. The reaction rate constant, total consumption, and consumption rate of O2 •− were determined. The rate constants of O2 •− in some ILs were found to follow pseudo 1st-order reaction, while in others, pseudo 2nd-order reaction kinetics were observed.

Ameliorating ER-stress attenuates Aeromonas hydrophila-induced mitochondrial dysfunctioning and caspase mediated HKM apoptosis in Clarias batrachus.

Endoplasmic reticulum (ER)-stress and unfolding protein response (UPR) has not been implied in Aeromonas hydrophila-pathogenicity. We report increased expression of the ER-stress markers: CHOP, BiP and phospho-eIF2α in A. hydrophila-infected headkidney macrophages (HKM) in Clarias batrachus. Pre-treatment with ER-stress inhibitor, 4-PBA alleviated ER-stress and HKM apoptosis suggesting ER-UPR critical for the process. The ER-Ca2+ released via inositol-triphosphate and ryanodine receptors induced calpain-2 mediated superoxide ion generation and consequent NF-κB activation. Inhibiting NF-κB activation attenuated NO production suggesting the pro-apoptotic role of NF-κB on HKM pathology. Calpain-2 activated caspase-12 to intensify the apoptotic cascade through mitochondrial-membrane potential (ψm) dissipation and caspase-9 activation. Altered mitochondrial ultra-structure consequent to ER-Ca2+ uptake via uniporters reduced ψm and released cytochrome C. Nitric oxide induced the cGMP/PKG-dependent activation of caspase-8 and truncated-Bid formation. Both the caspases converge onto caspase-3 to execute HKM apoptosis. These findings offer a possible molecular explanation for A. hydrophila pathogenicity.

Biochemical mechanisms of bornyl caffeate induced cytotoxicity in rat pheochromocytoma PC12 cells

The chemopreventive and antineoplastic activities of caffeic acid derivatives are highly dependent on the chemical structures and cancer cell types. The objective of the present study was to investigate the cytotoxicity of bornyl caffeate and the underlying molecular mechanisms in rat pheochromocytoma PC12 cells. Our initial studies demonstrated that bornyl caffeate exhibited potent cytotoxicity in PC12 cells in a concentration- and time-dependent manner. By examining the cell morphology on a fluorescence microscope and detecting the cell surface phosphoserine with Annexin V-FITC, we proposed that bornyl caffeate could induce apoptosis in PC12 cells. We tested this hypothesis by investigating the effects of bornyl caffeate on several apoptosis-related biomarkers. These experiments showed that bornyl caffeate induced the up-regulation of Bax and down-regulation of Bcl-xl, the disruption of mitochondrial membrane potential, the activation of caspase 3 and the cleavage of PARP. Mechanistic studies further revealed that bornyl caffeate caused the depletion of glutathione (GSH), generation of superoxide ion and progressive activation of p38 mitogen-activate protein kinase (MAPK) and c-Jun N-terminal kinase (JNK) in a concentration-dependent manner. In particular, GSH depletion appeared to be the most important mechanism underlying the cytotoxicity of bornyl caffeate. The preservation of the intracellular GSH contents with N-acetyl-l-cysteine (NAC), GSH and vitamin C abolished the effect of bornyl caffeate on the activation of p38 MAPK and JNK, preserved the integrity of mitochondrial membrane and ultimately rescued the cells from drug-induced cell death. These results suggest that bornyl caffeate induces apoptosis in PC12 cells via stimulating the depletion of GSH, the generation of reactive oxygen species (ROS) and the dissipation of mitochondrial transmembrane potential.

The novel NOX inhibitor 2‐acetylphenothiazine impairs collagen‐dependent thrombus formation in a GPVI‐dependent manner

NADPH oxidases (NOXs) contribute to platelet activation by a largely unknown mechanism. Here, we studied the effect of the novel NOX inhibitor 2-acetylphenothiazine (2-APT) on human platelet functional responses and intracellular signaling pathways. The generation of superoxide ions was assessed by single cell imaging on adhering platelets using dihydroethidium (DHE), while other reactive oxygen species (ROS) were detected with 5-(and-6)-carboxy-2',7'-dichlorodihydrofluorescein diacetate (CM-H(2)-DCFDA). Whole blood thrombus formation, washed platelet aggregation, integrin αIIbβ3 inside-out signalling, Syk phosphorylation and PKC activation were analysed to understand the functional consequences of NOX inhibition by 2-APT in platelets. Superoxide ion generation stimulated by platelet adhesion on collagen and fibrinogen was significantly inhibited by 2-APT in concentration-dependent manner (IC(50) = 306 nM and 227 nM, respectively), whereas cumulative ROS accumulation was not affected by this pharmacological agent. 2-APT also abolished collagen-dependent whole blood thrombus formation and washed platelet aggregation in response to collagen but not thrombin. The activation of integrin αIIbβ3 and PKC in response to the GPVI-specific agonist collagen-related peptide (CRP) was significantly reduced, whereas the same responses to thrombin were not significantly affected by 2-APT. Finally, Syk activation in response to collagen but not thrombin was inhibited by 2-APT. Taken together, our results suggest that 2-APT attenuates GPVI-specific signalling and is a novel inhibitor of collagen-induced platelet responses. Therefore, NOXs could represent a novel target for the discovery of anti-thrombotic drugs.

Generation of Superoxide Ion in Pyridinium, Morpholinium, Ammonium, and Sulfonium-Based Ionic Liquids and the Application in the Destruction of Toxic Chlorinated Phenols

Generation of superoxide ion (O2•–) was carried out in four ionic liquids (ILs) having the same anion, bis(trifluoromethylsulfonyl)imide [N(Tf)2]−, and different cations, N-hexylpyridinium [HPy]+, N-methoxyethyl-N-methylmorpholinium [MO1,1O2]+, N-ethyl-N,N-dimethyl-2-methoxyethylammonium [N112,1O2]+, and triethylsulfonium [S222]+. Cyclic voltammetry (CV) and chronoamperometry (CA) electrochemical techniques were used in this investigation. It was found that O2•– is not stable in the [HPy]+-based IL. On the other hand, CV showed that the electrochemically generated O2•– is stable in [MO1,1O2]+-, [N112,1O2]+-, and [S222]+-based ILs for the time duration of the experiment. The long-term stability of the generated O2•– was then investigated by dissolving potassium superoxide (KO2) in dimethyl sulfoxide (DMSO) in the presence of the corresponding IL. It was found that ILs containing [MO1,1O2]+ and [N112,1O2]+ offer a promising long-term stability of O2•– for various reactions to be used for several application...

Generation and stability of superoxide ion in tris(pentafluoroethyl)trifluorophosphate anion-based ionic liquids

Generation of the superoxide ion (O2−) in ionic liquids (ILs) media is one of the important areas which are currently being under investigation by several research groups worldwide. In this work, the superoxide ion was successfully generated and analyzed electrochemically using cyclic voltammetry (CV) and chronoamperometry (CA) techniques from O2 dissolved in 1-(2-methoxyethyl)-1-methylpiperidinium tris(pentafluoroethyl)trifluorophosphate [MOEMPip][TPTP] and trihexyl(tetradecyl)phosphonium tris(pentafluoroethyl)trifluorophosphate [P14,666][TPTP]. Furthermore, O2− was generated chemically by the addition of potassium superoxide to the studied ILs. UV/Vis spectrophotometer was used for testing the long term stability of the generated O2−. These results encourage more exploration on the use of these particular classes of ILs in various applications involving O2−. This study reports the first successful chemical generation of O2− in tris(pentafluoroethyl)trifluorophosphate anion-based ILs which opens the way for further related studies.

Application of 12CaO•7Al2O3 electride as a new electrode for superoxide ion generation and hydroxylation of an arylboronic acid

12CaO•7Al2O3 (C12A7) electride, which exhibits metallic conduction and 2.4eV work function, can be used as an electron emitter and chemical reagent. Herein we reveal a new application for C12A7 electride as electrode in electrochemical reactions. Cathodic reduction of oxygen at C12A7 electrode in acetonitrile generates superoxide ions (O2•−) using Bu4NClO4 as a supporting electrolyte. Iodometry reveals that this electrode shows a higher yield of O2•− ions than conventional electrodes such as Pt and glassy carbon. Moreover, O2•– ion–induced hydroxylation of p-(methylthio)phenylboronic acid using C12A7 electrode gives the corresponding phenol derivative with a yield of 90% at the charge apply of 2.5F·mol−1.