H2O2 Stability Research Articles

Density functional study of the electronic, bonding, elastic and infrared properties of tetragonal H2O2 ice

Hydrogen peroxide is one of the most important commercially used oxidant and exists widely in the environment. It crystallizes in a tetragonal phase via hydrogen bond at around −0.89 °C. However, many of its fundamental properties are still not well studied. To investigate systems containing hydrogen bond, van der Waals correction must be considered. In this work, we tested a series of local and non-local van der Waals corrections within the frame of density functional theory. The optPBE-vdW and the vdW-DF-CX functionals are found to be the best ones based on the relaxed lattice parameters. Then the electronic, bonding, elastic, infrared, piezoelectric and dielectric properties are studied and discussed. The results reveal that tetragonal H2O2 is an indirect band gap insulator. Bond critical point analysis, reduced density gradient analysis and crystal orbital Hamilton population analysis uncover that the H-O···H bonds are moderate hydrogen bonds, which contribute most to the formation of the crystal. The interactions between the O atoms of neighbouring H2O2 molecules also have a bit contribution. Elastic stability of tetragonal H2O2 is confirmed and its elastic anisotropy is illustrated by directional bulk and shear moduli. The vibrational modes at the Brillouin zone center are assigned, and their frequencies and eigen-displacements are calculated. Additionally, its infrared spectrum is simulated. Its Born effective charges, piezoelectric and dielectric coefficients are also obtained and discussed.

The interplay of low H2O2 doses, lytic cyanophage, and Microcystis aeruginosa: Implications for cyanobacterial bloom control and microcystin production/release

Low H2O2 doses can suppress cyanobacterial blooms without damaging non-target species but enable undesirable regrowth. Besides, the role of cyanophage in preventing regrowth after low H2O2 exposure remains unclear. Applying phages to cyanobacteria pre-exposed to low H2O2 in early growth stages may improve host removal and reduce microcystin (MC) production/release. Lytic cyanophage MDM-1 with a 172 PFU/cell burst size, 2-day short latent period against MCs-producing Microcystis, shows high H2O2 stability. Low H2O2 (1 to 2.5 mg/L) doses significantly (p < 0.05) inhibited Microcystis aeruginosa growth rate, biofilm and MCs concentration reduction in a dose-dependent manner but regrowth occurred at all concentrations. Phage treatment eliminated cells without H2O2 pretreatment within 3 days and reduced MC production. H2O2-pretreated M. aeruginosa cells altered the phage dynamics, affecting adsorption, latency, production, and cell lysis in response to H2O2-induced oxidative stress. At 1.5 mg H2O2/L pretreatment, cells were eliminated with reduced MC production, like untreated cells. H2O2 pretreatment with 2.0 and 2.5 mg/L resulted in an extension of the phage absorption phase and the latent period. This was accompanied by a reduction in lysis efficacy, attributed to the increased ROS production. At 2.5 mg H2O2/L, 17.10 % of phages remain un-adsorbed, with cell lysis rate dropped from 0.89 d−1 to 0.26 d−1 compared to the untreated control. The highest phage titer (70 %) was obtained with 1.5 mg/H2O2 pretreated cells. This study emphasizes that low-dose H2O2 eliminates Microcystis but severely affects phage lysis and MCs release depending on H2O2-induced ROS levels. It is a crucial consideration when using phages to control cyanobacterial blooms with H2O2-induced stress.

Flow-Through Electrochemical Membrane Reactor with a Self-Supported Carbon Membrane Electrode for Highly Efficient Synthesis of Hydrogen Peroxide.

In situ electroreduction of O2 to H2O2 by using electrons as reagents is known as a green process, which is highly desirable for environmental remediation and chemical industries. However, the development of a cost-effective electrode with superior H2O2 synthesis rate and stability is challenging. A self-supported carbon membrane (CM) was prepared in this study from activated carbon and phenolic resin by carbonization under a H2 atmosphere. It was employed as the cathode to build a flow-through electrochemical membrane reactor (FT-ECMR) for electrosynthesis of H2O2. The results showed that the CM had a small pore size (34 nm), a high porosity (42.3%), and a high surface area (450.7 m2 g-1). In contrast to most of the state-of-the-art self-supported carbon electrode reported in the previous works, the FT-ECMR exhibited a high concentration of continuous and stable H2O2 electrosynthesis (1042 mg L-1) as well as a H2O2 synthesis rate of 5.21 mg h-1 cm-2. It had also demonstrated a high oxygen conversion (0.37%) and current efficiency (88%). The outstanding performance of the FT-ECMR for H2O2 synthesis was attributed to the enhanced mass transfer of the reactor, the existence of a relatively high surface area of CM, and the abundant disordered carbon structures (sp3-C, defects, and edges). In conclusion, our work highlighted using the FT-ECMR with the CM to synthesize H2O2 efficiently and cost-effectively.

Electrochemical Cell for in-Situ Synthesis of Hydrogen Peroxide in Household Washing Machines

Hydrogen peroxide (H2O2) is used as bleaching agent in household appliances like washing machines. For the bleaching of laundry with H2O2, an alkaline environment is required in the washing machine, which is ensured by the use of an heavy-duty detergent. In powdered heavy-duty detergents for washing machines, H2O2 is provided in form of sodium percarbonate, which releases H2O2 as soon as it is dissolved in water. As long-term stability of H2O2 in liquids requires acidic environment, no sufficient amount of H2O2 based bleach can be stored in liquid heavy-duty detergents, resulting in a lower bleaching efficiency for laundry cleaning. However, liquid heavy-duty detergents can be dosed fully automatically in washing machines, which is convenient for the user and can reduce the detergent consumption by optimizing dosing amount [1]. To take advantage of a fully automatic dosing system and at the same time obtain an effective heavy-duty detergent with bleach capability, an additional in-situ bleach source is required. An attractive route for the in-situ production of H2O2 is the electrochemical reduction of oxygen (O2) at a carbon-based cathode in a flow cell. The use of a gas diffusion electrode (GDE) results in higher production rates by directly supplying gaseous O2 to the reaction site compared to a submerged cathode where O2 is dissolved in the electrolyte [2,3]. As evidenced by the lack of literature, this kind of a specific application-related flow cell design for the use in a washing machine has not yet been developed.Therefore, a compact and simple electrochemical flow cell was developed that can provide sufficient H2O2 quantities within the time scale of a washing cycle and can be installed in a washing machine. The novel cell consists of an electrolyte reservoir, which is integrated within the cell and is separated from the dimensionally stable anode (DSA) by a divided wall. The expanded metal design of the DSA allows a zero gap arrangement by allowing the separator to lie directly on the anode. Between separator and carbon-based GDE, the electrolyte can be pumped in a circuit via the reservoir. A three-way valve allows the electrolyte accumulated with H2O2 to be discharged to the washing machine. The GDE is supplied with atmospheric O2 from the non-anode-facing side. During operation, the cell is first filled with electrolyte via the filling hole. As soon as the anode chamber (between the anode and the divided wall) is completely filled, the liquid can flow over the divided wall and fill the reservoir. Subsequently, the circulation pump and the air supply of the GDE are started and the current is applied. During electrolysis, the H2O2 is produced in the GDE and accumulates in the circulated electrolyte. The divided wall and the separator prevent the direct oxidation of H2O2 at the anode. The O2 produced at the anode can escape via the gas vent. After a sufficient amount of H2O2 has been generated in the electrolyte, electrolysis is stopped and the H2O2-solution is pumped into the drum of the washing machine via the 3-way valve.The transient H2O2 faradaic efficiency and energy consumption were compared to literature data. The combination of in-situ H2O2 production with liquid heavy-duty detergent was compared to a solid heavy-duty detergent using a standard soiled cotton textiles test.[1] Smulders, E. (2001), Laundry Detergents, Wiley-VCH; 1. Edition.[2] Pérez, J. F., et al. (2016), Electroch. Com. 71, 65–68.[3] Muddemann, T., et al. (2021), Proc. 9, 1482. Figure 1

Fluorination of Covalent Organic Framework Reinforcing the Confinement of Pd Nanoclusters Enhances Hydrogen Peroxide Photosynthesis.

Metal-isolated clusters (MICs) physically confined on photoactive materials are of great interest in the field of photosynthesis of hydrogen peroxide (H2O2). Despite recent important endeavors, weak confinement of MICs in the reported photocatalytic systems leads to their low catalytic activity and stability. Herein, we report a new strategy of fluorinated covalent organic frameworks (COFs) to strongly confine Pd ICs for greatly boosting the photocatalytic activity and stability of H2O2 photosynthesis. Both experimental and theoretical results reveal that strong electronegative fluorine can increase the metal-support interaction and optimize the d-band center of Pd ICs, thus significantly enhancing the stability and activity of photocatalytic H2O2. An optimal TAPT-TFPA COFs@Pd ICs photocatalyst delivers a stable H2O2 yield rate of 2143 μmol h-1 g-1. Most importantly, the as-made TAPT-TFPA COFs@Pd ICs exhibit high catalytic stability over 100 h, which is the best among the reported materials.

Improving hydrogen peroxide stability of a dye-decolorising peroxidase from Irpex lacteus F17 by site-directed mutagenesis

Il-DyP4, a dye-decolorizing peroxidase (DyP) from Irpex lacteus F17, has a strong ability to oxidise harmful aromatic compounds, implying application potential in the field of environmental protection. However, the low H2O2 stability of Il-DyP4 hinders its practical application. To improve the H2O2 stability of Il-DyP4, oxidation-sensitive amino acids including three Met, one Cys and ten Tyr residues were mutated to less easily oxidizable residues such as Leu, Val and Phe by site-specific mutagenesis. Mutation of the M207 site, located on the surface of the enzyme and far away from the haem group, improved H2O2 stability by 5.3-fold or more. In addition, Y234, also on the enzyme surface, was replaced with Phe and the Y234F mutant displayed 7.3-fold increased H2O2 stability. Furthermore, mutants M207V and Y234F were selected for the decolorization of various types of synthetic dyes, revealing high decolorization activities, especially for M207V with enhanced catalytic activity. The stable DyP mutant M207V has the potential for decolorization of industrial dye wastewater.

Oxidative dissolution of (U,Ce)O2 materials in aqueous solutions containing H2O2

Homogeneous and heterogeneous U1-xCexO2 (with 0≤ x≤ 0.25) materials were prepared via wet and dry chemistry routes, respectively before being submitted to dynamic leaching experiments. The feeding solution containing 0.20 mmol.L−1 H2O2 was kept under air and renewed to guarantee the stability of H2O2 during the experiment. Normalized alteration rates were determined from U concentration in the leachates. For homogeneous (U,Ce)O2 materials, the dissolution rate was divided by a factor of 3 when increasing the Ce content from 0.08 to 0.25. Surface characterizations revealed that studtite precipitated all over UO2 pellet surface and only on the UO2 grains of heterogeneous U0.92Ce0.08O2 samples. The behaviour of this heterogeneous material was similar to that observed for (U,Pu)O2 in the same conditions, which revealed the reliability of cerium as a plutonium analogue.

A mutant R70V/E166A of short manganese peroxidase showing Mn2+-independent dye decolorization.

Il-MnP1, a short-type manganese peroxidase from Irpex lacteus F17, can oxidize some substrates in the absence of Mn2+, but the catalysis was much lower than in the presence of Mn2+. Here, we report a mutant R70V/E166A of Il-MnP1 with some unique properties, which possessed clearly higher catalysis for the decolorization of anthraquinone and azo dyes in the absence of Mn2+ than that of Il-MnP1. Importantly, the optimum pH of R70V/E166A for decolorization of anthraquinone dyes (Reactive Blue 19, RB19) was 6.5, and the mutant achieved high decolorization activities in the range of pH 4.0-7.0, whereas Il-MnP1 only showed decolorization for RB19 at pH 3.5-4.0. In addition, the optimum H2O2 concentration of R70V/E166A for RB19 decolorization was eight times that of Il-MnP1 and the H2O2 stability has improved 1.4 times compared with Il-MnP1. Furthermore, Mn2+ competitively inhibited the oxidation of RB19 by R70V/E166A, explaining the higher catalytic activity of the mutant R70V/E166A in the absence of Mn2+. Molecular docking results suggested that RB19 binds to the distal side of the heme plane in mutant R70V/E166A, which extended from the heme δ-side to the heme γ-side, and close to the mutated residues of R70V and E166A, whereas RB19 could not access the heme pocket of Il-MnP1 due to the steric hindrance of the side-chain group of Arg 70. Thus, this study constructed a useful mutant R70V/E166A and analyzed its higher Mn2+-independent activity, which is very important for better understanding the Mn2+-independent catalytic mechanism for short manganese peroxidases. KEY POINTS: • The mutant R70V/E166A of atypical MnP1 of I. lacteus F17 shows unique catalytic properties. • At pH 6.5, the R70V/E166A had a strong ability to decolorize anthraquinone dyes in the absence of Mn2+. • The binding sites of Reactive Blue 19 in mutant R70V/E166A were elucidated.

In-situ monitoring of hydrogen peroxide production at nickel single-atom electrocatalyst

Electrochemical oxygen reduction reaction (ORR) to hydrogen peroxide (H2O2) is a common method to address the growing demands of H2O2. To map a clear understanding of structure–activity relationship of electrocatalyst for H2O2 production, it is necessary to real-time quantitative monitor of H2O2 in the initial production process. However, we found that the common off-line methods such as spectrophotometry, titration, etc., are not reliably during in-situ ORR process. Here, a simple and real-time simultaneous electrochemical production and determination of H2O2 system is constructed by using a dual-functional nickel (Ni) single-atom electrocatalyst. The electro-production part is conducted with a DC power supply, air pump, and dual-electrode system, while the electro-detection part consists of a three-electrode system. Compared with traditional off-line H2O2 measure methods, the present on-line determination of H2O2 protocol provides more reliable results in the quantitative monitoring of H2O2, and with a wide detection concentration range from 20 pM to 22.2 mM and a low detection limit of 6.87 pM. NiOOH on single Ni site is an important intermediate for efficient detection of H2O2 in alkaline medium. The Ni-SAC sensor also shows well anti-interferential and selective ability, high reproducibility and stability of H2O2 sensing up to 12 days. This simple-to-operate method offers a new window to record a reliable structure–activity relationship on electrocatalyst engineering in electrochemistry.

Two‐electron Oxygen Reduction Reaction on Nanocarbon Materials for Onsite H2O2 Electrochemical Synthesis: Selectivity Enhancement via Oxygen and Nitrogen co‐Doping

AbstractProduction of hydrogen peroxide (H2O2) through the two‐electron pathway of electrocatalytic oxygen reduction reaction is a green and convenient route, which has attracted considerable attention in the field of energy and catalysis. However, the high cost of noble Pt‐based catalyst and H2O2 selectivity and stability need to be further refined for large‐scale production. Herein, we reported a O, N co‐doped mesoporous nanocarbon catalyst. The introduction of nitrogen atoms increases the electrochemically active surface area, promotes the mass transfer capacity, and reduces the impedance of electron transfer. The absolute contents of each oxygen and nitrogen functional group in the catalyst were calculated according to XPS, which reveals that pyridine nitrogen and pyrrole nitrogen might contribute most to the two‐electron electrocatalytic oxygen reduction reaction. In addition, O, N co‐doping significantly promoted the two‐electron pathway of electrocatalytic oxygen reduction, and the selectivity of hydrogen peroxide reached 93 %. The present work provides a reference for the rational design of functional groups of electrocatalysts for highly selective electrosynthesis of H2O2.

Characterization of three novel DyP-type peroxidases from Streptomyces chartreusis NRRL 3882.

Actinobacteria are known to produce extracellular enzymes including DyPs. We set out to identify and characterize novel peroxidases from Streptomyces chartreusis NRRL 3882, because S. chartreusis belongs to the small group of actinobacteria with three different DyPs. The genome of the actinomycete S. chartreusis NRRL 3882 was mined for novel DyP-type peroxidases. Three genes encoding for DyP-type peroxidases were cloned and overexpressed in Escherichia coli. Subsequent characterization of the recombinant proteins included examination of operating conditions such as pH, temperature and H2 O2 concentrations, as well as substrate spectrum. Despite their high sequence similarity, the enzymes named SCDYP1-SCDYP3 presented distinct preferences regarding their operating conditions. They showed great divergence in H2 O2 tolerance and stability, with SCDYP2 being most active at concentrations above 50 mmol l-1 . Moreover, SCDYP1 and SCDYP3 preferred acidic pH (typical for DyP-type peroxidases), whereas SCDYP2 was most active at pH8. Regarding the function of DyPs in nature, these results suggest that availability of different DyP variants with complementary activity profiles in one organism might convey evolutionary benefits. DyP-type peroxidases are able to degrade xenobiotic compounds and thus can be applied in biocatalysis and bioremediation. However, the native function of DyPs and the benefits for their producers largely remain to be elucidated.

Co-immobilization and compartmentalization of cholesterol oxidase, glucose oxidase and horseradish peroxidase for improved thermal and H2O2 stability

Glucose oxidase (GOX) and cholesterol oxidase (COX) are enzymes with numerous practical applications in medicine and industry. Although various methods for improving of enzyme stability have been proposed, we present novel approach for enzyme compartmentalization using polyelectrolytes layers deposited on electrospun fibers made of poly(D,L-lactide-co-glycolide) and commercial membrane UFX5. Compartmentalization has a series of advantages over simple co-immobilization offering providing of suitable microenvironment for the immobilized enzymes, ensuring proper substrate/product channeling and improving stability and reusability of biomolecules. The biosystems produced via compartmentalization, resulted in higher conversion efficiency of model reaction at 45 °C and 65 °C compared to free enzymes as well as negative effect of hydrogen peroxide was minimalized after immobilization. Moreover, after 5 catalytic cycles, biosystems based on UFX5 membrane and HRP or GOX or COX immobilized by compartmentalization reached efficiencies of 89% and 34%, respectively, with less than 10% enzyme elution from the support. Enzymes compartmentalized using ultrafiltration membrane showed also significant improvement of their biocatalytic productivity over repeated use, resulting in possible costs reduction of the desired process. Use of biosystems with electrospun fibers and co-immobilized enzymes resulted in enzyme elution of over 90% and very limited conversion efficiency.

Enhancement of leaching copper by organic agents from waste printed circuit boards in a sulfuric acid solution

Leaching copper from waste printed circuit boards (WPCBs) by hydrometallurgy has always been a hot research topic. At atmospheric pressure, hydrogen peroxide (H2O2) was used as an oxidant to study the leaching behavior of copper from WPCBs in sulfuric acid (H2SO4) solution with ethylene glycol (EG). To elucidate the leaching mechanism of copper from WPCBs, the effect of various parameters on the leaching performance with or without EG was investigated. The results showed that the copper leaching process from WPCBs in the presence of EG was found to conform to the ash diffusion-controlled shrinking core model according to the kinetic curve and a activation energy of 18.38 kJ/mol. Moreover, the presence of EG strengthened the stability of H2O2, improved dispersity and increased electrical activity of WPCBs, which enhanced the leaching of copper from WPCBs in the high leaching temperature (>323.15 K). As a result, apart from the fact that the optimal leaching concentration of H2O2 was reduced by the addition of EG, the improved copper leaching efficiency from WPCBs was achieved by the addition of EG, as demonstrated by a maximum copper leaching efficiency of 98.01% and a maximum loss rate of 29.68%. Besides, the mineralogical and morphological properties of leaching residue validated the leaching results. Based on this, our findings confirmed the enhanced leaching performance of copper from WPCBs by EG, which benefited for the efficient recovery of copper from WPCBs.

PMMA Microcapsules for the Inactivation of SARS-CoV-2

Surface disinfection currently plays a decisive role in the epidemiological situation caused by the SARS-CoV-2 coronavirus. However, most disinfection products available on the market have a high evaporation rate and only an immediate action and not continuous, creating the need for a high frequency of disinfection. To overcome this limitation, in the present work, poly(methyl methacrylate) (PMMA) microcapsules were developed with an active agent (hydrogen peroxide) encapsulated, which has the ability to inactivate/neutralize the SARS-CoV-2 virus. PMMA-H2O2 microcapsules have a spherical shape and a smooth structure with low porosity and were successfully attached to nonwoven fabrics, as observed from scanning electron microscopy. The thermogravimetric analysis shows that PMMA-H2O2 microcapsules have high thermal stability and can increase the stability of H2O2. Nonfabric substrates functionalized with PMMA-H2O2 microcapsules were tested by a highly sensitive and specific reverse transcription-quantitative real-time polymerase chain reaction (RT-qPCR)-based method to evaluate antiviral activity through the degradation of SARS-CoV-2 deoxyribonucleic acids. The highest percentage of viral nucleic acid elimination was obtained when exposing the viral sample for 1 h to PMMA-H2O2 microcapsules, resulting in an elimination of >97% of the coronavirus. In addition, the microcapsules are stable over a period of three weeks and retain the ability to eliminate SARS-CoV-2. Hence, it is demonstrated that this microcapsule system is efficient for SARS-CoV-2 elimination and inherent surface disinfection.

Hydrogen peroxide-assisted pasteurization: An alternative for household water disinfection

Decentralized treatments applied at the household level may be alternatives to positively impact global health. Pasteurization is a conventional disinfection method and efforts have been made to increase its efficiency and productivity in point-of-entry (POE) applications. To overcome limitations associated to this practice, we hypothesized that including oxidation prior to pasteurization would improve the treatment. This research aimed to evaluate the performance of hydrogen peroxide-assisted pasteurization and effects of H2O2 concentration and temperature organized by a full factorial experimental design. At optimal conditions, >9.3 log10 inactivation of Escherichia coli and >5.8 log10 Phi X174 bacteriophage were obtained. Observed values were modeled as empirical equations for E. coli and phage inactivation (R2 = 0.76 and 0.72, respectively). Temperature did not lead to significant differences in H2O2 residual, which is favorable for practical implementation. Synergistic effects were found for E. coli, and inactivation of Phi X174 tops results obtained by individual disinfection by pasteurization and H2O2 oxidation. Our study also suggests H2O2-assisted pasteurization increases oxidation potential, inferred by cell lysis and protein removal. Additionally, analyzing disinfection and H2O2 residuals during temperature ramp time endorsed that inactivation might happen at lower temperatures, and stability of H2O2 may provide a safer setup when heat sources cannot guarantee pasteurization to occur. Broadly, our research underscores potentials of H2O2-assisted pasteurization and, although we recommend further assessments considering pathogens, as well as case studies for specific scenarios, we believe H2O2 may improve performance and resilience of classic disinfection by pasteurization as a POE solution.

Formulations of selected Energy beverages promote pro-oxidant effects of ascorbic acid and long-term stability of hydrogen peroxide

Recently, autoxidation mediated by ascorbic acid (AA) and other ingredients, has been implicated in generation of hydrogen peroxide (H2O2) in so-called Energy beverages. Here, we report the use of cyclic voltammetry and the FOX assay to monitor at short and long incubation times, respectively, the production and stability of H2O2 generated by AA and redox-active ingredients. Levels of H2O2 in Energy drinks (36.5 ± 4.0 µM at 4 °C and 64.2 ± 7.6 µM at 20 °C) were found to be stable or increased (p < 0.05) upon vessel opening. A predictive model for the production of H2O2 as a function of AA concentration, temperature and incubation time, and depending on ingredients present, indicated that H2O2 peaked at 91–726 µM after 1 day and declined to ∼ 42–60 µM (4 °C) or zero after ∼10 days. The research supports that levels of H2O2 in beverages containing anti-oxidant mixtures and dissolved oxygen should be monitored and formulations modified to avoid AA autoxidation.

Co-Immobilization and Compartmentalization of Cholesterol Oxidase, Glucose Oxidase and Horseradish Peroxidase for Improved Thermal and H2o2 Stability

Co-Immobilization and Compartmentalization of Cholesterol Oxidase, Glucose Oxidase and Horseradish Peroxidase for Improved Thermal and H2o2 Stability

Co-Immobilization and Compartmentalization of Cholesterol Oxidase, Glucose Oxidase and Horseradish Peroxidase for Improved Thermal and H2o2 Stability

Co-Immobilization and Compartmentalization of Cholesterol Oxidase, Glucose Oxidase and Horseradish Peroxidase for Improved Thermal and H2o2 Stability

Improved H2o2 Photogeneration and Stability on Rational Tailored Polymeric Carbon Nitride Via Enhanced O2 Adsorption

Improved H2o2 Photogeneration and Stability on Rational Tailored Polymeric Carbon Nitride Via Enhanced O2 Adsorption

Retraction: Improved H2O2 photogeneration and stability on rational tailored polymeric carbon nitride via enhanced O2 adsorption

Retraction of ‘Improved H2O2 photogeneration and stability on rational tailored polymeric carbon nitride via enhanced O2 adsorption’ by Zehao Li et al., J. Mater. Chem. A, 2022, 10, 15051–15061, https://doi.org/10.1039/D2TA03580D.