H2O2 Formation Research Articles

Assessment of myco-fabricated Al2O3 NPs toxicity on cancer cells and pathogenic microbes by suppression of bacterial metabolic key enzymes.

There has been a recent change in global attention towards addressing antimicrobial resistance (AMR) as a result of the concerning increase in mortality rates. Nanomaterials have become highly favorable options for a wide range of industrial and biological uses. The objective of this study was to produce aluminum oxide nanoparticles (Al2O3 NPs) using a crude extract from the fungus Aspergillus sp. WAH23, and then analyze the nanoparticles using UV-analysis, electron microscopy (TEM and SEM), and (FT-IR) and X-ray diffraction (XRD). Results revealed that formed nanoparticles are spherical with an average size of 8.5 nm. XRD analysis confirmed the crystalline nature of the synthesized Al2O3 NPs. The Al2O3 nanoparticles exhibited antibacterial properties against a wide range of pathogenic microbes. The antibacterial efficacy of these nanoparticles on the examined bacterial strains was exhibited through their ability to hinder several metabolic processes, including phosphofructokinase (PFK), enolase, and glutamine synthetase. Additionally, the nanoparticles increased the activity of NADH-oxidase, the content of MDA, and the formation of H2O2. The study also examined the anticancer properties of Al2O3 nanoparticles on various types of cancer cells.

Tuning proton affinity on Co-N-C atomic interface to disentangle activity-selectivity trade-off in acidic oxygen reduction to H2O2.

In oxygen reduction reaction to H2O2via two-electron pathway (2e- ORR), adsorption strength of oxygen-containing intermediates determines both catalytic activity and selectivity. However, it also causes activity-selectivity trade-off. Herein, we propose a novel strategy through modulating the interaction between protons and *OOH intermediates to break the activity-selectivity trade-off for highly active and selective 2e- ORR. Taking the typical cobalt-nitrogen-carbon single-atom catalyst as an example, boron heteroatoms doped into second coordination sphere of CoN4 (Co1-NBC) increase proton affinity on catalyst surface, facilitating proton attack on the former oxygen of *OOH and thereby promoting H2O2 formation. As a result, Co1-NBC simultaneously achieves prominent 2e- ORR activity and selectivity in acid with onset potential of 0.724 V vs. RHE and H2O2 selectivity of 94%, surpassing most reported catalysts. Furthermore, Co1-NBC exhibits a record-high H2O2 productivity of 202.7 mg cm-2 h-1 and a remarkable stability of 60 h at 200 mA cm-2 in flow cell. This work provides new insights into resolving activity-selectivity trade-off in electrocatalysis.

Tuning proton affinity on Co–N–C atomic interface to disentangle activity‐selectivity trade‐off in acidic oxygen reduction to H2O2

In oxygen reduction reaction to H2O2via two‐electron pathway (2e‐ ORR), adsorption strength of oxygen‐containing intermediates determines both catalytic activity and selectivity. However, it also causes activity‐selectivity trade‐off. Herein, we propose a novel strategy through modulating the interaction between protons and *OOH intermediates to break the activity‐selectivity trade‐off for highly active and selective 2e‐ ORR. Taking the typical cobalt‐nitrogen‐carbon single‐atom catalyst as an example, boron heteroatoms doped into second coordination sphere of CoN4 (Co1‐NBC) increase proton affinity on catalyst surface, facilitating proton attack on the former oxygen of *OOH and thereby promoting H2O2 formation. As a result, Co1‐NBC simultaneously achieves prominent 2e‐ ORR activity and selectivity in acid with onset potential of 0.724 V vs. RHE and H2O2 selectivity of 94%, surpassing most reported catalysts. Furthermore, Co1‐NBC exhibits a record‐high H2O2 productivity of 202.7 mg cm‐2 h‐1 and a remarkable stability of 60 h at 200 mA cm‐2 in flow cell. This work provides new insights into resolving activity‐selectivity trade‐off in electrocatalysis.

Localized surface plasmon resonance effect-mediated in-situ photochemical–formation of H2O2 for high epoxidation performance over LaSrCoNiO6 nanoparticles

Selective aerobic epoxidation of allylic alcohols and olefins presents a promising solution to the modern chemical industry. However, the development of non-noble metal catalysts with superior catalytic performance for this reaction remains a significant challenge. This study introduces a plasmonic photothermal-catalytic system centered around nano LaSrCoNiO6 (LSCNi-N) catalyst, enabling the epoxidation of cinnamyl alcohol and styrene mediated by LSPR effect under visible light illumination (>420 nm). This catalyst exhibits superior epoxidation catalytic performance, with selectivities of up to 72.3 % in a 93.4 % conversion of cinnamyl alcohol and 91.8 % selectivity of styrene oxide at almost 100 % conversion of styrene. Mechanistic studies reveal that the high selectivity derives from the in-situ photochemical formation of H2O2 mediated by the localized surface plasmon resonance effect of LSCNi-N and hole scavenger effect of cinnamyl alcohol. These findings highlight the potential of designing plasmonic transition-metal oxidic catalysts to overcome challenges in selectively synthesizing fine chemicals through visible light catalysis.

Metal-Based Oxygen Reduction Electrocatalysts for Efficient Hydrogen Peroxide Production.

Hydrogen peroxide (H2O2) is a high-value chemical widely used in electronics, textiles, paper bleaching, medical disinfection, and wastewater treatment. Traditional production methods, such as the anthraquinone oxidation process and direct synthesis, require high energy consumption, and involve risks from toxic substances and explosions. Researchers are now exploring photochemical, electrochemical, and photoelectrochemical synthesis methods to reduce energy use and pollution. This review focuses on the 2-electron oxygen reduction reaction (2e- ORR) for the electrochemical synthesis of H2O2, and discusses how catalyst active sites influence O2 adsorption. Strategies to enhance H2O2 selectivity by regulating these sites are presented. Catalysts require strong O2 adsorption to initiate reactions and weak *OOH adsorption to promote H2O2 formation. The review also covers advances in single-atom catalysts (SACs), multi-metal-based catalysts, and highlights non-noble metal oxides, especially perovskite oxides, for their versatile structures and potential in 2e- ORR. The potential of localized surface plasmon resonance (LSPR) effects to enhance catalyst performance is also discussed. In conclusion, emphasis is placed on optimizing catalyst structures through theoretical and experimental methods to achieve efficient and selective H2O2 production, aiming for sustainable and commercial applications.

S-scheme3D/3D Bi0/BiOBr/P Doped g-C3 N4 with Oxygen Vacancies (Ov) for Photodegradation of Pharmaceuticals: In-situ H2O2 Production and Plasmon Induced Stability.

Complications accompanying photocatalyst stability and recombination of exciton charges in pollutants degradation has been addressed through the construction of heterojunctions, especially S-scheme heterojunction with strong and distinctive redox centres. Herein, an S-scheme BiOBr (BOR) and g-C3N4PO4 (CNPO) catalyst (BORCNPO) with oxygen vacancy (Ov) was synthesized for levofloxacin (LVX) and oxytetracycline (OTC) photodegradation under visible light. The 3D/3D BORCNPO catalyst possessed C-O-Br bridging bonds for efficient charge transfer during the fabrication of S-scheme heterojunction. In-situ H2O2 formation affirmed by potassium titanium (IV) oxalate spectrophotometric method improved the mineralization ability of BORCNPO7.5 catalyst. Bi0 surface plasmon resonance (SPR) enhanced formation and involvement of ⋅O2 - and the stability of the catalyst which increased reaction rate with increasing cycling experiments. XPS and radical trapping experiments supported the S-scheme charge transfer mechanism formation with high degradation rate of LVX which was 3 times higher than OTC degradation rate. Mineralization of pollutants and their intermediates were demonstrated with florescence excitation and emission matrix (FEEM) and quadruple time of flight high performance liquid chromatography (QTOF-HPLC). This work advances development of highly stable and efficient catalysts for photodegradation of pollutants through the formation of S-scheme heterostructure.

Stage-wise kinetic analysis of ammonia addition effects on two-stage ignition in dimethyl ether

Abstract Ammonia (NH3) has gained considerable attention as a promising carbon-free hydrogen carrier fuel for internal combustion engines, but its direct use in compression-ignition engines presents challenges, often requiring high-reactivity fuels to ignite the premixed NH3/air mixture and initiate combustion. This study focuses on the ignition process of binary NH3 and dimethyl ether (DME) mixtures, as DME is a carbon-neutral, high-reactivity fuel. A key novelty of this paper is the comparison of the ignition processes of DME and NH3/DME mixtures from a temporal, process-oriented perspective, analyzing chemical kinetics across distinct ignition phases rather than focusing solely on instantaneous reactions at discrete time points. The stage-wise analysis reveals that NH3 has minimal impact on the control mechanism governing the two-stage ignition process of DME. Specifically, DME still largely depends on OH radical proliferation during low-temperature oxidation (LTO), which releases heat as the reaction progresses. As the temperature increases, LTO branching pathways gradually shift to chain-propagation pathways, reducing overall reaction activity. The reactivity and temperature rise rate of the system are then governed by the H2O2 loop mechanism before thermal ignition. However, ammonia significantly extends the ignition delay of DME by competing with OH radicals, which are critical for DME oxidation, thus inhibiting ignition. As the ignition reaction proceeds, ammonia kinetics become more involved. For example, nitrogen-containing species from NH3 oxidation, such as NO, NO2, and NH2, react with CH3OCH2 to form CH3OCHO, reducing the flux through the LTO pathway of DME. While ammonia reaction pathways also produce OH radicals, this occurs at the expense of HO2 and H radicals, leading to H2O2 formation. Overall, these findings demonstrate the substantial impact of ammonia addition on DME ignition, highlighting the need for further research to better understand NH3/DME binary fuel ignition and to optimize the design and operation of NH3/DME dual-fuel engines for improved efficiency and reliability.

Efficient Catalytic Production of Reactive Oxygen Species through Piezoelectricity in Bismuth Sulfide Rich in Sulfur Vacancies.

Sulfur (S) vacancies in metal sulfides are of interest in electrocatalysis and photoelectronics, but their effect on the generation of reactive oxygen species (ROS) during mechanical catalysis is unclear. This study investigates the impact of S-vacancies in defective bismuth sulfide (Bi2S3-x) on ROS production under ultrasonic irradiation and organic contaminant decomposition. S-vacancies disrupt the centrosymmetric structure of intrinsic Bi2S3, inducing piezoelectric effects and enhancing the electrical energy in Bi2S3-x. The positively charged S-vacancies in Bi2S3-x promote the separation of ultrasound-activated electron-hole pairs by capturing electrons. As a result, the optimal rate of H2O2 formation and the reaction rate constant for degrading Rhodamine B dye on Bi2S3-x are found to be 1.9 and 37 times higher, respectively, than those on Bi2S3 under ultrasonic irradiation. The nonzero catalytic efficiency in centrosymmetric Bi2S3 is due to the flexoelectric catalytic effect from nonuniform strain. These results guide the piezocatalyst design and elucidate mechanical catalysis mechanisms.

Spontaneous Production of H2O2 at the Liquid-Ice Interface: A Potential Source of Atmospheric Oxidants.

We present experimental evidence for the spontaneous production of hydrogen peroxide (H2O2) at the liquid-ice interface during the freezing of dilute salt solutions. Specifically, sample solutions containing NaCl, NaBr, NH4Cl, and NaI at concentrations between 10-6 and 10-1 M were subjected to freezing-melting cycles and then analyzed for H2O2 content. The relationship between the production rate of H2O2 and the salt concentration follows that of the Workman-Reynolds freezing potential (WRFP) values as a function of the salt concentration. Our results suggest that H2O2 is formed at the liquid-ice interface from the self-recombination of hydroxyl radicals (OH·), produced from the oxidation of hydroxide anions due to the high electric field generated at the aqueous-ice interface under the WRFP effect. Furthermore, the involvement of O2 likely acting as an electron capturer could promote to produce more OH radicals and hydroperoxyl radicals (HO2·), thus enhancing the production of H2O2 at the liquid-ice interface. Overall, this study suggests a novel mechanism of H2O2 formation in ice via its spontaneous production at the liquid-ice interface, induced by the Workman-Reynolds effect.

Highly efficient electrosynthesis of hydrogen peroxide through reversible transformation between catechol and o-benzoquinone on polydopamine modified carbon black

Carbon-based materials are more promising catalysts for H2O2 electrochemical production. However, the common method for modifying carbon-based materials is surface functionalization with harsh and uncontrollable reaction conditions, hindering the precise regulation of the active sites. Herein, we proposed a carbon-based material modified by polydopamine (CB-PDA) that was easily prepared and used in air diffusion electrode system for H2O2 production. The rapid and reversible transformation between catechol and o-benzoquinone on PDA could improve the H2O2 selectivity from 75.5 % to 97.0 % during the electrocatalytic process. The detection of adsorbed *HOOH and *OOH in oxygen reduction reaction proved the preference of CB-PDA for the two-electron pathway. The H2O2 formation rate constant of CB-PDA increased significantly from 25.85 to 60.82 mM h−1. The highest cumulative H2O2 concentration could reach 10200 mg L−1 in 9 h. Long-term operation tests proved the good operational stability. Furthermore, this system was cost-effective without additional aeration energy consumption and could achieve rapid disinfection in 10 min, which would have great potential to be used in environmental remediation.

Photoinduction of Pt single atoms decorated on UiO-66-NH2 for photocatalytic extraction of uranium under open system

The photocatalytic method has been proven as one of the effective methods for uranium removal from radioactive wastewater. Herein, a photocatalyst UiO-66-NH2-Pt was prepared using the adsorption-photoinduction method. Pt was first adsorbed on the substrate and then photo-reduced under light irradiation to be doped into the structure of UiO-66-NH2. The characterization results implied the formation and atomic dispersion of Pt with a loading content of 1.90 wt%. The loading of Pt has promoted the effective separation and transfer of photogenerated electron-hole pairs, broadened the visible light adsorption range and narrowed down the bandgap, thus to enhance the photocatalytic activity. Then they were applied for the photo-removal of uranium under air atmosphere. The reaction rate of UiO-66-NH2-Pt was about 7 times that of pure UiO-66, confirming the higher photocatalytic activity after the loading of Pt. It showed good reusability and was also universal for different water matrix. The detection of hydroxyl radicals with EPR method indicated the formation of H2O2, which could react with uranyl ions to form metastudtite under air. This work further verified the feasibility of photoinduced synthesis of Pt single atom and provided a novel material for photocatalytic removal of uranyl ion under air.

Engineering peripheral S-doped atomic Fe-N4 in defect-rich porous carbon nanoshells for durable oxygen reduction reaction and Zn-air batteries

Iron-nitrogen-carbon (Fe-N-C) single-atom materials have emerged as the most promising catalysts for the oxygen reduction reaction (ORR), which yet suffers from inadequate stability arising from the attack of ·OH and HO2· radicals generated by H2O2. In this study, density functional theory (DFT) calculations reveal that the presence of peripheral S atoms can regulate the electronic structure of the Fe center and suppress the formation of H2O2 to enhance the catalyst's durability. Thereafter, atomic Fe-N4 with peripheral S doping is intricately engineered in defect-rich porous carbon nanoshells (Fe-NS-C) through an adsorption-pyrolysis method. The incorporation of S not only optimizes the coordination microenvironment of Fe-N4 but also induces a larger specific surface area and richer defects. The Fe-NS-C catalyst displays remarkable ORR performance, featuring a half-wave potential (E1/2) of 0.90 V. Its low H2O2 yield (below 1.1 %) and excellent stability (10 mV day in E1/2 after 10,000 cycles) further underscore the superiority of Fe-NS-C. When employed as the cathode for Zn-air battery, Fe-NS-C achieves an impressive peak power density of 230.1 mW cm−2 and stable charge/discharge potentials over an extended duration of 150 h. This study presents an effective strategy for engineering efficient and durable single-atom electrocatalysts for ORR and Zn-air batteries.

Introduction of a Hydroxyl Self-Sacrificing Surface on Ultrathin Poly(heptazine imide) Nanosheets by KCl Grafting: A New Strategy to Improve the Photocatalytic Production of H2O2.

The generation of H2O2 through photocatalysis is increasingly recognized as a viable approach for addressing the energy and environmental challenges encountered in industrial production processes. In this research, we synthesized ultrathin (1 nm) poly(heptazine imide) (PHI) nanosheets as a photocatalyst by a one-step KCl molten salt process. The utilization of Fourier transform infrared and X-ray photoelectron spectroscopy substantiated that the interlayer-bonded potassium atoms induce polarization in water molecules, facilitating the attachment of hydroxyl groups on the surfaces of nanosheets. These groups serve as self-sacrificing entities, promoting the reaction that leads to the generation of H2O2. The preparation temperature and KCl doping amount factors for the H2O2 generation rate were investigated, and the mechanism of the KCl-bonded structure on photogeneration charge separation transport was analyzed. Owing to the elevated crystallization and the presence of surface self-sacrificing hydroxyl groups, the rate of H2O2 production reaches 6117.5 and 308.35 μmol·g-1·h-1 under visible-light irradiation (λ ≥ 420 nm) in isopropanol solution and pure water, respectively. These rates are 30 and 18.7 times higher than those observed for bulk g-C3N4, respectively. The photocatalytic kinetic processes for H2O2 formation and decomposition were also calculated to investigate the catalyst activities.

PH Affects the Spontaneous Formation of H2O2 at the Air-Water Interfaces.

Recent studies have shown that the air-water interface of aqueous microdroplets is a source of OH radicals and hydrogen peroxide in the atmosphere. Several parameters such as droplet size, salt, and organic content have been suggested to play key roles in the formation of these oxidants. In this study, we focus on the effect of acidity on the spontaneous interfacial hydrogen peroxide formation of salt-containing droplets. Na2SO4, NaCl, and NaBr bulk solutions, at the range of pH 4 to 9.5, were nebulized, using ultra high-purity N2/O2 (80%/20%), and H2O2 was measured in the collected droplets. All of the experiments were performed in T = 292 ± 1 K and humidity levels of 90 ± 2%. For Na2SO4 and NaCl, the H2O2 concentration was increased by ∼40% under alkaline conditions, suggesting that OH- enriched environments promote its production. When CO2 was added in the ultrapure air, H2O2 was observed to be lower at higher pH. This suggests that dissolved CO2 can initiate reactions with OH radicals and electrons, impacting the interfacial H2O2 production. H2O2 formation in NaBr droplets did not display any dependence on the pH or the bath gas, showing that secondary reactions occur at the interface in the presence of Br-, which acts as an efficient interfacial source of electrons.

Unbiased Photoelectrochemical H2O2 Coupled to H2 Production via Dual Sb2S3‐Based Photoelectrodes with Ultralow Onset Potential

AbstractThe productions of hydrogen peroxide (H2O2) and hydrogen (H2) in a photoelectrochemical (PEC) water splitting cell suffer from an onset potential that limits solar conversion efficiencies. Moreover, the formation of H2O2 through two‐electron PEC water oxidation reaction competes with four‐electron oxidation evolution reaction. Herein, we developed the surface selenium doped antimony trisulfide photoelectrode with the integrated ruthenium cocatalyst (Ru/Sb2(S,Se)3) to achieve the low onset potential and high Faraday efficiency (FE) for selective H2O2 production. The photoanode exhibits an outstanding average FE of 85 % in the potential range of 0.4–1.6 VRHE and the H2O2 yield of 1.01 μmol cm−2 min−1 at 1.6 VRHE, especially at low potentials of 0.1–0.55 VRHE with 80.4 % FE. Impressively, an unassisted PEC system that employs light and electrolyte was constructed to simultaneously produce H2O2 and H2 production on both the Ru/Sb2(S,Se)3 photoanode and the Pt/TiO2/Sb2S3 photocathode. The integrated system enables the average PEC H2O2 production rate of 0.637 μmol cm−2 min−1 without applying any addition bias. To our knowledge, this is the first demonstration that Sb2S3‐based photoelectrodes exhibit H2O2/H2 two‐side production with a strict key factor of the system, which represents its powerful platform to achieve high efficiency and productivity and the feasibility to facilitate value‐added products in neutral conditions.

Photoelectrochemical Synthesis of Hydrogen Peroxide from Saline Water via the Two-Electron Water Oxidation Reaction.

Hydrogen peroxide (H2O2) production on the anode is more valuable than oxygen and chlorine evolution for photoelectrochemical saline water splitting. In this work, by the introduction of bicarbonate (HCO3-), H2O2 is produced from saline water (2 M KHCO3 + 0.5 M NaCl aqueous solution) via the two-electron water oxidation reaction by a photoanode of bismuth vanadate (BiVO4). Furthermore, the Faradaic efficiency (FE) and accumulation for H2O2 are improved by coating antimony tetroxide (Sb2O4) on BiVO4. A H2O2 FE of 26% at 1.54 V vs RHE is obtained by Sb2O4/BiVO4 and 49 ppm of H2O2 is accumulated after a 135 min chronoamperometry. Similar to that in KHCO3 pure water solution, infrared spectroscopy and electrochemical analysis confirm that HCO3- plays a surface-mediating role in the formation of H2O2 in KHCO3 saline water solution. The presence of HCO3- in the electrolyte is able to not only increase the photocurrent density but also effectively inhibit the chlorine evolution reaction.

Unbiased Photoelectrochemical H2O2 Coupled to H2 Production via Dual Sb2S3-Based Photoelectrodes with Ultralow Onset Potential.

The productions of hydrogen peroxide (H2O2) and hydrogen (H2) in a photoelectrochemical (PEC) water splitting cell suffer from an onset potential that limits solar conversion efficiencies. Moreover, the formation of H2O2 through two-electron PEC water oxidation reaction competes with four-electron oxidation evolution reaction. Herein, we developed the surface selenium doped antimony trisulfide photoelectrode with the integrated ruthenium cocatalyst (Ru/Sb2(S,Se)3) to achieve the low onset potential and high Faraday efficiency (FE) for selective H2O2 production. The photoanode exhibits an outstanding average FE of 85 % in the potential range of 0.4-1.6 VRHE and the H2O2 yield of 1.01 μmol cm-2 min-1 at 1.6 VRHE, especially at low potentials of 0.1-0.55 VRHE with 80.4 % FE. Impressively, an unassisted PEC system that employs light and electrolyte was constructed to simultaneously produce H2O2 and H2 production on both the Ru/Sb2(S,Se)3 photoanode and the Pt/TiO2/Sb2S3 photocathode. The integrated system enables the average PEC H2O2 production rate of 0.637 μmol cm-2 min-1 without applying any addition bias. To our knowledge, this is the first demonstration that Sb2S3-based photoelectrodes exhibit H2O2/H2 two-side production with a strict key factor of the system, which represents its powerful platform to achieve high efficiency and productivity and the feasibility to facilitate value-added products in neutral conditions.

Study on the effect of radiation-resistant resin on water radiolysis

In recent years, the use of radiation-resistant resins of polyimide and polyether ether ketone becomes increasing as vessels for irradiation and unsealed radioisotope experiments. However, in our radiolysis experiments, the possibility of interaction between radiolysis products of water and the resin was found, suggesting concerns that the resin may affect reactions in water in radiation fields. To clarify the interaction, dichromate (Cr2O72−) reduction and hydrogen peroxide (H2O2) formation in γ-radiolysis of water were compared with and without the resin. The Cr2O72− reduction amount in aqueous solution with the resin became larger than that without the resin at the same dose, indicating the promotion of Cr2O72− reduction by the resin. On the other hand, the H2O2 formation in pure water with and without an electron scavenger were almost independent of the presence of resin. These suggested the interaction between hydroxyl radical and the resin in contact with water in radiation fields.

Corrole–chelated phosphorus complex: enabling dual C–H chlorination and H₂O₂ generation

Corroles, despite their highly tunable and excellent photophysical and electrochemical properties, have rarely been explored as mainstream photocatalytic photosensitizers. Our study introduces a novel application of the highly oxidizing penta–CF3 substituted phosphorus corrole, P–(CF3)5, which has shown remarkable efficacy in the chlorination of phenol and related natural compounds (the beta 2, 3, 8, 17, 18-substituted isomer: 2,3,8,17,18–pentatrifluoromethyl–(5,10,15–tris(pentafluorophenyl) corrole phosphorus (V) difluoride). Here, we report the first case of the simultaneous photocatalytic chlorination of phenol or toluene and H2O2 formation, with the latter achieving a notable rate of > 7 mM/g/h under ambient conditions. Notably, the oxidation of toluene predominantly yields benzaldehyde over benzyl chloride. The H2O2 formation can be finely tuned by adjusting the water/acetonitrile ratio and acid concentration. Comprehensive experimental and theoretical (DFT) investigations were conducted to elucidate the underlying mechanisms of both chlorination and oxidation. This dual–function catalytic process not only enhances reaction efficiency but also underscores the potential of corrole–based catalysts in advancing sustainable and green chemical methodologies.

Bismuth titanate microplates with tunable oxygen vacancies for piezocatalytic hydrogen peroxide production

Piezocatalysis offers an encouraging alternative for the sustainable, on-demand, and decentralized production of hydrogen peroxide (H2O2), underscoring the importance of enhancing piezocatalytic efficiency. Enhancing piezocatalysts through defect engineering has shown considerable potential in boosting H2O2 production efficiency. However, the impact of oxygen vacancies on piezocatalytic activity remains unclear. Herein, we used a chemical probe method to quantify negative charges (q−) and superoxide radicals (O2−) to explore the relation between the oxygen vacancy concentration and piezocatalytic performance of bismuth titanate (Bi4Ti3O12) based catalysts. Results indicate that piezocatalytic H2O2 production in pure water demonstrates a volcanic trend with increasing oxygen vacancy concentration. This trend is attributed to the dual role of oxygen vacancies, which reduce the piezoelectric property of the piezocatalyst while simultaneously increasing the concentration of O2−, which is crucial for H2O2 formation through the O2 reduction pathway. This study provides insights into the interplay between oxygen vacancies, piezoelectric properties, and piezocatalytic activity, offering valuable guidance for the design of piezocatalysts for sustainable H2O2 production.