The surface chemical properties of CeO2 and Pr6O11 have been investigated with FT-IR spectroscopy. The reactivities of surface hydroxyls were tested through the reaction of CO. Surface formate species are formed on Ce...The surface chemical properties of CeO2 and Pr6O11 have been investigated with FT-IR spectroscopy. The reactivities of surface hydroxyls were tested through the reaction of CO. Surface formate species are formed on CeO2 and Pr6O11 under CO atmosphere at 200℃ . and the reaction becomcs more prevailing at higher temperatures especially for partially reduced samples. The surface formate species are produced via the reaction of CO with surface hydroxyls which was confirmed by the reaction of CO with D2-treated CeO2 and Pr6O11. The Surface formate can be oxidized to carbonate at temperatures exceeding 300 ℃, and the surface hydroxyls could be recovered as the formate species decompose or are oxidized to carbonate species. The roles played by the surface hydroxyls and surface active sites in the CO oxidation are discussed.展开更多
Hydrogen bonding is considered to have significant effect on the interaction between polymeric chains and on the viscoelasticity of the polymeric materials. In this paper, we attempt to discuss the relationship betwee...Hydrogen bonding is considered to have significant effect on the interaction between polymeric chains and on the viscoelasticity of the polymeric materials. In this paper, we attempt to discuss the relationship between hydrogen bonding density and damping behavior and mechanical properties of polyethylene-based polymeric materials. For this reason, a series of pendant chain hydrogen bonding polymers （PCHBP） with different hydrogen bonding density （HBD） were prepared by quantitatively changing the content of pendent hydroxyl groups on the main chain of polyethylene. It was found that PCItBP with low HBD showed similar properties to polyethylene, indicating that the property of the materials was dependent mainly on the structure of the main chain. However, PCHBP with high HBD exhibited two tandpeaks and a platform of loss modulus as well as a high storage modulus （about 400 MPa） at the second tand peak temperature, demonstrating that a polymeric material with high strength and damping properties was obtained. More importantly, the maximum of loss modulus showed a linear increase with the HBD, indicating that a higher HBD greatly improved the damping properties of the polymeric materials.展开更多
The thermodynamic properties of dibenzofurans （DFs）, xanthones （XTs） and an-thraquinones （AQs） with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10^5 pa were...The thermodynamic properties of dibenzofurans （DFs）, xanthones （XTs） and an-thraquinones （AQs） with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10^5 pa were calculated at the B3LYP/6-311G^＊ level using Gaussian 03 program. The isodesmic reactions were designed to calculate the standard free energy of formation （△fG^θ）. Three types of hydrogen bonds exist in the three kinds of chemicals and their bond energies were ascertained as 7-15, 15-23 and 49-58 kJ·mo1^-1 respectively by comparing the △fG^θ values. Electronic density topology analysis was applied to validate the strength of bond.展开更多
Revealing the structure evolution of interfacial active species during a dynamic catalytic process is a challenging but pivotal issue for the rational design of high-performance catalysts.Here,we successfully prepare ...Revealing the structure evolution of interfacial active species during a dynamic catalytic process is a challenging but pivotal issue for the rational design of high-performance catalysts.Here,we successfully prepare sub-nanometric Pt clusters(~0.8 nm)encapsulated within the defects of CeO_(2)nanorods via an in-situ defect engineering methodology.The as-prepared Pt@d-CeO_(2)catalyst significantly boosts the activity and stability in the water-gas shift(WGS)reaction compared to other analogs.Based on controlled experiments and complementary(in-situ)spectroscopic studies,a reversible encapsulation induced by active site transformation between the Pt^(2+)-terminal hydroxyl and Pt^(δ+)-O vacancy species at the interface is revealed,which enables to evoke the enhanced performance.Our findings not only offer practical guidance for the design of high-efficiency catalysts but also bring a new understanding of the exceptional performance of WGS in a holistic view,which shows a great application potential in materials and catalysis.展开更多
Fenton and Fenton-like processes,which could produce highly reactive species to degrade organic contaminants,have been widely used in the field of wastewater treatment.Therein,the chemistry of Fenton process including...Fenton and Fenton-like processes,which could produce highly reactive species to degrade organic contaminants,have been widely used in the field of wastewater treatment.Therein,the chemistry of Fenton process including the nature of active oxidants,the complicated reactions involved,and the behind reason for its strongly pH-dependent performance,is the basis for the application of Fenton and Fenton-like processes in wastewater treatment.Nevertheless,the conflicting views still exist about the mechanism of the Fenton process.For instance,reaching a unanimous consensus on the nature of active oxidants(hydroxyl radical or tetravalent iron)in this process remains challenging.This review comprehensively examined the mechanism of the Fenton process including the debate on the nature of active oxidants,reactions involved in the Fenton process,and the behind reason for the pH-dependent degradation of contaminants in the Fenton process.Then,we summarized several strategies that promote the Fe(Ⅱ)/Fe(Ⅲ)cycle,reduce the competitive consumption of active oxidants by side reactions,and replace the Fenton reagent,thus improving the performance of the Fenton process.Furthermore,advances for the future were proposed including the demand for the high-accuracy identification of active oxidants and taking advantages of the characteristic of target contaminants during the degradation of contaminants by the Fenton process.展开更多
Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study...Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain,a prevalent soil bacterial genus.Our research reveals that introducing a carbon source along with specific iron-binding ligands,including deferoxamine(DFO),diethylenetriamine pentaacetate(DTPA),citrate,and oxalate,robustly augments microbial superoxide generation.Moreover,our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(Ⅲ)/Fe(Ⅱ)and superoxide.Remarkably,among the tested ligands,only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(Ⅲ).We identify an optimal Fe(Ⅲ)to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture.This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals,significantly elevating bioremediation performance.Furthermore,our study reveals that DTPA augments superoxide production in cultures of diverse soils,with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation.This emphasizes the universal applicability of DTPA across multiple bacterial genera.In conclusion,our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals.These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation,offering innovative solutions for addressing environmental contamination challenges.展开更多
P450 enzymes-catalyzed aromatic hydroxylation plays an important role in detoxification,biosynthesis,and potential carcinogenic effect of aromatic compounds.Though it has been explored for decades,the actual process o...P450 enzymes-catalyzed aromatic hydroxylation plays an important role in detoxification,biosynthesis,and potential carcinogenic effect of aromatic compounds.Though it has been explored for decades,the actual process of aromatic hydroxylation and mechanism of regioselectivity catalyzed by cytochrome P450 monooxygenases remained ambiguous.Here,we have resolved these issues.With a stable chiral organofluorine probe,and especially with X-ray data of two isolated arene oxides derivatives,we demonstrate that an arene oxide pathway is definitely involved in P450-catalyzed aromatic hydroxylation.By the capture,isolation,identification and reactivity exploration of the arene 1,2-oxide and arene 2,3-oxide intermediates,together with advanced QM calculations,the mechanism of how two intermediates go to the same product has been elucidated.In addition to the model substrate,we also confirmed that an arene oxide intermediate is involved in the P450-catalyzed hydroxylation pathway of a natural product derivative methyl cinnamate,which indicates that this intermediate appears to be universal in P450-catalyzed aromatic hydroxylation.Our work not only provides the most direct evidence for the arene oxide pathway and new insights into the regioselectivity involved in P450-catalyzed aromatic hydroxylation,but also supplies a new synthetic approach to achieve the dearomatization of aromatic compounds.展开更多
Herein the use of rare-earth compounds in catalytic reduction systems for the end-group functionalization of carboxyl-terminated low-molecularweight fluoropolymers was explored.Leveraging the high catalytic activity a...Herein the use of rare-earth compounds in catalytic reduction systems for the end-group functionalization of carboxyl-terminated low-molecularweight fluoropolymers was explored.Leveraging the high catalytic activity and selectivity of rare-earth compounds along with no residual impact on polymer product's performance,highly efficient catalytic reduction systems containing sodium borohydride(NaBH_(4))and rare-earth chloride(RECl_(3))were specifically designed for a telechelic carboxyl-terminated liquid fluoroeslastomer,aiming to facilitate the conversion of chainend carboxyl groups into hydroxyl groups and improvement in end-group reactivity.To achieve this,lanthanum chloride(LaCl_(3)),cerium chloride(CeCl_(3)),and neodymium chloride(NdCl_(3))were used separately to form catalytic reduction systems with NaBH_(4).The effects of solvent dosage,reaction temperature,reaction time length,and reductant dosage on carboxylic conversion were investigated,and the molecular chain structure,molecular weight,and functional group content of the raw materials and the products were analyzed and characterized by means of infrared spectroscopy(FTIR),proton nuclear magnetic resonance(^(1)H-NMR),fluorine-19 nuclear magnetic resonance(^(19)F-NMR),gel permeation chromatography(GPC),and chemical titration.Moreover,the catalytic activity and selectivity of the rare-earth chlorides,as well as the corresponding underlying interactions were discussed.Results indicated that the rare-earth-containing catalytic reduction systems studied in this work could efficiently convert the chain-end carboxyl groups into highly active hydroxyl groups,with a highest conversion up to 87.0%and differing catalytic reduction activities ranked as NaBH_(4)/CeCl_(3)>NaBH_(4)/LaCl_(3)>NaBH_(4)/NdCl_(3).Compared with the conventional lithium aluminum hydride(LiAIH_(4))reduction system,the NaBH_(4)/RECl_(3)systems provide multiple advantages such as mild reaction conditions,high conversion ratio with good selectivity,and environmental innocuity,and are potentially applicable as new reduction-catalysis combinations for the synthesis and functionalization of polymer materials.展开更多
ABBOTT et al. considered that there might be two types of hydroxyls with different site energies in the dioctahedral silicates. Giese holds a similar opinion. However, so far no detailed research has been done on the ...ABBOTT et al. considered that there might be two types of hydroxyls with different site energies in the dioctahedral silicates. Giese holds a similar opinion. However, so far no detailed research has been done on the orientating features, types and genesis of orientations展开更多
Achieving sustainable energy and chemical production has become an important issue for human society.Photocatalysis has attracted much attention due to its ability to harness solar energy to drive chemical reactions.M...Achieving sustainable energy and chemical production has become an important issue for human society.Photocatalysis has attracted much attention due to its ability to harness solar energy to drive chemical reactions.Metal sulfide-based photocatalysts(e.g.,Cd S,Zn In2S4)have shown substantial potential in biomass-based hydroxyl compound valorization.In this review,we summarize the recent progress in metal sulfide-based photocatalysts for the photo upgrading of biomass-derived hydroxyl compounds coupled with reduction reactions(e.g.,CO_(2)reduction,H_(2)O_(2)generation,and H_(2)evolution).The mechanism of biomass redox reactions is discussed,highlighting the potential of realizing the valorization of biomass-derived compounds coupled with the reduction reactions,which is beneficial for researchers to actively explore biomass biorefinery pathways in order to modulate the selectivity of the valueadded products.Various modification strategies are presented,including elemental doping,defect engineering,heterojunction construction,and cocatalyst loading.These strategies modulate the energy band structure,surface electron density,and built-in electric field strength of metal sulfide-based photocatalysts,thereby enhancing their photocatalytic performance.The challenges and prospects of metal sulfidebased photocatalysts in biomass valorization are analyzed.This approach contributes to the development of photocatalysts that can accelerate biomass photo-upgrading coupling reactions.This review aims to provide deeper insights into the photocatalytic biorefinery pathways and contribute to the development of functionalized photocatalysts that can accelerate biomass photo upgrading,highlighting the synergistic effects of multiple coupling reactions.展开更多
Bacterial biofilm infections,characterized by high mortality and challenging recovery,pose a significant global health risk.Developing innovative antibacterial materials and therapies,particularly those that mitigate ...Bacterial biofilm infections,characterized by high mortality and challenging recovery,pose a significant global health risk.Developing innovative antibacterial materials and therapies,particularly those that mitigate resistance,is essential for effectively addressing biofilm-associated infections.Chemical dynamic therapy(CDT),which relies on hydroxyl radicals(·OH)generated from hydrogen peroxide(H_(2)O_(2))to eliminate bacteria,has demonstrated potential in treating planktonic infections.However,traditional CDT is less effective against biofilm-related infections due to limited endogenous H_(2)O_(2) and the protective extracellular polymeric matrix within biofilms.In this study,a composite nanoplatform based on CuO_(2) with self-supplying H_(2)O_(2) capabilities and Fe_(3)O_(4) with photothermal properties was designed to improve CDT efficacy for biofilm eradication.The Fe_(3)O_(4)/CuO_(2) composite nanoparticles(FC NPs)were synthesized by incorporating CuO_(2) into hollow mesoporous Fe_(3)O_(4) using an in-situ growth technique.Within the mildly acidic biofilm microenvironment,CuO_(2) decomposes to release Cu^(2+)and H_(2)O_(2).The Cu^(2+)subsequently catalyzes the Fenton-like conversion of the released H_(2)O_(2) into·OH.Concurrently,near-infrared(NIR)irradiation of Fe_(3)O_(4) generates significant heat,boosting·OH production and increasing bacterial membrane permeability,thereby enhancing bacterial vulnerability to·OH.This nanoplatform demonstrated remarkable CDT efficacy,eradicating over 99.99%of methicillin-resistant Staphylococcus aureus(MRSA)and 99.97%of Pseudomonas aeruginosa biofilms within five minutes of NIR irradiation in vitro.Furthermore,in vivo experiments validated the nanoplatform's ability to eradicate biofilms and facilitate the healing of MRSA-infected wounds without adverse effects.This H_(2)O_(2) self-supplying and heat-enhancing approach presents a promising strategy to overcome the limitations of CDT in biofilm-related infection treatment.展开更多
This study investigated the impacts of spring runoff on the formation of halobenzoquinones(HBQs)and their correlation with common water quality parameters(WQPs)and aromatic amino acids(AAs)in source water.Source water...This study investigated the impacts of spring runoff on the formation of halobenzoquinones(HBQs)and their correlation with common water quality parameters(WQPs)and aromatic amino acids(AAs)in source water.Source water and treated water samples were collected at two drinking water treatment plants in 2021,2022,and 2023.HBQs and aromatic AAs were analyzed using solid phase extraction with high performance liquid chromatography–tandem mass spectrometry methods.The only HBQs detected in treated water were 2,6-dichloro-1,4-benzoquinone(DCBQ)and hydroxy–DCBQ(OH-DCBQ).The concentration of DCBQ was 3-4 times higher during spring runoff events than during non-spring-runoff periods,suggesting the impact of spring runoff on the formation of DCBQ.The DCBQ concentrations in finished water positively correlated with the color,dissolved organic carbon,total organic nitrogen,and specific ultraviolet absorbance WQPs of source water in 2021 and 2022.The temporal trend of the total aromatic AAs determined in source water was strongly and positively correlated to DCBQ in finished water.Finally,there was a significant positive correlation between the concentration of DCBQ determined immediately following the addition of chlorine and the presence of its transformation product,OH-DCBQ,in finished water.The results also showed that powdered activated carbon can remove some of the HBQ precursors in the sourcewater to reduce DCBQ formation.This study demonstrated that WQPs and aromatic AAs are useful indicators for the removal of precursors to reduce HBQ formation during drinking water treatment.展开更多
The Fenton-like reaction between Cu^(2+)and H_(2)O_(2)was employed in chemical mechanical polishing to achieve efficient and high-quality processing of tungsten.The microstructure evolution and material removal rate o...The Fenton-like reaction between Cu^(2+)and H_(2)O_(2)was employed in chemical mechanical polishing to achieve efficient and high-quality processing of tungsten.The microstructure evolution and material removal rate of tungsten during polishing process were investigated via scanning electron microscopy,X-ray photoelectron spectroscopy,ultraviolet−visible spectrophotometry,and electrochemical experiments.The passivation behavior and material removal mechanism were discussed.Results show that the use of mixed H_(2)O_(2)+Cu(NO_(3))_(2)oxidant can achieve higher polishing efficiency and surface quality compared with the single oxidant Cu(NO_(3))_(2)or H_(2)O_(2).The increase in material removal rate is attributed to the rapid oxidation of W into WO_(3)via the chemical reaction between the substrate and hydroxyl radicals produced by the Fenton-like reaction.In addition,material removal rate and static etch rate exhibit significantly different dependencies on the concentration of Cu(NO_(3))_(2),while the superior oxidant for achieving the balance between polishing efficiency and surface quality is 0.5 wt.%H_(2)O_(2)+1.0 wt.%Cu(NO_(3))_(2).展开更多
Given that a large amount of crude oil remains on the surface of rocks and is difficult to produce after conventional waterflooding,a new superwetting oil displacement system incorporating the synergy between a hydrox...Given that a large amount of crude oil remains on the surface of rocks and is difficult to produce after conventional waterflooding,a new superwetting oil displacement system incorporating the synergy between a hydroxyl anion compound(1OH-1C)and an extended surfactant(S-C_(13)PO_(13)S)was designed.The interfacial tension,contact angle and emulsification performance of the system were measured.The oil displacement effects and improved oil recovery(IOR)mechanisms of 1OH-1C,S-C_(13)PO_(13)S and their compound system were investigated by microscopic visualization oil displacement experiments and core displacement experiments.The results show that 1OH-1C creates a superwetting interface and electrostatic separation pressure on the solid surface,which destroys the strong interactions between crude oil and quartz to peel off the oil film.S-C_(13)PO_(13)S has low interfacial tension,which can promote the flow of remaining oil and emulsify it into oil-in-water emulsions.The compound system of 1OH-1C and S-C_(13)PO_(13)S has both superwettability and low IFT,which can effectively improve oil recovery through a synergistic effect.The oil displacement experiment of low-permeability natural core shows that the compound solution can increase the oil recovery by 16.4 percentage points after waterflooding.This new high-efficiency system is promising for greatly improving oil recovery in low-permeability reservoirs.展开更多
Solar-driven CO_(2)conversion and pollutant removal with an S-scheme heterojunction provides promising approach to alleviate energy shortage and environmental crisis,yet the comprehensive regulation of the charge sepa...Solar-driven CO_(2)conversion and pollutant removal with an S-scheme heterojunction provides promising approach to alleviate energy shortage and environmental crisis,yet the comprehensive regulation of the charge separation and the activation sites of reactant molecules remains challenging.Herein,a dual-active groups regulated S-scheme heterojunction for hydroxy-regulated BiOBr modified amino-functionalized g-C_(3)N_(4)(labeled as HBOB/ACN)was designed by spatially separated dual sites with hydroxyl group(OH)and amino group(NH_(2))toward simultaneously photocatalytic CO_(2)reduction and ciprofloxacin(CIP)oxidation.The optimized HBOB/ACN delivers around 2.74-fold CO yield rate and 1.61-times CIP removal rate in comparison to BiOBr/g-C_(3)N_(4)(BOB/CN)without surface groups,which chiefly ascribed the synergistic effect of OH and NH_(2)group.A series of experiments and theoretical calculation unveiled that the OH and NH_(2)group trapped holes and electrons to participate in CIP oxidation and CO_(2)reduction,respectively.Besides,dual-functional coupled reaction system realized the complete utilization of carriers.This work affords deep insights for dual-group modified S-scheme heterojunctions with redox active sites toward dual-functional coupled reaction system for environment purification and solar fuel production.展开更多
Addressing inadequate OH^(*)adsorption in Ru Co alloy catalysts is crucial for boosting intermediate coverage and redirecting the water-splitting pathway.Herein,the adaptive P sites were strategically incorporated to ...Addressing inadequate OH^(*)adsorption in Ru Co alloy catalysts is crucial for boosting intermediate coverage and redirecting the water-splitting pathway.Herein,the adaptive P sites were strategically incorporated to overcome the aforementioned challenge.The P sites,as potent OH^(*)adsorption centers,synergize with Co sites to promote water dissociation and enrich surrounding Ru sites with H*intermediates,thus triggering the Volmer-Tafel route for hydrogen evolution reaction(HER).Besides,during the oxygen evolution reaction(OER),the surface of P-Ru Co was reconstructed into Ru-doped Co OOH with anchored PO_(4)^(3-).These PO_(4)^(3-)not only circumvent the intrinsic OH^(*)adsorption limitations of Ru-Co OOH in the adsorbate evolution mechanism(AEM)by rerouting to a more expeditious lattice oxygen oxidation mechanism(LOM)but also improve the coverage of key oxygen-containing intermediates,significantly accelerating OER kinetics.Consequently,the P-Ru Co demonstrates exceptional bifunctional performance,with overpotentials of 29 m V for HER and 222 m V for OER at 10 m A cm^(-2).Remarkably,the mass activities of PRu Co for HER(5.48 A mg^(-1))and OER(2.13 A mg^(-1))are 6.2 and 11.2 times higher than those of its commercial counterparts(Ru/C for HER and RuO_(2)for OER),respectively.When integrated into an anionexchange-membrane electrolyzer,this catalyst achieves ampere-level current densities of 1.32 A cm^(-2)for water electrolysis and 1.23 A cm^(-2)for seawater electrolysis at 2.1 V,with a 500-h durability.展开更多
UiO-66-H MOFs can effectively catalyze the direct selective oxidation of methane(DSOM)to high value-added oxygenates under mild conditions.However,UiO-66-NH_(2)with benzene-1,4-dicarboxylate(NH_(2)-BDC)ligand modifyin...UiO-66-H MOFs can effectively catalyze the direct selective oxidation of methane(DSOM)to high value-added oxygenates under mild conditions.However,UiO-66-NH_(2)with benzene-1,4-dicarboxylate(NH_(2)-BDC)ligand modifying the Zr-oxo nodes exhibits relatively inferior catalytic performance for DSOM.Here,a combination of density functional theory(DFT)calculations and experiments was employed to explore the underlying reasons for the limited catalytic activity of UiO-66-NH_(2).The results indicate that the methane hydroxylation performance of UiO-66-NH_(2)is almost unaffected by the increase of·OH concentration.This is attributed to the formation of substantial non-covalent hydrogen bonds between the oxygen atoms of oxygenic species on the Zr-oxo nodes and the hydrogen atoms of-NH_(2)groups,which diminishes the spin density distribution on the active sites of(·OH)m/UiO-66-NH_(2),leading to minimal change of the adsorption energy of CH_(4).Additionally,the calculated adsorption energies(Eads)of CH_(4)exhibit a linear relationship with the catalytic activity of UiO-66-NH_(2)for DSOM reaction.展开更多
Hydroxyl radical(·OH)formation from Fe(Ⅱ)-bearing clay mineral oxygenation in the shallow subsurface has been well documented under moderate environmental conditions.However,the impact of freezing processes on t...Hydroxyl radical(·OH)formation from Fe(Ⅱ)-bearing clay mineral oxygenation in the shallow subsurface has been well documented under moderate environmental conditions.However,the impact of freezing processes on the·OH production capability of Fe(Ⅱ)-bearing clay minerals for organic contaminant degradation,particularly in seasonally frozen soils,remains unclear.In this study,we investigated the influence of pre-freezing durations on the mineral proprieties,·OH production,and phenol degradation during the oxygenation of reduced Fe-rich nontronite(rNAu-2)and Fe-poor montmorillonite(rSWy-3).During the freezing process of reduced clay minerals(1 mM Fe(Ⅱ)),the content of edge surface Fe and Fe(Ⅱ)decreased by up to 46%and 58%,respectively,followed by a slight increased as clay mineral particles aggregated and subsequently partially disaggregated.As the edge surface Fe(Ⅱ)is effective in O_(2) activation but less effective in the transformation of H_(2)O_(2) to·OH,the redistribution of edge surface Fe(Ⅱ)leads to that·OH production and phenol degradation increased initially and then decreased with pre-freezing durations ranging from 0 to 20 days.Moreover,the rate constants of phenol degradation for both the rapid and slow reaction phases also first increase and then decrease with freezing time.However,pre-freezing significantly influenced the rapid phase of phenol degradation by rNAu-2 but affected the slow phase by rSWy-3 due to the much higher edge-surface Fe(Ⅱ)content in rNAu-2.Overall,these findings provide novel insights into the mechanism of·OH production and contaminant degradation during the freeze-thaw processes in clay-rich soils.展开更多
Innately designed to induce physiological changes,pharmaceuticals are foreknowingly hazardous to the ecosystem.Advanced oxidation processes(AOPs)are recognized as a set of contemporary and highly efficient methods bei...Innately designed to induce physiological changes,pharmaceuticals are foreknowingly hazardous to the ecosystem.Advanced oxidation processes(AOPs)are recognized as a set of contemporary and highly efficient methods being used as a contrivance for the removal of pharmaceutical residues.Since reactive oxygen species(ROS)are formed in these processes to interact and contribute directly toward the oxidation of target contaminant(s),a profound insight regarding the mechanisms of ROS leading to the degradation of pharmaceuticals is fundamentally significant.The conceptualization of some specific reaction mechanisms allows the design of an effective and safe degradation process that can empirically reduce the environmental impact of themicropollutants.This review mainly deliberates themechanistic reaction pathways for ROS-mediated degradation of pharmaceuticals often leading to complete mineralization,with a focus on acetaminophen as a drug waste model.展开更多
The development of efficient and robust non-precious metal electrocatalyst to drive the sluggish hydrogen oxidation reaction(HOR)is the key to the practical application of anion exchange membrane fuel cells(AEMFC),whi...The development of efficient and robust non-precious metal electrocatalyst to drive the sluggish hydrogen oxidation reaction(HOR)is the key to the practical application of anion exchange membrane fuel cells(AEMFC),which relies on the rational regulation of intermediates’binding strength.Herein,we reported a simple strategy to manipulate the adsorption energy of OH^(∗)on electrocatalyst surface via engineering Ni/NbO_(x) heterostructures with manageable oxygen vacancy(Ov).Theoretical calculations confirm that the electronic effect between Ni and NbO_(x) could weaken the hydrogen adsorption on Ni,and the interfacial oxygen vacancy tailor hydroxide binding energy(OHBE).The optimized HBE and OHBE contribute to reduce formation energy of water during the alkaline HOR process.Furthermore,in situ Raman spectroscopy monitor the dynamic process that OH^(∗)adsorbed on oxygen vacancy and react with adjacent H^(∗)adsorbed Ni,confirming the vital role of OH^(∗)for alkaline HOR process.As a result,the optimal Ni/NbO_(x) exhibits a remarkable intrinsic activity with a specific activity of 0.036mA/cm^(2),which is 4-fold than that of pristine Ni counterpart and surpasses most non-precious electrocatalysts ever reported.展开更多
文摘The surface chemical properties of CeO2 and Pr6O11 have been investigated with FT-IR spectroscopy. The reactivities of surface hydroxyls were tested through the reaction of CO. Surface formate species are formed on CeO2 and Pr6O11 under CO atmosphere at 200℃ . and the reaction becomcs more prevailing at higher temperatures especially for partially reduced samples. The surface formate species are produced via the reaction of CO with surface hydroxyls which was confirmed by the reaction of CO with D2-treated CeO2 and Pr6O11. The Surface formate can be oxidized to carbonate at temperatures exceeding 300 ℃, and the surface hydroxyls could be recovered as the formate species decompose or are oxidized to carbonate species. The roles played by the surface hydroxyls and surface active sites in the CO oxidation are discussed.
基金supported by the National Natural Science Foundation of China(Nos.51003018 and 21374009)Program of International S&T Cooperation Special Project(No.2011DFR50770)the Fundamental Research Funds of the Central University(No.HEUCFJ161003)
文摘Hydrogen bonding is considered to have significant effect on the interaction between polymeric chains and on the viscoelasticity of the polymeric materials. In this paper, we attempt to discuss the relationship between hydrogen bonding density and damping behavior and mechanical properties of polyethylene-based polymeric materials. For this reason, a series of pendant chain hydrogen bonding polymers （PCHBP） with different hydrogen bonding density （HBD） were prepared by quantitatively changing the content of pendent hydroxyl groups on the main chain of polyethylene. It was found that PCItBP with low HBD showed similar properties to polyethylene, indicating that the property of the materials was dependent mainly on the structure of the main chain. However, PCHBP with high HBD exhibited two tandpeaks and a platform of loss modulus as well as a high storage modulus （about 400 MPa） at the second tand peak temperature, demonstrating that a polymeric material with high strength and damping properties was obtained. More importantly, the maximum of loss modulus showed a linear increase with the HBD, indicating that a higher HBD greatly improved the damping properties of the polymeric materials.
文摘The thermodynamic properties of dibenzofurans （DFs）, xanthones （XTs） and an-thraquinones （AQs） with one and two positions substituted with hydroxyls in the ideal gas state at 298.15 K and 1.013×10^5 pa were calculated at the B3LYP/6-311G^＊ level using Gaussian 03 program. The isodesmic reactions were designed to calculate the standard free energy of formation （△fG^θ）. Three types of hydrogen bonds exist in the three kinds of chemicals and their bond energies were ascertained as 7-15, 15-23 and 49-58 kJ·mo1^-1 respectively by comparing the △fG^θ values. Electronic density topology analysis was applied to validate the strength of bond.
文摘Revealing the structure evolution of interfacial active species during a dynamic catalytic process is a challenging but pivotal issue for the rational design of high-performance catalysts.Here,we successfully prepare sub-nanometric Pt clusters(~0.8 nm)encapsulated within the defects of CeO_(2)nanorods via an in-situ defect engineering methodology.The as-prepared Pt@d-CeO_(2)catalyst significantly boosts the activity and stability in the water-gas shift(WGS)reaction compared to other analogs.Based on controlled experiments and complementary(in-situ)spectroscopic studies,a reversible encapsulation induced by active site transformation between the Pt^(2+)-terminal hydroxyl and Pt^(δ+)-O vacancy species at the interface is revealed,which enables to evoke the enhanced performance.Our findings not only offer practical guidance for the design of high-efficiency catalysts but also bring a new understanding of the exceptional performance of WGS in a holistic view,which shows a great application potential in materials and catalysis.
基金supported by the National Natural Science Foundation of China(Nos.22206050 and 52270047).
文摘Fenton and Fenton-like processes,which could produce highly reactive species to degrade organic contaminants,have been widely used in the field of wastewater treatment.Therein,the chemistry of Fenton process including the nature of active oxidants,the complicated reactions involved,and the behind reason for its strongly pH-dependent performance,is the basis for the application of Fenton and Fenton-like processes in wastewater treatment.Nevertheless,the conflicting views still exist about the mechanism of the Fenton process.For instance,reaching a unanimous consensus on the nature of active oxidants(hydroxyl radical or tetravalent iron)in this process remains challenging.This review comprehensively examined the mechanism of the Fenton process including the debate on the nature of active oxidants,reactions involved in the Fenton process,and the behind reason for the pH-dependent degradation of contaminants in the Fenton process.Then,we summarized several strategies that promote the Fe(Ⅱ)/Fe(Ⅲ)cycle,reduce the competitive consumption of active oxidants by side reactions,and replace the Fenton reagent,thus improving the performance of the Fenton process.Furthermore,advances for the future were proposed including the demand for the high-accuracy identification of active oxidants and taking advantages of the characteristic of target contaminants during the degradation of contaminants by the Fenton process.
基金supported by the National Natural Science Foundation of China(Nos.52170156,52250056,and 52293443)the Shenzhen Science and Technology Program(No.KQTD20190929172630447).
文摘Harnessing bacteria for superoxide production in bioremediation holds immense promise,yet its practical application is hindered by slow production rates and the relatively weak redox potential of superoxide.This study delves into a cost-effective approach to amplify superoxide production using an Arthrobacter strain,a prevalent soil bacterial genus.Our research reveals that introducing a carbon source along with specific iron-binding ligands,including deferoxamine(DFO),diethylenetriamine pentaacetate(DTPA),citrate,and oxalate,robustly augments microbial superoxide generation.Moreover,our findings suggest that these iron-binding ligands play a pivotal role in converting superoxide into hydroxyl radicals by modulating the electron transfer rate between Fe(Ⅲ)/Fe(Ⅱ)and superoxide.Remarkably,among the tested ligands,only DTPA emerges as a potent promoter of this conversion process when complexed with Fe(Ⅲ).We identify an optimal Fe(Ⅲ)to DTPA ratio of approximately 1:1 for enhancing hydroxyl radical production within the Arthrobacter culture.This research underscores the efficacy of simultaneously introducing carbon sources and DTPA in facilitating superoxide production and its subsequent conversion to hydroxyl radicals,significantly elevating bioremediation performance.Furthermore,our study reveals that DTPA augments superoxide production in cultures of diverse soils,with various soil microorganisms beyond Arthrobacter identified as contributors to superoxide generation.This emphasizes the universal applicability of DTPA across multiple bacterial genera.In conclusion,our study introduces a promising methodology for enhancing microbial superoxide production and its conversion into hydroxyl radicals.These findings hold substantial implications for the deployment of microbial reactive oxygen species in bioremediation,offering innovative solutions for addressing environmental contamination challenges.
文摘P450 enzymes-catalyzed aromatic hydroxylation plays an important role in detoxification,biosynthesis,and potential carcinogenic effect of aromatic compounds.Though it has been explored for decades,the actual process of aromatic hydroxylation and mechanism of regioselectivity catalyzed by cytochrome P450 monooxygenases remained ambiguous.Here,we have resolved these issues.With a stable chiral organofluorine probe,and especially with X-ray data of two isolated arene oxides derivatives,we demonstrate that an arene oxide pathway is definitely involved in P450-catalyzed aromatic hydroxylation.By the capture,isolation,identification and reactivity exploration of the arene 1,2-oxide and arene 2,3-oxide intermediates,together with advanced QM calculations,the mechanism of how two intermediates go to the same product has been elucidated.In addition to the model substrate,we also confirmed that an arene oxide intermediate is involved in the P450-catalyzed hydroxylation pathway of a natural product derivative methyl cinnamate,which indicates that this intermediate appears to be universal in P450-catalyzed aromatic hydroxylation.Our work not only provides the most direct evidence for the arene oxide pathway and new insights into the regioselectivity involved in P450-catalyzed aromatic hydroxylation,but also supplies a new synthetic approach to achieve the dearomatization of aromatic compounds.
文摘Herein the use of rare-earth compounds in catalytic reduction systems for the end-group functionalization of carboxyl-terminated low-molecularweight fluoropolymers was explored.Leveraging the high catalytic activity and selectivity of rare-earth compounds along with no residual impact on polymer product's performance,highly efficient catalytic reduction systems containing sodium borohydride(NaBH_(4))and rare-earth chloride(RECl_(3))were specifically designed for a telechelic carboxyl-terminated liquid fluoroeslastomer,aiming to facilitate the conversion of chainend carboxyl groups into hydroxyl groups and improvement in end-group reactivity.To achieve this,lanthanum chloride(LaCl_(3)),cerium chloride(CeCl_(3)),and neodymium chloride(NdCl_(3))were used separately to form catalytic reduction systems with NaBH_(4).The effects of solvent dosage,reaction temperature,reaction time length,and reductant dosage on carboxylic conversion were investigated,and the molecular chain structure,molecular weight,and functional group content of the raw materials and the products were analyzed and characterized by means of infrared spectroscopy(FTIR),proton nuclear magnetic resonance(^(1)H-NMR),fluorine-19 nuclear magnetic resonance(^(19)F-NMR),gel permeation chromatography(GPC),and chemical titration.Moreover,the catalytic activity and selectivity of the rare-earth chlorides,as well as the corresponding underlying interactions were discussed.Results indicated that the rare-earth-containing catalytic reduction systems studied in this work could efficiently convert the chain-end carboxyl groups into highly active hydroxyl groups,with a highest conversion up to 87.0%and differing catalytic reduction activities ranked as NaBH_(4)/CeCl_(3)>NaBH_(4)/LaCl_(3)>NaBH_(4)/NdCl_(3).Compared with the conventional lithium aluminum hydride(LiAIH_(4))reduction system,the NaBH_(4)/RECl_(3)systems provide multiple advantages such as mild reaction conditions,high conversion ratio with good selectivity,and environmental innocuity,and are potentially applicable as new reduction-catalysis combinations for the synthesis and functionalization of polymer materials.
文摘ABBOTT et al. considered that there might be two types of hydroxyls with different site energies in the dioctahedral silicates. Giese holds a similar opinion. However, so far no detailed research has been done on the orientating features, types and genesis of orientations
基金the financial support from the National Natural Science Foundation of China(No.22178181)the Fundamental Research Funds for the Central Universities(Nankai University(No.63253204))。
文摘Achieving sustainable energy and chemical production has become an important issue for human society.Photocatalysis has attracted much attention due to its ability to harness solar energy to drive chemical reactions.Metal sulfide-based photocatalysts(e.g.,Cd S,Zn In2S4)have shown substantial potential in biomass-based hydroxyl compound valorization.In this review,we summarize the recent progress in metal sulfide-based photocatalysts for the photo upgrading of biomass-derived hydroxyl compounds coupled with reduction reactions(e.g.,CO_(2)reduction,H_(2)O_(2)generation,and H_(2)evolution).The mechanism of biomass redox reactions is discussed,highlighting the potential of realizing the valorization of biomass-derived compounds coupled with the reduction reactions,which is beneficial for researchers to actively explore biomass biorefinery pathways in order to modulate the selectivity of the valueadded products.Various modification strategies are presented,including elemental doping,defect engineering,heterojunction construction,and cocatalyst loading.These strategies modulate the energy band structure,surface electron density,and built-in electric field strength of metal sulfide-based photocatalysts,thereby enhancing their photocatalytic performance.The challenges and prospects of metal sulfidebased photocatalysts in biomass valorization are analyzed.This approach contributes to the development of photocatalysts that can accelerate biomass photo-upgrading coupling reactions.This review aims to provide deeper insights into the photocatalytic biorefinery pathways and contribute to the development of functionalized photocatalysts that can accelerate biomass photo upgrading,highlighting the synergistic effects of multiple coupling reactions.
基金financially supported by the National Natural Science Foundation of China(No.22175125)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.21KJA150008)+2 种基金the Natural Science Foundation of Jiangsu Province(No.BK20231314)the Key Laboratory of Polymeric Materials Design and Synthesis for Biomedical Function,Soochow Universitythe Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘Bacterial biofilm infections,characterized by high mortality and challenging recovery,pose a significant global health risk.Developing innovative antibacterial materials and therapies,particularly those that mitigate resistance,is essential for effectively addressing biofilm-associated infections.Chemical dynamic therapy(CDT),which relies on hydroxyl radicals(·OH)generated from hydrogen peroxide(H_(2)O_(2))to eliminate bacteria,has demonstrated potential in treating planktonic infections.However,traditional CDT is less effective against biofilm-related infections due to limited endogenous H_(2)O_(2) and the protective extracellular polymeric matrix within biofilms.In this study,a composite nanoplatform based on CuO_(2) with self-supplying H_(2)O_(2) capabilities and Fe_(3)O_(4) with photothermal properties was designed to improve CDT efficacy for biofilm eradication.The Fe_(3)O_(4)/CuO_(2) composite nanoparticles(FC NPs)were synthesized by incorporating CuO_(2) into hollow mesoporous Fe_(3)O_(4) using an in-situ growth technique.Within the mildly acidic biofilm microenvironment,CuO_(2) decomposes to release Cu^(2+)and H_(2)O_(2).The Cu^(2+)subsequently catalyzes the Fenton-like conversion of the released H_(2)O_(2) into·OH.Concurrently,near-infrared(NIR)irradiation of Fe_(3)O_(4) generates significant heat,boosting·OH production and increasing bacterial membrane permeability,thereby enhancing bacterial vulnerability to·OH.This nanoplatform demonstrated remarkable CDT efficacy,eradicating over 99.99%of methicillin-resistant Staphylococcus aureus(MRSA)and 99.97%of Pseudomonas aeruginosa biofilms within five minutes of NIR irradiation in vitro.Furthermore,in vivo experiments validated the nanoplatform's ability to eradicate biofilms and facilitate the healing of MRSA-infected wounds without adverse effects.This H_(2)O_(2) self-supplying and heat-enhancing approach presents a promising strategy to overcome the limitations of CDT in biofilm-related infection treatment.
基金supported by grants from the Natural Sciences and Engineering Research Council of Canada(NSERC)Alberta Innovates,and the Canada Research Chairs Program.The authors acknowledge the support of the NSERC Postgraduate Doctoral Scholarship(NJPW),the Alberta Innovates Graduate Student Scholarship(KC),and the 75th Anniversary Graduate Student Award and the Graduate Student Recruitment Scholarship of the Faculty of Medicine and Dentistry at the University of Alberta(KNMC).
文摘This study investigated the impacts of spring runoff on the formation of halobenzoquinones(HBQs)and their correlation with common water quality parameters(WQPs)and aromatic amino acids(AAs)in source water.Source water and treated water samples were collected at two drinking water treatment plants in 2021,2022,and 2023.HBQs and aromatic AAs were analyzed using solid phase extraction with high performance liquid chromatography–tandem mass spectrometry methods.The only HBQs detected in treated water were 2,6-dichloro-1,4-benzoquinone(DCBQ)and hydroxy–DCBQ(OH-DCBQ).The concentration of DCBQ was 3-4 times higher during spring runoff events than during non-spring-runoff periods,suggesting the impact of spring runoff on the formation of DCBQ.The DCBQ concentrations in finished water positively correlated with the color,dissolved organic carbon,total organic nitrogen,and specific ultraviolet absorbance WQPs of source water in 2021 and 2022.The temporal trend of the total aromatic AAs determined in source water was strongly and positively correlated to DCBQ in finished water.Finally,there was a significant positive correlation between the concentration of DCBQ determined immediately following the addition of chlorine and the presence of its transformation product,OH-DCBQ,in finished water.The results also showed that powdered activated carbon can remove some of the HBQ precursors in the sourcewater to reduce DCBQ formation.This study demonstrated that WQPs and aromatic AAs are useful indicators for the removal of precursors to reduce HBQ formation during drinking water treatment.
文摘The Fenton-like reaction between Cu^(2+)and H_(2)O_(2)was employed in chemical mechanical polishing to achieve efficient and high-quality processing of tungsten.The microstructure evolution and material removal rate of tungsten during polishing process were investigated via scanning electron microscopy,X-ray photoelectron spectroscopy,ultraviolet−visible spectrophotometry,and electrochemical experiments.The passivation behavior and material removal mechanism were discussed.Results show that the use of mixed H_(2)O_(2)+Cu(NO_(3))_(2)oxidant can achieve higher polishing efficiency and surface quality compared with the single oxidant Cu(NO_(3))_(2)or H_(2)O_(2).The increase in material removal rate is attributed to the rapid oxidation of W into WO_(3)via the chemical reaction between the substrate and hydroxyl radicals produced by the Fenton-like reaction.In addition,material removal rate and static etch rate exhibit significantly different dependencies on the concentration of Cu(NO_(3))_(2),while the superior oxidant for achieving the balance between polishing efficiency and surface quality is 0.5 wt.%H_(2)O_(2)+1.0 wt.%Cu(NO_(3))_(2).
基金Supported by the National Key R&D Program of China(2019YFA0708700,2023YFF0614100)CNPC Major Science and Technology Project(2021ZZ01,2023ZZ04).
文摘Given that a large amount of crude oil remains on the surface of rocks and is difficult to produce after conventional waterflooding,a new superwetting oil displacement system incorporating the synergy between a hydroxyl anion compound(1OH-1C)and an extended surfactant(S-C_(13)PO_(13)S)was designed.The interfacial tension,contact angle and emulsification performance of the system were measured.The oil displacement effects and improved oil recovery(IOR)mechanisms of 1OH-1C,S-C_(13)PO_(13)S and their compound system were investigated by microscopic visualization oil displacement experiments and core displacement experiments.The results show that 1OH-1C creates a superwetting interface and electrostatic separation pressure on the solid surface,which destroys the strong interactions between crude oil and quartz to peel off the oil film.S-C_(13)PO_(13)S has low interfacial tension,which can promote the flow of remaining oil and emulsify it into oil-in-water emulsions.The compound system of 1OH-1C and S-C_(13)PO_(13)S has both superwettability and low IFT,which can effectively improve oil recovery through a synergistic effect.The oil displacement experiment of low-permeability natural core shows that the compound solution can increase the oil recovery by 16.4 percentage points after waterflooding.This new high-efficiency system is promising for greatly improving oil recovery in low-permeability reservoirs.
文摘Solar-driven CO_(2)conversion and pollutant removal with an S-scheme heterojunction provides promising approach to alleviate energy shortage and environmental crisis,yet the comprehensive regulation of the charge separation and the activation sites of reactant molecules remains challenging.Herein,a dual-active groups regulated S-scheme heterojunction for hydroxy-regulated BiOBr modified amino-functionalized g-C_(3)N_(4)(labeled as HBOB/ACN)was designed by spatially separated dual sites with hydroxyl group(OH)and amino group(NH_(2))toward simultaneously photocatalytic CO_(2)reduction and ciprofloxacin(CIP)oxidation.The optimized HBOB/ACN delivers around 2.74-fold CO yield rate and 1.61-times CIP removal rate in comparison to BiOBr/g-C_(3)N_(4)(BOB/CN)without surface groups,which chiefly ascribed the synergistic effect of OH and NH_(2)group.A series of experiments and theoretical calculation unveiled that the OH and NH_(2)group trapped holes and electrons to participate in CIP oxidation and CO_(2)reduction,respectively.Besides,dual-functional coupled reaction system realized the complete utilization of carriers.This work affords deep insights for dual-group modified S-scheme heterojunctions with redox active sites toward dual-functional coupled reaction system for environment purification and solar fuel production.
基金supported by the National Natural Science Foundation of China(Nos.52301279 and 51901115)the Shandong Provincial Natural Science Foundation,China(ZR2023MB122 and ZR2019PEM001)+1 种基金the Outstanding Youth Innovation Team of Universities in Shandong Province(2024KJH067)the Innovation fund project for graduate student of China University of Petroleum(East China)supported by the Fundamental Research Funds for the Central Universities(No.23CX04010A)。
文摘Addressing inadequate OH^(*)adsorption in Ru Co alloy catalysts is crucial for boosting intermediate coverage and redirecting the water-splitting pathway.Herein,the adaptive P sites were strategically incorporated to overcome the aforementioned challenge.The P sites,as potent OH^(*)adsorption centers,synergize with Co sites to promote water dissociation and enrich surrounding Ru sites with H*intermediates,thus triggering the Volmer-Tafel route for hydrogen evolution reaction(HER).Besides,during the oxygen evolution reaction(OER),the surface of P-Ru Co was reconstructed into Ru-doped Co OOH with anchored PO_(4)^(3-).These PO_(4)^(3-)not only circumvent the intrinsic OH^(*)adsorption limitations of Ru-Co OOH in the adsorbate evolution mechanism(AEM)by rerouting to a more expeditious lattice oxygen oxidation mechanism(LOM)but also improve the coverage of key oxygen-containing intermediates,significantly accelerating OER kinetics.Consequently,the P-Ru Co demonstrates exceptional bifunctional performance,with overpotentials of 29 m V for HER and 222 m V for OER at 10 m A cm^(-2).Remarkably,the mass activities of PRu Co for HER(5.48 A mg^(-1))and OER(2.13 A mg^(-1))are 6.2 and 11.2 times higher than those of its commercial counterparts(Ru/C for HER and RuO_(2)for OER),respectively.When integrated into an anionexchange-membrane electrolyzer,this catalyst achieves ampere-level current densities of 1.32 A cm^(-2)for water electrolysis and 1.23 A cm^(-2)for seawater electrolysis at 2.1 V,with a 500-h durability.
基金the financial support from National Natural Science Foundation of China(22363001,22378379,22479032,22022814)the National Key R&D Project(2022YFA1503900)+6 种基金the Natural Science Special Foundation of Guizhou University(No.202140)National Natural Science Foundation of China for Single-Atom Catalysis(22388102)the Youth Innovation Promotion Association CAS(Y2021057)Dalian Science Foundation for Distinguished Young Scholars(2021RJ10)Grant.YLU-DNL Fund(2022010)the Young Top-notch Talents of Liaoning Province(XLYC2203140)the Liaoning Foundation for Distinguished Young Scholars(2025JH6/101100011).
文摘UiO-66-H MOFs can effectively catalyze the direct selective oxidation of methane(DSOM)to high value-added oxygenates under mild conditions.However,UiO-66-NH_(2)with benzene-1,4-dicarboxylate(NH_(2)-BDC)ligand modifying the Zr-oxo nodes exhibits relatively inferior catalytic performance for DSOM.Here,a combination of density functional theory(DFT)calculations and experiments was employed to explore the underlying reasons for the limited catalytic activity of UiO-66-NH_(2).The results indicate that the methane hydroxylation performance of UiO-66-NH_(2)is almost unaffected by the increase of·OH concentration.This is attributed to the formation of substantial non-covalent hydrogen bonds between the oxygen atoms of oxygenic species on the Zr-oxo nodes and the hydrogen atoms of-NH_(2)groups,which diminishes the spin density distribution on the active sites of(·OH)m/UiO-66-NH_(2),leading to minimal change of the adsorption energy of CH_(4).Additionally,the calculated adsorption energies(Eads)of CH_(4)exhibit a linear relationship with the catalytic activity of UiO-66-NH_(2)for DSOM reaction.
基金supported by the National Natural Science Foundation of China(Nos.U22A20591,42077185,42107217)the Sichuan Province Science and Technology Program for Distinguished Young Scholars(No.2022JDJQ0010)+1 种基金the Sichuan Science and Technology Program(No.2024NSFSC0842)the State Key Laboratory of Geohazard Prevention and Geoenvironment Protection(No.SKLGP2020Z002)。
文摘Hydroxyl radical(·OH)formation from Fe(Ⅱ)-bearing clay mineral oxygenation in the shallow subsurface has been well documented under moderate environmental conditions.However,the impact of freezing processes on the·OH production capability of Fe(Ⅱ)-bearing clay minerals for organic contaminant degradation,particularly in seasonally frozen soils,remains unclear.In this study,we investigated the influence of pre-freezing durations on the mineral proprieties,·OH production,and phenol degradation during the oxygenation of reduced Fe-rich nontronite(rNAu-2)and Fe-poor montmorillonite(rSWy-3).During the freezing process of reduced clay minerals(1 mM Fe(Ⅱ)),the content of edge surface Fe and Fe(Ⅱ)decreased by up to 46%and 58%,respectively,followed by a slight increased as clay mineral particles aggregated and subsequently partially disaggregated.As the edge surface Fe(Ⅱ)is effective in O_(2) activation but less effective in the transformation of H_(2)O_(2) to·OH,the redistribution of edge surface Fe(Ⅱ)leads to that·OH production and phenol degradation increased initially and then decreased with pre-freezing durations ranging from 0 to 20 days.Moreover,the rate constants of phenol degradation for both the rapid and slow reaction phases also first increase and then decrease with freezing time.However,pre-freezing significantly influenced the rapid phase of phenol degradation by rNAu-2 but affected the slow phase by rSWy-3 due to the much higher edge-surface Fe(Ⅱ)content in rNAu-2.Overall,these findings provide novel insights into the mechanism of·OH production and contaminant degradation during the freeze-thaw processes in clay-rich soils.
基金the Ministry of Higher Education,Research and Innovation-Oman for their support of this research through TRC block funding grant No.BFP/RGP/EBR/22/378.
文摘Innately designed to induce physiological changes,pharmaceuticals are foreknowingly hazardous to the ecosystem.Advanced oxidation processes(AOPs)are recognized as a set of contemporary and highly efficient methods being used as a contrivance for the removal of pharmaceutical residues.Since reactive oxygen species(ROS)are formed in these processes to interact and contribute directly toward the oxidation of target contaminant(s),a profound insight regarding the mechanisms of ROS leading to the degradation of pharmaceuticals is fundamentally significant.The conceptualization of some specific reaction mechanisms allows the design of an effective and safe degradation process that can empirically reduce the environmental impact of themicropollutants.This review mainly deliberates themechanistic reaction pathways for ROS-mediated degradation of pharmaceuticals often leading to complete mineralization,with a focus on acetaminophen as a drug waste model.
基金supported by Jilin Province Science and Technology Development Program(Nos.20200201001JC,20210502002ZP,20230101367JC,20220301011GX)Jilin Province Science and Technology Major Project(No.222648GX0105103875).
文摘The development of efficient and robust non-precious metal electrocatalyst to drive the sluggish hydrogen oxidation reaction(HOR)is the key to the practical application of anion exchange membrane fuel cells(AEMFC),which relies on the rational regulation of intermediates’binding strength.Herein,we reported a simple strategy to manipulate the adsorption energy of OH^(∗)on electrocatalyst surface via engineering Ni/NbO_(x) heterostructures with manageable oxygen vacancy(Ov).Theoretical calculations confirm that the electronic effect between Ni and NbO_(x) could weaken the hydrogen adsorption on Ni,and the interfacial oxygen vacancy tailor hydroxide binding energy(OHBE).The optimized HBE and OHBE contribute to reduce formation energy of water during the alkaline HOR process.Furthermore,in situ Raman spectroscopy monitor the dynamic process that OH^(∗)adsorbed on oxygen vacancy and react with adjacent H^(∗)adsorbed Ni,confirming the vital role of OH^(∗)for alkaline HOR process.As a result,the optimal Ni/NbO_(x) exhibits a remarkable intrinsic activity with a specific activity of 0.036mA/cm^(2),which is 4-fold than that of pristine Ni counterpart and surpasses most non-precious electrocatalysts ever reported.
