Electrosynthesis of hydrogen peroxide(H2O2)is an on-site method that enables independent distribution applications in many fields due to its small-scale and sustainable features.The crucial point remains developing hi...Electrosynthesis of hydrogen peroxide(H2O2)is an on-site method that enables independent distribution applications in many fields due to its small-scale and sustainable features.The crucial point remains developing highly active,selective and cost-effective electrocatalysts.The electrosynthesis of H2O2 in acidic media is more practical owing to its stability and no need for further purification.We herein report a phosphorus and selenium tuning Co-based non-precious catalyst(CoPSe)toward two-electron oxygen reduction reaction(2e–ORR)to produce H2O2 in acidic media.The starting point of using both P and Se is finding a balance between strong ORR activity of CoSe and weak activity of CoP.The results demonstrated that the CoPSe catalyst exhibited the optimized 2e–ORR activity compared with CoP and CoSe.It disclosed an onset potential of 0.68 V and the H2O2 selectivity 76%-85%in a wide potential range(0–0.5 V).Notably,the CoPSe catalyst overcomes a significant challenge of a narrow-range selectivity for transitionmetal based 2e–ORR catalysts.Finally,combining with electro-Fenton reaction,an on-site system was constructed for efficient degradation of organic pollutants.This work provides a promising non-precious Co-based electrocatalyst for the electrosynthesis of H2O2 in acidic media.展开更多
A novel metal-organic complex Cu（p-FBA）2（phen）（H2O） （p-FBA = p-fluorobenzoic acid,phen = 1,10-phenanthroline） has been synthesized and structurally characterized by X-ray single-crystal diffraction,elemental a...A novel metal-organic complex Cu（p-FBA）2（phen）（H2O） （p-FBA = p-fluorobenzoic acid,phen = 1,10-phenanthroline） has been synthesized and structurally characterized by X-ray single-crystal diffraction,elemental analysis and IR spectra. The crystal belongs to triclinic,space group P1 with a = 7.8043（7）,b = 10.4069（9）,c = 14.3658（13） ,α = 105.3170（10）,β = 96.877（2）,γ = 96.7580（10）o,V = 1103.56（17） 3,Mr = 539.96,Z = 2,Dc = 1.625 g/cm3,μ = 1.050 mm-1,F（000） = 550,the final R = 0.0324 and wR = 0.0952. In the crystal,the structure consists of discrete molecules containing a five-coordinate copper（Ⅱ ） in a distorted square pyramidal configuration. Intramolecular O-H···O hydrogen bonds,weak intermolecular C-H···O hydrogen bonds and π-π stacking link the molecules into a one-dimensional chain structure. The study on the title complex has been performed with quantum chemistry calculation by means of G03W package on the Lanl2dz basis set. The stabilities of the complex together with the orbital energies and composition characteristics of some frontier molecular orbitals have been investigated.展开更多
The core-shell structured Au@Bi2S3 nanorods have been prepared through direct in-situ growth of Bi2S3 at the surface of pre-synthesized gold nanorods.The product was characterized by X-ray diffraction,transmission ele...The core-shell structured Au@Bi2S3 nanorods have been prepared through direct in-situ growth of Bi2S3 at the surface of pre-synthesized gold nanorods.The product was characterized by X-ray diffraction,transmission electron microscopy and energy-dispersive X-ray spectroscopy.Then the obtained Au@Bi2S3 nanorods were coated onto glassy carbon electrode to act as a scaffold for fabrication of electrochemical DNA biosensor on the basis of the coordination of-NH2 modified on 5’-end of probe DNA and Au@Bi2S3.Electrochemical characterization assays demonstrate that the Au@Bi2S3 nanorods behave as an excellent electronic transport channel to promote the electron transfer kinetics and increase the effective surface area by their nanosize effect.The hybridization experiments reveal that the Au@Bi2S3 matrix-based DNA biosensor is capable of recognizing complementary DNA over a wide concentration ranging from 10 fmol/L to 1 nmol/L.The limit of detection was estimated to be 2 fmol/L(S/N=3).The biosensor also presents remarkable selectivity to distinguish fully complementa ry sequences from basemismatched and non-complementary ones,showing great promising in practical application.展开更多
A novel water cluster [Mn（phen）2·H2O·Cl]·p-FBA·3H2O （p-FBA = p-fluorobenzoic acid and phen = 1,10-phenanthroline） was synthesized by the hydrothermal reaction of MnCl2 with p-FBA and phen at 1...A novel water cluster [Mn（phen）2·H2O·Cl]·p-FBA·3H2O （p-FBA = p-fluorobenzoic acid and phen = 1,10-phenanthroline） was synthesized by the hydrothermal reaction of MnCl2 with p-FBA and phen at 150 ℃ and characterized by elemental analysis,IR spectra and TG. Its crystal structure was determined by X-ray single-crystal diffraction study. The crystal belongs to the triclinic system,space group P1,with a = 10.5768（1）,b = 11.5960（1）,c = 12.9916（2） ,α = 101.816（2）,β = 95.397（2）,γ = 103.052（2）o,V = 1502.8（3） 3,Z = 2,Dc = 1.463 g/cm3,R = 0.0399 and wR = 0.0997. The crystal structure shows that the manganese（Ⅱ ） ion is six-coordinated by four nitrogen atoms,one chloride ion and one oxygen atom forming a distorted octahedral coordination geometry. The structure includes three acyclically connected water molecules and one coordinated water molecule thus forming a （H2O）4 water cluster. This water pattern forms a cross-linked discrete ring. The steady （H2O）4 is further extended into a cage-like structure by the hydrogen-bonding interaction formed by dissociative aqua molecule and Cl-ligand. The dimer structure is further extended into a one-dimensional （1D） structure through C-H···O interaction. π···π Stacking interaction among adjacent phen aromatic rings further stabilizes the crystal structure.展开更多
This paper mainly discusses the protection of water resource environment in Three Gorge Water Reservoir, a systematic investigation and analysis of the landfill leachate＇s polluting components, hazardous and changing...This paper mainly discusses the protection of water resource environment in Three Gorge Water Reservoir, a systematic investigation and analysis of the landfill leachate＇s polluting components, hazardous and changing rule in landfill leachate from hinterland landfill located in the surrounding area have been carried out, and proposed the countermeasures for disposition the leachate furtherly.展开更多
L-aspartic acid （Asp） pillared hydrotalcites were prepared by direct reaction of the L-Asp anion with layered double hydroxides （LDHs）. The obtained samples were characterized by X-ray diffractometry （XRD）, Four...L-aspartic acid （Asp） pillared hydrotalcites were prepared by direct reaction of the L-Asp anion with layered double hydroxides （LDHs）. The obtained samples were characterized by X-ray diffractometry （XRD）, Fourier transform infrared （FTIR）, and thermogravimetric and differential thermal analysis （TG/DTA）. The results show that the initial interlayer carbonate ions can be completely replaced by the L-Asp anion under the controlled conditions. The pillared hydrotalcites have a crystallized supramolecular structure and thermal stability. The L-Asp pillared LDHs were used in the enantiosorption of enantiopure phenylalanine （Pile）, the results suggest that L-Asp pillared LDHs exhibit an excellent enantiosorption capability for D-Phe, and the adsorption isotherm fits Freundlich equation.展开更多
Add the masking agent and biscyclohexanoneoxalyldihydraone into the diluted clarificd liquid of the landfill leachate which was treatmented by digestion and centrifugal filtration to complexate all heavy metal ion in ...Add the masking agent and biscyclohexanoneoxalyldihydraone into the diluted clarificd liquid of the landfill leachate which was treatmented by digestion and centrifugal filtration to complexate all heavy metal ion in the trcatmented liquid, and extracted using CHCl3 many time, then it were demasking and decomposing respectively, and adjusted different pH and formed Me^n＋-PAN coordination compound when these metal ion reaction with PAN. The Fluoresence quenching of Rh6G （λex/λem=543mn/558nm） when the metal ion coordination compound was add into the Rh6G solution step by step, the quenching intensity was directly proportional to the concentration of the metal ion in the certain range. So a new method of fast and simple for determination of trace metal ion in landfill lcachate was established to determine metal ion in sample of different landfill leachate in Three Gorge Water Reservoir, and comparison the classic assay method with satisfactory results.展开更多
The objectives of this study were to explore alternatives for using fruit waste and sugarcane bagasse as important sources for new products and potential applications in the food industry. Fast foods are part of moder...The objectives of this study were to explore alternatives for using fruit waste and sugarcane bagasse as important sources for new products and potential applications in the food industry. Fast foods are part of modern life, as well as sources for producing biofuels based on biomass. The mineral content and compounds of nutritional interest, such as lipophilic substances, were determined in fruit waste （orange peels, passion fruit, bananas, grapes） and sugarcane bagasse. Significant differences were found in the samples tested, where minerals, such as potassium, nitrogen, zinc and iron, were found in fruit residues （bananas, oranges, passion fruit） and sugarcane bagasse. Banana residues were the most important source of minerals, followed by orange peels. Gas chromatography mass spectrography （GC-MS） analyses of the lipophilic fractions obtained from the plant residues revealed the presence of mostly saturated （palmitic, stearic） and unsaturated （oleic and linoleic） fatty acids, as well as other nutritionally valuable compounds, such as antioxidants （flavones in orange residues）. The residues studied here can be used for future research to optimize pretreatment and hydrolysis of biomass for bioethanol production.展开更多
The photocatalytic degradation of dye pollutant sulforhodamine-B （SRB） in aqueous titanium dioxide （TiO2） dispersions was examined under three lighting regimes： UV light （330 nm〈λ〈 380 nm）, sunlight, and vis...The photocatalytic degradation of dye pollutant sulforhodamine-B （SRB） in aqueous titanium dioxide （TiO2） dispersions was examined under three lighting regimes： UV light （330 nm〈λ〈 380 nm）, sunlight, and visible light （λ〉450 nm）, all investigated at pH=2.5. Total organic carbon （TOC） and chemical oxygen demand （CODer） assays show that the degradation rate of SRB is much higher when irradiated with UV and sunlight compared with visible light. The temporal concentration changes of SRB illustrated a first-order reaction and the rate constant, k, is 0.197 min^-1, 0.152 min^-1, 0.027 min^-1, respectively, under the three lighting conditions. The final mineralized products were amine compounds identified by infrared spectrophotometry. When irradiated with visible light, the photocatalytic degradation rate could be improved by lowering the H2O2 concentration and inhibited by increasing the H2O2 concentration, but results contrary to the above were obtained when UV light was used for irradiation.展开更多
Energy storage is an ever-growing global concern due to increased energy needs and resource exhaustion.Sodium-ion batteries(SIBs)have called increasing attention and achieved substantial progress in recent years owing...Energy storage is an ever-growing global concern due to increased energy needs and resource exhaustion.Sodium-ion batteries(SIBs)have called increasing attention and achieved substantial progress in recent years owing to the abundance and even distribution of Na resources in the crust,and the predicted low cost of the technique.Nevertheless,SIBs still face challenges like lower energy density and inferior cycling stability compared to mature lithium-ion batteries(LIBs).Enhancing the electrochemical performance of SIBs requires an in-deep and comprehensive understanding of the improvement strategies and the underlying reaction mechanism elucidated by in situ techniques.In this review,commonly applied in situ techniques,for instance,transmission electron microscopy(TEM),Raman spectroscopy,X-ray diffraction(XRD),and X-ray absorption near-edge structure(XANES),and their applications on the representative cathode and anode materials with selected samples are summarized.We discuss the merits and demerits of each type of material,strategies to enhance their electrochemical performance,and the applications of in situ characterizations of them during the de/sodiation process to reveal the underlying reaction mechanism for performance improvement.We aim to elucidate the composition/structure-per formance relationship to provide guidelines for rational design and preparation of electrode materials toward high electrochemical performance.展开更多
In a pH 2.4 Britton-Robinson buffer medium, the anthracycline antibiotics mitoxantrone（MXT） could react with metal ions such as Pd（Ⅱ）, Co（Ⅱ） and Cu（Ⅱ） to form 1：2（molar ratio） cationic chelates, which fu...In a pH 2.4 Britton-Robinson buffer medium, the anthracycline antibiotics mitoxantrone（MXT） could react with metal ions such as Pd（Ⅱ）, Co（Ⅱ） and Cu（Ⅱ） to form 1：2（molar ratio） cationic chelates, which further reacted with the anionic dye titan yellow to form 1：2 ternary ion-association complexes by electrostatic interaction. As a result, the intensity of resonance Rayleigh scattering（RRS） was enhanced greatly. These RRS spectral characteristics of various metal ion systems were similar, and the maximum RRS wavelengths were all located at 454 nm. But the increments of RRS intensities were different in the series of Pd（Ⅱ）〉Co（Ⅱ）〉Cu（Ⅱ）. The enhanced RRS intensities were proportional to the concentration of MXT in a range of 0.03-2.4μg/mL and the detection limit（3σ） was 0.009μg/mL for the Pd（Ⅱ） system. In this study, the optimum conditions of the reactions and the effects of foreign substances were investigated, in addition, the composition and reaction mechanism of ion-association complexes were discussed. Thus a highly sensitive, simple and rapid method is proposed for the determination of MXT in urine and serum samples.展开更多
Organic compounds represent an appealing group of electrode materials for rechargeable batteries due to their merits of biomass,sustainability,environmental friendliness,and processability.Disodium terephthalate(Na_(2...Organic compounds represent an appealing group of electrode materials for rechargeable batteries due to their merits of biomass,sustainability,environmental friendliness,and processability.Disodium terephthalate(Na_(2)C_(8)H_(4)O_(4),Na_(2)TP),an organic salt with a theoretical capacity of 255 mAh·g^(-1),is electroactive towards both lithium and sodium.However,its electrochemical energy storage(EES)process has not been directly observed via in situ characterization techniques and the underlying mechanisms are still under debate.Herein,in situ Raman spectroscopy was employed to track the de/lithiation and de/sodiation processes of Na2TP.The appearance and then disappearance of the–COOLi Raman band at 1625 cm^(-1) during the de/lithiation,and the increase and then decrease of the–COONa Raman band at 1615 cm^(-1) during the de/sodiation processes of Na2TP elucidate the one-step with the 2Li+or 2Na+transfer mechanism.We also found that the inferior cycling stability of Na2TP as an anode for sodium-ion batteries(SIBs)than lithium-ion batteries(LIBs)could be due to the larger ion radium of Na+than Li+,which results in larger steric resistance and polarization during EES.The Na2TP,therefore,shows greater changes in spectra during de/sodiation than de/lithiation.We expect that our findings could provide a reference for the rational design of organic compounds for EES.展开更多
Developing multifunctional electrocatalysts with high catalytic activity,longterm stability,and low cost is essential for electrocatalytic energy conversion.Herein,sea urchinlike NiMoO_(4) nanorod arrays grown on nick...Developing multifunctional electrocatalysts with high catalytic activity,longterm stability,and low cost is essential for electrocatalytic energy conversion.Herein,sea urchinlike NiMoO_(4) nanorod arrays grown on nickel foam has been developed as a bifunctional electrocatalyst for urea oxidation and hydrogen evolution.The NiMoO_(4)‐200/NF catalyst exhibits efficient activity toward hydrogen evolution reaction with a low overpotential of only 68 mV in 1.0 mol/L KOH to gain a current density of 10 mA cm^(–2).The NiMoO_(4)‐300/NF catalyst exhibits a prominent oxygen evolution reaction(OER)catalytic activity with an overpotential of 288 mV at 50 mA cm^(–2),as well as for urea oxidation reaction with an ultralow potential of 1.36 V at 10 mA cm^(–2).The observed difference in electrocatalytic activity and selectivity,derived by temperature variation,is ascribed to different lattice oxygen contents.The lattice oxygen of NiMoO_(4)‐300/NF is more than that of NiMoO_(4)‐200/NF,and the lattice oxygen is conducive to the progress of OER.A urea electrolyzer was assembled with Ni‐MoO_(4)‐200/NF and NiMoO_(4)‐300/NF as cathode and anode respectively,delivering a current density of 10 mA cm^(–2)at a cell voltage of merely 1.38 V.The NiMoO_(4)nanorod arrays has also been successfully applied for photovoltage‐driven urea electrolysis and hydrogen production,revealing its great potential for solar‐driven energy conversion.展开更多
As state-of-the-art electrochemical energy conversion and storage(EECS)techniques,fuel cells and rechargeable batteries have achieved great success in the past decades.However,modern societies’ever-growing demand in ...As state-of-the-art electrochemical energy conversion and storage(EECS)techniques,fuel cells and rechargeable batteries have achieved great success in the past decades.However,modern societies’ever-growing demand in energy calls for EECS devices with high efficiency and enhanced performance,which mainly rely on the rational design of catalysts,electrode materials,and electrode/electrolyte interfaces in EESC,based on in-deep and comprehensive mechanistic understanding of the relevant electrochemical redox reactions.Such an understanding can be realized by monitoring the dynamic redox reaction processes under realistic operation conditions using in situ techniques,such as in situ Raman,Fourier transform infrared(FTIR),and X-ray diffraction(XRD)spectroscopy.These techniques can provide characteristic spectroscopic information of molecules and/or crystals,which are sensitive to structure/phase changes resulted from different electrochemical working conditions,hence allowing for intermediates identification and mechanisms understanding.This review described and summarized recent progress in the in situ studies of fuel cells and rechargeable batteries via Raman,FTIR,and XRD spectroscopy.The applications of these in situ techniques on typical electrocatalytic electrooxidation reaction and oxygen reduction reaction(ORR)in fuel cells,on representative high capacity and/or resource abundance cathodes and anodes,and on the solid electrolyte interface(SEI)in rechargeable batteries are discussed.We discuss how these techniques promote the development of novel EECS systems and highlight their critical importance in future EECS research.展开更多
Surface-enhanced Raman spectroscopy(SERS)has advanced significantly since its inception.Numerous experimental and theoretical efforts have been made to understand the SERS effect and demonstrate its potential.Due to i...Surface-enhanced Raman spectroscopy(SERS)has advanced significantly since its inception.Numerous experimental and theoretical efforts have been made to understand the SERS effect and demonstrate its potential.Due to its extremely high sensitivity and selectivity and ability to provide molecular fingerprint information,SERS has a wide range of applications in surface and interfacial chemistry,energy,materials,biomedicine,environmental analysis,etc.This review aims to provide readers with an understanding of the principles,methodologies,and applications of SERS.We briefly introduce the fundamental theory of the SERS enhancement mechanism and summarize the details of the preparation of SERS-active substrates.Recent applications of SERS in energy systems are then highlighted,including probing surface reactions and interfacial charge transfer of batteries and electrocatalysts.Finally,the challenges and prospects of SERS research are discussed.展开更多
The process of photocatalysis,regarded as a promising approach for tackling the energy crisis and environmental pollution issues,is crucial for turning solar light into chemical resources.However,the solar-chemical co...The process of photocatalysis,regarded as a promising approach for tackling the energy crisis and environmental pollution issues,is crucial for turning solar light into chemical resources.However,the solar-chemical conversion efficiency of typical semiconductor catalysts is still too low,so it is vital to figure out how to boost photocatalytic performance of semiconductors.Under visible light illumination,the local surface plasmon resonance(LSPR)induced by coinage metal would enhance the local electric field and improve photocatalytic performance of semiconductors,especially in the visible range.Therefore,its attachment to semiconductors has been regarded as an efficient strategy to improve photocatalytic performance.This paper reviews the latest research progress of plasmonic photocatalysis from theory to application.Starting from the excitation and relaxation of plasmons,four main mechanisms of plasmon-enhanced semiconductor photocatalysis are introduced,including enhanced light absorption and scattering,local electromagnetic field enhancement,improved hot carriers(HCs)injection and enhanced thermal effect.Secondly,the current mainstream plasmonic photocatalysts,such as monometallic,bimetallic and non-noble metal-based plasmonic catalysts,are reviewed.Finally,the applications of plasmonic photocatalysts in H_(2) production,CO_(2) reduction,and antibacterial are further summarized.展开更多
A new solid substrate-room temperature phosphorescence （SS-RTP） quenching method for the determination of trace As（V） has been developed, based on the facts that 9-hydroxy-2,3,4,9-tetrahydro-1,10-anthraquinone （R...A new solid substrate-room temperature phosphorescence （SS-RTP） quenching method for the determination of trace As（V） has been developed, based on the facts that 9-hydroxy-2,3,4,9-tetrahydro-1,10-anthraquinone （R） can emit intense and stable SS-RTP on solid substrate, and α,α＇-dipyridyl can activate As（V） catalysis of the reaction of H2O2 oxidizing R to non-phosphorescence compound R＇, which can cause the sharp quenching of SS-RTP. Under the optimum condition, the relationship between the ΔIp of the emitting intensity and 1.60-160 fg·spot^-1 As（V） （corresponding concentration： 0.0040-0.40 ng·mL^-1, sample volume： 0.4 μL·spot^-1） conformed to Beer＇ law. The regression equation of working curve can be expressed as ΔIp= 20.46＋0.5492CAs（v） fig·spot^-1） （r= 0.9995, n = 6）. The limit detection （LD） is 0.27 fg·spot^-1 [As（V） corresponding concentration： 6.8 × 10^-13 g·mL^-1, n=11]. The samples containing 0.0040 and 0.40 ng·mL^-1 As（V） were repeatedly determined for 11 times. RSD are 3.0% and 2.7% respectively. The SS-RTP mechanism was also discussed. R was synthesized in this paper. Meanwhile, the structure was determined by NMR, IR, mass spectra and elemental analysis.展开更多
The unsymmetrical bis-Schiff base manganese（III） and cobalt（II） complexes with either benzo-10-aza-crown ether pendants （MnL1Cl, MnLZCl） or morpholino pendant （MnL3Cl, CoL3） have been employed as models for hy...The unsymmetrical bis-Schiff base manganese（III） and cobalt（II） complexes with either benzo-10-aza-crown ether pendants （MnL1Cl, MnLZCl） or morpholino pendant （MnL3Cl, CoL3） have been employed as models for hy- drolase by studying the kinetics of their hydrolysis reactions with p-nitrophenyl picolinate （PNPP）. A kinetic model of PNPP cleavage catalyzed by these complexes is proposed. The effects of complex structures and reaction temperature on the rate of PNPP hydrolysis have been examined. All four complexes exhibit high catalytic activity and the rate increases with pH under 25℃. The complexes of ligands containing a crown ether group exhibit higher catalytic activities than the non-crown analogues. The catalytic activity of the complexes follows the order Mn（III） 〉 Co（II） under the same ligands.展开更多
基金the National Natural Science Foundation of China(Nos.21805052,21974031,2278092)Science and Technology Research Project of Guangzhou(Nos.202102020787 and 202201000002)+2 种基金Department of Science&Technology of Guangdong Province(No.2022A156)Key Discipline of Materials Science and Engineering,Bureau of Education of Guangzhou(No.20225546)the Innovation&Entrepreneurship for the College Students of Guangzhou University(No.XJ202111078175).
文摘Electrosynthesis of hydrogen peroxide(H2O2)is an on-site method that enables independent distribution applications in many fields due to its small-scale and sustainable features.The crucial point remains developing highly active,selective and cost-effective electrocatalysts.The electrosynthesis of H2O2 in acidic media is more practical owing to its stability and no need for further purification.We herein report a phosphorus and selenium tuning Co-based non-precious catalyst(CoPSe)toward two-electron oxygen reduction reaction(2e–ORR)to produce H2O2 in acidic media.The starting point of using both P and Se is finding a balance between strong ORR activity of CoSe and weak activity of CoP.The results demonstrated that the CoPSe catalyst exhibited the optimized 2e–ORR activity compared with CoP and CoSe.It disclosed an onset potential of 0.68 V and the H2O2 selectivity 76%-85%in a wide potential range(0–0.5 V).Notably,the CoPSe catalyst overcomes a significant challenge of a narrow-range selectivity for transitionmetal based 2e–ORR catalysts.Finally,combining with electro-Fenton reaction,an on-site system was constructed for efficient degradation of organic pollutants.This work provides a promising non-precious Co-based electrocatalyst for the electrosynthesis of H2O2 in acidic media.
基金supported by the Postgraduate Foundation of Taishan University (No. Y07--2-16)
文摘A novel metal-organic complex Cu（p-FBA）2（phen）（H2O） （p-FBA = p-fluorobenzoic acid,phen = 1,10-phenanthroline） has been synthesized and structurally characterized by X-ray single-crystal diffraction,elemental analysis and IR spectra. The crystal belongs to triclinic,space group P1 with a = 7.8043（7）,b = 10.4069（9）,c = 14.3658（13） ,α = 105.3170（10）,β = 96.877（2）,γ = 96.7580（10）o,V = 1103.56（17） 3,Mr = 539.96,Z = 2,Dc = 1.625 g/cm3,μ = 1.050 mm-1,F（000） = 550,the final R = 0.0324 and wR = 0.0952. In the crystal,the structure consists of discrete molecules containing a five-coordinate copper（Ⅱ ） in a distorted square pyramidal configuration. Intramolecular O-H···O hydrogen bonds,weak intermolecular C-H···O hydrogen bonds and π-π stacking link the molecules into a one-dimensional chain structure. The study on the title complex has been performed with quantum chemistry calculation by means of G03W package on the Lanl2dz basis set. The stabilities of the complex together with the orbital energies and composition characteristics of some frontier molecular orbitals have been investigated.
基金supported by the National Natural Science Foundation of China (Nos.21802064,21275127)Natural Science Foundation of Fujian Province,China (Nos.2018J01435,2017J01419)Foundation of Key Laboratory of Sensor Analysis of Tumor Marker,Ministry of Education,Qingdao University of Science and Technology
文摘The core-shell structured Au@Bi2S3 nanorods have been prepared through direct in-situ growth of Bi2S3 at the surface of pre-synthesized gold nanorods.The product was characterized by X-ray diffraction,transmission electron microscopy and energy-dispersive X-ray spectroscopy.Then the obtained Au@Bi2S3 nanorods were coated onto glassy carbon electrode to act as a scaffold for fabrication of electrochemical DNA biosensor on the basis of the coordination of-NH2 modified on 5’-end of probe DNA and Au@Bi2S3.Electrochemical characterization assays demonstrate that the Au@Bi2S3 nanorods behave as an excellent electronic transport channel to promote the electron transfer kinetics and increase the effective surface area by their nanosize effect.The hybridization experiments reveal that the Au@Bi2S3 matrix-based DNA biosensor is capable of recognizing complementary DNA over a wide concentration ranging from 10 fmol/L to 1 nmol/L.The limit of detection was estimated to be 2 fmol/L(S/N=3).The biosensor also presents remarkable selectivity to distinguish fully complementa ry sequences from basemismatched and non-complementary ones,showing great promising in practical application.
基金supported by the Postgraduate Foundation of Taishan University (No. Y07-2-16)
文摘A novel water cluster [Mn（phen）2·H2O·Cl]·p-FBA·3H2O （p-FBA = p-fluorobenzoic acid and phen = 1,10-phenanthroline） was synthesized by the hydrothermal reaction of MnCl2 with p-FBA and phen at 150 ℃ and characterized by elemental analysis,IR spectra and TG. Its crystal structure was determined by X-ray single-crystal diffraction study. The crystal belongs to the triclinic system,space group P1,with a = 10.5768（1）,b = 11.5960（1）,c = 12.9916（2） ,α = 101.816（2）,β = 95.397（2）,γ = 103.052（2）o,V = 1502.8（3） 3,Z = 2,Dc = 1.463 g/cm3,R = 0.0399 and wR = 0.0997. The crystal structure shows that the manganese（Ⅱ ） ion is six-coordinated by four nitrogen atoms,one chloride ion and one oxygen atom forming a distorted octahedral coordination geometry. The structure includes three acyclically connected water molecules and one coordinated water molecule thus forming a （H2O）4 water cluster. This water pattern forms a cross-linked discrete ring. The steady （H2O）4 is further extended into a cage-like structure by the hydrogen-bonding interaction formed by dissociative aqua molecule and Cl-ligand. The dimer structure is further extended into a one-dimensional （1D） structure through C-H···O interaction. π···π Stacking interaction among adjacent phen aromatic rings further stabilizes the crystal structure.
文摘This paper mainly discusses the protection of water resource environment in Three Gorge Water Reservoir, a systematic investigation and analysis of the landfill leachate＇s polluting components, hazardous and changing rule in landfill leachate from hinterland landfill located in the surrounding area have been carried out, and proposed the countermeasures for disposition the leachate furtherly.
基金Project(20376085) supported by the National Natural Science Foundation of ChinaProject(05C053) supported by Education Department of Hunan Province, China
文摘L-aspartic acid （Asp） pillared hydrotalcites were prepared by direct reaction of the L-Asp anion with layered double hydroxides （LDHs）. The obtained samples were characterized by X-ray diffractometry （XRD）, Fourier transform infrared （FTIR）, and thermogravimetric and differential thermal analysis （TG/DTA）. The results show that the initial interlayer carbonate ions can be completely replaced by the L-Asp anion under the controlled conditions. The pillared hydrotalcites have a crystallized supramolecular structure and thermal stability. The L-Asp pillared LDHs were used in the enantiosorption of enantiopure phenylalanine （Pile）, the results suggest that L-Asp pillared LDHs exhibit an excellent enantiosorption capability for D-Phe, and the adsorption isotherm fits Freundlich equation.
文摘Add the masking agent and biscyclohexanoneoxalyldihydraone into the diluted clarificd liquid of the landfill leachate which was treatmented by digestion and centrifugal filtration to complexate all heavy metal ion in the trcatmented liquid, and extracted using CHCl3 many time, then it were demasking and decomposing respectively, and adjusted different pH and formed Me^n＋-PAN coordination compound when these metal ion reaction with PAN. The Fluoresence quenching of Rh6G （λex/λem=543mn/558nm） when the metal ion coordination compound was add into the Rh6G solution step by step, the quenching intensity was directly proportional to the concentration of the metal ion in the certain range. So a new method of fast and simple for determination of trace metal ion in landfill lcachate was established to determine metal ion in sample of different landfill leachate in Three Gorge Water Reservoir, and comparison the classic assay method with satisfactory results.
文摘The objectives of this study were to explore alternatives for using fruit waste and sugarcane bagasse as important sources for new products and potential applications in the food industry. Fast foods are part of modern life, as well as sources for producing biofuels based on biomass. The mineral content and compounds of nutritional interest, such as lipophilic substances, were determined in fruit waste （orange peels, passion fruit, bananas, grapes） and sugarcane bagasse. Significant differences were found in the samples tested, where minerals, such as potassium, nitrogen, zinc and iron, were found in fruit residues （bananas, oranges, passion fruit） and sugarcane bagasse. Banana residues were the most important source of minerals, followed by orange peels. Gas chromatography mass spectrography （GC-MS） analyses of the lipophilic fractions obtained from the plant residues revealed the presence of mostly saturated （palmitic, stearic） and unsaturated （oleic and linoleic） fatty acids, as well as other nutritionally valuable compounds, such as antioxidants （flavones in orange residues）. The residues studied here can be used for future research to optimize pretreatment and hydrolysis of biomass for bioethanol production.
基金Project supported by the National Natural Science Foundation of China (No. 20373074) the National Basic Research Programme (973) of China (No. 2003CB415006-3).
文摘The photocatalytic degradation of dye pollutant sulforhodamine-B （SRB） in aqueous titanium dioxide （TiO2） dispersions was examined under three lighting regimes： UV light （330 nm〈λ〈 380 nm）, sunlight, and visible light （λ〉450 nm）, all investigated at pH=2.5. Total organic carbon （TOC） and chemical oxygen demand （CODer） assays show that the degradation rate of SRB is much higher when irradiated with UV and sunlight compared with visible light. The temporal concentration changes of SRB illustrated a first-order reaction and the rate constant, k, is 0.197 min^-1, 0.152 min^-1, 0.027 min^-1, respectively, under the three lighting conditions. The final mineralized products were amine compounds identified by infrared spectrophotometry. When irradiated with visible light, the photocatalytic degradation rate could be improved by lowering the H2O2 concentration and inhibited by increasing the H2O2 concentration, but results contrary to the above were obtained when UV light was used for irradiation.
基金supported by the National Natural Science Foundation of China(22005130,21925404,21902137,21991151,and 22021001)the National Key Research and Development Program of China(2019YFA0705400 and 2020YFB1505800)the Natural Science Foundation of Fujian Province of China(2021J01988)。
文摘Energy storage is an ever-growing global concern due to increased energy needs and resource exhaustion.Sodium-ion batteries(SIBs)have called increasing attention and achieved substantial progress in recent years owing to the abundance and even distribution of Na resources in the crust,and the predicted low cost of the technique.Nevertheless,SIBs still face challenges like lower energy density and inferior cycling stability compared to mature lithium-ion batteries(LIBs).Enhancing the electrochemical performance of SIBs requires an in-deep and comprehensive understanding of the improvement strategies and the underlying reaction mechanism elucidated by in situ techniques.In this review,commonly applied in situ techniques,for instance,transmission electron microscopy(TEM),Raman spectroscopy,X-ray diffraction(XRD),and X-ray absorption near-edge structure(XANES),and their applications on the representative cathode and anode materials with selected samples are summarized.We discuss the merits and demerits of each type of material,strategies to enhance their electrochemical performance,and the applications of in situ characterizations of them during the de/sodiation process to reveal the underlying reaction mechanism for performance improvement.We aim to elucidate the composition/structure-per formance relationship to provide guidelines for rational design and preparation of electrode materials toward high electrochemical performance.
基金Supported by Education Committee of Chongqing City, China(No.KJ081306)
文摘In a pH 2.4 Britton-Robinson buffer medium, the anthracycline antibiotics mitoxantrone（MXT） could react with metal ions such as Pd（Ⅱ）, Co（Ⅱ） and Cu（Ⅱ） to form 1：2（molar ratio） cationic chelates, which further reacted with the anionic dye titan yellow to form 1：2 ternary ion-association complexes by electrostatic interaction. As a result, the intensity of resonance Rayleigh scattering（RRS） was enhanced greatly. These RRS spectral characteristics of various metal ion systems were similar, and the maximum RRS wavelengths were all located at 454 nm. But the increments of RRS intensities were different in the series of Pd（Ⅱ）〉Co（Ⅱ）〉Cu（Ⅱ）. The enhanced RRS intensities were proportional to the concentration of MXT in a range of 0.03-2.4μg/mL and the detection limit（3σ） was 0.009μg/mL for the Pd（Ⅱ） system. In this study, the optimum conditions of the reactions and the effects of foreign substances were investigated, in addition, the composition and reaction mechanism of ion-association complexes were discussed. Thus a highly sensitive, simple and rapid method is proposed for the determination of MXT in urine and serum samples.
基金supported by the National Natural Science Foundation of China(Nos.22005130,22272069,22004054,and 21925404)the Natural Science Foundation of Fujian Province of China(Nos.2021J01988 and 2020J05163).
文摘Organic compounds represent an appealing group of electrode materials for rechargeable batteries due to their merits of biomass,sustainability,environmental friendliness,and processability.Disodium terephthalate(Na_(2)C_(8)H_(4)O_(4),Na_(2)TP),an organic salt with a theoretical capacity of 255 mAh·g^(-1),is electroactive towards both lithium and sodium.However,its electrochemical energy storage(EES)process has not been directly observed via in situ characterization techniques and the underlying mechanisms are still under debate.Herein,in situ Raman spectroscopy was employed to track the de/lithiation and de/sodiation processes of Na2TP.The appearance and then disappearance of the–COOLi Raman band at 1625 cm^(-1) during the de/lithiation,and the increase and then decrease of the–COONa Raman band at 1615 cm^(-1) during the de/sodiation processes of Na2TP elucidate the one-step with the 2Li+or 2Na+transfer mechanism.We also found that the inferior cycling stability of Na2TP as an anode for sodium-ion batteries(SIBs)than lithium-ion batteries(LIBs)could be due to the larger ion radium of Na+than Li+,which results in larger steric resistance and polarization during EES.The Na2TP,therefore,shows greater changes in spectra during de/sodiation than de/lithiation.We expect that our findings could provide a reference for the rational design of organic compounds for EES.
文摘Developing multifunctional electrocatalysts with high catalytic activity,longterm stability,and low cost is essential for electrocatalytic energy conversion.Herein,sea urchinlike NiMoO_(4) nanorod arrays grown on nickel foam has been developed as a bifunctional electrocatalyst for urea oxidation and hydrogen evolution.The NiMoO_(4)‐200/NF catalyst exhibits efficient activity toward hydrogen evolution reaction with a low overpotential of only 68 mV in 1.0 mol/L KOH to gain a current density of 10 mA cm^(–2).The NiMoO_(4)‐300/NF catalyst exhibits a prominent oxygen evolution reaction(OER)catalytic activity with an overpotential of 288 mV at 50 mA cm^(–2),as well as for urea oxidation reaction with an ultralow potential of 1.36 V at 10 mA cm^(–2).The observed difference in electrocatalytic activity and selectivity,derived by temperature variation,is ascribed to different lattice oxygen contents.The lattice oxygen of NiMoO_(4)‐300/NF is more than that of NiMoO_(4)‐200/NF,and the lattice oxygen is conducive to the progress of OER.A urea electrolyzer was assembled with Ni‐MoO_(4)‐200/NF and NiMoO_(4)‐300/NF as cathode and anode respectively,delivering a current density of 10 mA cm^(–2)at a cell voltage of merely 1.38 V.The NiMoO_(4)nanorod arrays has also been successfully applied for photovoltage‐driven urea electrolysis and hydrogen production,revealing its great potential for solar‐driven energy conversion.
基金supported by the National Key Research and Development Program of China(Nos.2020YFB1505800 and 2019YFA0705400)the National Natural Science Foundation of China(NSFC)(Nos.201925404,21902137,22005130,and 22021001)+1 种基金the Fundamental Research Funds for the Central Universities(Nos.20720210069 and 20720210043)the Science and Technology Planning Project of Fujian Province(No.2019Y4001).
文摘As state-of-the-art electrochemical energy conversion and storage(EECS)techniques,fuel cells and rechargeable batteries have achieved great success in the past decades.However,modern societies’ever-growing demand in energy calls for EECS devices with high efficiency and enhanced performance,which mainly rely on the rational design of catalysts,electrode materials,and electrode/electrolyte interfaces in EESC,based on in-deep and comprehensive mechanistic understanding of the relevant electrochemical redox reactions.Such an understanding can be realized by monitoring the dynamic redox reaction processes under realistic operation conditions using in situ techniques,such as in situ Raman,Fourier transform infrared(FTIR),and X-ray diffraction(XRD)spectroscopy.These techniques can provide characteristic spectroscopic information of molecules and/or crystals,which are sensitive to structure/phase changes resulted from different electrochemical working conditions,hence allowing for intermediates identification and mechanisms understanding.This review described and summarized recent progress in the in situ studies of fuel cells and rechargeable batteries via Raman,FTIR,and XRD spectroscopy.The applications of these in situ techniques on typical electrocatalytic electrooxidation reaction and oxygen reduction reaction(ORR)in fuel cells,on representative high capacity and/or resource abundance cathodes and anodes,and on the solid electrolyte interface(SEI)in rechargeable batteries are discussed.We discuss how these techniques promote the development of novel EECS systems and highlight their critical importance in future EECS research.
基金supported by the National Key Research and Development Program of China (2020YFB1505800)the National Natural Science Foundation of China (22005130,21925404,22174165,21902137,and 21991151)+1 种基金the China Postdoctoral Science Foundation (Bx20220187)the Natural Science Foundation of Fujian Province of China (2021J01988).
文摘Surface-enhanced Raman spectroscopy(SERS)has advanced significantly since its inception.Numerous experimental and theoretical efforts have been made to understand the SERS effect and demonstrate its potential.Due to its extremely high sensitivity and selectivity and ability to provide molecular fingerprint information,SERS has a wide range of applications in surface and interfacial chemistry,energy,materials,biomedicine,environmental analysis,etc.This review aims to provide readers with an understanding of the principles,methodologies,and applications of SERS.We briefly introduce the fundamental theory of the SERS enhancement mechanism and summarize the details of the preparation of SERS-active substrates.Recent applications of SERS in energy systems are then highlighted,including probing surface reactions and interfacial charge transfer of batteries and electrocatalysts.Finally,the challenges and prospects of SERS research are discussed.
基金supported by the National Key Research and Development Program of China(2019YFA0705400)the National Natural Science Foundation of China(22104124,22005130,22272069,and 22104135)+1 种基金the State Key Laboratory of Fine Chemicals,Dalian University of Technology(KF2002)the Fundamental Research Funds for the Central Universities(20720220117).
文摘The process of photocatalysis,regarded as a promising approach for tackling the energy crisis and environmental pollution issues,is crucial for turning solar light into chemical resources.However,the solar-chemical conversion efficiency of typical semiconductor catalysts is still too low,so it is vital to figure out how to boost photocatalytic performance of semiconductors.Under visible light illumination,the local surface plasmon resonance(LSPR)induced by coinage metal would enhance the local electric field and improve photocatalytic performance of semiconductors,especially in the visible range.Therefore,its attachment to semiconductors has been regarded as an efficient strategy to improve photocatalytic performance.This paper reviews the latest research progress of plasmonic photocatalysis from theory to application.Starting from the excitation and relaxation of plasmons,four main mechanisms of plasmon-enhanced semiconductor photocatalysis are introduced,including enhanced light absorption and scattering,local electromagnetic field enhancement,improved hot carriers(HCs)injection and enhanced thermal effect.Secondly,the current mainstream plasmonic photocatalysts,such as monometallic,bimetallic and non-noble metal-based plasmonic catalysts,are reviewed.Finally,the applications of plasmonic photocatalysts in H_(2) production,CO_(2) reduction,and antibacterial are further summarized.
文摘A new solid substrate-room temperature phosphorescence （SS-RTP） quenching method for the determination of trace As（V） has been developed, based on the facts that 9-hydroxy-2,3,4,9-tetrahydro-1,10-anthraquinone （R） can emit intense and stable SS-RTP on solid substrate, and α,α＇-dipyridyl can activate As（V） catalysis of the reaction of H2O2 oxidizing R to non-phosphorescence compound R＇, which can cause the sharp quenching of SS-RTP. Under the optimum condition, the relationship between the ΔIp of the emitting intensity and 1.60-160 fg·spot^-1 As（V） （corresponding concentration： 0.0040-0.40 ng·mL^-1, sample volume： 0.4 μL·spot^-1） conformed to Beer＇ law. The regression equation of working curve can be expressed as ΔIp= 20.46＋0.5492CAs（v） fig·spot^-1） （r= 0.9995, n = 6）. The limit detection （LD） is 0.27 fg·spot^-1 [As（V） corresponding concentration： 6.8 × 10^-13 g·mL^-1, n=11]. The samples containing 0.0040 and 0.40 ng·mL^-1 As（V） were repeatedly determined for 11 times. RSD are 3.0% and 2.7% respectively. The SS-RTP mechanism was also discussed. R was synthesized in this paper. Meanwhile, the structure was determined by NMR, IR, mass spectra and elemental analysis.
文摘The unsymmetrical bis-Schiff base manganese（III） and cobalt（II） complexes with either benzo-10-aza-crown ether pendants （MnL1Cl, MnLZCl） or morpholino pendant （MnL3Cl, CoL3） have been employed as models for hy- drolase by studying the kinetics of their hydrolysis reactions with p-nitrophenyl picolinate （PNPP）. A kinetic model of PNPP cleavage catalyzed by these complexes is proposed. The effects of complex structures and reaction temperature on the rate of PNPP hydrolysis have been examined. All four complexes exhibit high catalytic activity and the rate increases with pH under 25℃. The complexes of ligands containing a crown ether group exhibit higher catalytic activities than the non-crown analogues. The catalytic activity of the complexes follows the order Mn（III） 〉 Co（II） under the same ligands.
