Role Of H2O2 Research Articles

In vivo hydrogen peroxide diffusivity in brain tissue supports volume signaling activity

Hydrogen peroxide is a major redox signaling molecule underlying a novel paradigm of cell function and communication. A role for H2O2 as an intercellular signaling molecule and neuromodulator in the brain has become increasingly apparent, with evidence showing this biological oxidant to regulate neuronal polarity, connectivity, synaptic transmission and tuning of neuronal networks. This notion is supported by its ability to diffuse in the extracellular space, from source of production to target. It is, thus, crucial to understand extracellular H2O2 concentration dynamics in the living brain and the factors which shape its diffusion pattern and half-life. To address this issue, we have used a novel microsensor to measure H2O2 concentration dynamics in the brain extracellular matrix both in an ex vivo model using rodent brain slices and in vivo. We found that exogenously applied H2O2 is removed from the extracellular space with an average half-life of t1/2 = 2.2 s in vivo. We determined the in vivo effective diffusion coefficient of H2O2 to be D* = 2.5 × 10−5 cm2 s−1. This allows it to diffuse over 100 μm in the extracellular space within its half-life. Considering this, we can tentatively place H2O2 within the class of volume neurotransmitters, connecting all cell types within the complex network of brain tissue, regardless of whether they are physically connected. These quantitative details of H2O2 diffusion and half-life in the brain allow us to interpret the physiology of the redox signal and lay the pavement to then address dysregulation in redox homeostasis associated with disease processes.

Photocatalytic activity of CoFe2O4/g-C3N4 nanocomposite toward degradation of different organic pollutants and their inactivity toward hydrogen production: The role of the conduction band position

Recently, graphitic carbon nitride (g-C3N4)-based composite photocatalyst has been investigated as a promising photocatalyst for degradation of organic pollutants. In this paper, a simple calcination method was used to prepare CoFe2O4/g-C3N4 p-n heterojunction photocatalysts. The morphological structure, optical, and electrochemical properties of the as-synthesized CoFe2O4/g-C3N4 p-n junction photocatalysts were characterized. Furthermore, the photocatalytic activity of the CoFe2O4/g-C3N4 p-n junction photocatalysts was evaluated not only for degradation of methyl orange (MO) but also for non-colored 4-chlorophenol (4-CP) under visible light irradiation. The 3% CoFe2O4/g-C3N4 of showed the highest photocatalytic activity that can activate H2O2 and degrade MO up to 98% in 4 h. The remarkable enhancement was mainly ascribed to the interfacial transfer of photogenerated charge carriers and the role of H2O2 in the generation of more hydroxyl radicals via photo-Fenton-like reaction. Additionally, scavenger experiments showed that hydroxyl radicals are the dominant active oxygen species responsible for the photodegradation reaction, while superoxide radicals play a minor role. Importantly, this composite showed no activity toward hydrogen production due to the positive band position of CoFe2O4. This work may provide a simple and low-cost method for large-scale production of visible-light-active photocatalyst that can be applied for environmental remediation applications.

Influence of H2O2-Induced Oxidative Stress on In Vitro Growth and Moniliformin and Fumonisins Accumulation by Fusarium proliferatum and Fusarium subglutinans.

Fusarium proliferatum and Fusarium subglutinans are common pathogens of maize which are known to produce mycotoxins, including moniliformin (MON) and fumonisins (FBs). Fungal secondary metabolism and response to oxidative stress are interlaced, where hydrogen peroxide (H2O2) plays a pivotal role in the modulation of mycotoxin production. The objective of this study is to examine the effect of H2O2-induced oxidative stress on fungal growth, as well as MON and FBs production, in different isolates of these fungi. When these isolates were cultured in the presence of 1, 2, 5, and 10 mM H2O2, the fungal biomass of F. subglutinans isolates showed a strong sensitivity to increasing oxidative conditions (27–58% reduction), whereas F. proliferatum isolates were not affected or even slightly improved (45% increase). H2O2 treatment at the lower concentration of 1 mM caused an almost total disappearance of MON and a strong reduction of FBs content in the two fungal species and isolates tested. The catalase activity, surveyed due to its crucial role as an H2O2 scavenger, showed no significant changes at 1 mM H2O2 treatment, thus indicating a lack of correlation with MON and FB changes. H2O2 treatment was also able to reduce MON and FB content in certified maize material, and the same behavior was observed in the presence and absence of these fungi, highlighting a direct effect of H2O2 on the stability of these mycotoxins. Taken together, these data provide insights into the role of H2O2 which, when increased under stress conditions, could affect the vegetative response and mycotoxin production (and degradation) of these fungi.

Insights into the role of in-situ and ex-situ hydrogen peroxide for enhanced ferrate(VI) towards oxidation of organic contaminants

Recently, several studies have been conscious of the promotion effect of hydrogen peroxide (H2O2), a self-decay product of ferrate (Fe(VI)), on Fe(VI) to oxidize contaminations, but the pivotal activation mechanism has not been thoroughly evaluated. This work aims to compare and reveal the promoting mechanism of H2O2 in Fe(VI) and Fe(VI)−H2O2 processes, and to illustrate the practical use potential of Fe(VI)−H2O2 system. Many lines of evidence verified the involvement of •OH and O2•− in pollutant degradation were excluded in Fe(VI) and Fe(VI)−H2O2 systems, meaning that high dosage of H2O2 cannot trigger an activation pathway different from in-situ H2O2. The better oxidation performance of the Fe(VI)−H2O2 system than Fe(VI) alone was ascribed to the catalytic role of in-situ and ex-situ H2O2, which can directly and/ or indirectly facilitate the formation of Fe(IV) and Fe(V). Considering the structural similarity of peroxymonosulfate (PMS) and peroxydisulfate (PDS) with H2O2 as well as their universality in water pollutant remediation, the oxidation properties and reactive oxidants of Fe(VI)−PMS and Fe(VI)−PDS processes were also examined. Besides, the Fe(VI)−H2O2 system suffered from less restriction by inorganic ions and natural organic matter, and exhibited satisfactory pollutant removal effects in real water. Overall, this work provides a further and comprehensive cognition about the role of H2O2 in Fe(VI) and Fe(VI)−H2O2 systems.

Induction of tolerance to cryogenic protocols in Solanum tuberosum by salicylic acid is mediated by enzymatic antioxidant activity and hydrogen peroxide

ABSTRACT Two applications of cryogenic protocols are cryotherapy and cryopreservation for virus cleaning and germplasm storage. They are based on exposing explants to ultra-low temperature (−196°C) in liquid nitrogen. Ultra-low temperature in cryogenics implies abiotic stress, leading to the production of reactive oxygen species (ROS), which are the main reason for the low survival and death of explants. Hydrogen peroxide (H2O2) is an important ROS produced by stress. Enzymatic antioxidants like catalase (CAT) and peroxidase (POX) are essential for avoiding damage due to H2O2, which is a primary signal against stress. Salicylic acid (SA) is involved in tolerance to stress-like cryogeny. Information about the relationship between SA-cryogeny-antioxidant enzymatic activity is scarce. The objective was to evaluate the induction of cryogeny tolerance by SA associated with antioxidant activities like CAT, POX, and H2O2 and proline accumulation in tissue, during cryogenic protocols in two clones of potato (Solanum tuberosum L.). SA-induced cryogenic tolerance in both clones, mediated by reducing CAT enzymatic activity, higher H2O2 content, proline accumulation and higher water potential before cryogeny. Enhanced CAT and POX activities after cryogeny were related to decreased H2O2 content and higher survival. Results suggest the signalling role of H2O2 in the induction of tolerance to cryogenic stress.

Electrochemical Insight into the Role of H2O2 in Galvanostatic Passivation of AISI 316L Austenitic Stainless Steel in Citric Acid Electrolyte

Electrochemical Insight into the Role of H2O2 in Galvanostatic Passivation of AISI 316L Austenitic Stainless Steel in Citric Acid Electrolyte

Salt tolerance induced by hydrogen peroxide priming on seed is related to improvement of ion homeostasis and antioxidative defense in sunflower plants

Salt-induced redox and ion imbalance may lead to increased oxidative stress and impair the plant growth. However, among the many reactive oxygen species (ROS) produced under stress, hydrogen peroxide (H2O2) plays a central role in several signal transduction pathways triggering a series of physiological mechanisms and increase plant tolerance to salt stress. Thus, this study aimed to evaluate the changes in the balance of inorganic and organic solutes induced by seed priming with H2O2 in leaves and roots of sunflower plants grown under salt stress. In this study, six treatments were tested: T1 - control (absence of NaCl and absence of H2O2); T2 - salt control (presence of 100 mM NaCl and absence of H2O2); T3 − 100 mM H2O2 (12 h) + 100 mM NaCl; T4 − 10 mM H2O2 (12 h) + 100 mM NaCl; T5 − 1 mM H2O2 (24 h) + 100 mM NaCl; T6 − 0.1 mM H2O2 (36 h) + 100 mM NaCl. Our results show that, the role of H2O2 in increase of the salt tolerance is directly associated with reduction on Na+ (on average 46%) and Cl- (on average 24%) contents in the leaves, besides a positive regulation of K+ and NO3 - absorption (for three harvests). In addition, H2O2 priming also decreased the oxidative damage, mainly by increasing the activity of catalase enzyme (CAT) in leaves (on average 49% at 2nd and 3rd harvests) and roots (on average 39% at 3rd harvest).

Abstract 1021: A novel interaction between hydrogen peroxide metabolism and LDL-uptake controls immunergulatory properties in human dendritic cells - Potential implications for tumor immune escape

Abstract Introduction: Recent studies indicate that depletion of reactive oxygen species (ROS) such as hydrogen peroxide (H2O2) may actually allow tumors to evade immunological rejection prompting us to analyze the impact of H2O2-depletion on dendritic cells (DCs) as they play a pivotal role in tumor immunology. Methods: Primary human monocytes from healthy donors were differentiated/maturated to DCs w/o concomitant enzymatic H2O2-depletion (i.e. purified catalase). DCs were then analyzed for the expression of typical maturation-markers (i.e. CD80/86) and their functionality (i.e. induction/suppression of T-cell proliferation, secretion of distinct cytokines). To identify the underlying mechanisms for the differences observed we analyzed the role of H2O2- and cholesterol-metabolism as they are interconnected in monocyte-driven phagocytosis. Results: Depletion of H2O2 not only impaired DC-maturation (i.e. impaired upregulation of CD80/86), but additionally induced immunosuppressive properties such as suppression of T-cell proliferation via IDO, both typical features of so called regulatory DCs found in the tumor-microenvironment. However, the impact of H2O2-depletion throughout DC differentiation/maturation appears to be rather complex: Thus differentiated/matured DCs did not only feature properties of pro-tumorigenic macrophages (i.e. CD163- and PAI-1-expression) but also were capable of inducing IL10/IL17 double-expressing T-cells which have been reported to contribute to tumor-immune-escape in AML. Paradoxically, extracellular H2O2-depletion resulted in increased intracellular H2O2-levels, and increased LDL uptake, which has been reported to potentially affect immunological tumor rejection. Finally, we were able to establish a direct link between H2O2-production, LDL uptake, and induction of immunosuppressive DCs as both, inhibition of LDL uptake and depletion of intracellular H2O2, restored maturation and abrogated immunosuppressive properties. Conclusion: Alongside with earlier findings such as the ability of hepatic stromal cells to induce myeloid-derived suppressor cells via contact-dependent H2O2-depletion, the here presented study sheds new light on the role of H2O2 in tumor-immunology. Importantly, our findings unravel a so far unrecognized interaction between H2O2- and LDL-metabolism controlling distinct properties in DCs, which might in return explain the association between lipid metabolism and impaired immunity in some tumors. Bearing in mind that tumors employ several mechanisms to deplete ROS incl. H2O2 we believe that these findings may contribute to the development of novel (immune-) therapeutic approaches for cancer patients. Citation Format: Ann-Katrin Menzner, Tanja Rottmar, Simon Voelkl, Jacobus J. Bosch, Dimitrios Mougiakakos, Andreas Mackensen, Yazid J. Resheq. A novel interaction between hydrogen peroxide metabolism and LDL-uptake controls immunergulatory properties in human dendritic cells - Potential implications for tumor immune escape [abstract]. In: Proceedings of the Annual Meeting of the American Association for Cancer Research 2020; 2020 Apr 27-28 and Jun 22-24. Philadelphia (PA): AACR; Cancer Res 2020;80(16 Suppl):Abstract nr 1021.

The interplay between oxidative stress and bioenergetic failure in neuropsychiatric illnesses: can we explain it and can we treat it?

Nitro-oxidative stress and lowered antioxidant defences play a key role in neuropsychiatric disorders such as major depression, bipolar disorder and schizophrenia. The first part of this paper details mitochondrial antioxidant mechanisms and their importance in reactive oxygen species (ROS) detoxification, including details of NO networks, the roles of H2O2 and the thioredoxin/peroxiredoxin system, and the relationship between mitochondrial respiration and NADPH production. The second part highlights and identifies the causes of the multiple pathological sequelae arising from self-amplifying increases in mitochondrial ROS production and bioenergetic failure. Particular attention is paid to NAD+ depletion as a core cause of pathology; detrimental effects of raised ROS and reactive nitrogen species on ATP and NADPH generation; detrimental effects of oxidative and nitrosative stress on the glutathione and thioredoxin systems; and the NAD+-induced signalling cascade, including the roles of SIRT1, SIRT3, PGC-1α, the FOXO family of transcription factors, Nrf1 and Nrf2. The third part discusses proposed therapeutic interventions aimed at mitigating such pathology, including the use of the NAD+ precursors nicotinamide mononucleotide and nicotinamide riboside, both of which rapidly elevate levels of NAD+ in the brain and periphery following oral administration; coenzyme Q10 which, when given with the aim of improving mitochondrial function and reducing nitro-oxidative stress in the brain, may be administered via the use of mitoquinone, which is in essence ubiquinone with an attached triphenylphosphonium cation; and N-acetylcysteine, which is associated with improved mitochondrial function in the brain and produces significant decreases in oxidative and nitrosative stress in a dose-dependent manner.

Deciphering the possible role of H2O2 in methylmercury-induced neurotoxicity in Xenopus laevis

BackgroundsMethylmercury (MeHg) is regarded as a developmental neurotoxicant but the detailed mechanism remains not completely clear.MethodsThe Xenopus laevis embryos were exposed to methylmercury chloride and the expression of neurodevelopment and oxidative stress genes was detected by qRT-PCR or Western blotting. PC12 cells were exposed to various levels of H2O2, and then cell cycle, neurite length, neurodevelopment-related genes, protein expression of apoptosis and autophagy were detected.ResultsThe genes of neurodevelopment and oxidative stress were disrupted by methylmercury chloride and H2O2 were increased interestingly in X. laevis embryos. Then, PC12 cells were exposed to H2O2 and the results showed the cell cycle, neurite length, and neurodevelopment-related genes, the proteins apoptosis and autophagy were changed.ConclusionThese results supported the idea that neurodevelopment-related gene expression was regulated by oxidative stress and that apoptosis and autophagy pathways were activated by H2O2 and involved in methylmercury neurotoxicity.

BK channel openers NS1619 and NS11021 reverse hydrogen peroxide-induced membrane potential changes in skeletal muscle

Large conductance calcium-activated potassium (BK) channels play a crucial role in the repolarization and after-hyperpolarization phases of the cell membrane. The channel openers are also used in treatment of some diseases, including hypo/hyperkalemic periodic paralysis. However, little is known about the effects of BK channels and the channel activators on membrane potentials in skeletal muscle. In addition, the effects of reactive oxygen species (ROS) on BK channels in skeletal muscle are also unknown. Therefore, the aim of this study was to determine the effects of BK channel openers and ROS on membrane potentials in skeletal muscle fibers. For this purpose, resting membrane potentials and action potentials (AP) of frog gastrocnemius muscles were recorded in the presence of commonly used BK channel openers NS1619 and NS11021, H2O2 (a type of ROS), and both using intracellular microelectrode technique. The channel activators significantly and dose-dependently decreased amplitude and increased rise time of AP but did not impact repolarization. The presence of H2O2 plus NS1619 or NS11021 resulted in significant change because the channel openers completely reversed the deleterious effects of hydrogen peroxide on the repolarization phase of AP in skeletal muscle fibers. In the present study, the contributions of BK channel activation and the modulatory role of H2O2 on membrane potentials was demonstrated in skeletal muscle fibers, for the first time. Moreover, it should be noted that BK channel openers should be used in the treatment of reactive oxygen species-induced skeletal muscle diseases.

Supercritical Fenton Oxidation: New Advanced Oxidation Technology

AbstractThe roles of H2O2 in supercritical water oxidation (SCWO) were investigated. The results showed that some of the H2O2 could persist for a short time in SCW, and organic pollutants were main...

The Role of H2O2 and K2S2O8 as Oxidizing Agents for Accelerated Corrosion Testing

In this work, the application of hydrogen peroxide (H2O2) and potassium persulfate (K2S2O8) in accelerated corrosion testing was considered. H2O2 is already used as an accelerant in the standard immersion test ASTM G110, and K2S2O8 is an oxidizing agent that shows promise for corrosion testing applications. A Koutecky-Levich approach was used to investigate the cathodic kinetics of both oxidizing agents as well as dissolved oxygen (O2). Cathodic kinetics for O2, H2O2, and S2O82− were faster when measured on a platinum electrode than when measured on an AA2060-T3 electrode. This difference was attributed to the additional limit to cathodic kinetics posed by the protective oxide film on aluminum. H2O2 was a more potent accelerant than K2S2O8 at a concentration of 0.1 M due to the faster cathodic kinetics of H2O2 on aluminum. However, K2S2O8 was more convenient to use in a laboratory setting due to its stability during storage. The severity of tests using K2S2O8 was increased by lowering the solution pH to 2.28. At the low solution pH, cathodic kinetics and extent of attack increased.

Role of H2O2 on photosynthetic characteristics of soybean genotypes under low water input

Soybean is subjected to abiotic stresses that immensely affect its productivity during its lifespan and threaten food security globally. Recent research recommends that chemical substances could be applied to plants as an alternative to traditional agriculture to better abide abiotic stresses. Hydrogen peroxide (H2O2) is a potential agent that can serve for this purpose. Up to today, responses of exogenous H2O2 on photosynthetic machinery in plants exposed to drought is poorly investigated. Therefore, the effects of exogenous low dose H2O2 on plant chlorophyll fluorescence in two soy bean genotypes (Glycine max L. Merrill), 537 (tolerant) and 520 (susceptible), under drought were evaluated. Drought which we had found significantly reduced water potential of leaves and photosynthetic pigment concentration in two genotypes, did not cause change in Fv/Fm and ΦPSII of tolerant genotype, contrarily subsided qP and ETR values. However, Fv/Fm, ΦPSII, qP and ETR failed in susceptible genotypes under drought. Increases in NPQ were determined under stress in both genotypes. Exogenous H2O2 mitigated the drought-induced impairment in photosystem II efficiency in both genotypes. This data indicates that low dose H2O2 further enhanced the tolerance to drought via regulation of the photochemical process in both genotypes.

A Role for H2O2 and TRPM2 in the Induction of Cell Death: Studies in KGN Cells.

Recent studies showed that KGN cells, derived from a human granulosa cell tumor (GCT), express NADPH oxidase 4 (NOX4), an important source of H2O2. Transient receptor potential melastatin 2 (TRPM2) channel is a Ca2+ permeable cation channel that can be activated by H2O2 and plays an important role in cellular functions. It is also able to promote susceptibility to cell death. We studied expression and functionality of TRPM2 in KGN cells and examined GCT tissue microarrays (TMAs) to explore in vivo relevance. We employed live cell, calcium and mitochondrial imaging, viability assays, fluorescence activated cell sorting (FACS) analysis, Western blotting and immunohistochemistry. We confirmed that KGN cells produce H2O2 and found that they express functional TRPM2. H2O2 increased intracellular Ca2+ levels and N-(p-Amylcinnamoyl)anthranilic acid (ACA), a TRPM2 inhibitor, blocked this action. H2O2 caused mitochondrial fragmentation and apoptotic cell death, which could be attenuated by a scavenger (Trolox). Immunohistochemistry showed parallel expression of NOX4 and TRPM2 in all 73 tumor samples examined. The results suggest that GCTs can be endowed with a system that may convey susceptibility to cell death. If so, induction of oxidative stress may be beneficial in GCT therapy. Our results also imply a therapeutic potential for TRPM2 as a drug target in GCTs.

Catalytic/inhibitory effect of the joint presence of two dyes on its destruction by underwater plasma processes: a tool for optimization parameters of treatment

The underwater plasma was used for the destruction of two-dye mixture. The Direct Blue azo dye and xanthene dye of Rhodamine 6G used as the model pollutants. The concentration of one of them is varied for modeling the processes in which one of the classes of the dye exceeded other dyes. The catalytic/inhibitory effect of the joint presence of two dyes is studied. The effect of initial temperature and the role of H2O2 in the mechanism of destruction were also investigated. It was established that the processes of decay of organic dyes proceed through the stages of the formation of intermediate products, which are catalysts or inhibitors of further degradation processes. An increase in the temperature of the solution has almost no effect on the degree of decolorization of the solution of the dye mixture. It is established that the destruction of Direct Blue 1 occurs under the action of hydrogen peroxide or HO2 radicals, while Rhodamine 6G is destroyed by interaction with hydroxide radicals. The comparison of energy yield values with published data showed that underwater plasma is an effective method for removing the organic dyes from wastewater.

Enhanced photocatalytic decolorization of Congo red dye with surface-modified zinc oxide using copper(II)–amino acid complex

Photocatalytic decolorization of Congo red dye has been investigated using surface-modified ZnO nanoparticles by adsorbing copper(glycinato) complex on the surface of nanosized ZnO. The complex-adsorbed photocatalyst is shown to exhibit enhanced photodecolorization of the dye compared to the pure ZnO nanoparticles. Effect of catalyst dose, initial dye concentration, and role of H2O2 as oxidizing agent has been studied in order to optimize the condition for efficient decolorization. The nanosized ZnO was prepared by precipitation method onto which the amino acid complex was adsorbed. The synthesized catalysts were characterized by XRD, UV, FTIR, SEM, and EDAX. Comparative evaluation of photodecolorization of the dye was investigated for both the nanosized ZnO and the complex-adsorbed ZnO nanoparticles under optimized conditions.

Decolorization effect and related mechanism of atmospheric pressure plasma jet on Eriochrome Black T.

In this study, Eriochrome Black T (EBT) in water was decolorized by means of argon atmospheric pressure plasma jet (APPJ), which showed great decolorization performance. The results showed that the relatively high decolorization rate (approximately 80%) was obtained after plasma treatment for 6 min. Changes to some reactive oxygen and nitrogen species (RONS) in the liquid phase were detected. The contents of peroxide, HO·, O2 -·, and NO· in the plasma-treated EBT solution were much less than those in the activated water. The roles of H2O2 and HO· in the decolorization of EBT solution were explored by evaluating the effects of their scavengers, and by exploring the direct effect of H2O2. The results indicated that reactive oxygen species (ROS), especially HO· and O2 -·, played significant roles in the decolorization of the EBT solution. Analysis of degradation by-products indicated that plasma discharge could destroy the azo bond first and gradually break the aromatic rings of EBT molecules into small molecular compounds.

SCC evaluation of a 2297 Al-Li alloy rolled plate using the slow-strain rate technique

The stress corrosion cracking (SCC) susceptibility of 2297 Al-Li alloy in 1 M NaCl + 0.01 M H2O2 solution (CP solution) and 1 M NaCl + 0.01 M H2O2 + 0.6 M Na2SO4 solution (CPS solution) was investigated by slow-strain rate tests at various strain rates ranging from 10−5 s−1 to 10−7 s−1. The roles of H2O2 and SO42− in the corrosion process were estimated by potentiodynamic polarization and electrochemical impedance spectroscopy. 2297 Al-Li alloy does not fracture ascribed to SCC in CP solution, while it undergoes SCC in CPS solution. In CPS solution, with a decreasing strain rate from 10−5 s−1 to 10−7 s−1, the SCC susceptibility firstly rises and then declines exhibiting a peak value at a strain rate of 10−6 s−1. H2O2 promotes the active dissolution while SO42− lowers the corrosion rate. The SCC fracture is associated with a decline in the dissolution rate of the crack tip by SO42−, which leads to stress concentration. In CPS solution, a reduction in the local dissolution rate of the crack tip leads to stress concentration, resulting in SCC fracture. As the preferred initiation site for a crack, pits also show a noteworthy effect on SCC of 2297 Al-Li alloy.

Effects of H2O2 generation over visible light-responsive Bi/Bi2O2−xCO3 nanosheets on their photocatalytic NOx removal performance

The photocatalytic removal of gaseous NOx is commonly accompanied by secondary pollution, which necessitates the development of highly efficient nanostructured catalysts with a decreased propensity to toxic intermediate production. Herein, we describe the synthesis of plasmonic Bi/Bi2O2−xCO3 and demonstrate the presence of surface oxygen vacancies therein, revealing that the maximal NOx removal efficiency of Bi/Bi2O2−xCO3 under visible light irradiation reached 50.5% and exceeded that of a commercial photocatalyst, while the production of toxic NO2 as a by-product was completely suppressed (the selectivity reached up to 98%). In-situ introduction of plasmonic Bi on the surface of Bi2O2−xCO3 promoted the generation of H2O2 by capturing electrons from the defect states of Bi2O2−xCO3 via the two-electron reduction of O2 and thus inhibited NO2 production (as confirmed by scavenger experiments), additionally broadening the light absorption range of the above photocatalyst. Moreover, surface oxygen vacancies in Bi–O layers provided a channel for electron transfer between Bi and Bi2O2−xCO3, which resulted in increased charge separation efficiency (maximum photocurrent = 1.1 μA cm−2, 14.5 times higher than that of pristine Bi2O2CO3). Furthermore, the toxicity assessment authenticated good biocompatibility of Bi/Bi2O2−xCO3. Thus, this study sheds light on the possible roles of H2O2 in NOx degradation and provides an efficient surface engineering strategy to prepare highly reactive and selective photocatalysts.