Rate Of H2O2 Generation Research Articles

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.

Unveiling O2 adsorption on non-metallic active site for selective photocatalytic H2O2 production

Photocatalytic oxygen reduction reaction (ORR) offers a promising pathway for sustainable hydrogen peroxide (H2O2) production but faces challenges in developing catalysts with good ORR selectivity. Herein, we report that tailoring O2 adsorption on non-metallic active sites can optimize ORR selectivity. This concept is demonstrated on three carbon nitrides with different atomic configurations: polymeric carbon nitride (PCN), lithium-poly triazine imide (Li-PTI), and sodium-poly heptazine imide (Na-PHI). Na-PHI emerges as a strong candidate for H2O2 production due to the end-on adsorption mode and suitable adsorption strength with O2. Synthesized Na-PHI, PCN, and Li-PTI are characterized, with Na-PHI showing superior light absorption, charge carrier separation, and remarkable selectivity (92 %) for two-electron ORR. Consequently, Na-PHI achieves a high H2O2 generation rate of 3.48 mmol g−1 h−1, surpassing Li-PTI and PCN by 9.2 and 33 times, respectively. This study underscores the importance of O2 adsorption on non-metallic active sites for selective photocatalytic H2O2 generation.

Engineering atomic Rb-N configurations to tune radical pathways for highly selective photocatalytic H2O2 synthesis coupled with biomass valorization

Photocatalytic oxygen reduction for hydrogen peroxide (H₂O₂) synthesis presents a green and cost-effective production method. However, achieving highly selective H₂O₂ synthesis remains challenging, necessitating precise control over free radical reaction pathways and minimizing undesirable oxidative by-products. Herein, we report for the visible light-driven simultaneous co-photocatalytic reduction of O2 to H2O2 and oxidation of biomass using the atomic rubidium-nitride modified carbon nitride (CNRb). The optimized CNRb catalyst demonstrates a record photoreduction rate of 8.01 mM h−1 for H2O2 generation and photooxidation rate of 3.75 mM h−1 for furfuryl alcohol to furoic acid, achieving a remarkable solar-to-chemical conversion (SCC) efficiency of up to 2.27%. Experimental characterizations and DFT calculation disclosed that the introducing atomic Rb–N configurations allows for the high-selective generation of superoxide radicals while suppressing hydroxyl free radical formation. This is because the Rb–N serves as the new alternative site to perceive a stronger connection position for O2 adsorption and reinforce the capability to extract protons, thereby triggering a high selective redox product formation. This study holds great potential in precisely regulating reactive radical processes at the atomic level, thereby paving the way for efficient synthesis of H2O2 coupled with biomass valorization.

Boosting acidic hydrogen peroxide electrosynthesis on 2D metal-organic framework nanosheets based on cobalt porphyrins

The 2-electron electrocatalytic oxygen reduction reaction (2e− ORR) to hydrogen peroxide (H2O2) represents a promising strategy to resolve the high energy consumption and increasing environmental concerns inherent in the traditional anthraquinone process. The acidic 2e− ORR has emerged as an exciting alternative for industrial-level H2O2 production, whereas is hampered by the inferior H2O2 selectivity due to the uncontrollable proton-coupled electron transfer processes in an acidic environment. Herein, an ultrathin 2D metal–organic frameworks (MOFs) nanosheet based on cobalt tetra(4-carboxyphenyl) porphine (Co-TCPP NSs) is designed to promote H2O2 selectivity up to 96.5 %, accompanied with a remarkable H2O2 generation rate of 4677.42 mg·L−1·h−1. Of note, the Co-TCPP NSs also demonstrate its potential for the electro-Fenton process with a cumulative H2O2 concentration of 1.21 wt%, highlighting its practical potential in portable H2O2 generation electrochemical devices for distributed applications. Our findings demonstrated that the efficient H2O2 electrosynthesis could be attributed to the attenuated *OOH adsorption over Co-N4 moiety on the Co-TCPP NSs, which consequently suppresses its further reduction to form H2O. This work highlights the potential of 2D MOF architecture for the 2e− ORR and provides an atomic-level insight into the enhanced H2O2 selectivity.

Z-Scheme g-C3N4-Au-MoO3-x heterojunction for boosted photocatalytic H2O2 production and enhanced selective oxidation of cyclohexane

Rational design of Z-Scheme photocatalyst with outstanding charge separation and robust redox capabilities for photocatalytic H2O2 generation and cyclohexane oxidation under mild conditions still poses a significant hurdle. In response to this challenge, ternary g-C3N4-Au-MoO3-x composite catalyst was developed though combining in-situ reduced MoO3-x-Au composite and exfoliated g-C3N4 nanosheets using an ultrasonic liquid-phase approach. In addition, variations in the synthesis procedures led to the preparation of g-C3N4−MoO3-x, g-C3N4-Au, and Au-g-C3N4−MoO3-x composites, aimed at exploring their effectiveness in both H2O2 production and catalyzing cyclohexane oxidation. Notably, the g-C3N4-Au-MoO3-x composite exhibited an impressive optical rate of H2O2 generation at 723.18 µmol·L−1·h−1, achieving a 11.94-fold enhancement compared to Au-g-C3N4−MoO3-x. Meanwhile, the conversion rate of cyclohexane reached 11.59 %, with a high selectivity of 97.43 % towards KA oil (cyclohexanol and cyclohexanone), and a KA oil production rate of 1166.86 µmol·L−1·g−1. Through analyzing the photoelectrochemical properties and band energy structures, it has been established that the involvement of an Au mediator was essential and vital for the Z-Scheme electron transfer in g-C3N4-Au-MoO3-x. The incorporation of a Z-scheme heterojunction has resulted in increased light absorption, reduced charge recombination rates, and a substantial elevation in the levels of ·O2− and ·OH radicals, leading to a significant enhancement in photocatalytic efficiency for both H2O2 generation and cyclohexane oxidation. This study opens the door to on-site immediate production of hydrogen peroxide to boost the oxidation efficiency in the photocatalytic cyclohexane oxidation process.

Reactive oxygen boosts photocatalytic oxytetracycline degradation and H2O2 production by K, O and cyano co-modified carbon nitride

Engineering photocatalysts to enhance the production of reactive oxygen species holds great importance in realizing effective water purification and hydrogen peroxide (H2O2) generation. Herein, the K, O, and cyano co-modified carbon nitride (KOCN) was constructed using thermal polymerization. Under visible light irradiation, KOCN showed excellent oxytetracycline hydrochloride (OTC) degradation efficiency and H2O2 generation rate. During the photocatalysis, rich reactive oxygens involving ·O2-, 1O2, H2O2, and ·OH were detected. Additionally, the production of H2O2 was attributed to a two-step single-electron oxygen reduction reaction (ORR). DFT and characterization analyses confirmed that the doping of K and O as well as the formation of cyano groups expanded the visible light response range, adjusted the band structure, and improved the separation of photogenerated carriers. This study presents a novel approach for developing efficient, stable, and reusable photocatalysts to address contemporary environmental challenges.

Site engineering of linear conjugated polymers to regulate oxygen adsorption affinity for boosting photocatalytic production of hydrogen peroxide without sacrificial agent

Artificial photosynthesis of hydrogen peroxide (H2O2) is a hopeful alternative to the industrial anthraquinone process. However, rational fabrication of the photocatalysts for the production of H2O2 without any sacrificial agents is still a formidable challenge. Herein, two kinds of linear conjugated polymers (LCPs) including pyridinic N functionalized polymer (DEB-N2) and pyridinic N non-contained polymer (DEB-N0) were successfully synthesized. DEB-N2 displays enhanced light capturing ability and good dispersion in water, leading to a substantial initial H2O2 generation rate of 3492μmol g-1h−1 as well as remarkable photocatalytic stability in pure water. Furthermore, the temperature programmed desorption (TPD) and density functional theory (DFT) analysis reveal that highly electronegative pyridine-N atoms in DEB-N2 boost the adsorption affinity of oxygen molecules, which facilitates the occurrence of the oxygen reduction reaction, therefore enhancing the performance of photocatalytic H2O2 production. This study unveils that the presence of pyridinic N in DEB-N2 has a significant impact on photocatalytic H2O2 production, suggesting the precise manipulation of the chemical structure of polymer photocatalysts is essential to achieve efficient solar-to-chemical energy conversion.

Interface-engineering derived WS2/S-g-C3N4 nanosheet Z-scheme heterostructures towards enhanced photocatalytic redox and H2O2 generation

The growth of WS2 on S-doped graphic carbon nitrides (g-C3N4) was controlled to utilize horizontal implanting and get fine interfacial characteristic. Superior thin S-doped g-C3N4 nanosheets were fabricated via a two-step thermal polymerization at high temperature. Subsequent solvothermal procedure was used to create WS2/S-g-C3N4 (WS2/SCN) photocatalytic heterojunctions with optimized component ratios, in which doped S components in g-C3N4 play an important role for the horizontal growth and homogeneous distribution of WS2 nanosheets. Z-scheme charge transfer mechanism was proposed according to various characterizations. Photocatalytic rhodamine B (Rh B) degradation test indicated that WS2/SCN 15 % (sample WS2/SCN-3) revealed the best performance, in which Rh B of 92.8 % was photocatalytic oxidated with 20 min. Photocatalytic hydrogen generation experiments indicated that sample WS2/SCN-3 exhibited a H2 generation rate of 1380 μmol·g−1∙h−1, which was 3.7 times of that of S-g-C3N4 nanosheets. These WS2/S-g-C3N4 heterojunctions also exhibited excellent performance for photocatalytic H2O2 evolution. Sample WS2/SCN-3 exhibited a H2O2 generation rate of 5216 μmol·g−1·h−1 which was 6.4 times that of S-g-C3N4 sample. This excellent photocatalytic activity is scribed to WS2/S-g-C3N4 layered heterojunctions with well-developed interface characteristic. The result supplied an efficient approach for the preparation of photocatalysts.

Overcome the trade-off in electro-fenton chemistry for in situ H2O2 generation-activation by tandem CoFe bimetallic single-atom configuration

Dual-atomic catalysts (DACs) demonstrated remarkable potential in addressing key challenges in electro-Fenton (EF) processes. In this study, we synthesized an EF DACs comprising both CoN4 and FeN4 sites, which was achieved a high H2O2 generation rate (1.68 mM−1h−1) and 100 % bisphenol A degradation efficiency via successive two-electron oxygen reduction and one-electron Fenton reactions (2e− ORR + 1e− Fenton). Our findings indicated that the single-atom nitrogen coordination of CoN4 and FeN4 sites plays crucial roles in regulating the adsorption of key intermediates of *OOH and *H2O2. The bimetallic sites independently regulated the binding energies of *OOH on CoN4 (pyrrole-type) for favorable H2O2 generation and its subsequent activation on adjacent FeN4 (pyridine-type). Thus, the dual-site engineering addresses the trade-off of in situ H2O2 generation-activation in EF chemistry, realizing high electron utilization efficiency and fast pollutant degradation toward efficient and sustainable water treatment.

Enhancement of H2O2 generation rate in porphyrin photocatalysts via crystal facets regulation to create strong internal electric field

Enhancement of H2O2 generation rate in porphyrin photocatalysts via crystal facets regulation to create strong internal electric field

The overlooked reaction of H2O2 decomposition over carbonaceous cathodes

Electrochemical 2-electron oxygen reduction over carbon cathode is an important method to produce H2O2 in situ. Besides the H2O2 generation rate, the H2O2 decomposition rate is also crucial to the cumulative concentration of H2O2. It is generally believed that H2O2 decomposition will produce H2O and O2 by electro-reduction or carbon catalysis. Herein, a new H2O2 decomposition pathway is proved: carbonaceous materials may react with H2O2 spontaneously to release CO2 and CO at room temperature and atmospheric pressure. At low H2O2 concentrations, the reaction produced CO mainly and then CO2. But at high H2O2 concentrations, CO2 was a preponderant product over CO. The reaction was exothermal which causes the rise of solution temperature, promoting H2O2 decomposition to produce O2. The continuous decomposition of H2O2 raised the pH value, while the generated CO2 dissolved in the solution to reduce the pH value. These two effects together determined pH tendency. With the increase of pH value, H2O2 decomposition triggered by alkaline conditions produced H2O and O2. The applied negative voltage accelerated H2O2 decomposition via reacting with charcoal. Furthermore, this reaction showed universality to carbonaceous materials. The above results are of great value for understanding the decomposition mechanism of H2O2 and setting a reasonable target for cumulative H2O2 concentration via electrochemical oxygen reduction.

Asymmetric acceptor-donor-acceptor type covalent organic frameworks with dual O2 reduction moieties for boosting H2O2 photosynthesis

The study of hydrogen peroxide production by O2 reduction reaction using covalent organic framework (COF) photocatalysts has attracted extensive attention in recent years. However, there are still great challenges in accurately controlling their structures to achieve rapid carrier separation and efficient O2 reduction. Based on this, we constructed the A1-D-A2 COF photocatalytic material (TT-DTDA-COF) with asymmetric dual acceptor sites by connecting thieno [3,2-b] thiophene, benzene, and triazine as the basic units through imine bonds. Under the synergistic effect of thieno [3,2-b] thiophene and triazine electron acceptors, the separation and transfer efficiency of TT-DTDA-COF photogenerated carriers was significantly enhanced. At the same time, according to the in-situ infrared and DFT calculation results, it was found that these two acceptor units served as O2 reduction sites, which realized the multi-site adsorption reduction of O2, and effectively enhanced the efficiency of photocatalytic O2 reduction to H2O2. The experimental results showed that the H2O2 generation rate of TT-DTDA-COF with A1-D-A2 dual receptor structure was 1302 μmol·g−1·h−1 under visible light irradiation, which was 3.4 times higher than that of TB-DTDA-COF with single receptor D-A structure and higher than that of most of the materials reported so far. This study provides a new idea for accurately designing COF-based photocatalysts to achieve efficient O2 reduction to produce H2O2.

Grafting small organic molecules on donor-acceptor polymers to regulate electron push-pull interactions for efficient H2O2 production

Pyrene units are grafted on a D-A polymer by amidation to construct a D + -A structure and improve H2O2 production. Experimental results show that the H2O2 generation rate of this D + -A polymer (PTM-PY) is 2.94 mmol g−1 h−1, which is higher than the original D-A polymer (PTM) under the same conditions. Mechanistic studies reveal that the increased photocatalytic performance of PTM-PY is attributed to the enhanced light-harvesting capacity and electron push-pull interactions after grafting pyrene as a donor. Therefore, grafting the appropriate small organic molecules on the D-A polymer skeleton can improve their performance further, in addition to the routine methods of optimizing the donor/acceptor ratio and reaction conditions. This is the first report of small organic molecules grafted on a D-A polymer to construct a D + -A polymer for photocatalytic H2O2 generation.

N and O vacancies regulation over semiconductor heterojunction to synergistically boost photocatalytic hydrogen peroxide production

Defect engineering represents a potent strategy for the modification of electronic properties by introducing atomic vacancies in photocatalysts. However, the synergistic enhancement attributable to different types of atomic vacancies within a heterojunction, as well as their underlying mechanisms, remains sparsely studied. Here, the flexible g-C3N4 materials with varying nitrogen vacancies were prepared via a facile calcination method under different atmospheric conditions and then composited with CeO2 nanocubes to construct Z-scheme heterojunction. It was observed that CeO2 has abundant O vacancies, and the g-C3N4 form tertiary nitrogen defects at the center of the heptazine units under an NH3 atmosphere treatment. The resulting enhancement in the interfacial built-in electric field, coupled with the synergistic effect of O and N vacancies within the Z-scheme heterojunction, has been demonstrated to significantly enhance charge transfer efficiency. This results in an optimized photoactivity with a H2O2 generation rate of 2.01 mmol g–1 h–1. This work opens an avenue for constructing and optimizing the heterogeneous photocatalysts by defect engineering technology, and provides deep insight to understand the nature of vacancy engineering in designing effective catalysts for solar energy conversion.

Carbon Quantum Dots Confined into Covalent Triazine Frameworks for Efficient Overall Photocatalytic H2O2 Production

AbstractPorous organic polymers have an outstanding performance in the field of photocatalysis with the advantage of diverse structure composition and purposeful molecular design. However, the inherent high impedance and poor electrical conductivity of organic semiconductors still restrict the charge transfer efficiency and thus discount the photocatalytic performance. Herein, the study reports a highly conductive covalent triazine framework (CTF) loading carbon quantum dots (CQDs) into porous as electron transport medium. The addition of CQDs (0.5 wt%) can enhance the electronic conductivity of CTF by tenfold. In addition, the as‐prepared CQD‐CTFs express much‐promoted charge separation and transfer efficiency. Furthermore, the embedded CQDs can improve the oxidization capacity and increase the affinity of H+ due to the more negative zeta potential. The enhanced oxidizing ability and increased H+ affinity are positive for water oxidation reaction (WOR) and oxygen reduction reaction (ORR) process in hydrogen peroxide (H2O2) generation, respectively. The optimized CQD‐CTF exhibits a high H2O2 generation rate of up to 1036 µmol g−1 h−1 in pure water without any sacrificial agent under visible light, which is 4.6 times than pristine CTF. This work provides a new idea for efficient H2O2 production of organic semiconductors.

Cationic surface polarization centers on ionic carbon nitride for efficient solar-driven H2O2 production and pollutant abatement

Solar-driven H2O2 production and emerging organic pollutants (EOPs) elimination are of great significance from the perspective of environmental sustainability. The efficiency of the photocatalytic reaction system is the key challenge to be addressed. In this work, the strategy of constructing surface ionic local polarization centers to enhance the exciton dissociation of the polymeric photocatalytic is demonstrated. Selected bipyridinium cation (TMAP) is complexed on a K+-incorporated carbon nitride (CNK) framework, and the combination of local polarization centers both on the surface (bipyridinium cation) and bulk (K+ cation) contributes to a superior photocatalytic H2O2 production performance, affording a remarkable H2O2 generation rate of 46.8 µmol h−1 mg−1 and a high apparent quantum yield (AQY) value of 77.5% under irradiation of 405 nm photons. As substantiated experimentally by steady state/transient spectroscopy techniques, the surface local polarization centers increase the population of the long-lived trapped electrons, and thereby promote the interfacial charge transfer process for chemical conversion reaction. The strategy is potentially applicable to the design of a wide range of efficient solar-to-chemical conversion systems.

Deciphering the Kinetics of Spontaneous Generation of H2O2 in Individual Water Microdroplets.

Spontaneous generation of H2O2 in sub-10 μm-sized water microdroplets has received increasing interest since its first discovery in 2019. On the other hand, due to the short lifetime of these microdroplets (rapid evaporation) and lack of suitable tools to real-time monitor the generation of H2O2 in individual microdroplets, such a seemingly thermodynamically unfavorable process has also raised vigorous debates on the origin of H2O2 and the underlying mechanism. Herein, we prepared water microdroplets with a long lifetime (>1 h) by virtue of microwell confinement and dynamically monitored the spontaneous generation of H2O2 in individual microdroplets via time-lapsed fluorescence imaging. It was unveiled that H2O2 was continuously generated in the as-prepared water microdroplets and an apparent equilibrium concentration of ∼3 μM of H2O2 in the presence of a H2O2-consuming reaction can be obtained. Through engineering the geometry of these microdroplets, we further revealed that the generation rates of H2O2 in individual microdroplets were positively proportional to their surface-to-volume ratios. This also allowed us to extract a maximal H2O2 generation rate of 7.7 nmol m-2 min-1 in the presence of a H2O2-consuming reaction and derive the corresponding probability of spontaneous conversion of interfacial H2O into H2O2 for the first time, that is, ∼1 of 65,000 water molecules in 1 s. These findings delivered strong evidence that the spontaneous generation of H2O2 indeed occurs at the surface of microdroplets and provided us with an important starting point to further enhance the yield of H2O2 in water microdroplets for future applications.

Atomically Dispersed Iron Active Sites on Covalent Organic Frameworks for Artificial Photosynthesis of Hydrogen Peroxide

AbstractArtificial photosynthesis has been regarded as a promising solution toward solar energy conversion, generating storable and transportable chemical fuels such as hydrogen (H2) and hydrogen peroxide (H2O2). However, the design of robust catalytic sites not only affects the activity, but also identify the atomic‐level correlation between active sites and natural photosynthesis performance. Herein, a synthesis method of single‐atomic Iron (Fe) active sites anchored on novel covalent organic framework (COF) for the production of H2O2 under visible light irradiation. When benzyl alcohol is the most sacrificial agent, the state‐of‐the‐art Fe‐based COF exhibits an excellent H2O2 generation rate of 4130 µmol g−1 h−1, over 5.3 times higher than that of pristine COF, achieving an apparent quantum yield of 6.4% at 420 nm. The enhanced photocatalytic performance is ascribed to the synergistic effect of atomically dispersed Fe sites and COF hosts, reducing the reaction energy barrier for the formation of *OOH intermediates and optimizing the adsorption of O2 and thus promoting two‐electron oxygen reduction reaction (ORR). This work establishes an atomic‐level engineering approach to build atomically dispersed Fe active sites on COF photocatalysts and provides in‐depth insight upon the ORR mechanism for promising artificial photosynthesis of H2O2.

Anthraquinone centers modified covalent organic frameworks for boosted photocatalytic O2-to-H2O2 synthesis: Inhibiting the in-situ decomposition of H2O2

Photocatalytic O2 reduction presents a sustainable strategy for H2O2 synthesis, while the in-situ decomposition of H2O2 significantly deteriorates the activity and stability. Here, by introducing anthraquinone centers into covalent organic frameworks (DQTb-COFs), for the first time, we realized the suppression of in-site decomposition of generated H2O2via site-engineering of COFs. Under visible light irradiation, DQTb-COFs achieves an H2O2 generation rate of 1844.1 μmol h−1 g−1 without sacrificial agents, which is about 3.4 times that of its counterpart without anthraquinone centers (DATb-COFs). The generated H2O2 on DATb-COFs is readily reduced into hydroxyl radicals (•OH), which is not observable on DQTb-COFs. Experiments and calculations demonstrated that the anthraquinone centers of DQTb-COFs can enhance the generation of H2O2 by facilitating the utilization of O2 and promoting the desorption of H2O2. This work highlights how to inhibit the in-situ decomposition of H2O2via site-engineering of COFs, and blazes a new trail for highly efficient H2O2 photosynthesis.

Triggering Dual Two-electron Pathway for H2 O2 Generation by Multiple [Bi-O]n Interlayers in Ultrathin Bi12 O17 Cl2 towards Efficient Piezo-self-Fenton Catalysis.

Piezo-self-Fenton system (PESF) has been emerging as a promising water treatment technology but suffering from unsatisfied H2 O2 production efficiency. Herein, we rationally design a Bi12 O17 Cl2 piezo-catalyst with multiple [Bi-O]n interlayers towards highly efficient H2 O2 production. The introduction of [Bi3 O4.25 ] layers initiates dual two-electron pathway for H2 O2 generation by altering the interlayer properties. It is found that the additional [Bi3 O4.25 ] layers not only enhance the polarization electric field but also serve as active sites for triggering dual pathways of two-electron O2 reduction and H2 O oxidation reaction for H2 O2 production. Therefore, the Bi12 O17 Cl2 exhibits an ultrahigh rate of H2 O2 generation (7.76 mM h-1 g-1 ) in pure water. Based on the adequate H2 O2 yield, a PESF was constructed for acetaminophen (ACE) degradation with an apparent rate constant of 0.023 min-1 . This work not only presents a potential strategy of tuning the activity of bismuth based piezo-catalysts but also provides a good example on the construction of highly efficient PESF for environmental remediation by using natural mechanical energy.