Nano-zinc oxides(ZnO)demonstrate remarkable antibacterial properties.To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation(MAO)coatings,this study investigates...Nano-zinc oxides(ZnO)demonstrate remarkable antibacterial properties.To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation(MAO)coatings,this study investigates the preparation of ZnO-containing micro-arc oxidation coatings with dual functionality by incorporating nano-ZnO into MAO electrolyte.The influence of varying ZnO concentrations on the microstructure,corrosion resistance,and antibacterial properties of the coating was examined through microstructure analysis,immersion tests,electrochemical experiments,and antibacterial assays.The findings revealed that the addition of nano-ZnO significantly enhanced the corrosion resistance of the MAO-coated alloy.Specifically,when the ZnO concentration in the electrolyte was 5 g/L,the corrosion rate was more than ten times lower compared to the MAO coatings without ZnO.Moreover,the antibacterial efficacy of ZnO+MAO coating,prepared with a ZnO concentration of 5 g/L,surpassed 95%after 24 h of co-culturing with Staphylococcus aureus(S.aureus).The nano-ZnO+MAO-coated alloy exhibited exceptional degradation resistance,corrosion resistance,and antibacterial effectiveness.展开更多
This study presents a novel approach to improving the anticorrosive performance of AZ31 Mg alloy by exploiting the role of the hydration reaction to induce interactions between Quinolin-8-ol(8HQ)molecules and the poro...This study presents a novel approach to improving the anticorrosive performance of AZ31 Mg alloy by exploiting the role of the hydration reaction to induce interactions between Quinolin-8-ol(8HQ)molecules and the porous MgO layer formed via plasma electrolytic oxidation(PEO).The AZ31 Mg alloy,initially coated with a PEO layer,underwent a dipping treatment in an ethanolic solution of 0.05 M 8HQ at 50℃ for 3 h.The results were compared with those from a different procedure where the PEO layer was subjected to a hydration reaction for 2 h at 90℃ before immersion in the 8HQ solution under the same conditions.The hydration treatment played a crucial role by converting MgO to Mg(OH)_(2),significantly enhancing the surface reactivity.This transformation introduced hydroxyl groups(−OH)on the surface,which facilitated donor-acceptor interactions with the electron-accepting sites on 8HQ molecules.The calculated binding energy(Ebinding)from DFT indicated that the interaction energy of 8HQ with Mg(OH)_(2) was lower compared to 8HQ with MgO,suggesting easier adsorption of 8HQ molecules on the hydrated surface.This,combined with the increased number of active sites and enhanced surface area,allowed for extensive surface coverage by 8HQ,leading to the formation of a stable,flake-like protective layer that sealed the majority of pores on the PEO layer.DFT calculations further suggested that the hydration treatment provided multiple active sites,enabling effective contact with 8HQ and rapid electron transfer,creating ideal conditions for charge-transfer-induced physical and chemical bonding.This study shows that hydration and 8HQ treatments significantly enhance the corrosion resistance of Mg alloys,highlighting their potential for advanced anticorrosive coatings.展开更多
TC4 micro-arc oxidation(MAO)coatings were prepared by adding SiO_(2) nanoparticles or sodium silicate to the sodium meta-aluminate-based electrolyte.The effect of additives was investigated by XRD,SEM,EDS,electrochemi...TC4 micro-arc oxidation(MAO)coatings were prepared by adding SiO_(2) nanoparticles or sodium silicate to the sodium meta-aluminate-based electrolyte.The effect of additives was investigated by XRD,SEM,EDS,electrochemical and wear tests.The results show that additives can considerably accelerate the formation of MAO coatings.The coatings are mostly composed of rutile and anatase TiO_(2),α-Al_(2)O_(3),γ-Al_(2)O_(3),Al_(2)TiO_(5) and SiO_(2).Sodium silicate and SiO_(2) nanoparticles added to the coating can effectively reduce the size of micropores and increase its thickness,whereas SiO_(2) nanoparticles with superior physical properties can be directly deposited at the discharge channel,significantly increasing the coating's resistance to wear and corrosion.The coating with SiO_(2) nanoparticles exhibits the best overall performance,with the lowest corrosion rate and average friction coefficient of 4.095×10^(-5)mm/a and 0.30,respectively.展开更多
To efficiently diminish the Pt consumption while concurrently enhancing the anodic reaction kinetics,a straightforward synthesis for PtPdAg nanotrees(NTs)with exceedingly low Pt content is presented,utilizing the galv...To efficiently diminish the Pt consumption while concurrently enhancing the anodic reaction kinetics,a straightforward synthesis for PtPdAg nanotrees(NTs)with exceedingly low Pt content is presented,utilizing the galvanic replacement reaction between the initially prepared PdAg NTs and Pt ions.Due to the multilevel porous tree-like structure and the incorporation of low amounts of Pt,the electrocatalytic activity and stability of PtPdAg NTs are markedly enhanced,achieving 1.65 and 1.69 A·mg^(-1)Pt+Pd for the anodic reactions of formic acid oxidation(FAOR)and methanol oxidation(MOR)within DLFCs,surpassing the performance of PdAg NTs,as well as that of commercial Pt and Pd black.Density functional theory(DFT)calculations reveal that the addition of low amounts of Pt leads to an increase in the d-band center of PtPdAg NTs and lower the COads adsorption energy to-1.23 eV,enhancing the anti-CO toxicity properties optimally.This approach offers an effective means for designing low Pt catalysts as exceptional anodic electrocatalysts for direct liquid fuel cells.展开更多
By introduction of hydrogen peroxide into the reaction system of ZrOCl_(2)·8H_(2)O and K14[As_(2)W_(19)O_(67)(H_(2)O)],a novel polyoxometalate K_(8)Na_(19.5)H_(0.5)[Zr_(2)(O_(2))_(2)(β-AsVW_(10)O_(38))]4·68...By introduction of hydrogen peroxide into the reaction system of ZrOCl_(2)·8H_(2)O and K14[As_(2)W_(19)O_(67)(H_(2)O)],a novel polyoxometalate K_(8)Na_(19.5)H_(0.5)[Zr_(2)(O_(2))_(2)(β-AsVW_(10)O_(38))]4·68H_(2)O(1)has been successfully obtained via one-pot method and systematically characterized by IR,XPS,solid UV spectra,PXRD pattern,and TGA analysis.The analysis of X-ray crystallography exhibits that compound 1 crystallizes in the triclinic space group P-1 and presents a novel square-shaped Zr-substituted tetrameric polyoxometalate.The catalytic oxidation of sulfides by 1 are carried out,which demonstrate that 1 exhibits a good performance for the catalytic oxidation of sulfides to sulfones with high conversion(100%)and high selectivity(100%).展开更多
Hexafluoropropylene oxide(HFPO)is a crucial fluorinated chemical mainly synthesized from hexafluoropropylene(HFP)through the oxidation of oxygen.However,the reaction network and kinetic characteristics are not fully u...Hexafluoropropylene oxide(HFPO)is a crucial fluorinated chemical mainly synthesized from hexafluoropropylene(HFP)through the oxidation of oxygen.However,the reaction network and kinetic characteristics are not fully understood yet,resulting in a lack of theoretical basis for synthesis process improvement.Here,the free radical reaction mechanism and complete reaction network involved in the noncatalytic oxidation of HFP to synthesize HFPO was explored by density functional theory.Transition state theory was employed to calculate the intrinsic reaction rate constants for elementary reactions.Based on theoretical reaction rate ratios,reaction pathways were selected,and a simplified reaction network was derived.It was found that byproducts were formed owing to the decomposition of HFPO and subsequent reactions with excessive oxygen while oxygen tended to participate more in the main reaction under oxygen-deficient conditions.The variations in reaction pathways occurring at different HFP/oxygen molar ratios was well elucidated by comparing with experimental data.This research establishes a robust theoretical foundation for optimizing and regulating the synthesis of HFPO.展开更多
Catalytic oxidation of NO at room temperature was carried out over nitrogen(N)-doped sludge char(SC)prepared from pyrolysis ofmunicipal sewage sludge,and urea was adopted as nitrogen source.The effects of different N-...Catalytic oxidation of NO at room temperature was carried out over nitrogen(N)-doped sludge char(SC)prepared from pyrolysis ofmunicipal sewage sludge,and urea was adopted as nitrogen source.The effects of different N-doping methods(one-step and two-step method),dried sludge(DS)/urea mass ratios(5:1,4:1,3:1,2:1,and 1:1),SC preparation procedures(pyrolysis only,pyrolysis with acid washing,and pyrolysis with KOH activation and acid washing),and different pyrolysis temperatures(500,600,700,and 800°C)on the catalytic oxidation of NO were compared to optimize the procedure for SC preparation.The results indicated that N-doping could obviously promote the catalytic performance of SC.The one-step method with simultaneous sludge pyrolysis(at 700°C),KOH activation,and N-doping(DS/urea of 3:1)was the optimal procedure for preparing the N-doped SC with the NO conversion rate of 54.7%,whereas the optimal NO conversion rate of SC without N-doping was only 47.3%.Urea worked both as carbon and nitrogen source,which could increase about 2.9%-16.5%of carbon and 24.8%-42.7%of nitrogen content in SC pyrolyzed at 700°C.N-doping significantly promoted microporosity of SC.The optimal N-doped SC showed specific surface areas of 571.38 m^(2)/g,much higher than 374.34 m^(2)/g of the optimal SC without N-doping.In addition,N-doping also increased amorphousness and surface basicity of SC through the formation of N-containing groups.Finally,three reaction paths,i.e.microporous reactor,active sites,and basic site control path,were proposed to explain the mechanism of N-doping on promoting the catalytic performance of NO.展开更多
Oxidation behavior of NiCrAlY nanocrystalline coatings with different Cr contents at 1050 and 1150℃is investigated.The results indicate that Al2O3 scales can be formed on NiCrAlY nanocrystalline coatings after oxidat...Oxidation behavior of NiCrAlY nanocrystalline coatings with different Cr contents at 1050 and 1150℃is investigated.The results indicate that Al2O3 scales can be formed on NiCrAlY nanocrystalline coatings after oxidation at high temperature.And their formation and thickening cannot be affected by the change of Cr contents in NiCrAlY coatings.During service,Cr in the coating can affect the microstructure of Ni-based single crystal superalloy.At 1050℃,Cr in the coating can diffuse into the superalloy,destroy its microstructure,and lead to the formation of interdiffusion zone and the precipitation of needle-like topologically closed-packed phase.The higher the Cr content in NiCrAlY the coating is,the more obvious the phenomenon is.However,after oxidation at 1150℃for 100 h,no obvious changes were observed in the microstructure of CMSX-4 single crystal superalloy beneath the three kinds of NiCrAlY nanocrystalline coatings.展开更多
In this work,a series of Ce-Ti composite oxides with different Ti/Ce molar ratios was prepared by coprecipitation method,and investigated for the catalytic degradation of toluene and selective catalytic reduction of N...In this work,a series of Ce-Ti composite oxides with different Ti/Ce molar ratios was prepared by coprecipitation method,and investigated for the catalytic degradation of toluene and selective catalytic reduction of NO.The phase transition process between Ce species and Ti species is limited by modulating the interaction between Ce4+and Ti4+,while a completely amorphous composite is generated with an appropriate molar ratio of Ti/Ce(1.5/1).The catalyst CeTi1.5Oxexhibits the best catalytic performance,where the values of T90and T50for deep degradation of toluene are 297 and 330℃respectively at high weight hours space velocity(WHSV=120000 mL/(g·h)).Compared with CeO_(2),T90and T50decrease by48 and 34℃respectively while declining by 67 and 70℃compared to TiO_(2).For the SCR reaction,CeTi1.5Oxreaches 100%NO conversion at 250℃with WHSV=60000 mL/(g·h),reduced by 50℃compared to pure CeO_(2).The amorphous nanostructure with highly dispersed Ce and Ti species was confirmed by transmission electron microscopy(TEM)and X-ray diffraction(XRD)characterizations.The X-ray photoelectron spectroscopy(XPS)and Raman analyses show that a large number of active Ce-O-Ti species and surface oxygen vacancies are generated due to the strong interaction between Ti^(4+)and Ce^(4+)in CeTi_(1.5)O_(x).Additionally,H_(2)-TPR and O_(2)-TPD further confirm that the interaction promotes the low-temperature reducibility and mobility of surface-active oxygen species.Meanwhile,in-situ DRIFTS study reveals that CeTi1.5Oxwith amorphous nanostructure can dramatically enhance the dissociative and complete oxidation capacity for toluene.展开更多
The direct oxidation of methane to methanol(DOMM) has been recognized as a significant technology for efficiently utilizing low-concentration coalbed methane(LCMM) and supplying liquid fuel.Herein,the noble metals(Pt,...The direct oxidation of methane to methanol(DOMM) has been recognized as a significant technology for efficiently utilizing low-concentration coalbed methane(LCMM) and supplying liquid fuel.Herein,the noble metals(Pt,Pd and Ru) modified Cu/alkalized sepiolite(CuX/SEPA) catalysts were prepared and used for the DOMM in a gas-phase system at low temperatures.The CuRu/SEPA exhibited the highest methanol production of 53 μmol·g^(-1)·h^(-1) and methanol selectivity of 90% under the optimal reaction conditions.Various characterizations demonstrated that the addition of Ru promoted the formation of Cu^(2+)and the contraction of Cu—Si/Al bonds to reduce the distance between framework Al atoms of SEPA to further generate more Al pairs,which facilitated the formation of reactive dicopper species([Cu_(2)O]^(2+)or [Cu_(2)O_(2)]^(2+)).Investigation of the reaction mechanism revealed that [Cu_(2)O]^(2+) or [Cu_(2)O_(2)]^(2+) species could adsorb and activate methane to form CH_(3)O^(*) species and ultimately generated methanol with the assistance of water.展开更多
Iron-Vanadium(FeV)catalyst showed a unique catalytic activity for the selective oxidation of methanol to formaldehyde;however,due to its complex compositions,the identification of catalytic active sites still remains ...Iron-Vanadium(FeV)catalyst showed a unique catalytic activity for the selective oxidation of methanol to formaldehyde;however,due to its complex compositions,the identification of catalytic active sites still remains challenging,inhibiting the rational design of excellent FeV-based catalysts.Here,in this work,a series of FeV catalysts with various compositions,including FeVO_(4),isolated VO_(x),low-polymerized V_(n)O_(x),and crystalline V_(2)O_(5) were prepared by controlling the preparation conditions,and were applied to methanol oxidation to formaldehyde reaction.A FeV_(1.1) catalyst,which consisted of FeVO_(4) and low-polymerized V_(n)O_(x) species showed an excellent catalytic performance with a methanol conversion of 92.3%and a formaldehyde selectivity of 90.6%,which was comparable to that of conventional iron-molybdate catalyst.The results of CH_(3)OH-IR,O_(2) pulse and control experiments revealed a crucial synergistic effect between FeVO_(4) and low-polymerized V_(n)O_(x).It enhanced the oxygen supply capacity and suitable binding and adsorption strengths for formaldehyde intermediates,contributing to the high catalytic activity and formaldehyde selectivity.This study not only advances the understanding of FeV structure but also offers valuable guidelines for selective methanol oxidation to formaldehyde.展开更多
A novel tetra-europium(III)-containing antimonotungstate,Na_(8.2)[H_(2)N(CH_(3))_(2)]_(9)[Na_(10.8)(tar)_(4)(H_(2)O)_(20)(Eu_(2)Sb_(2)W_(21)O_(72))_(2)]·44.5H_(2)O(EuSbW,H_(4)tar=dl-tartaric acid),has been synthe...A novel tetra-europium(III)-containing antimonotungstate,Na_(8.2)[H_(2)N(CH_(3))_(2)]_(9)[Na_(10.8)(tar)_(4)(H_(2)O)_(20)(Eu_(2)Sb_(2)W_(21)O_(72))_(2)]·44.5H_(2)O(EuSbW,H_(4)tar=dl-tartaric acid),has been synthesized and characterized.The dimeric polyoxoanion of EuSbW consists of two Dawson-like{Eu_(2)Sb_(2)W_(21)}units bridged by four dl-tartaric acid ligands.The adjacent carboxyl and hydroxy groups in each tartaric acid simultaneously chelate with W and Eu atoms from different{Eu_(2)Sb_(2)W_(21)}units,thereby forming the dimeric structure.EuSbW represents an extremely rare polyoxometalate where four tartaric acid ligands function as connectors to bridge two{Eu_(2)Sb_(2)W_(21)}units.Additionally,EuSbW exhibits excellent catalytic activity and reusability in the oxidation of thioethers and alcohols,achieving 100%conversion and>99%selectivity for various thioethers,and 85–100%conversion with 90–99%selectivity for diverse alcohols under mild conditions.展开更多
Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mec...Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mechanism of arsenopyrite by evaluating the effects of physical and chemical changes of arsenopyrite in BOS chemical oxidation stage on mineral dissolution kinetics,as well as microbial growth activity and community structure composition in bio-oxidation stage.The results showed that the chemical oxidation contributed to destroying the physical and chemical structure of arsenopyrite surface and reducing the particle size,and led to the formation of nitrogenous substances on mineral surface.These chemical oxidation behaviors effectively promoted Fe^(3+)cycling in the bio-oxidation system and weakened the inhibitory effect of the sulfur film on ionic diffusion,thereby enhancing the dissolution kinetics of the arsenopyrite.Therefore,the bio-oxidation efficiency of arsenopyrite was significantly increased in the two-stage oxidation process.After 18 d,the two-stage oxidation process achieved total extraction rates of(88.8±2.0)%,(86.7±1.3)%,and(74.7±3.0)%for As,Fe,and S elements,respectively.These values represented a significant increase of(50.8±3.4)%,(47.1±2.7)%,and(46.0±0.7)%,respectively,compared to the one-stage bio-oxidation process.展开更多
Enhancing the activity of photocatalysts is a critical challenge for improving the photocatalytic degradation of contaminated wastewater.Here,a novel Ce single-atom-doped titanate nanotube photocatalyst(CeH_(2)Ti_(2)O...Enhancing the activity of photocatalysts is a critical challenge for improving the photocatalytic degradation of contaminated wastewater.Here,a novel Ce single-atom-doped titanate nanotube photocatalyst(CeH_(2)Ti_(2)O_(5)·H_(2)O)was successfully synthesized using a onepot solvothermal method.Degradation experiments revealed that the optimal Ce doping ratio was 1.0%.The ultraviolet-visible diffuse reflectance spectroscopy results showed that the bandgap of the Ce-doped sample decreased from 3.02 to 2.87 eV,enhancing the absorption in the visible spectral range.At the same time,the BrunauerEmmett-Teller specific surface area increased from 63.68 to 88.95 m^(2)g^(-1).The 1.0%Ce-H_(2)Ti_(2)O_(5)·H_(2)O(HTC_(1))could degrade 99.04%of 100 mg L-1rhodamine B(RhB)after 40 min of visible-light irradiation.The degradation efficiency decreased by only 21.24%after five cycles.The results of free-radical quenching and electron spin resonance spectroscopy analyses indicated that HTC_(1)achieved efficient degradation of RhB through a direct hole oxidation mechanism.Compared with pure protonated titanate nanotubes(H_(2)Ti_(2)O_(5)·H_(2)O),HTC_(1)had a higher specific surface area,more electron traps,narrower bandgap,longer hole lifetime,and suppressed photogenerated charge recombination rate owing to the Ce single-atom doping.展开更多
The electrocatalytic oxidation of glycerol toward formic acid is one of the most promising pathways for transformation and utilization of glycerol.Herein,a series of well-defined Ni_(n)(SR)_(2n) nanoclusters(n=4,5,6;d...The electrocatalytic oxidation of glycerol toward formic acid is one of the most promising pathways for transformation and utilization of glycerol.Herein,a series of well-defined Ni_(n)(SR)_(2n) nanoclusters(n=4,5,6;denoted as Ni NCs)were prepared for the electrocatalytic glycerol oxidation toward formic acid,in which Ni_(6)-PET-50CV afforded the most excellent electrocatalytic performance with a high formic acid selectivity of 93% and a high glycerol conversion of 86%.This was attributed to the lowest charge transfer impedance and the most rapid reaction kinetics.Combined electrochemical measurements and X-ray absorption fine structure measurements revealed that the structures of Ni NCs remained intact after CV scanning pretreatment and electrocatalysis via forming the Ni–O bond.Additionally,the kinetic studies and in-situ Fourier transformed infrared suggested a sequential oxidation mechanism,in which the main reaction steps of glycerol→glyceraldehyde→glyceric acid were very rapid to produce a high selectivity of formic acid even though the low glycerol conversion.This work presents an opportunity to study Ni NCs for the efficient electrocatalytic oxidation of biomass-derived polyhydroxyl platform molecules to produce value-added carboxylic acids.展开更多
Atomically precise metal nanoclusters(NCs)have been deemed as a new generation of metal nanomaterials in the field of solar energy conversion due to their unique atomic stacking manner,quantum confinement effects,ligh...Atomically precise metal nanoclusters(NCs)have been deemed as a new generation of metal nanomaterials in the field of solar energy conversion due to their unique atomic stacking manner,quantum confinement effects,light-harvesting capability and multitude of active sites.Nonetheless,wide-spread application of monometallic NCs is blocked by the ultrashort carrier lifespan,uncontrollable charge transport pathway,and light-induced poor stability,impeding the construction of robust and stable metal NC-based photosystems.Herein,we report the fabrication of stable alloy(Au_(1-x)Pt_(x))NCs photosystem,for which tailor-made negatively charged l-glutathione(GSH)-capped Au_(1-x)Pt_(x)NCs as the building blocks are controllably deposited on the Bi VO_(4)(BVO)by a self-assembly approach for steering enhanced light absorption and interfacial charge transfer over alloy NCs-based photoanodes(Au_(1-x)Pt_(x)/BVO).The self-assembled Au_(1-x)Pt_(x)/BVO composite photoanode exhibits the significantly enhanced photoelectrochemical water oxidation performances compared with pristine BVO and Au_(x)/BVO photoanodes,which is caused by the Pt atom doping into the Au_(x)NCs for elevating photosensitivity and boosting the stability.The synergy of Au and Pt atoms in alloy NCs protects the gold core from rapid oxidation,improving the photostability and accelerating the surface charge transfer kinetics.Our work would significantly inspire ongoing interest in unlocking the charge transport characteristics of atomically precise alloy NCs for solar energy conversion.展开更多
Efficiently utilizing ammonia(carbon-free fuel)via low-temperature fuel cells is severely hindered by the sluggish kinetics of ammonia oxidation reaction(AOR).Herein,platinum-iridium-tungsten nanocubes(PtIrW-NCBs)with...Efficiently utilizing ammonia(carbon-free fuel)via low-temperature fuel cells is severely hindered by the sluggish kinetics of ammonia oxidation reaction(AOR).Herein,platinum-iridium-tungsten nanocubes(PtIrW-NCBs)with exposed{100}-rich facets were synthesized by a glucose-assisted solvent-thermal method,in which alloying W not only can facilitate the formation of such specific nanostructures to expose more active sites for AOR,but also modulate the electronic structure of PtIr to promote the kinetics of AOR.The PtIrW-NCBs featuring the small nanoparticle size of 5.05±0.07 nm exhibit superior AOR performance,wherein the onset potential is down to 0.319 V and the mass activity is 30.15 A g_((PGM=Pt,Ir))^(-1)at 0.50 V vs.RHE,significantly higher than those of reported majority of AOR catalysts and even commercial PtIr/C.Meanwhile,in situ Fourier transform infrared spectroscopy measurement further reveals that AOR on PtIrW-NCBs dominantly undergoes the dimerization path of NH_(x)(1≤x≤2).In addition,the theoretical calculations also identify that alloying W into PtIr can contribute additional electrons to 5d orbitals of PtIr,enabling the d-band center approaching the Femi level,which in turn induces the high-filling of bonding orbitals of N-N bond in^(*)N_(2)H_(4),promoting the dimerization of^(*)NH_(2)to^(*)N_(2)H_(4)and thus leading to high AOR activity of PtIrW.This work provides new insights for designing efficient AOR electrocatalysts.展开更多
The widespread occurrence of antibiotics in wastewater aroused serious attention.UV-based advanced oxidation processes(UV-AOPs)are powerful technologies in removing antibiotics in wastewater,which include UV/catalyst,...The widespread occurrence of antibiotics in wastewater aroused serious attention.UV-based advanced oxidation processes(UV-AOPs)are powerful technologies in removing antibiotics in wastewater,which include UV/catalyst,UV/H_(2)O_(2),UV/Fenton,UV/persulfate,UV/chlorine,UV/ozone,and UV/peracetic acid.In this review,we collated recent advances in application of UV-AOPs for the abatement of fiuoroquinolones(FQs)as widely used class of antibiotics.Representative FQs of ciprofioxacin,norfioxacin,ofioxacin,and enrofioxacin were most extensively studied in the state-of-art studies.The evolvement of gas-state and solid-state UV light sources was presented and batch and continuous fiow UV reactors were compared towards practical applications in UV-AOPs.Generally,degradation of FQs followed the pseudo-first order kinetics in UV-AOPs and strongly affected by the operating factors and components of water matrix.Participation of reactive species and transformation mechanisms of FQs were compared among different UV-AOPs.Challenges and future prospects were pointed out for providing insights into the practical application of UV-AOPs for antibiotic remediation in wastewater.展开更多
Addressing the contamination of antibiotics has attracted ever-increasing and imperative attention due to their widespread existence,easy-to-cause drug-resistant bacteria infection,coupled with their intrinsic toxicit...Addressing the contamination of antibiotics has attracted ever-increasing and imperative attention due to their widespread existence,easy-to-cause drug-resistant bacteria infection,coupled with their intrinsic toxicity and hazard to environments and human health.Herein,a novel CC/CoNi-LDH-10%Ce anode material was directly constructed through a simple and rapid electrodeposition strategy,serving as an efficacious electrocatalyst for removing ciprofloxacin(CIP)from aqueous solution.Such novel CC/CoNi-LDH-10%Ce anode delivered a higher charge transfer,relatively abundant oxygen vacancies,and a higher electrochemical active area.The as-fabricated CC/CoNi-LDH-10%Ce electrode achieved a substantially boosted CIP removal efficiency of 52.5%relative to that of pure CC at about 23.9%.Notably,doping an appropriate amount of Ce^(3+)can endow the pristine CC/CoNi-LDH with richer oxygen vacancies and excellent electrocatalytic performance.Additionally,the electrocatalytic oxidation of CIP was attributed to both direct oxidation on the electrode surface and indirect oxidation induced by the generated active species(superoxide radicals and hydroxyl radicals).This study provides a simple,universal and flexible tactic for other researchers in designing and manufacturing avenues of electrodes.展开更多
The oxygen evolution reaction(OER)serves as a fundamental half–reaction in the electrolysis of water for hydrogen production,which is restricted by the sluggish OER reaction kinetics and unable to be practically appl...The oxygen evolution reaction(OER)serves as a fundamental half–reaction in the electrolysis of water for hydrogen production,which is restricted by the sluggish OER reaction kinetics and unable to be practically applied.The traditional lattice oxygen oxidation mechanism(LOM)offers an advantageous route by circumventing the formation of M-OOH^(*)in the adsorption evolution mechanism(AEM),thus enhancing the reaction kinetics of the OER but resulting in possible structural destabilization due to the decreased M–O bond order.Fortunately,the asymmetry of tetrahedral and octahedral sites in transition metal spinel oxides permits the existence of non-bonding oxygen,which could be activated by rational band structure design for direct O-O coupling,where the M–O bond maintains its initial bond order.Here,non-bonding oxygen was introduced into NiFe_(2)O_(4)via annealing in an oxygen-deficient atmosphere.Then,in-situ grown sulfate species on octahedral nickel sites significantly improved the reactivity of the non-bonding oxygen electrons,thereby facilitating the transformation of the redox center from metal to oxygen.LOM based on non-bonding oxygen(LOMNB)was successfully activated within NiFe_(2)O_(4),exhibiting a low overpotential of 206 mV to achieve a current density of 10 mA cm^(-2)and excellent durability of stable operation for over 150 h.Additionally,catalysts featuring varying band structures were synthesized for comparative analysis,and it was found that the reversible redox processes of non-bonding oxygen and the accumulation of non-bonding oxygen species containing 2p holes are critical prerequisites for triggering and sustaining the LOMNB pathway in transition metal spinel oxides.These findings may provide valuable insights for the future development of spinel-oxide-based LOM catalysts.展开更多
基金supported by the National Natural Science Foundation of China(No.52001034)the China Postdoctoral Science Foundation(No.2023M731677)the Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX23_3032).
文摘Nano-zinc oxides(ZnO)demonstrate remarkable antibacterial properties.To further enhance the corrosion resistance and antibacterial efficiency of magnesium alloy micro-arc oxidation(MAO)coatings,this study investigates the preparation of ZnO-containing micro-arc oxidation coatings with dual functionality by incorporating nano-ZnO into MAO electrolyte.The influence of varying ZnO concentrations on the microstructure,corrosion resistance,and antibacterial properties of the coating was examined through microstructure analysis,immersion tests,electrochemical experiments,and antibacterial assays.The findings revealed that the addition of nano-ZnO significantly enhanced the corrosion resistance of the MAO-coated alloy.Specifically,when the ZnO concentration in the electrolyte was 5 g/L,the corrosion rate was more than ten times lower compared to the MAO coatings without ZnO.Moreover,the antibacterial efficacy of ZnO+MAO coating,prepared with a ZnO concentration of 5 g/L,surpassed 95%after 24 h of co-culturing with Staphylococcus aureus(S.aureus).The nano-ZnO+MAO-coated alloy exhibited exceptional degradation resistance,corrosion resistance,and antibacterial effectiveness.
基金supported by the National Research Foundation of Korea(NRF)funded by the Korean government(MSIT)(No.2022R1A2C1006743).
文摘This study presents a novel approach to improving the anticorrosive performance of AZ31 Mg alloy by exploiting the role of the hydration reaction to induce interactions between Quinolin-8-ol(8HQ)molecules and the porous MgO layer formed via plasma electrolytic oxidation(PEO).The AZ31 Mg alloy,initially coated with a PEO layer,underwent a dipping treatment in an ethanolic solution of 0.05 M 8HQ at 50℃ for 3 h.The results were compared with those from a different procedure where the PEO layer was subjected to a hydration reaction for 2 h at 90℃ before immersion in the 8HQ solution under the same conditions.The hydration treatment played a crucial role by converting MgO to Mg(OH)_(2),significantly enhancing the surface reactivity.This transformation introduced hydroxyl groups(−OH)on the surface,which facilitated donor-acceptor interactions with the electron-accepting sites on 8HQ molecules.The calculated binding energy(Ebinding)from DFT indicated that the interaction energy of 8HQ with Mg(OH)_(2) was lower compared to 8HQ with MgO,suggesting easier adsorption of 8HQ molecules on the hydrated surface.This,combined with the increased number of active sites and enhanced surface area,allowed for extensive surface coverage by 8HQ,leading to the formation of a stable,flake-like protective layer that sealed the majority of pores on the PEO layer.DFT calculations further suggested that the hydration treatment provided multiple active sites,enabling effective contact with 8HQ and rapid electron transfer,creating ideal conditions for charge-transfer-induced physical and chemical bonding.This study shows that hydration and 8HQ treatments significantly enhance the corrosion resistance of Mg alloys,highlighting their potential for advanced anticorrosive coatings.
基金Sichuan Science and Technology Program(2022YFSY0018)。
文摘TC4 micro-arc oxidation(MAO)coatings were prepared by adding SiO_(2) nanoparticles or sodium silicate to the sodium meta-aluminate-based electrolyte.The effect of additives was investigated by XRD,SEM,EDS,electrochemical and wear tests.The results show that additives can considerably accelerate the formation of MAO coatings.The coatings are mostly composed of rutile and anatase TiO_(2),α-Al_(2)O_(3),γ-Al_(2)O_(3),Al_(2)TiO_(5) and SiO_(2).Sodium silicate and SiO_(2) nanoparticles added to the coating can effectively reduce the size of micropores and increase its thickness,whereas SiO_(2) nanoparticles with superior physical properties can be directly deposited at the discharge channel,significantly increasing the coating's resistance to wear and corrosion.The coating with SiO_(2) nanoparticles exhibits the best overall performance,with the lowest corrosion rate and average friction coefficient of 4.095×10^(-5)mm/a and 0.30,respectively.
基金supported by the National Natural Science Foundation of China(Nos.22202104,22279062,22232004 and 22072067)the Natural Science Foundation of Jiangsu Province(No.BK20220933)Shuangchuang Doctor Plan of Jiangsu Province(No.JSSCBS20220273).
文摘To efficiently diminish the Pt consumption while concurrently enhancing the anodic reaction kinetics,a straightforward synthesis for PtPdAg nanotrees(NTs)with exceedingly low Pt content is presented,utilizing the galvanic replacement reaction between the initially prepared PdAg NTs and Pt ions.Due to the multilevel porous tree-like structure and the incorporation of low amounts of Pt,the electrocatalytic activity and stability of PtPdAg NTs are markedly enhanced,achieving 1.65 and 1.69 A·mg^(-1)Pt+Pd for the anodic reactions of formic acid oxidation(FAOR)and methanol oxidation(MOR)within DLFCs,surpassing the performance of PdAg NTs,as well as that of commercial Pt and Pd black.Density functional theory(DFT)calculations reveal that the addition of low amounts of Pt leads to an increase in the d-band center of PtPdAg NTs and lower the COads adsorption energy to-1.23 eV,enhancing the anti-CO toxicity properties optimally.This approach offers an effective means for designing low Pt catalysts as exceptional anodic electrocatalysts for direct liquid fuel cells.
基金financially supported by the National Natural Science Foundation of China(No.22071043).
文摘By introduction of hydrogen peroxide into the reaction system of ZrOCl_(2)·8H_(2)O and K14[As_(2)W_(19)O_(67)(H_(2)O)],a novel polyoxometalate K_(8)Na_(19.5)H_(0.5)[Zr_(2)(O_(2))_(2)(β-AsVW_(10)O_(38))]4·68H_(2)O(1)has been successfully obtained via one-pot method and systematically characterized by IR,XPS,solid UV spectra,PXRD pattern,and TGA analysis.The analysis of X-ray crystallography exhibits that compound 1 crystallizes in the triclinic space group P-1 and presents a novel square-shaped Zr-substituted tetrameric polyoxometalate.The catalytic oxidation of sulfides by 1 are carried out,which demonstrate that 1 exhibits a good performance for the catalytic oxidation of sulfides to sulfones with high conversion(100%)and high selectivity(100%).
基金supported by the National Key Research&Development Program of China(2021YFB3803200)the National Natural Science Foundation of China(22288102).
文摘Hexafluoropropylene oxide(HFPO)is a crucial fluorinated chemical mainly synthesized from hexafluoropropylene(HFP)through the oxidation of oxygen.However,the reaction network and kinetic characteristics are not fully understood yet,resulting in a lack of theoretical basis for synthesis process improvement.Here,the free radical reaction mechanism and complete reaction network involved in the noncatalytic oxidation of HFP to synthesize HFPO was explored by density functional theory.Transition state theory was employed to calculate the intrinsic reaction rate constants for elementary reactions.Based on theoretical reaction rate ratios,reaction pathways were selected,and a simplified reaction network was derived.It was found that byproducts were formed owing to the decomposition of HFPO and subsequent reactions with excessive oxygen while oxygen tended to participate more in the main reaction under oxygen-deficient conditions.The variations in reaction pathways occurring at different HFP/oxygen molar ratios was well elucidated by comparing with experimental data.This research establishes a robust theoretical foundation for optimizing and regulating the synthesis of HFPO.
基金supported by Shanghai Pujiang Program(No.22PJD001)the Fundamental Research Funds for the Central Universities(No.2232021G-11).
文摘Catalytic oxidation of NO at room temperature was carried out over nitrogen(N)-doped sludge char(SC)prepared from pyrolysis ofmunicipal sewage sludge,and urea was adopted as nitrogen source.The effects of different N-doping methods(one-step and two-step method),dried sludge(DS)/urea mass ratios(5:1,4:1,3:1,2:1,and 1:1),SC preparation procedures(pyrolysis only,pyrolysis with acid washing,and pyrolysis with KOH activation and acid washing),and different pyrolysis temperatures(500,600,700,and 800°C)on the catalytic oxidation of NO were compared to optimize the procedure for SC preparation.The results indicated that N-doping could obviously promote the catalytic performance of SC.The one-step method with simultaneous sludge pyrolysis(at 700°C),KOH activation,and N-doping(DS/urea of 3:1)was the optimal procedure for preparing the N-doped SC with the NO conversion rate of 54.7%,whereas the optimal NO conversion rate of SC without N-doping was only 47.3%.Urea worked both as carbon and nitrogen source,which could increase about 2.9%-16.5%of carbon and 24.8%-42.7%of nitrogen content in SC pyrolyzed at 700°C.N-doping significantly promoted microporosity of SC.The optimal N-doped SC showed specific surface areas of 571.38 m^(2)/g,much higher than 374.34 m^(2)/g of the optimal SC without N-doping.In addition,N-doping also increased amorphousness and surface basicity of SC through the formation of N-containing groups.Finally,three reaction paths,i.e.microporous reactor,active sites,and basic site control path,were proposed to explain the mechanism of N-doping on promoting the catalytic performance of NO.
基金supported by the National Natural Science Foundation of China(No.52001142)Young Elite Scientists Sponsorship Program by CAST(No.2022QNRC001)Postgraduate Research&Practice Innovation Program of Jiangsu Province(No.KYCX22_3793).
文摘Oxidation behavior of NiCrAlY nanocrystalline coatings with different Cr contents at 1050 and 1150℃is investigated.The results indicate that Al2O3 scales can be formed on NiCrAlY nanocrystalline coatings after oxidation at high temperature.And their formation and thickening cannot be affected by the change of Cr contents in NiCrAlY coatings.During service,Cr in the coating can affect the microstructure of Ni-based single crystal superalloy.At 1050℃,Cr in the coating can diffuse into the superalloy,destroy its microstructure,and lead to the formation of interdiffusion zone and the precipitation of needle-like topologically closed-packed phase.The higher the Cr content in NiCrAlY the coating is,the more obvious the phenomenon is.However,after oxidation at 1150℃for 100 h,no obvious changes were observed in the microstructure of CMSX-4 single crystal superalloy beneath the three kinds of NiCrAlY nanocrystalline coatings.
基金Project supported by the National Natural Science Foundation of China(22072096,22108184)。
文摘In this work,a series of Ce-Ti composite oxides with different Ti/Ce molar ratios was prepared by coprecipitation method,and investigated for the catalytic degradation of toluene and selective catalytic reduction of NO.The phase transition process between Ce species and Ti species is limited by modulating the interaction between Ce4+and Ti4+,while a completely amorphous composite is generated with an appropriate molar ratio of Ti/Ce(1.5/1).The catalyst CeTi1.5Oxexhibits the best catalytic performance,where the values of T90and T50for deep degradation of toluene are 297 and 330℃respectively at high weight hours space velocity(WHSV=120000 mL/(g·h)).Compared with CeO_(2),T90and T50decrease by48 and 34℃respectively while declining by 67 and 70℃compared to TiO_(2).For the SCR reaction,CeTi1.5Oxreaches 100%NO conversion at 250℃with WHSV=60000 mL/(g·h),reduced by 50℃compared to pure CeO_(2).The amorphous nanostructure with highly dispersed Ce and Ti species was confirmed by transmission electron microscopy(TEM)and X-ray diffraction(XRD)characterizations.The X-ray photoelectron spectroscopy(XPS)and Raman analyses show that a large number of active Ce-O-Ti species and surface oxygen vacancies are generated due to the strong interaction between Ti^(4+)and Ce^(4+)in CeTi_(1.5)O_(x).Additionally,H_(2)-TPR and O_(2)-TPD further confirm that the interaction promotes the low-temperature reducibility and mobility of surface-active oxygen species.Meanwhile,in-situ DRIFTS study reveals that CeTi1.5Oxwith amorphous nanostructure can dramatically enhance the dissociative and complete oxidation capacity for toluene.
基金financial assistance from the Anhui Provincial Major Science and Technology Project(202003a05020022)the Institute of Energy,Hefei Comprehensive National Science Center(21KZS219)。
文摘The direct oxidation of methane to methanol(DOMM) has been recognized as a significant technology for efficiently utilizing low-concentration coalbed methane(LCMM) and supplying liquid fuel.Herein,the noble metals(Pt,Pd and Ru) modified Cu/alkalized sepiolite(CuX/SEPA) catalysts were prepared and used for the DOMM in a gas-phase system at low temperatures.The CuRu/SEPA exhibited the highest methanol production of 53 μmol·g^(-1)·h^(-1) and methanol selectivity of 90% under the optimal reaction conditions.Various characterizations demonstrated that the addition of Ru promoted the formation of Cu^(2+)and the contraction of Cu—Si/Al bonds to reduce the distance between framework Al atoms of SEPA to further generate more Al pairs,which facilitated the formation of reactive dicopper species([Cu_(2)O]^(2+)or [Cu_(2)O_(2)]^(2+)).Investigation of the reaction mechanism revealed that [Cu_(2)O]^(2+) or [Cu_(2)O_(2)]^(2+) species could adsorb and activate methane to form CH_(3)O^(*) species and ultimately generated methanol with the assistance of water.
文摘Iron-Vanadium(FeV)catalyst showed a unique catalytic activity for the selective oxidation of methanol to formaldehyde;however,due to its complex compositions,the identification of catalytic active sites still remains challenging,inhibiting the rational design of excellent FeV-based catalysts.Here,in this work,a series of FeV catalysts with various compositions,including FeVO_(4),isolated VO_(x),low-polymerized V_(n)O_(x),and crystalline V_(2)O_(5) were prepared by controlling the preparation conditions,and were applied to methanol oxidation to formaldehyde reaction.A FeV_(1.1) catalyst,which consisted of FeVO_(4) and low-polymerized V_(n)O_(x) species showed an excellent catalytic performance with a methanol conversion of 92.3%and a formaldehyde selectivity of 90.6%,which was comparable to that of conventional iron-molybdate catalyst.The results of CH_(3)OH-IR,O_(2) pulse and control experiments revealed a crucial synergistic effect between FeVO_(4) and low-polymerized V_(n)O_(x).It enhanced the oxygen supply capacity and suitable binding and adsorption strengths for formaldehyde intermediates,contributing to the high catalytic activity and formaldehyde selectivity.This study not only advances the understanding of FeV structure but also offers valuable guidelines for selective methanol oxidation to formaldehyde.
基金supported by the Natural Science Foundation of Jiangxi Province(20232ACB213005).
文摘A novel tetra-europium(III)-containing antimonotungstate,Na_(8.2)[H_(2)N(CH_(3))_(2)]_(9)[Na_(10.8)(tar)_(4)(H_(2)O)_(20)(Eu_(2)Sb_(2)W_(21)O_(72))_(2)]·44.5H_(2)O(EuSbW,H_(4)tar=dl-tartaric acid),has been synthesized and characterized.The dimeric polyoxoanion of EuSbW consists of two Dawson-like{Eu_(2)Sb_(2)W_(21)}units bridged by four dl-tartaric acid ligands.The adjacent carboxyl and hydroxy groups in each tartaric acid simultaneously chelate with W and Eu atoms from different{Eu_(2)Sb_(2)W_(21)}units,thereby forming the dimeric structure.EuSbW represents an extremely rare polyoxometalate where four tartaric acid ligands function as connectors to bridge two{Eu_(2)Sb_(2)W_(21)}units.Additionally,EuSbW exhibits excellent catalytic activity and reusability in the oxidation of thioethers and alcohols,achieving 100%conversion and>99%selectivity for various thioethers,and 85–100%conversion with 90–99%selectivity for diverse alcohols under mild conditions.
基金Project(52274348)supported by the National Natural Science Foundation of ChinaProject(2022JH1/10400024)supported by the Major Projects for the“Revealed Top”Science and Technology of Liaoning Province,China。
文摘Applying bio-oxidation waste solution(BOS)to chemical-biological two-stage oxidation process can significantly improve the bio-oxidation efficiency of arsenopyrite.This study aims to clarify the enhanced oxidation mechanism of arsenopyrite by evaluating the effects of physical and chemical changes of arsenopyrite in BOS chemical oxidation stage on mineral dissolution kinetics,as well as microbial growth activity and community structure composition in bio-oxidation stage.The results showed that the chemical oxidation contributed to destroying the physical and chemical structure of arsenopyrite surface and reducing the particle size,and led to the formation of nitrogenous substances on mineral surface.These chemical oxidation behaviors effectively promoted Fe^(3+)cycling in the bio-oxidation system and weakened the inhibitory effect of the sulfur film on ionic diffusion,thereby enhancing the dissolution kinetics of the arsenopyrite.Therefore,the bio-oxidation efficiency of arsenopyrite was significantly increased in the two-stage oxidation process.After 18 d,the two-stage oxidation process achieved total extraction rates of(88.8±2.0)%,(86.7±1.3)%,and(74.7±3.0)%for As,Fe,and S elements,respectively.These values represented a significant increase of(50.8±3.4)%,(47.1±2.7)%,and(46.0±0.7)%,respectively,compared to the one-stage bio-oxidation process.
基金financially supported by the National Key Technology R&D Program of China(No.2021YFB3500801)
文摘Enhancing the activity of photocatalysts is a critical challenge for improving the photocatalytic degradation of contaminated wastewater.Here,a novel Ce single-atom-doped titanate nanotube photocatalyst(CeH_(2)Ti_(2)O_(5)·H_(2)O)was successfully synthesized using a onepot solvothermal method.Degradation experiments revealed that the optimal Ce doping ratio was 1.0%.The ultraviolet-visible diffuse reflectance spectroscopy results showed that the bandgap of the Ce-doped sample decreased from 3.02 to 2.87 eV,enhancing the absorption in the visible spectral range.At the same time,the BrunauerEmmett-Teller specific surface area increased from 63.68 to 88.95 m^(2)g^(-1).The 1.0%Ce-H_(2)Ti_(2)O_(5)·H_(2)O(HTC_(1))could degrade 99.04%of 100 mg L-1rhodamine B(RhB)after 40 min of visible-light irradiation.The degradation efficiency decreased by only 21.24%after five cycles.The results of free-radical quenching and electron spin resonance spectroscopy analyses indicated that HTC_(1)achieved efficient degradation of RhB through a direct hole oxidation mechanism.Compared with pure protonated titanate nanotubes(H_(2)Ti_(2)O_(5)·H_(2)O),HTC_(1)had a higher specific surface area,more electron traps,narrower bandgap,longer hole lifetime,and suppressed photogenerated charge recombination rate owing to the Ce single-atom doping.
文摘The electrocatalytic oxidation of glycerol toward formic acid is one of the most promising pathways for transformation and utilization of glycerol.Herein,a series of well-defined Ni_(n)(SR)_(2n) nanoclusters(n=4,5,6;denoted as Ni NCs)were prepared for the electrocatalytic glycerol oxidation toward formic acid,in which Ni_(6)-PET-50CV afforded the most excellent electrocatalytic performance with a high formic acid selectivity of 93% and a high glycerol conversion of 86%.This was attributed to the lowest charge transfer impedance and the most rapid reaction kinetics.Combined electrochemical measurements and X-ray absorption fine structure measurements revealed that the structures of Ni NCs remained intact after CV scanning pretreatment and electrocatalysis via forming the Ni–O bond.Additionally,the kinetic studies and in-situ Fourier transformed infrared suggested a sequential oxidation mechanism,in which the main reaction steps of glycerol→glyceraldehyde→glyceric acid were very rapid to produce a high selectivity of formic acid even though the low glycerol conversion.This work presents an opportunity to study Ni NCs for the efficient electrocatalytic oxidation of biomass-derived polyhydroxyl platform molecules to produce value-added carboxylic acids.
基金The support by the award Program for Minjiang scholar professorship is greatly acknowledgedfinancially supported by the National Natural Science Foundation of China(Nos.21703038,22072025)The financial support from State Key Laboratory of Structural Chemistry,Fujian Institute of Research on the Structure of Matter,Chinese Academy of Science is acknowledged(No.20240018)。
文摘Atomically precise metal nanoclusters(NCs)have been deemed as a new generation of metal nanomaterials in the field of solar energy conversion due to their unique atomic stacking manner,quantum confinement effects,light-harvesting capability and multitude of active sites.Nonetheless,wide-spread application of monometallic NCs is blocked by the ultrashort carrier lifespan,uncontrollable charge transport pathway,and light-induced poor stability,impeding the construction of robust and stable metal NC-based photosystems.Herein,we report the fabrication of stable alloy(Au_(1-x)Pt_(x))NCs photosystem,for which tailor-made negatively charged l-glutathione(GSH)-capped Au_(1-x)Pt_(x)NCs as the building blocks are controllably deposited on the Bi VO_(4)(BVO)by a self-assembly approach for steering enhanced light absorption and interfacial charge transfer over alloy NCs-based photoanodes(Au_(1-x)Pt_(x)/BVO).The self-assembled Au_(1-x)Pt_(x)/BVO composite photoanode exhibits the significantly enhanced photoelectrochemical water oxidation performances compared with pristine BVO and Au_(x)/BVO photoanodes,which is caused by the Pt atom doping into the Au_(x)NCs for elevating photosensitivity and boosting the stability.The synergy of Au and Pt atoms in alloy NCs protects the gold core from rapid oxidation,improving the photostability and accelerating the surface charge transfer kinetics.Our work would significantly inspire ongoing interest in unlocking the charge transport characteristics of atomically precise alloy NCs for solar energy conversion.
基金supported by the National Natural Science Foundation of China(22379031)the Guangxi Science and Technology Project of China(AB16380030)+1 种基金the National Research Foundation,SingaporeA*STAR(Agency for Science,Technology and Research)under its LCER Phase 2 Programme Hydrogen&Emerging Technologies FI,Directed Hydrogen Programme(U2305D4003)。
文摘Efficiently utilizing ammonia(carbon-free fuel)via low-temperature fuel cells is severely hindered by the sluggish kinetics of ammonia oxidation reaction(AOR).Herein,platinum-iridium-tungsten nanocubes(PtIrW-NCBs)with exposed{100}-rich facets were synthesized by a glucose-assisted solvent-thermal method,in which alloying W not only can facilitate the formation of such specific nanostructures to expose more active sites for AOR,but also modulate the electronic structure of PtIr to promote the kinetics of AOR.The PtIrW-NCBs featuring the small nanoparticle size of 5.05±0.07 nm exhibit superior AOR performance,wherein the onset potential is down to 0.319 V and the mass activity is 30.15 A g_((PGM=Pt,Ir))^(-1)at 0.50 V vs.RHE,significantly higher than those of reported majority of AOR catalysts and even commercial PtIr/C.Meanwhile,in situ Fourier transform infrared spectroscopy measurement further reveals that AOR on PtIrW-NCBs dominantly undergoes the dimerization path of NH_(x)(1≤x≤2).In addition,the theoretical calculations also identify that alloying W into PtIr can contribute additional electrons to 5d orbitals of PtIr,enabling the d-band center approaching the Femi level,which in turn induces the high-filling of bonding orbitals of N-N bond in^(*)N_(2)H_(4),promoting the dimerization of^(*)NH_(2)to^(*)N_(2)H_(4)and thus leading to high AOR activity of PtIrW.This work provides new insights for designing efficient AOR electrocatalysts.
基金the financial support from National Natural Science Foundation of China(Nos.52100204 and 52330005)Beijing Outstanding Young Scientist Program(No.BJJWZYJH01201910004016)。
文摘The widespread occurrence of antibiotics in wastewater aroused serious attention.UV-based advanced oxidation processes(UV-AOPs)are powerful technologies in removing antibiotics in wastewater,which include UV/catalyst,UV/H_(2)O_(2),UV/Fenton,UV/persulfate,UV/chlorine,UV/ozone,and UV/peracetic acid.In this review,we collated recent advances in application of UV-AOPs for the abatement of fiuoroquinolones(FQs)as widely used class of antibiotics.Representative FQs of ciprofioxacin,norfioxacin,ofioxacin,and enrofioxacin were most extensively studied in the state-of-art studies.The evolvement of gas-state and solid-state UV light sources was presented and batch and continuous fiow UV reactors were compared towards practical applications in UV-AOPs.Generally,degradation of FQs followed the pseudo-first order kinetics in UV-AOPs and strongly affected by the operating factors and components of water matrix.Participation of reactive species and transformation mechanisms of FQs were compared among different UV-AOPs.Challenges and future prospects were pointed out for providing insights into the practical application of UV-AOPs for antibiotic remediation in wastewater.
基金the funds granted by the Ningxia Natural Science Foundation(2023AAC05003,2024AAC03048,2024AAC03051)the National Natural Science Foundation of China(22108130,22368039)+1 种基金the Ningxia Key Research&Development Program(2023BDE03001)the Ningxia Overseas Returnee Innovation and Entrepreneurship Project for the financial support。
文摘Addressing the contamination of antibiotics has attracted ever-increasing and imperative attention due to their widespread existence,easy-to-cause drug-resistant bacteria infection,coupled with their intrinsic toxicity and hazard to environments and human health.Herein,a novel CC/CoNi-LDH-10%Ce anode material was directly constructed through a simple and rapid electrodeposition strategy,serving as an efficacious electrocatalyst for removing ciprofloxacin(CIP)from aqueous solution.Such novel CC/CoNi-LDH-10%Ce anode delivered a higher charge transfer,relatively abundant oxygen vacancies,and a higher electrochemical active area.The as-fabricated CC/CoNi-LDH-10%Ce electrode achieved a substantially boosted CIP removal efficiency of 52.5%relative to that of pure CC at about 23.9%.Notably,doping an appropriate amount of Ce^(3+)can endow the pristine CC/CoNi-LDH with richer oxygen vacancies and excellent electrocatalytic performance.Additionally,the electrocatalytic oxidation of CIP was attributed to both direct oxidation on the electrode surface and indirect oxidation induced by the generated active species(superoxide radicals and hydroxyl radicals).This study provides a simple,universal and flexible tactic for other researchers in designing and manufacturing avenues of electrodes.
文摘The oxygen evolution reaction(OER)serves as a fundamental half–reaction in the electrolysis of water for hydrogen production,which is restricted by the sluggish OER reaction kinetics and unable to be practically applied.The traditional lattice oxygen oxidation mechanism(LOM)offers an advantageous route by circumventing the formation of M-OOH^(*)in the adsorption evolution mechanism(AEM),thus enhancing the reaction kinetics of the OER but resulting in possible structural destabilization due to the decreased M–O bond order.Fortunately,the asymmetry of tetrahedral and octahedral sites in transition metal spinel oxides permits the existence of non-bonding oxygen,which could be activated by rational band structure design for direct O-O coupling,where the M–O bond maintains its initial bond order.Here,non-bonding oxygen was introduced into NiFe_(2)O_(4)via annealing in an oxygen-deficient atmosphere.Then,in-situ grown sulfate species on octahedral nickel sites significantly improved the reactivity of the non-bonding oxygen electrons,thereby facilitating the transformation of the redox center from metal to oxygen.LOM based on non-bonding oxygen(LOMNB)was successfully activated within NiFe_(2)O_(4),exhibiting a low overpotential of 206 mV to achieve a current density of 10 mA cm^(-2)and excellent durability of stable operation for over 150 h.Additionally,catalysts featuring varying band structures were synthesized for comparative analysis,and it was found that the reversible redox processes of non-bonding oxygen and the accumulation of non-bonding oxygen species containing 2p holes are critical prerequisites for triggering and sustaining the LOMNB pathway in transition metal spinel oxides.These findings may provide valuable insights for the future development of spinel-oxide-based LOM catalysts.
