Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLD...Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.展开更多
Hydrogen peroxide(H_(2)O_(2)),as a green oxidant,plays a vital role in various applications,including environmental remediation,disinfection,and chemical synthesis[1].The conventional anthraquinone process,despite its...Hydrogen peroxide(H_(2)O_(2)),as a green oxidant,plays a vital role in various applications,including environmental remediation,disinfection,and chemical synthesis[1].The conventional anthraquinone process,despite its industrial maturity and high yield,suffers from high energy consumption,carbon emissions,safety risks,and reliance on precious metals[2].Despite ongoing optimizations,a more sustainable alternative is urgently needed.The direct synthesis of hydrogen peroxide from water and oxygen has long been considered as an ideal alternative due to its theoretical 100%atom efficiency and environmental sustainability.展开更多
BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)i...BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)is the most advanced nonin-vasive preoperative method.However,it is limited in its visualization function.AIM To investigate the use of intraluminal MRI for perianal fistulas via a novel direct MRI fistulography method.METHODS We mixed 3%hydrogen peroxide(HP)with gadolinium for HPMRI fistulogra-phy,retrospectively analyzing 60 cases of complex/recurrent fistula-in-ano using physical examination,trans-perineal ultrasonography(TPUS),low-spatial-reso-lution MRI,and high-resolution direct HPMRI fistulography.We assessed detec-tion rates of fistula tracks,internal openings,their relationship with anal sphinc-ters,and perianal abscesses using statistical analyses,including interobserver agreement(Kappa statistic),and compared results with intraoperative findings.RESULTS Surgical confirmation in 60 cases showed that high-resolution direct HPMRI fis-tulography provided superior detection rates for internal openings(153)and fistula tracks(162)compared to physical exams,TPUS,and low-spatial-resolution MRI(Z>5.7,P<0.05).The effectiveness of physical examination and TPUS was also inferior to that of our method for detecting perianal abscesses(54)(Z=6.773,3.694,P<0.05),whereas that of low-spatial-resolution MRI was not significantly different(Z=1.851,P=0.06).High-resolution direct HPMRI fistulography also achieved the highest interobserver agreement(Kappa:0.89,0.85,and 0.80),while low-spatial-resolution MRI showed moderate agreement(Kappa:0.78,0.74,and 0.69).TPUS and physical examination had lower agreement(Kappa range:0.33-0.63).CONCLUSION High-resolution direct HPMRI fistulography enhances the visualization of recurrent and complex fistula-in-ano,including branched fistulas,allowing for precise planning and improved surgical outcomes.展开更多
Selective electrocatalysis of two-electron oxygen reduction reaction(2e^(-)ORR)has been recognized as a sustainable and on-site process for hydrogen peroxide(H_(2)O_(2))production.Great progress has been achieved for ...Selective electrocatalysis of two-electron oxygen reduction reaction(2e^(-)ORR)has been recognized as a sustainable and on-site process for hydrogen peroxide(H_(2)O_(2))production.Great progress has been achieved for 2e^(-)ORR in alkaline media.However,it is challenged by insufficient activity and selectiv-ity of the catalysts in acidic electrolytes.Herein,we report sulfur-poisoned PtNi/C catalysts(PtNiSx/C)that could regulate ORR from the 4e^(-)to 2e^(-)pathway.The identified PtNiS0.6/C offers high activity in terms of onset potential of∼0.69 V(vs.RHE)and∼80%selectivity.The mass activity is also compara-ble and outperforms representative Pt-based precious and transition-metal-based catalysts.In addition,it is interestingly found that the Faradaic efficiency further increased to 95%during the long-term elec-trolysis test due to Ni atom surface migration.The electrochemical production of the H_(2)O_(2)system was applied to the electro-Fenton process,which has realized the effective degradation of organic pollutants.This work offers a strategy by sulfur poisoning PtNi/C catalyst to realize Pt-based 2e^(-)ORR active catalysts to electrolysis of H_(2)O_(2)in acidic media.展开更多
Hydrogen peroxide(H_(2)O_(2))is a crucial,eco-friendly oxidizing agent with a wide range of industrial,environmental,and biomedical applications.Traditional production methods,such as the anthraquinone process,face si...Hydrogen peroxide(H_(2)O_(2))is a crucial,eco-friendly oxidizing agent with a wide range of industrial,environmental,and biomedical applications.Traditional production methods,such as the anthraquinone process,face significant challenges in terms of energy consumption and environmental impact.As a sustainable alternative,photocatalytic H_(2)O_(2) production,driven by solar energy,has emerged as a promising approach.This review discusses the key advancements in photocatalytic H_(2)O_(2) synthesis,focusing on overcoming challenges such as charge recombination,selectivity for the two-electron oxygen reduction reaction(2e^(-)ORR),and catalyst stability.Recent innovations in photocatalyst design,including high-entropy materials,single-atom catalysts,and covalent organic frameworks(COFs),have significantly enhanced efficiency and stability.Furthermore,novel strategies for optimizing charge separation,light harvesting,and mass transfer are explored.The integration of artificial intelligence and bioinspired systems holds potential for accelerating progress in this field.This review provides a comprehensive overview of current challenges and cutting-edge solutions,offering valuable insights for the development of scalable,decentralized H_(2)O_(2) production systems that contribute to a more sustainable future.展开更多
A mesocosm-based study was conducted to assess the effect of glucose and hydrogen peroxide on periphyton communities. These chemicals have been found to be effective at controlling cyanobacteria blooms in the water co...A mesocosm-based study was conducted to assess the effect of glucose and hydrogen peroxide on periphyton communities. These chemicals have been found to be effective at controlling cyanobacteria blooms in the water column but their impact on attached communities is unknown. The experimental design included a total of 4 treatments: control (no chemicals;3 replicates);hydrogen peroxide (3 replicates);glucose alone (3 different concentrations [no replicates]);and additive glucose (3 replicates). After 34 days, mean values of chlorophyll a were lower in all experimental treatments compared to the control;mean AFDM values were lower in all treatments except the unreplicated high glucose alone treatment. In contrast, mean autotrophic index values (AFDM/chlorophyll a) were greater in all treatments compared to the control, indicating heterotrophs were more resistant to the chemical treatments than autotrophs. Periphyton community biodiversity was much lower in the additive glucose and moderate glucose alone treatments than the hydrogen peroxide and control treatments. The relative abundance of the bacteria Asticcacaulis and Sphingorhabdus responded positively to the glucose treatments, whereas relative abundance of Nevskia and Caenimonas declined in both the hydrogen peroxide and glucose treatments. In terms of relative abundance, no cyanobacteria taxa were detected among the top 20 taxa. We conclude that the autotrophic component of periphyton communities is especially vulnerable to hydrogen peroxide and glucose treatments, and that any management strategy employing these chemicals should be aware of this potential impact.展开更多
Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants.Hydrogen peroxide,commonly found in natural water at micromolar concentrations,possesses much more aggre...Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants.Hydrogen peroxide,commonly found in natural water at micromolar concentrations,possesses much more aggressive oxidation ability than oxygen and can complicate the pyrrhotite oxidation process.Here,the effects of micromolar H_(2)O_(2) on the biotic and abiotic oxidation of pyrrhotite were examined at pH 1.93 and 6.45,respectively.Pyrrhotite oxidation was much more severe in acidic solutions compared to near neutral solutions.Jarosite with a high Fe/S molar ratio was widely detected in the precipitate collected in acidic solutions,and the introduction of external H_(2)O_(2) influenced the crystallinity of jarosite.A layer of iron-deficient iron-sulfur oxide formed on the surface of pyrrhotite prevents its continuous oxidation,and the presence of Acidithiobacillus ferrooxidans enhanced this situation by promoting the release of Fe from the pyrrhotite.Additionally,the presence of external micromolar H_(2)O_(2) also determined the elemental state on pyrrhotite surface,as it found that the contribution of Fe^(3+)and S(S^(4+)and S^(6+))species on pyrrhotite surface increased with the increase of H_(2)O_(2) concentration in the solutions,especially in the presence of Acidithiobacillus ferrooxidans.展开更多
Enhancing rubber-bitumen compatibility is crucial to improve pavement performance and durability.To investigate the compatibility improvement between H2O2-activated waste crumb rubber(AWCR)and bitumen,coarse and fine ...Enhancing rubber-bitumen compatibility is crucial to improve pavement performance and durability.To investigate the compatibility improvement between H2O2-activated waste crumb rubber(AWCR)and bitumen,coarse and fine waste crumb rubber(WCR)were treated and analyzed through multi-scale characterization and molecular simulation.Microstructure and chemical changes of WCR and AWCR were analyzed with scanning electron microscope(SEM),contact angle tests and Fourier transform infrared spectroscopy(FTIR).Compatibility was also indirectly evaluated through modified boiling tests and storage stability tests.Besides,molecular dynamics was used to explore the interaction between WCR/AWCR and bitumen.SEM,contact angle,and FTIR results showed bond breakage of C=C and C–C and increased polar groups like–OH and–COOH in AWCR,resulting in a rougher texture and higher surface energy.Compared with WCR,AWCR showed a lower bitumen stripping rate after boiling,and the binder with AWCR also had a lower softening point difference and segregation rate after storage.Molecular dynamics simulations further confirmed that AWCR has a closer solubility parameter and higher binding energy to bitumen than WCR,reflected in a relatively slower diffusion rate.This study provides comprehensive evidence for an eco-friendly method of WCR surface treatment for more efficient recycling of tire rubber in asphalt pavements.展开更多
This letter addresses Pravda's innovative review,which proposes hydrogen pe-roxide as the primary pathogenic factor in ulcerative colitis(UC).Although the author presents intriguing mechanistic insights and report...This letter addresses Pravda's innovative review,which proposes hydrogen pe-roxide as the primary pathogenic factor in ulcerative colitis(UC).Although the author presents intriguing mechanistic insights and reports encouraging clinical outcomes with reducing agents,several methodological and clinical considera-tions require discussion.We examine three key aspects:The selective evidence synthesis approach;the need for rigorous clinical validation of proposed thera-pies;and the integration of this novel hypothesis with established inflammatory bowel disease pathogenesis.Given the complexity of UC,future therapeutic ad-vances may require collaborative approaches that integrate redox-based mecha-nisms into existing evidence-based frameworks rather than replacing current paradigms.展开更多
The photocatalytic hydrogen peroxide(H_(2)O_(2))production by graphitic carbon nitride is a sustainable and environment-benign alternative approach of conventional anthraquinone autoxidation technology,but it is great...The photocatalytic hydrogen peroxide(H_(2)O_(2))production by graphitic carbon nitride is a sustainable and environment-benign alternative approach of conventional anthraquinone autoxidation technology,but it is great challenges to promote two-electron O_(2)reduction and water oxidation.Herein,we present the well-dispersed graphitic carbon nitride quantum dots decorated with cyano groups(Na-CNQD and K-CNQD)by thermal polymerization of melamine in the presence of metal fluoride.The quantum confinement and edge effect have endowed the photocatalysts with rich active sites,wide light absorption range and the inhibited charge recombination.The cyano moieties function as O_(2)reduction centers to accept the photogenerated electrons and facilitate their rapid transfer to O_(2)molecules.This process enables the selective two-electron reduction of O_(2),leading to the production of H_(2)O_(2).Concurrently,the valence band holes on the heptazine moiety oxidize water into H_(2)O_(2).These synergistic effects promote photocatalytic H_(2)O_(2)production from O_(2)and H_(2)O without the need for additional photosensitizers,organic scavengers and co-catalysts.In contrast,pristine carbon nitride nanosheets remain inactive under the same conditions.This study offers new strategies for rational design of carbon-based materials for solar-to-chemical energy conversion.展开更多
Mesenchymal stem cells(MSCs)possess unique properties such as immunomodu-lation,paracrine actions,multilineage differentiation,and self-renewal.Therefore,MSC-based cell therapy is an innovative approach to treating va...Mesenchymal stem cells(MSCs)possess unique properties such as immunomodu-lation,paracrine actions,multilineage differentiation,and self-renewal.Therefore,MSC-based cell therapy is an innovative approach to treating various degenera-tive illnesses,including cardiovascular diseases.However,several challenges,including low transplant survival rates,low migration to the ischemic myocar-dium,and poor tissue retention,restrict the application of MSCs in clinical settings.These undesirable cell therapy outcomes mainly originated due to the overproduction of reactive oxygen species(ROS)in the injured heart.MSCs'stress-coping capacity can be enhanced by preconditioning them under conditions similar to the microenvironment of wounded tissues.Hydrogen peroxide(H_(2)O_(2))is a ROS that has been shown to activate protective cellular mechanisms such as survival,proliferation,migration,paracrine effects,and differentiation at suble-thal doses.These processes are induced via phosphatidylinositol 3-kinase/protein kinase B,p38 mitogen-activated protein kinases,c-Jun N-terminal kinase,Janus kinase/signal transducer and activator of the transcription,Notch1,and Wnt sig-naling pathways.H_(2)O_(2) preconditioning could lead to many clinical benefits,including ischemic injury reduction,enhanced survival of cellular transplants,and tissue regeneration.In this review,we present an overview of stem cell preconditioning methods and the biological functions activated by H_(2)O_(2) precondi-tioning.Furthermore,this review explores the molecular mechanisms underlying the protective cellular functions stimulated under H_(2)O_(2) preconditioning.展开更多
Photocatalytic H_(2)O_(2) production still confronts the challenges of its dependence on organic electron donors or high-purity O_(2),which restricts the practical application,and there are few studies on the photo sy...Photocatalytic H_(2)O_(2) production still confronts the challenges of its dependence on organic electron donors or high-purity O_(2),which restricts the practical application,and there are few studies on the photo synthesis of H_(2)O_(2) via both oxygen reduction reaction(ORR)and water oxidation reaction(WOR).In this paper,bismuth yttrium oxyhalides Bi_(2)YO_(4)X(X=Cl,Br,or I)are demonstrated to afford sufficient driving forces to produce H_(2)O_(2) in the absence of sacrificial reagents.After modification with Pt and IrO_(2) as cocatalysts,which can selectively promote both ORR and WOR reactions on Bi_(2)YO_(4)Cl,the IrO_(2)-Pt/Bi_(2)YO_(4)Cl sample yields H_(2)O_(2) production activity of 647μmol L^(-1)h^(-1)with negligible decay in the long-term reaction using only H_(2)O and an air atmosphere as the electron donors and O_(2) source.Detailed characterizations reveal that the ORR reaction obeys a two-electron pathway.We present the first example of oxyhalides(Bi_(2)YO_(4)X)capable of efficient photocata lytic H_2O_(2) generation with record-breaking activity.展开更多
As a versatile and environmentally benign oxidant,hydrogen peroxide(H_(2)O_(2))is highly desired in sanitation,disinfection,environmental remediation,and the chemical industry.Compared with the conventional anthraquin...As a versatile and environmentally benign oxidant,hydrogen peroxide(H_(2)O_(2))is highly desired in sanitation,disinfection,environmental remediation,and the chemical industry.Compared with the conventional anthraquinone process,the electrosynthesis of H_(2)O_(2)through the two-electron oxygen reduction reaction(2e^(−)ORR)is an efficient,competitive,and promising avenue.Electrocatalysts and devices are two core factors in 2e^(−)ORR,but the design principles of catalysts for different pH conditions and the development trends of relevant synthesis devices remain unclear.To this end,this review adopts a multiscale perspective to summarize recent advancements in the design principles,catalytic mechanisms,and application prospects of 2e^(−)ORR catalysts,with a particular focus on the influence of pH conditions,aiming at providing guidance for the selective design of advanced 2e^(−)ORR catalysts for highly-efficient H_(2)O_(2)production.Moreover,in response to diverse on-site application demands,we elaborate on the evolution of H_(2)O_(2)electrosynthesis devices,from rotating ring-disk electrodes and H-type cells to diverse flow-type cells.We elaborate on their characteristics and shortcomings,which can be beneficial for their further upgrades and customized applications.These insights may inspire the rational design of innovative catalysts and devices with high performance and wide serviceability for large-scale implementations.展开更多
Cobalt pentlandite(Co9S8)is a promising non-precious catalyst due to its superior oxygen reduction reaction activity and excellent stability.However,its oxygen reduction reaction catalytic activity has traditionally b...Cobalt pentlandite(Co9S8)is a promising non-precious catalyst due to its superior oxygen reduction reaction activity and excellent stability.However,its oxygen reduction reaction catalytic activity has traditionally been limited to the four-electron pathway because of strong*OOH intermediate adsorption.In this study,we synthesized electron-deficient Co9S8 nanocrystals with an increased number of Co^(3+)states compared to conventional Co9S8.This was achieved by incorporating a high density of surface ligands in small-sized Co9S8nanocrystals,which enabled the transition of the electrochemical reduction pathway from four-electron oxygen reduction reaction to two-electron oxygen reduction reaction by decreasing*OOH adsorption strength.As a result,the Co^(3+)-enriched Co9S8 nanocrystals exhibited a high onset potential of 0.64 V(vs RHE)for two-electron oxygen reduction reaction,achieving H_(2)O_(2) selectivity of 70-80%over the potential range from 0.05 to 0.6 V.Additionally,these nanocrystals demonstrated a stable H_(2)O_(2) electrosynthesis at a rate of459.12 mmol g^(-1) h^(-1) with a H_(2)O_(2) Faradaic efficiency over 90%under alkaline conditions.This study provides insights into nanoscale catalyst design for modulating electrochemical reactions.展开更多
H_2O_(2) is one of the most important chemicals in the world.Recently,the electrochemical synthesis of H_2O_(2)by two-electron oxygen reduction reaction(2e^(-)ORR)has attracted great interest.Carbon-based catalysts sh...H_2O_(2) is one of the most important chemicals in the world.Recently,the electrochemical synthesis of H_2O_(2)by two-electron oxygen reduction reaction(2e^(-)ORR)has attracted great interest.Carbon-based catalysts show great promise for electrocatalytic production of H_2O_(2),due to the ease of regulation of the carbon materials with regard to the pore structure,surface properties,and heteroatom doping.Biomass as the carbon precursor has the advantages of low cost,sustainable supply,and extensive availability.Conversion of biomass to functional carbon-based materials shows the attractive merits,such as low carbon emission in the life cycle and diversity of the obtained carbon materials due to the wide source of biomass feedstocks.In this article,a comprehensive review on the mechanisms and processes of electrochemical synthesis of H_2O_(2) by 2e^(-)ORR over carbon-based catalysts is provided.The potential biomass feedstock used for obtaining the carbon-based catalysts,and the strategies to prepare the catalysts by carbonization and heteroatom doping,as well as optimization of electrodes and design of electrolyzer,are discussed.It is recommended that future work focus on developing efficient methods to prepare the catalysts from low-cost biomass feedstock,understanding the mechanisms of 2e^(-)ORR over the catalysts,optimization of electrode materials loaded with biomass-derived catalysts,as well as development of electrolyzers for larger-scale applications.展开更多
Hydrogen peroxide(H_(2)O_(2))is an eco-friendly chemical with widespread industrial applications.However,the commercial anthraquinone process for H_(2)O_(2) production is energy-intensive and environmentally harmful,h...Hydrogen peroxide(H_(2)O_(2))is an eco-friendly chemical with widespread industrial applications.However,the commercial anthraquinone process for H_(2)O_(2) production is energy-intensive and environmentally harmful,highlighting the need for more sustainable alternatives.The electrochemical production of H_(2)O_(2) via the two-electron water oxidation reaction(2e^(−)WOR)presents a promising route but is often hindered by low efficiency and selectivity,due to the competition with the oxygen evolution reaction.In this study,we employed high-throughput computational screening and microkinetic modeling to design a series of efficient 2e^(−)WOR electrocatalysts from a library of 240 single-metal-embedded nitrogen heterocycle aromatic molecules(M-NHAMs).These catalysts,primarily comprising post-transition metals,such as Cu,Ni,Zn,and Pd,exhibit high activity for H_(2)O_(2) conversion with a limiting potential approaching the optimal value of 1.76 V.Additionally,they exhibit excellent selectivity,with Faradaic efficiencies exceeding 80%at overpotentials below 300 mV.Structure-performance analysis reveals that the d-band center and magnetic moment of the metal center correlated strongly with the oxygen adsorption free energy(ΔGO*),suggesting these parameters as key catalytic descriptors for efficient screening and performance optimization.This study contributes to the rational design of highly efficient and selective electrocatalysts for electrochemical production of H_(2)O_(2),offering a sustainable solution for green energy and industrial applications.展开更多
Photocatalytic hydrogen peroxide(H_(2)O_(2))production offers a sustainable route to convert water and oxygen into H_(2)O_(2)using solar energy.However,achieving long-term stability in photocatalysts remains a critica...Photocatalytic hydrogen peroxide(H_(2)O_(2))production offers a sustainable route to convert water and oxygen into H_(2)O_(2)using solar energy.However,achieving long-term stability in photocatalysts remains a critical challenge due to mismatched kinetics between oxygen reduction(ORR)and water oxidation(WOR),which leads to hole accumulation and oxidative degradation.Here,we report a redox-mediated strategy to address this bottleneck by designing a hydroquinone-embedded covalent organic framework(Tz-QH-COF)that enables reversible hole buffering and kinetic balance.The hydroquinone(QH)units act as dynamic hole reservoirs,capturing excess holes during ORR and converting to benzoquinone(Q),which is regenerated to QH via WOR,thereby preventing oxidative decomposition.This reversible QH/Q cycle,directly visualized through in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy,ensures unmatched stability,achieving continuous H_(2)O_(2) production for 528 h(22 d)with an accumulated yield of 18.6 mmol L^(–1)—the highest reported duration for organic photocatalysts.Density functional theory calculations reveal that the QH units exhibit a strong oxygen adsorption energy and favorable two-electron ORR/WOR pathways with low energy barriers.The synergy between experimental and theoretical insights elucidates a redox-mediated charge-balance mechanism,advancing the design of robust photocatalysts for solar-driven H_(2)O_(2) synthesis.展开更多
Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate...Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate interactions of the reactants,and limited active site exposure hinder treatment efficiency.Porous carbocatalysts with high specific surface area,tunable pore size,and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants.The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions.Additionally,the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites,which further enhances the catalytic activity.This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts.Moreover,engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances.Challenges and future research opportunities pertaining to the design,optimization,mechanistic investigation,and practical application of porous carbocatalysts in peroxide activation are also proposed.展开更多
Hydrogen peroxide(H_(2)O_(2))production via electrochemical two-electron oxygen reduction reaction(ORR)holds a great promise for sustainable energy storage.However,the issues such as high energy consumption and diffic...Hydrogen peroxide(H_(2)O_(2))production via electrochemical two-electron oxygen reduction reaction(ORR)holds a great promise for sustainable energy storage.However,the issues such as high energy consumption and difficult extraction of thermodynamically unstable H_(2)O_(2) still need to be resolved.Herein,we reported a unified system for energy-out production and downstream conversion of H_(2)O_(2).By replacing the sluggish oxygen evolution reaction with a hydrazine oxidation reaction(HzOR),the cell of twoelectron ORR coupled with HzOR achieves the co-generation of electricity energy and valuable H_(2)O_(2).By employing Ru single atoms anchored on cobalt hydroxide(for HzOR)and NiSe_(2)(for ORR)as electrocatalysts,both exhibiting onset potentials near the theoretical values for their respective reactions,the ORR‖HzOR cell exhibits an energy output of 3.58 mW cm^(-2) and generates 0.66 kWh of electricity per kg of H_(2)O_(2).with a production rate of 583 mmol h^(-1) H_(2)O_(2).The produced H_(2)O_(2) was subsequently in-situ upgraded via three downstream conversion pathways to yield value-added products of sodium percarbonate,sodium peroxyborate,and ethylene glycol.A techno-economic analysis confirmed the economic viability of this ORR‖HzOR coupled with downstream conversion system.展开更多
BACKGROUND Current disinfection methods for gastrointestinal endoscopes consume a significant amount of water resources and produce a large volume of waste.AIM To achieve the objectives of efficiency,speed,and cost-ef...BACKGROUND Current disinfection methods for gastrointestinal endoscopes consume a significant amount of water resources and produce a large volume of waste.AIM To achieve the objectives of efficiency,speed,and cost-effectiveness,this study utilized vaporized hydrogen peroxide(VHP)generated from sodium percarbonate granules to conduct an anhydrous disinfection test on gastrointestinal endoscopes.METHODS The experimental device rapidly converts sodium percarbonate granules into VHP,and performs disinfection experiments on gastrointestinal endoscope models,disposable endoscopes,and various types of reusable gastrointestinal endoscopes.Variables such as the intraluminal flow rate(FR),relative humidity(RH),exposure dosage,and organic burden are used to explore the factors influencing the disinfection of long and narrow lumens with VHP.RESULTS The device generates a certain concentration of VHP that can achieve high-level disinfection of endoscope models within 30 minutes.RH,exposure dosage,and organic burden significantly affect the disinfection efficacy of VHP,whereas the intraluminal FR does not significantly impact disinfection efficacy.All ten artificially contaminated disposable endoscopes achieved satisfactory disinfection results.Furthermore,when this device was used to treat various types of reusable endoscopes,the disinfection and sterilization effects were not significantly different from those of automatic endoscope disinfection machines(using peracetic acid disinfectant solution)(P>0.05),and the economic cost of disinfectant required per endoscope was lower(1.5 China Yuan),with a shorter disinfection time(30 minutes).CONCLUSION The methods and results of this study provide a basis for further research on the use of VHP for the disinfection of gastrointestinal endoscopes,as well as for the development of anhydrous disinfection technology for gastrointestinal endoscopes.展开更多
基金financially supported by the Science and Technology Project of PetroChina Company Limited,China(No.2022DJ6314)the National Natural Science Foundation of China(No.52173056)。
文摘Dynamic melt modification of polyethylene via the direct grafting of peroxide fragments shows promise for the development of processable functionalized materials.In this study,four linear low-density polyethylenes(LLDPEs)with comparable molecular weights but different short-chain branch(SCB)contents(ranging of 5-66 per 1000 carbon atoms)were modified via dynamic melt mixing using 2 wt% benzoyl peroxide at 145℃ and 50 r/min for 30 min.The influence of SCB content on the processability and structure of the resulting products was systematically investigated.All modified products exhibited good melt processability with melt flow rates(MFR)ranging from 0.46 g/10min to 1.07 g/10min.Products derived from low-SCB LLDPEs showed a lower MFR,higher cross-linking content,a larger number of long-chain branches,and a higher degree of benzoyl grafting.In contrast,those produced from high-SCB LLDPEs exhibited improved processability,reduced cross-linking,fewer long-chain branches,and lower benzoyl grafting levels.A detailed structural investigation of the soluble and insoluble fractions,which were separated using trichlorobenzene fractionation,was conducted to analyze the structural features of various modified products and demonstrate that the SCB content(i.e.,tertiary carbon density)significantly influences radical coupling during dynamic modification.Elevated tertiary carbon density,by introducing greater steric hindrance,suppresses radical coupling during dynamic modification,thereby reducing the efficiency of both crosslinking and peroxide fragment grafting.These findings provide new insights into the structure-reactivity relationships in peroxide-induced polyethylene modification and lay the foundation for tailoring material properties via dynamic processing.
文摘Hydrogen peroxide(H_(2)O_(2)),as a green oxidant,plays a vital role in various applications,including environmental remediation,disinfection,and chemical synthesis[1].The conventional anthraquinone process,despite its industrial maturity and high yield,suffers from high energy consumption,carbon emissions,safety risks,and reliance on precious metals[2].Despite ongoing optimizations,a more sustainable alternative is urgently needed.The direct synthesis of hydrogen peroxide from water and oxygen has long been considered as an ideal alternative due to its theoretical 100%atom efficiency and environmental sustainability.
基金Supported by Bozhou Key Research and Development Project,No.bzzc2020031.
文摘BACKGROUND Fistula-in-ano is an abnormal tunnel formation linking the anal canal with the perineum and perianal skin.Multiple imagining methods are available to evaluate it,among which magnetic resonance imaging(MRI)is the most advanced nonin-vasive preoperative method.However,it is limited in its visualization function.AIM To investigate the use of intraluminal MRI for perianal fistulas via a novel direct MRI fistulography method.METHODS We mixed 3%hydrogen peroxide(HP)with gadolinium for HPMRI fistulogra-phy,retrospectively analyzing 60 cases of complex/recurrent fistula-in-ano using physical examination,trans-perineal ultrasonography(TPUS),low-spatial-reso-lution MRI,and high-resolution direct HPMRI fistulography.We assessed detec-tion rates of fistula tracks,internal openings,their relationship with anal sphinc-ters,and perianal abscesses using statistical analyses,including interobserver agreement(Kappa statistic),and compared results with intraoperative findings.RESULTS Surgical confirmation in 60 cases showed that high-resolution direct HPMRI fis-tulography provided superior detection rates for internal openings(153)and fistula tracks(162)compared to physical exams,TPUS,and low-spatial-resolution MRI(Z>5.7,P<0.05).The effectiveness of physical examination and TPUS was also inferior to that of our method for detecting perianal abscesses(54)(Z=6.773,3.694,P<0.05),whereas that of low-spatial-resolution MRI was not significantly different(Z=1.851,P=0.06).High-resolution direct HPMRI fistulography also achieved the highest interobserver agreement(Kappa:0.89,0.85,and 0.80),while low-spatial-resolution MRI showed moderate agreement(Kappa:0.78,0.74,and 0.69).TPUS and physical examination had lower agreement(Kappa range:0.33-0.63).CONCLUSION High-resolution direct HPMRI fistulography enhances the visualization of recurrent and complex fistula-in-ano,including branched fistulas,allowing for precise planning and improved surgical outcomes.
基金financially supported by the National Natu-ral Science Foundation of China(Nos.21805052 and 22227804)the Guangdong Basic and Applied Basic Research Foundation(No.2023B1515020110)+4 种基金the Science and Technology Research Project of Guangzhou(Nos.202102020787 and 2023A03J0030)the De-partment of Science&Technology of Guangdong Province(No.2022A156)the Key Laboratory of Optoelectronic Materials and Sensors in Guangdong Provincial Universities(No.2023KSYS008)the Key Discipline of Materials Science and Engineering,Bureau of Education of Guangzhou(No.20225546)the College Student Innovation and Entrepreneurship Training Program of Guangzhou University(No.XJ202311078029).
文摘Selective electrocatalysis of two-electron oxygen reduction reaction(2e^(-)ORR)has been recognized as a sustainable and on-site process for hydrogen peroxide(H_(2)O_(2))production.Great progress has been achieved for 2e^(-)ORR in alkaline media.However,it is challenged by insufficient activity and selectiv-ity of the catalysts in acidic electrolytes.Herein,we report sulfur-poisoned PtNi/C catalysts(PtNiSx/C)that could regulate ORR from the 4e^(-)to 2e^(-)pathway.The identified PtNiS0.6/C offers high activity in terms of onset potential of∼0.69 V(vs.RHE)and∼80%selectivity.The mass activity is also compara-ble and outperforms representative Pt-based precious and transition-metal-based catalysts.In addition,it is interestingly found that the Faradaic efficiency further increased to 95%during the long-term elec-trolysis test due to Ni atom surface migration.The electrochemical production of the H_(2)O_(2)system was applied to the electro-Fenton process,which has realized the effective degradation of organic pollutants.This work offers a strategy by sulfur poisoning PtNi/C catalyst to realize Pt-based 2e^(-)ORR active catalysts to electrolysis of H_(2)O_(2)in acidic media.
基金financial support from the National Natural Science Foundation of China(No.22279143).
文摘Hydrogen peroxide(H_(2)O_(2))is a crucial,eco-friendly oxidizing agent with a wide range of industrial,environmental,and biomedical applications.Traditional production methods,such as the anthraquinone process,face significant challenges in terms of energy consumption and environmental impact.As a sustainable alternative,photocatalytic H_(2)O_(2) production,driven by solar energy,has emerged as a promising approach.This review discusses the key advancements in photocatalytic H_(2)O_(2) synthesis,focusing on overcoming challenges such as charge recombination,selectivity for the two-electron oxygen reduction reaction(2e^(-)ORR),and catalyst stability.Recent innovations in photocatalyst design,including high-entropy materials,single-atom catalysts,and covalent organic frameworks(COFs),have significantly enhanced efficiency and stability.Furthermore,novel strategies for optimizing charge separation,light harvesting,and mass transfer are explored.The integration of artificial intelligence and bioinspired systems holds potential for accelerating progress in this field.This review provides a comprehensive overview of current challenges and cutting-edge solutions,offering valuable insights for the development of scalable,decentralized H_(2)O_(2) production systems that contribute to a more sustainable future.
文摘A mesocosm-based study was conducted to assess the effect of glucose and hydrogen peroxide on periphyton communities. These chemicals have been found to be effective at controlling cyanobacteria blooms in the water column but their impact on attached communities is unknown. The experimental design included a total of 4 treatments: control (no chemicals;3 replicates);hydrogen peroxide (3 replicates);glucose alone (3 different concentrations [no replicates]);and additive glucose (3 replicates). After 34 days, mean values of chlorophyll a were lower in all experimental treatments compared to the control;mean AFDM values were lower in all treatments except the unreplicated high glucose alone treatment. In contrast, mean autotrophic index values (AFDM/chlorophyll a) were greater in all treatments compared to the control, indicating heterotrophs were more resistant to the chemical treatments than autotrophs. Periphyton community biodiversity was much lower in the additive glucose and moderate glucose alone treatments than the hydrogen peroxide and control treatments. The relative abundance of the bacteria Asticcacaulis and Sphingorhabdus responded positively to the glucose treatments, whereas relative abundance of Nevskia and Caenimonas declined in both the hydrogen peroxide and glucose treatments. In terms of relative abundance, no cyanobacteria taxa were detected among the top 20 taxa. We conclude that the autotrophic component of periphyton communities is especially vulnerable to hydrogen peroxide and glucose treatments, and that any management strategy employing these chemicals should be aware of this potential impact.
基金supported by the National Key Research and Development Program of China(No.2022YFC3203301)the Natural Science Foundation of China(No.41406098).
文摘Pyrrhotite oxidation poses a big threat to water environment duo to its high potential for generating pollutants.Hydrogen peroxide,commonly found in natural water at micromolar concentrations,possesses much more aggressive oxidation ability than oxygen and can complicate the pyrrhotite oxidation process.Here,the effects of micromolar H_(2)O_(2) on the biotic and abiotic oxidation of pyrrhotite were examined at pH 1.93 and 6.45,respectively.Pyrrhotite oxidation was much more severe in acidic solutions compared to near neutral solutions.Jarosite with a high Fe/S molar ratio was widely detected in the precipitate collected in acidic solutions,and the introduction of external H_(2)O_(2) influenced the crystallinity of jarosite.A layer of iron-deficient iron-sulfur oxide formed on the surface of pyrrhotite prevents its continuous oxidation,and the presence of Acidithiobacillus ferrooxidans enhanced this situation by promoting the release of Fe from the pyrrhotite.Additionally,the presence of external micromolar H_(2)O_(2) also determined the elemental state on pyrrhotite surface,as it found that the contribution of Fe^(3+)and S(S^(4+)and S^(6+))species on pyrrhotite surface increased with the increase of H_(2)O_(2) concentration in the solutions,especially in the presence of Acidithiobacillus ferrooxidans.
基金supported by the research project“Green-health-safety Nexus for New Urban Spaces-GreeNexUS”(HORIZON MSCA-2021 DN,Marie Sklodowska-Curie Actions)Grant Agreement No.101073437:research grant under the title"Impact Absorbing Pavements with Improved Accessibility Features(DC9-IAP)".
文摘Enhancing rubber-bitumen compatibility is crucial to improve pavement performance and durability.To investigate the compatibility improvement between H2O2-activated waste crumb rubber(AWCR)and bitumen,coarse and fine waste crumb rubber(WCR)were treated and analyzed through multi-scale characterization and molecular simulation.Microstructure and chemical changes of WCR and AWCR were analyzed with scanning electron microscope(SEM),contact angle tests and Fourier transform infrared spectroscopy(FTIR).Compatibility was also indirectly evaluated through modified boiling tests and storage stability tests.Besides,molecular dynamics was used to explore the interaction between WCR/AWCR and bitumen.SEM,contact angle,and FTIR results showed bond breakage of C=C and C–C and increased polar groups like–OH and–COOH in AWCR,resulting in a rougher texture and higher surface energy.Compared with WCR,AWCR showed a lower bitumen stripping rate after boiling,and the binder with AWCR also had a lower softening point difference and segregation rate after storage.Molecular dynamics simulations further confirmed that AWCR has a closer solubility parameter and higher binding energy to bitumen than WCR,reflected in a relatively slower diffusion rate.This study provides comprehensive evidence for an eco-friendly method of WCR surface treatment for more efficient recycling of tire rubber in asphalt pavements.
文摘This letter addresses Pravda's innovative review,which proposes hydrogen pe-roxide as the primary pathogenic factor in ulcerative colitis(UC).Although the author presents intriguing mechanistic insights and reports encouraging clinical outcomes with reducing agents,several methodological and clinical considera-tions require discussion.We examine three key aspects:The selective evidence synthesis approach;the need for rigorous clinical validation of proposed thera-pies;and the integration of this novel hypothesis with established inflammatory bowel disease pathogenesis.Given the complexity of UC,future therapeutic ad-vances may require collaborative approaches that integrate redox-based mecha-nisms into existing evidence-based frameworks rather than replacing current paradigms.
基金supported by the National Natural Science Foundation of China(22361024 and 22471055)Natural Science Foundation of Jiangxi Province(20232ACB203001)+1 种基金Natural Science Foundation of Hebei Province(B2024202021,B2022202039)S&T Program of Hebei(236Z4308G)。
文摘The photocatalytic hydrogen peroxide(H_(2)O_(2))production by graphitic carbon nitride is a sustainable and environment-benign alternative approach of conventional anthraquinone autoxidation technology,but it is great challenges to promote two-electron O_(2)reduction and water oxidation.Herein,we present the well-dispersed graphitic carbon nitride quantum dots decorated with cyano groups(Na-CNQD and K-CNQD)by thermal polymerization of melamine in the presence of metal fluoride.The quantum confinement and edge effect have endowed the photocatalysts with rich active sites,wide light absorption range and the inhibited charge recombination.The cyano moieties function as O_(2)reduction centers to accept the photogenerated electrons and facilitate their rapid transfer to O_(2)molecules.This process enables the selective two-electron reduction of O_(2),leading to the production of H_(2)O_(2).Concurrently,the valence band holes on the heptazine moiety oxidize water into H_(2)O_(2).These synergistic effects promote photocatalytic H_(2)O_(2)production from O_(2)and H_(2)O without the need for additional photosensitizers,organic scavengers and co-catalysts.In contrast,pristine carbon nitride nanosheets remain inactive under the same conditions.This study offers new strategies for rational design of carbon-based materials for solar-to-chemical energy conversion.
文摘Mesenchymal stem cells(MSCs)possess unique properties such as immunomodu-lation,paracrine actions,multilineage differentiation,and self-renewal.Therefore,MSC-based cell therapy is an innovative approach to treating various degenera-tive illnesses,including cardiovascular diseases.However,several challenges,including low transplant survival rates,low migration to the ischemic myocar-dium,and poor tissue retention,restrict the application of MSCs in clinical settings.These undesirable cell therapy outcomes mainly originated due to the overproduction of reactive oxygen species(ROS)in the injured heart.MSCs'stress-coping capacity can be enhanced by preconditioning them under conditions similar to the microenvironment of wounded tissues.Hydrogen peroxide(H_(2)O_(2))is a ROS that has been shown to activate protective cellular mechanisms such as survival,proliferation,migration,paracrine effects,and differentiation at suble-thal doses.These processes are induced via phosphatidylinositol 3-kinase/protein kinase B,p38 mitogen-activated protein kinases,c-Jun N-terminal kinase,Janus kinase/signal transducer and activator of the transcription,Notch1,and Wnt sig-naling pathways.H_(2)O_(2) preconditioning could lead to many clinical benefits,including ischemic injury reduction,enhanced survival of cellular transplants,and tissue regeneration.In this review,we present an overview of stem cell preconditioning methods and the biological functions activated by H_(2)O_(2) precondi-tioning.Furthermore,this review explores the molecular mechanisms underlying the protective cellular functions stimulated under H_(2)O_(2) preconditioning.
基金supported by the National Natural Science Foundation of China(22479040,22279138)the Natural Science Foundation of Tianjin(24JCQNJC00360)+3 种基金Government Guide the Development of Local Science and Technology Special Funds(246Z3707G)Young Scientific and Technological Talents(Level Three)in Tianjin(QN20230343)Hebei Yanzhao Golden Platform Talent Gathering Plan Backbone Talent Project(HJYB202501)the Natural Science Foundation of Liaoning Province(2022-MS023)。
文摘Photocatalytic H_(2)O_(2) production still confronts the challenges of its dependence on organic electron donors or high-purity O_(2),which restricts the practical application,and there are few studies on the photo synthesis of H_(2)O_(2) via both oxygen reduction reaction(ORR)and water oxidation reaction(WOR).In this paper,bismuth yttrium oxyhalides Bi_(2)YO_(4)X(X=Cl,Br,or I)are demonstrated to afford sufficient driving forces to produce H_(2)O_(2) in the absence of sacrificial reagents.After modification with Pt and IrO_(2) as cocatalysts,which can selectively promote both ORR and WOR reactions on Bi_(2)YO_(4)Cl,the IrO_(2)-Pt/Bi_(2)YO_(4)Cl sample yields H_(2)O_(2) production activity of 647μmol L^(-1)h^(-1)with negligible decay in the long-term reaction using only H_(2)O and an air atmosphere as the electron donors and O_(2) source.Detailed characterizations reveal that the ORR reaction obeys a two-electron pathway.We present the first example of oxyhalides(Bi_(2)YO_(4)X)capable of efficient photocata lytic H_2O_(2) generation with record-breaking activity.
基金supported by the National Natural Science Foundation of China(Nos.22102073,22075147).
文摘As a versatile and environmentally benign oxidant,hydrogen peroxide(H_(2)O_(2))is highly desired in sanitation,disinfection,environmental remediation,and the chemical industry.Compared with the conventional anthraquinone process,the electrosynthesis of H_(2)O_(2)through the two-electron oxygen reduction reaction(2e^(−)ORR)is an efficient,competitive,and promising avenue.Electrocatalysts and devices are two core factors in 2e^(−)ORR,but the design principles of catalysts for different pH conditions and the development trends of relevant synthesis devices remain unclear.To this end,this review adopts a multiscale perspective to summarize recent advancements in the design principles,catalytic mechanisms,and application prospects of 2e^(−)ORR catalysts,with a particular focus on the influence of pH conditions,aiming at providing guidance for the selective design of advanced 2e^(−)ORR catalysts for highly-efficient H_(2)O_(2)production.Moreover,in response to diverse on-site application demands,we elaborate on the evolution of H_(2)O_(2)electrosynthesis devices,from rotating ring-disk electrodes and H-type cells to diverse flow-type cells.We elaborate on their characteristics and shortcomings,which can be beneficial for their further upgrades and customized applications.These insights may inspire the rational design of innovative catalysts and devices with high performance and wide serviceability for large-scale implementations.
基金supported by the Korea Institute of Energy Technology Evaluation and Planning(KETEP)and the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea(no.20224000000020)supported by the MSIT(Ministry of Science and ICT),Korea,under the ICAN(ICT Challenge and Advanced Network of HRD)support program(IITP-2024-RS-2024-00437186)supervised by the IITP(Institute for Information&Communications Technology Planning&Evaluation)。
文摘Cobalt pentlandite(Co9S8)is a promising non-precious catalyst due to its superior oxygen reduction reaction activity and excellent stability.However,its oxygen reduction reaction catalytic activity has traditionally been limited to the four-electron pathway because of strong*OOH intermediate adsorption.In this study,we synthesized electron-deficient Co9S8 nanocrystals with an increased number of Co^(3+)states compared to conventional Co9S8.This was achieved by incorporating a high density of surface ligands in small-sized Co9S8nanocrystals,which enabled the transition of the electrochemical reduction pathway from four-electron oxygen reduction reaction to two-electron oxygen reduction reaction by decreasing*OOH adsorption strength.As a result,the Co^(3+)-enriched Co9S8 nanocrystals exhibited a high onset potential of 0.64 V(vs RHE)for two-electron oxygen reduction reaction,achieving H_(2)O_(2) selectivity of 70-80%over the potential range from 0.05 to 0.6 V.Additionally,these nanocrystals demonstrated a stable H_(2)O_(2) electrosynthesis at a rate of459.12 mmol g^(-1) h^(-1) with a H_(2)O_(2) Faradaic efficiency over 90%under alkaline conditions.This study provides insights into nanoscale catalyst design for modulating electrochemical reactions.
基金supported by the National Natural Science Foundation of China(Nos.22478222,22178197,and U23A6005)the Dr.Jentai Yang Sustainable Environmental Protection and Eco-humanistic Education Fund(No.20253000027)which isadministered by the Overseas Chinese Environmental Engineers and Scientists Association。
文摘H_2O_(2) is one of the most important chemicals in the world.Recently,the electrochemical synthesis of H_2O_(2)by two-electron oxygen reduction reaction(2e^(-)ORR)has attracted great interest.Carbon-based catalysts show great promise for electrocatalytic production of H_2O_(2),due to the ease of regulation of the carbon materials with regard to the pore structure,surface properties,and heteroatom doping.Biomass as the carbon precursor has the advantages of low cost,sustainable supply,and extensive availability.Conversion of biomass to functional carbon-based materials shows the attractive merits,such as low carbon emission in the life cycle and diversity of the obtained carbon materials due to the wide source of biomass feedstocks.In this article,a comprehensive review on the mechanisms and processes of electrochemical synthesis of H_2O_(2) by 2e^(-)ORR over carbon-based catalysts is provided.The potential biomass feedstock used for obtaining the carbon-based catalysts,and the strategies to prepare the catalysts by carbonization and heteroatom doping,as well as optimization of electrodes and design of electrolyzer,are discussed.It is recommended that future work focus on developing efficient methods to prepare the catalysts from low-cost biomass feedstock,understanding the mechanisms of 2e^(-)ORR over the catalysts,optimization of electrode materials loaded with biomass-derived catalysts,as well as development of electrolyzers for larger-scale applications.
基金supported by the National Natural Science Foundation of China (22209061 and 22462006)Start-up Fund for Senior Talents in Jiangsu University (21JDG060)the Fundamental Research Funds for the Central Universities (20720220009)
文摘Hydrogen peroxide(H_(2)O_(2))is an eco-friendly chemical with widespread industrial applications.However,the commercial anthraquinone process for H_(2)O_(2) production is energy-intensive and environmentally harmful,highlighting the need for more sustainable alternatives.The electrochemical production of H_(2)O_(2) via the two-electron water oxidation reaction(2e^(−)WOR)presents a promising route but is often hindered by low efficiency and selectivity,due to the competition with the oxygen evolution reaction.In this study,we employed high-throughput computational screening and microkinetic modeling to design a series of efficient 2e^(−)WOR electrocatalysts from a library of 240 single-metal-embedded nitrogen heterocycle aromatic molecules(M-NHAMs).These catalysts,primarily comprising post-transition metals,such as Cu,Ni,Zn,and Pd,exhibit high activity for H_(2)O_(2) conversion with a limiting potential approaching the optimal value of 1.76 V.Additionally,they exhibit excellent selectivity,with Faradaic efficiencies exceeding 80%at overpotentials below 300 mV.Structure-performance analysis reveals that the d-band center and magnetic moment of the metal center correlated strongly with the oxygen adsorption free energy(ΔGO*),suggesting these parameters as key catalytic descriptors for efficient screening and performance optimization.This study contributes to the rational design of highly efficient and selective electrocatalysts for electrochemical production of H_(2)O_(2),offering a sustainable solution for green energy and industrial applications.
文摘Photocatalytic hydrogen peroxide(H_(2)O_(2))production offers a sustainable route to convert water and oxygen into H_(2)O_(2)using solar energy.However,achieving long-term stability in photocatalysts remains a critical challenge due to mismatched kinetics between oxygen reduction(ORR)and water oxidation(WOR),which leads to hole accumulation and oxidative degradation.Here,we report a redox-mediated strategy to address this bottleneck by designing a hydroquinone-embedded covalent organic framework(Tz-QH-COF)that enables reversible hole buffering and kinetic balance.The hydroquinone(QH)units act as dynamic hole reservoirs,capturing excess holes during ORR and converting to benzoquinone(Q),which is regenerated to QH via WOR,thereby preventing oxidative decomposition.This reversible QH/Q cycle,directly visualized through in situ attenuated total reflection surface-enhanced infrared absorption spectroscopy,ensures unmatched stability,achieving continuous H_(2)O_(2) production for 528 h(22 d)with an accumulated yield of 18.6 mmol L^(–1)—the highest reported duration for organic photocatalysts.Density functional theory calculations reveal that the QH units exhibit a strong oxygen adsorption energy and favorable two-electron ORR/WOR pathways with low energy barriers.The synergy between experimental and theoretical insights elucidates a redox-mediated charge-balance mechanism,advancing the design of robust photocatalysts for solar-driven H_(2)O_(2) synthesis.
基金supports from the National Natural Science Foundation of China(Nos.22478426 and 22278436)Young Elite Scientists Sponsorship Program by BAST(No.1101020370359)Science Foundation of China University of Petroleum,Beijing(No.2462021QNXZ009)。
文摘Advanced oxidation processes(AOPs)governed by peroxide activation to produce highly oxidative active species have been extensively explored for environmental remediation.Nevertheless,the low diffusion rates,inadequate interactions of the reactants,and limited active site exposure hinder treatment efficiency.Porous carbocatalysts with high specific surface area,tunable pore size,and programmable active sites demonstrate outstanding performance in activating diverse types of peroxides to generate active species for treatment of aqueous organic pollutants.The pore-rich structures enhance reaction kinetics for peroxide activation by facilitating diffusion of the reactants and their interactions.Additionally,the structural flexibility of porous structures favors the accommodation of highly dispersed metal species and allows for precise tuning of the microenvironment around the active sites,which further enhances the catalytic activity.This review critically summarizes the recent research progress in the applications of engineered porous carbocatalysts for peroxide activation and outlines the prevailing pore construction methods in carbocatalysts.Moreover,engineering strategies to regulate the mass transfer efficiency and fine-tune the microenvironment around the active sites are systematically addressed to enhance their catalytic peroxide activation performances.Challenges and future research opportunities pertaining to the design,optimization,mechanistic investigation,and practical application of porous carbocatalysts in peroxide activation are also proposed.
基金the National Natural Science Foundation of China(U21A20286 to Y.H.,22206054 to Y.H.,and 22478310 to J.Z.)the Fundamental Research Funds for the Central China Normal University(CCNU)。
文摘Hydrogen peroxide(H_(2)O_(2))production via electrochemical two-electron oxygen reduction reaction(ORR)holds a great promise for sustainable energy storage.However,the issues such as high energy consumption and difficult extraction of thermodynamically unstable H_(2)O_(2) still need to be resolved.Herein,we reported a unified system for energy-out production and downstream conversion of H_(2)O_(2).By replacing the sluggish oxygen evolution reaction with a hydrazine oxidation reaction(HzOR),the cell of twoelectron ORR coupled with HzOR achieves the co-generation of electricity energy and valuable H_(2)O_(2).By employing Ru single atoms anchored on cobalt hydroxide(for HzOR)and NiSe_(2)(for ORR)as electrocatalysts,both exhibiting onset potentials near the theoretical values for their respective reactions,the ORR‖HzOR cell exhibits an energy output of 3.58 mW cm^(-2) and generates 0.66 kWh of electricity per kg of H_(2)O_(2).with a production rate of 583 mmol h^(-1) H_(2)O_(2).The produced H_(2)O_(2) was subsequently in-situ upgraded via three downstream conversion pathways to yield value-added products of sodium percarbonate,sodium peroxyborate,and ethylene glycol.A techno-economic analysis confirmed the economic viability of this ORR‖HzOR coupled with downstream conversion system.
基金Supported by the Joint Logistics Support Force Comprehensive Equipment Research Project,No.LB2023B010100-09.
文摘BACKGROUND Current disinfection methods for gastrointestinal endoscopes consume a significant amount of water resources and produce a large volume of waste.AIM To achieve the objectives of efficiency,speed,and cost-effectiveness,this study utilized vaporized hydrogen peroxide(VHP)generated from sodium percarbonate granules to conduct an anhydrous disinfection test on gastrointestinal endoscopes.METHODS The experimental device rapidly converts sodium percarbonate granules into VHP,and performs disinfection experiments on gastrointestinal endoscope models,disposable endoscopes,and various types of reusable gastrointestinal endoscopes.Variables such as the intraluminal flow rate(FR),relative humidity(RH),exposure dosage,and organic burden are used to explore the factors influencing the disinfection of long and narrow lumens with VHP.RESULTS The device generates a certain concentration of VHP that can achieve high-level disinfection of endoscope models within 30 minutes.RH,exposure dosage,and organic burden significantly affect the disinfection efficacy of VHP,whereas the intraluminal FR does not significantly impact disinfection efficacy.All ten artificially contaminated disposable endoscopes achieved satisfactory disinfection results.Furthermore,when this device was used to treat various types of reusable endoscopes,the disinfection and sterilization effects were not significantly different from those of automatic endoscope disinfection machines(using peracetic acid disinfectant solution)(P>0.05),and the economic cost of disinfectant required per endoscope was lower(1.5 China Yuan),with a shorter disinfection time(30 minutes).CONCLUSION The methods and results of this study provide a basis for further research on the use of VHP for the disinfection of gastrointestinal endoscopes,as well as for the development of anhydrous disinfection technology for gastrointestinal endoscopes.
