Solid-state electrolytes have attracted considerable attention in new energyrelated devices due to their high safety and broad application platform.Polyoxometalates(POMs)are a kind of molecular-level cluster compounds...Solid-state electrolytes have attracted considerable attention in new energyrelated devices due to their high safety and broad application platform.Polyoxometalates(POMs)are a kind of molecular-level cluster compounds with unique structures.In recent years,owing to their abundant physicochemical properties(including high ionic conductivity and reversible redox activity),POMs have shown great potential in becoming a new generation of solid-state electrolytes.In this review,an overview is investigated about how POMs have evolved as ion-conducting materials from basic research to novel solid-state electrolytes in energy devices.First,some expressive POM-based ion-conducting materials in recent years are introduced and classified,mainly inspecting their structural and functional relationship.After that,it is further focused on the application of these ionconducting electrolytes in the fields of proton exchange membranes,supercapacitors,and ion batteries.In addition,some properties of POMs(such as inherent dimension,capable of forming stable hydrogen bonds,and reversible bonding to water molecules)enable these functional POM-based electrolytes to be employed in innovative applications such as ion selection,humidity sensing,and smart materials.Finally,some fundamental recommendations are given on the current opportunities and challenges of POM-based ion-conducting electrolytes.展开更多
With the aim of deep desulfurization, silica-supported polyoxometalate-based ionic liquids were successfully prepared by a one-pot hydrothermal process and employed in heterogeneous oxidative desulfurization of variou...With the aim of deep desulfurization, silica-supported polyoxometalate-based ionic liquids were successfully prepared by a one-pot hydrothermal process and employed in heterogeneous oxidative desulfurization of various sulfur compounds. The compositions and structures of the hybrid samples were characterized by various methods such as FT-IR, XPS, Raman,UV–Vis, wide-angle XRD and N_2 adsorption–desorption. The experimental results indicated that the hybrid materials presented a high dispersion of tungsten species and excellent catalytic activity for the removal of 4,6-dimethyldibenzothiophene without any organic solvent as extractant, and the sulfur removal could reach 100.0% under mild conditions.The catalytic performance on various substrates was also investigated in detail. After cycling seven cycles, the sulfur removal of the heterogeneous system still reached 93.0%. The GC-MS analysis results demonstrated that the sulfur compound was first adsorbed by the catalyst and subsequently oxidized to its corresponding sulfone.展开更多
Heterogeneously catalyzed hydrolytic dehydrogenation of ammonia borane is a remarkable structure sensitive reaction. In this work, a strategy by using polyoxometalates(POMs) as the ligands is proposed to engineer the ...Heterogeneously catalyzed hydrolytic dehydrogenation of ammonia borane is a remarkable structure sensitive reaction. In this work, a strategy by using polyoxometalates(POMs) as the ligands is proposed to engineer the surface and electronic properties of Pt/CNT catalysts toward the enhanced hydrogen generation rate and durability. Three kinds of POMs, i.e., silicotungstic acid(STA), phosphotungstic acid(PTA)and molybdophosphoric acid(PMA), are comparatively studied, among which the STA shows positive effects on the catalytic activity and durability. A catalyst structure-performance relationship is established by a combination of kinetic and isotopic analyses with multiple characterization techniques, such as HAADF-STEM, EDS, Raman spectroscopy and XPS. It is shown that the STA compared to the other two POMs can increase the Pt binding energy and thus promote the reaction. The insights demonstrated here could open a new avenue for boosting the reaction by employing the POMs as the ligands to engineer the catalyst electronic properties.展开更多
Thin layers of an electrostatically associated adduct RuPVP-AuNP:POM formed between the polyoxomolybdate, [S2 Mo18 O62 ]4, the polycationic metallopolymer [Ru(bpy)2(PVP)10 ](ClO4)2 and DMAP-protected gold nanoparticle...Thin layers of an electrostatically associated adduct RuPVP-AuNP:POM formed between the polyoxomolybdate, [S2 Mo18 O62 ]4, the polycationic metallopolymer [Ru(bpy)2(PVP)10 ](ClO4)2 and DMAP-protected gold nanoparticle have been deposited onto electrodes using two separate methods, alternate immersion layer-by-layer assembly and pre-assembled drop-casting; PVP is poly(4-vinylpyridine), BPY is 2,2'-bipyridyl, and DMAP is 4-dimethylaminopyridine. Significantly, the efficiency of the photocatalysis depends markedly on the structure of the [RuPVP-AuNP:POM] even when photonic properties are very similar. Strikingly, despite their similar photonic properties, an additional optical transition is observed in UV-vis and the Raman spectra of pre-assembled drop cast [RuPVP-AuNP:POM], which was not seen in dip coated [RuPVP-AuNP:POM]. Importantly, this electronic communication enhances the photocatalytic oxidation of benzaldehyde by a factor of more than four. While there is clear evidence for photosensitisation in the drop cast not present for the dip coated systems, the magnitude of the photocurrent, i.e.,(82.2 6.6) nA·cm 2for pre-assembled drop cast [RuPVP-AuNP:POM] at a ruthenium to Au nanoparticle mole ratio of 48:1, is twice as large as that those found in [Ru-PVP:POM] film.展开更多
A series of photocatalysts, K11[Ln(PW11O39)2]/PVA (Ln=La, Ce, Pr, Nd, Sm) were prepared by K11[Ln(PW11O39)2] (Ln=La, Ce, Pr, Nd, Sm) containing five kinds of lanthanides and polyvinyl alcohol as the support. The catal...A series of photocatalysts, K11[Ln(PW11O39)2]/PVA (Ln=La, Ce, Pr, Nd, Sm) were prepared by K11[Ln(PW11O39)2] (Ln=La, Ce, Pr, Nd, Sm) containing five kinds of lanthanides and polyvinyl alcohol as the support. The catalysts obtained were characterized by Fourier transform infrared spectra, UV-vis spectra, powder X-ray diffraction, and scanning electron microscopy, indicating that the structure of K11[Ln(PW11O39)2] and polyvinyl alcohol remained intact, respectively. The photocatalysts exhibited efficient catalytic activity to degrade methyl orange, Congo Red, Ponceau 2R. The maximal degradation conversions of the three kinds of dyes were 99.58%, 47.61%, 72.42%, respectively.展开更多
The synergistic effect of H_3PMo_(12)O_(40) or H_3PW_(12)O_(40) polyoxometalate solution(POM) and TiO_2 to catalyze formic acid oxidation was investigated. Under UV irradiation, hole and electron were photogenerated b...The synergistic effect of H_3PMo_(12)O_(40) or H_3PW_(12)O_(40) polyoxometalate solution(POM) and TiO_2 to catalyze formic acid oxidation was investigated. Under UV irradiation, hole and electron were photogenerated by TiO_2. Formic acid was oxided by the photogenerated hole and photogenerated electron was transferred to reduce polyoxometalate. With this design, formic acid can be converted into electricity in the fuel cell and hydrogen can be generated in the electrolysis cell without noble metal catalyst. Unlike other noble metal catalysts applied in the fuel cells and electrolysis cell, POM and TiO_2 are stable and low cost. The maximum output power density of liquid formic acid fuel cell after 12 h UV irradiation is 5.21 mW/cm^2 for phosphmolybdic acid and 22.81 m W/cm^2 for phosphotungstic acid respectively. The applied potential for the hydrogen evolution is as low as 0.8 V for phosphmolybdic acid and 0.6 V for phosphotungstic acid.展开更多
Two novel rare earth tungstosilicic polyoxometalate containing 5-fluorouracil,K26(C4H4FN2O2)8Pr(SiW11O39)4·10H2O(FPSW) and K26(C4H4FN2O2)8Sm(SiW11O39)4·9H2O(FSSW),were synthesized and their structure were ch...Two novel rare earth tungstosilicic polyoxometalate containing 5-fluorouracil,K26(C4H4FN2O2)8Pr(SiW11O39)4·10H2O(FPSW) and K26(C4H4FN2O2)8Sm(SiW11O39)4·9H2O(FSSW),were synthesized and their structure were characterized by using elemental analysis,FTIR spectra,X-ray powder diffraction and TG.The antitumor activity tests of the compounds FPSW and FSSW were carried out by the methyl thiazolyl tetrazolium method in hepatocellular carcinoma cell HepG-2.The results showed that FPSW and FSSW could inhibit the HepG-2 cells in vitro significantly.The EC50 of FPSW and FSSW is 1.94×10-5 and 1.32×10-5 mol·L-1 respectively.The therapeutic index of FPSW and FSSW is 0.76 and 1.58 respectively.展开更多
Polyoxometalates have been explored as multi-electron active species in both aqueous and non-aqueous redox flow batteries. Although non-aqueous systems in principle offer a wider voltage window for redox flow battery ...Polyoxometalates have been explored as multi-electron active species in both aqueous and non-aqueous redox flow batteries. Although non-aqueous systems in principle offer a wider voltage window for redox flow battery operation, realization of this potential requires a judicious choice of solvent as well as polyoxometalate properties. We demonstrate here the superior performance of N,N-dimethylformamide(DMF)compared to acetonitrile as a solvent for redox flow batteries based on Li3PMo12O40. This compound displays two 1-electron transfers in acetonitrile but can access an extra quasi-reversible 2-electron redox process in DMF. A cell containing 10 mM solution of Li3PMo12O40 in DMF produced a cell voltage of 0.7 V with 2-electron transfers(State of Charge = 60%) and showed a good cyclability. As a means to boost energy density, operation of the redox flow battery at a higher concentration of 0.1 M Li3PMo12O40 produced cells with cell voltage of 0.6 V in acetonitrile and a cell voltage of 1.0 V in DMF;both showed excellent coulombic efficiencies of more than 90% over the course of 30 cycles. Energy density was also increased by employing an asymmetric cell with different polyoxometalates on each side to extend cell voltage.Li6P2W18O62 exhibited 3 quasi-reversible 2-electron transfers in the potential range between-2.05 V and-0.5 V vs. Ag/Ag+. 10 mM Li6P2W18O62/Li3PMo12O40 in DMF produced a cell with cell voltage of 1.3 V involving 4-electron transfers(State of Charge = 50%) with coulombic efficiency of nearly 100% and energy efficiency of nearly 70% throughout the test with more than 20 cycles. These promising results demonstrate proof-of-concept approaches to improving the performance of polyoxometalates in non-aqueous redox flow batteries.展开更多
Iridium(Ir)-based nanomaterials are promising electrocatalysts for water splitting,and to alleviate their costs as well as improve the performances are always important tasks.Polyoxometalates(POMs)composed of abundant...Iridium(Ir)-based nanomaterials are promising electrocatalysts for water splitting,and to alleviate their costs as well as improve the performances are always important tasks.Polyoxometalates(POMs)composed of abundant metal,oxygen,and heteroatoms are nanoclusters with defined structures.Benefitting from the inherent advantages of POMs,highly dispersive and"unprotected"Ir nanoparticles originating from Ir-based colloid solution were successfully anchored on POM-derived WO_(3)/rGO nanocomposites for the first time.Interestingly,the obtained hybrid material Ir/WO_(x)/rGO delivered improved electrocatalytic performance for water splitting,which is attributed to the addition of only quite small amount of POM derivatives.This work is also the first proof that POM can be employed as precursor to construct metal oxides to support Ir catalysts,providing a new vision for the design of advanced multi-metal electrocatalysts.展开更多
A novel heterogeneous catalyst for ultrasound-assisted oxidative desulfurization(UAODS)was designed and synthesized by confining polyoxometalates(POMs)clusters within porous metal-organic gel.The catalyst microstructu...A novel heterogeneous catalyst for ultrasound-assisted oxidative desulfurization(UAODS)was designed and synthesized by confining polyoxometalates(POMs)clusters within porous metal-organic gel.The catalyst microstructures were characterized by XRD,SEM-EDX,FT-IR,N_(2)adsorption-desorption,and XPS.Effects of POM loading,catalyst dosage,and ultrasonic power were also investigated.Results indicate that 60%-PMA@MOX(Al)exhibits optimal catalytic activity,with a sulfur removal rate of 98.61%and excellent reusability.Moreover,a kinetic study of different desulfurization approaches demonstrates that the unique thermal and cavitation effects of ultrasound can effectively improve the efficiency of oxidative desulfurization.展开更多
A highly efficient catalyst of graphene-supported mixed-valent Mn_(16)-containing polyoxometalate is reported here by electrochemical strategy. The modified electrode with the catalyst exhibits an excellent electrocat...A highly efficient catalyst of graphene-supported mixed-valent Mn_(16)-containing polyoxometalate is reported here by electrochemical strategy. The modified electrode with the catalyst exhibits an excellent electrocatalytic performance for water oxidation, which will contribute to the development of highly efficient catalysts for oxygen evolution.展开更多
In this work, we have developed an electrochemical sensor for nitrite detection, based on a polyoxometalate (POM) namely mono-lacunary keggin anion [SiW11O39]8﹣ cited as (SiW11). Electrochemical characterization of S...In this work, we have developed an electrochemical sensor for nitrite detection, based on a polyoxometalate (POM) namely mono-lacunary keggin anion [SiW11O39]8﹣ cited as (SiW11). Electrochemical characterization of SiW11 shows two-step reduction processes, with formal potentials of ﹣0.5 V (I) and ﹣0.68 V (II). Oppositely charged polyelectrolyte (poly (allylamine hydrochloride) (PAH)) and (SiW11) were assembled alternately to modify glassy carbon electrode. The electrochemical behavior of the modified electrode was studied in detail using cyclic voltammetry (CV). The results showed that SiW11/PAH/GC electrode present good electrocatalytic activity for the reduction of nitrite. The sensor showed a dynamic range from 100 μM to 3.6 mMof nitrite and no interference from other classical anions. Experimental factors that affect electron-transfer rate in these films, such as pH effect and layers number, were systematically analyzed.展开更多
Nanocluster polyoxometalates with a structure of buckyball (fullerene) are a promising means of targeted delivery of drugs in the body. In this paper, based on an analysis of histological sections of liver and kidney ...Nanocluster polyoxometalates with a structure of buckyball (fullerene) are a promising means of targeted delivery of drugs in the body. In this paper, based on an analysis of histological sections of liver and kidney and peripheral blood, showed a significant reduction of toxicity of buckyballs, containing ions of molybdenum (VI), the substitution of Mo (V) ions to Fe (III), in contrast to buckyballs based on Mo (V). The absence of accumulation of molybdenum in rats with a daily intramuscular injection of aqueous solutions of both drugs within a month was confirmed.展开更多
Redox flow batteries have received wide attention for electrochemical energy conversion and storage devices due to their specific advantage of uncoupled power and energy devices,and therefore potentially to reduce the...Redox flow batteries have received wide attention for electrochemical energy conversion and storage devices due to their specific advantage of uncoupled power and energy devices,and therefore potentially to reduce the capital costs of energy storage.Terrific structural features of polyoxometalates exhibit unique advantages in redox flow batteries,such as,stable chemical properties,multi-electron reaction,good redox reversibility,low permeability,etc,which furnishes a novel perspective for settling various problems of redox flow batteries.This was a comprehensive and critical review of this type of batteries,focusing mainly on the chemistry of polyoxometalate electrolyte materials and introducing a systematic classification.Finally,challenges and perspectives of polyoxometalate electrolyte materials and polyoxometalate redox flow batteries are discussed.展开更多
The potential of polyoxometalate ionic liquid POM-IL supported on low-cost and available eco-friendly Saudi raw bentonite in the adsorption of MB cationic dye was investigated. For this purpose, TOA</span><su...The potential of polyoxometalate ionic liquid POM-IL supported on low-cost and available eco-friendly Saudi raw bentonite in the adsorption of MB cationic dye was investigated. For this purpose, TOA</span><sub><span style="font-family:Verdana;">x</span></sub><span style="font-family:Verdana;">[</span></span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">α</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:""><span style="font-family:Verdana;">-XW</span><sub><span style="font-family:Verdana;">11</span></sub><span style="font-family:Verdana;">O</span><sub><span style="font-family:Verdana;">39</span></sub><span style="font-family:Verdana;">]@Bentonite (X</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">= Si, P;TOA = TetraOctylAmmonium), namely SWB and PWB were prepared and characterized by IR, XRD,</span><span style="font-family:""> </span><span style="font-family:Verdana;">XRF, SEM, TEM and BET. Batch adsorption experiments showed that SWB and PWB have higher adsorption capacity than the raw bentonite with an enhancement of about 37% for SWB. The adsorption capacities of both SWB and PWB improved with increasing contact time and temperature and decreased with higher salt concentration in solution. The pH is shown to have insignificant effect on the adsorption of MB onto SWB and PWB</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> This result is quite meaningful in the adsorption process application since it makes pH complicated adjustment of the discharged contaminated water before treatment unnecessary. The Kinetic study expressed that the pseudo-second-order model described the adsorption process better than the pseudo first order. The experimental isotherm data were found to fit the Langmuir model compared to the Freundlich model with a maximum adsorption capacity 277.78 mg/g and 113.6 for PWB and SWB respectively. The thermodynamic parameters illustrated that the adsorption process was favorable, spontaneous and endothermic.展开更多
In this work,an amino-modified cellulose nanofiber sponge was prepared and used as a support for polyoxometalate(POM)catalysts with a high loading efficiency.Fourier transform infrared spectroscopy,thermogravimetric a...In this work,an amino-modified cellulose nanofiber sponge was prepared and used as a support for polyoxometalate(POM)catalysts with a high loading efficiency.Fourier transform infrared spectroscopy,thermogravimetric analysis,and energy-dispersive X-ray spectroscopy revealed that an Anderson-type POM,(NH4)4[CuMo6O18(OH)6]·5H2O was successfully immobilized on the sponge based on electrostatic interactions.Morphological analysis indicated that the POM-loaded sponge retained its porous structure and that the POM was homogeneously distributed on the sponge walls.The POM-loaded sponge exhibited excellent mechanical properties by recovering 79.9%of its original thickness following a 60%compression strain.The POM-loaded sponge was found to effectively catalyze the hydroboration of phenylacetylenes,yielding excellent conversion and regioselectivity of up to 96%and 99%,respectively.Its catalytic activity remained unchanged after five reuse cycles.These findings represent a scalable strategy for immobilizing POMs on porous supports.展开更多
The design and syntheses of metal-organic cages(MOCs)based on polyoxometalates(POMs)building blocks have attracted increasing attention due to their intriguing molecular architectures and physicochemical properties.In...The design and syntheses of metal-organic cages(MOCs)based on polyoxometalates(POMs)building blocks have attracted increasing attention due to their intriguing molecular architectures and physicochemical properties.In this work,we have successfully synthesized and systematically characterized a tetrahedral polyoxometalate-based organic cage(POC),K_(3)Na_(17)H_(12)[(C_(4)H_(6)O_(6))_(6)[Ni_(4)(OH)_(3)(A-α-SiW_(9)O_(34))]_(4)]·96H_(2)O(Ni_(16)L_(6)(SiW_(9))_(4)),using tritopic Ni_(4)-substituted Keggin cluster(Ni_(4)SiW_(9))as nodes and flexible L-(+)-tartaric acid ligands as linkers.The resulting POC tetrahedron has been firstly investigated as efficient catalyst for visible-light-driven hydrogen production,achieving a turnover number of 15,500 after 96-h photocatalysis.Such high catalytic performance of Ni_(16)L_(6)(SiW_(9))_(4)POC catalyst could be attributed to its unique cage structure,thereby offering more efficient catalytic component accessibility.In addition,spectroscopic analyses illustrated the photocatalytic mechanism and the structural stability of the TBA-Ni_(16)L_(6)(SiW_(9))_(4)catalyst during the photocatalytic process.展开更多
基金financial support from the National Natural Science Foundation of China(No.21871042,21471028,No.21671036,No.21673098,No.21975211)support from the Innovative Research Group Project of NSFC(22021001)+5 种基金the National Key Research and Development Program(2021YFA1502300)Changbai Mountain Scholarship,Natural Science Foundation of Jilin Province(No.20200201083JC)Natural Science Foundation of Department of Education of Jilin Province(No.JJKH20201169KJ)the Fundamental Research Funds for the Central Universities(20720190035)Nanqiang Young Top-notch Talent Fellowship in Xiamen Universitysupported by Open Research Fund of State Key Laboratory of Polymer Physics and Chemistry,Changchun Institute of Applied Chemistry,Chinese Academy of Sciences.
文摘Solid-state electrolytes have attracted considerable attention in new energyrelated devices due to their high safety and broad application platform.Polyoxometalates(POMs)are a kind of molecular-level cluster compounds with unique structures.In recent years,owing to their abundant physicochemical properties(including high ionic conductivity and reversible redox activity),POMs have shown great potential in becoming a new generation of solid-state electrolytes.In this review,an overview is investigated about how POMs have evolved as ion-conducting materials from basic research to novel solid-state electrolytes in energy devices.First,some expressive POM-based ion-conducting materials in recent years are introduced and classified,mainly inspecting their structural and functional relationship.After that,it is further focused on the application of these ionconducting electrolytes in the fields of proton exchange membranes,supercapacitors,and ion batteries.In addition,some properties of POMs(such as inherent dimension,capable of forming stable hydrogen bonds,and reversible bonding to water molecules)enable these functional POM-based electrolytes to be employed in innovative applications such as ion selection,humidity sensing,and smart materials.Finally,some fundamental recommendations are given on the current opportunities and challenges of POM-based ion-conducting electrolytes.
基金financially supported by the National Nature Science Foundation of China (Nos. 21776116, 21576122, 21722604)Postdoctoral Foundation of China (No. 2017M621646)+1 种基金Postdoctoral Foundation of Jiangsu Province (No. 2018K083C)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘With the aim of deep desulfurization, silica-supported polyoxometalate-based ionic liquids were successfully prepared by a one-pot hydrothermal process and employed in heterogeneous oxidative desulfurization of various sulfur compounds. The compositions and structures of the hybrid samples were characterized by various methods such as FT-IR, XPS, Raman,UV–Vis, wide-angle XRD and N_2 adsorption–desorption. The experimental results indicated that the hybrid materials presented a high dispersion of tungsten species and excellent catalytic activity for the removal of 4,6-dimethyldibenzothiophene without any organic solvent as extractant, and the sulfur removal could reach 100.0% under mild conditions.The catalytic performance on various substrates was also investigated in detail. After cycling seven cycles, the sulfur removal of the heterogeneous system still reached 93.0%. The GC-MS analysis results demonstrated that the sulfur compound was first adsorbed by the catalyst and subsequently oxidized to its corresponding sulfone.
基金supported by the National Natural Science Foundation of China(21776077)the Program for Professor of Special Appointment(Eastern Scholar)at Shanghai Institutions of Higher Learning+3 种基金the Shanghai Rising-Star Program(17QA1401200)the Open Project of SKLOCE(SKL-Che-15C03)the Shanghai Natural Science Foundation(17ZR1407300 and 17ZR1407500)the State Key Laboratory of Organic-Inorganic Composites(oic201801007)。
文摘Heterogeneously catalyzed hydrolytic dehydrogenation of ammonia borane is a remarkable structure sensitive reaction. In this work, a strategy by using polyoxometalates(POMs) as the ligands is proposed to engineer the surface and electronic properties of Pt/CNT catalysts toward the enhanced hydrogen generation rate and durability. Three kinds of POMs, i.e., silicotungstic acid(STA), phosphotungstic acid(PTA)and molybdophosphoric acid(PMA), are comparatively studied, among which the STA shows positive effects on the catalytic activity and durability. A catalyst structure-performance relationship is established by a combination of kinetic and isotopic analyses with multiple characterization techniques, such as HAADF-STEM, EDS, Raman spectroscopy and XPS. It is shown that the STA compared to the other two POMs can increase the Pt binding energy and thus promote the reaction. The insights demonstrated here could open a new avenue for boosting the reaction by employing the POMs as the ligands to engineer the catalyst electronic properties.
基金Projects(07/RFP/MASF386,201109019) supported by the Science Foundation Ireland and Ministry of Environmental Protection under the Research Frontiers Program,Ireland
文摘Thin layers of an electrostatically associated adduct RuPVP-AuNP:POM formed between the polyoxomolybdate, [S2 Mo18 O62 ]4, the polycationic metallopolymer [Ru(bpy)2(PVP)10 ](ClO4)2 and DMAP-protected gold nanoparticle have been deposited onto electrodes using two separate methods, alternate immersion layer-by-layer assembly and pre-assembled drop-casting; PVP is poly(4-vinylpyridine), BPY is 2,2'-bipyridyl, and DMAP is 4-dimethylaminopyridine. Significantly, the efficiency of the photocatalysis depends markedly on the structure of the [RuPVP-AuNP:POM] even when photonic properties are very similar. Strikingly, despite their similar photonic properties, an additional optical transition is observed in UV-vis and the Raman spectra of pre-assembled drop cast [RuPVP-AuNP:POM], which was not seen in dip coated [RuPVP-AuNP:POM]. Importantly, this electronic communication enhances the photocatalytic oxidation of benzaldehyde by a factor of more than four. While there is clear evidence for photosensitisation in the drop cast not present for the dip coated systems, the magnitude of the photocurrent, i.e.,(82.2 6.6) nA·cm 2for pre-assembled drop cast [RuPVP-AuNP:POM] at a ruthenium to Au nanoparticle mole ratio of 48:1, is twice as large as that those found in [Ru-PVP:POM] film.
基金Project supported by China Academy of Engineering Physics (6260107025)
文摘A series of photocatalysts, K11[Ln(PW11O39)2]/PVA (Ln=La, Ce, Pr, Nd, Sm) were prepared by K11[Ln(PW11O39)2] (Ln=La, Ce, Pr, Nd, Sm) containing five kinds of lanthanides and polyvinyl alcohol as the support. The catalysts obtained were characterized by Fourier transform infrared spectra, UV-vis spectra, powder X-ray diffraction, and scanning electron microscopy, indicating that the structure of K11[Ln(PW11O39)2] and polyvinyl alcohol remained intact, respectively. The photocatalysts exhibited efficient catalytic activity to degrade methyl orange, Congo Red, Ponceau 2R. The maximal degradation conversions of the three kinds of dyes were 99.58%, 47.61%, 72.42%, respectively.
文摘The synergistic effect of H_3PMo_(12)O_(40) or H_3PW_(12)O_(40) polyoxometalate solution(POM) and TiO_2 to catalyze formic acid oxidation was investigated. Under UV irradiation, hole and electron were photogenerated by TiO_2. Formic acid was oxided by the photogenerated hole and photogenerated electron was transferred to reduce polyoxometalate. With this design, formic acid can be converted into electricity in the fuel cell and hydrogen can be generated in the electrolysis cell without noble metal catalyst. Unlike other noble metal catalysts applied in the fuel cells and electrolysis cell, POM and TiO_2 are stable and low cost. The maximum output power density of liquid formic acid fuel cell after 12 h UV irradiation is 5.21 mW/cm^2 for phosphmolybdic acid and 22.81 m W/cm^2 for phosphotungstic acid respectively. The applied potential for the hydrogen evolution is as low as 0.8 V for phosphmolybdic acid and 0.6 V for phosphotungstic acid.
基金Project supported by Institution of Chemical Materials,China Academy of Engineering Physics
文摘Two novel rare earth tungstosilicic polyoxometalate containing 5-fluorouracil,K26(C4H4FN2O2)8Pr(SiW11O39)4·10H2O(FPSW) and K26(C4H4FN2O2)8Sm(SiW11O39)4·9H2O(FSSW),were synthesized and their structure were characterized by using elemental analysis,FTIR spectra,X-ray powder diffraction and TG.The antitumor activity tests of the compounds FPSW and FSSW were carried out by the methyl thiazolyl tetrazolium method in hepatocellular carcinoma cell HepG-2.The results showed that FPSW and FSSW could inhibit the HepG-2 cells in vitro significantly.The EC50 of FPSW and FSSW is 1.94×10-5 and 1.32×10-5 mol·L-1 respectively.The therapeutic index of FPSW and FSSW is 0.76 and 1.58 respectively.
文摘Polyoxometalates have been explored as multi-electron active species in both aqueous and non-aqueous redox flow batteries. Although non-aqueous systems in principle offer a wider voltage window for redox flow battery operation, realization of this potential requires a judicious choice of solvent as well as polyoxometalate properties. We demonstrate here the superior performance of N,N-dimethylformamide(DMF)compared to acetonitrile as a solvent for redox flow batteries based on Li3PMo12O40. This compound displays two 1-electron transfers in acetonitrile but can access an extra quasi-reversible 2-electron redox process in DMF. A cell containing 10 mM solution of Li3PMo12O40 in DMF produced a cell voltage of 0.7 V with 2-electron transfers(State of Charge = 60%) and showed a good cyclability. As a means to boost energy density, operation of the redox flow battery at a higher concentration of 0.1 M Li3PMo12O40 produced cells with cell voltage of 0.6 V in acetonitrile and a cell voltage of 1.0 V in DMF;both showed excellent coulombic efficiencies of more than 90% over the course of 30 cycles. Energy density was also increased by employing an asymmetric cell with different polyoxometalates on each side to extend cell voltage.Li6P2W18O62 exhibited 3 quasi-reversible 2-electron transfers in the potential range between-2.05 V and-0.5 V vs. Ag/Ag+. 10 mM Li6P2W18O62/Li3PMo12O40 in DMF produced a cell with cell voltage of 1.3 V involving 4-electron transfers(State of Charge = 50%) with coulombic efficiency of nearly 100% and energy efficiency of nearly 70% throughout the test with more than 20 cycles. These promising results demonstrate proof-of-concept approaches to improving the performance of polyoxometalates in non-aqueous redox flow batteries.
基金supported by Beijing Municipal Science and Technology Project(No.Z161100001116080)Cross training plan for high level talents in Beijing colleges and university+5 种基金Major Project of the Ministry of Science and Technology(No.2016YFA0200904,2016YFC0600605)Chinese Academy of Geological Sciences Fundamental Research projects(No.YYWF201619)Comprehensive geological survey of Yunnan Anning Mine Concentration Zone(No.DD20190589)National Natural Science Foundation of China(No.21271068,21401050)the Natural Science Foundation of Hubei Province(No.2015CFA131)Wuhan Applied Basic Research Program(No.2014010101010020)Z.X.,P.W.,P.J.,and M.L.provided the research funding
文摘Iridium(Ir)-based nanomaterials are promising electrocatalysts for water splitting,and to alleviate their costs as well as improve the performances are always important tasks.Polyoxometalates(POMs)composed of abundant metal,oxygen,and heteroatoms are nanoclusters with defined structures.Benefitting from the inherent advantages of POMs,highly dispersive and"unprotected"Ir nanoparticles originating from Ir-based colloid solution were successfully anchored on POM-derived WO_(3)/rGO nanocomposites for the first time.Interestingly,the obtained hybrid material Ir/WO_(x)/rGO delivered improved electrocatalytic performance for water splitting,which is attributed to the addition of only quite small amount of POM derivatives.This work is also the first proof that POM can be employed as precursor to construct metal oxides to support Ir catalysts,providing a new vision for the design of advanced multi-metal electrocatalysts.
基金the Project of Jilin Provincial Department of Education (JJKH20190827KJ)the Outstanding Young Talents Fund Project of Jilin Provincial Department of Science and Technology (20190103117JH) for financially support
文摘A novel heterogeneous catalyst for ultrasound-assisted oxidative desulfurization(UAODS)was designed and synthesized by confining polyoxometalates(POMs)clusters within porous metal-organic gel.The catalyst microstructures were characterized by XRD,SEM-EDX,FT-IR,N_(2)adsorption-desorption,and XPS.Effects of POM loading,catalyst dosage,and ultrasonic power were also investigated.Results indicate that 60%-PMA@MOX(Al)exhibits optimal catalytic activity,with a sulfur removal rate of 98.61%and excellent reusability.Moreover,a kinetic study of different desulfurization approaches demonstrates that the unique thermal and cavitation effects of ultrasound can effectively improve the efficiency of oxidative desulfurization.
基金supported by the National Natural Science Foundation of China(No.21371173,51402298,91545125)the China Postdoctoral Foundation(No.2014M550846)
文摘A highly efficient catalyst of graphene-supported mixed-valent Mn_(16)-containing polyoxometalate is reported here by electrochemical strategy. The modified electrode with the catalyst exhibits an excellent electrocatalytic performance for water oxidation, which will contribute to the development of highly efficient catalysts for oxygen evolution.
文摘In this work, we have developed an electrochemical sensor for nitrite detection, based on a polyoxometalate (POM) namely mono-lacunary keggin anion [SiW11O39]8﹣ cited as (SiW11). Electrochemical characterization of SiW11 shows two-step reduction processes, with formal potentials of ﹣0.5 V (I) and ﹣0.68 V (II). Oppositely charged polyelectrolyte (poly (allylamine hydrochloride) (PAH)) and (SiW11) were assembled alternately to modify glassy carbon electrode. The electrochemical behavior of the modified electrode was studied in detail using cyclic voltammetry (CV). The results showed that SiW11/PAH/GC electrode present good electrocatalytic activity for the reduction of nitrite. The sensor showed a dynamic range from 100 μM to 3.6 mMof nitrite and no interference from other classical anions. Experimental factors that affect electron-transfer rate in these films, such as pH effect and layers number, were systematically analyzed.
文摘Nanocluster polyoxometalates with a structure of buckyball (fullerene) are a promising means of targeted delivery of drugs in the body. In this paper, based on an analysis of histological sections of liver and kidney and peripheral blood, showed a significant reduction of toxicity of buckyballs, containing ions of molybdenum (VI), the substitution of Mo (V) ions to Fe (III), in contrast to buckyballs based on Mo (V). The absence of accumulation of molybdenum in rats with a daily intramuscular injection of aqueous solutions of both drugs within a month was confirmed.
基金supported by the National Natural Science Foundation of China(No.22178012,21722601)China Postdoctoral Science Foundation(No.2019M660389).
文摘Redox flow batteries have received wide attention for electrochemical energy conversion and storage devices due to their specific advantage of uncoupled power and energy devices,and therefore potentially to reduce the capital costs of energy storage.Terrific structural features of polyoxometalates exhibit unique advantages in redox flow batteries,such as,stable chemical properties,multi-electron reaction,good redox reversibility,low permeability,etc,which furnishes a novel perspective for settling various problems of redox flow batteries.This was a comprehensive and critical review of this type of batteries,focusing mainly on the chemistry of polyoxometalate electrolyte materials and introducing a systematic classification.Finally,challenges and perspectives of polyoxometalate electrolyte materials and polyoxometalate redox flow batteries are discussed.
文摘The potential of polyoxometalate ionic liquid POM-IL supported on low-cost and available eco-friendly Saudi raw bentonite in the adsorption of MB cationic dye was investigated. For this purpose, TOA</span><sub><span style="font-family:Verdana;">x</span></sub><span style="font-family:Verdana;">[</span></span><span style="font-family:Verdana;"><i></span><i><span style="font-family:Verdana;">α</span></i><i><span style="font-family:Verdana;"></i></span></i><span style="font-family:""><span style="font-family:Verdana;">-XW</span><sub><span style="font-family:Verdana;">11</span></sub><span style="font-family:Verdana;">O</span><sub><span style="font-family:Verdana;">39</span></sub><span style="font-family:Verdana;">]@Bentonite (X</span></span><span style="font-family:""> </span><span style="font-family:Verdana;">= Si, P;TOA = TetraOctylAmmonium), namely SWB and PWB were prepared and characterized by IR, XRD,</span><span style="font-family:""> </span><span style="font-family:Verdana;">XRF, SEM, TEM and BET. Batch adsorption experiments showed that SWB and PWB have higher adsorption capacity than the raw bentonite with an enhancement of about 37% for SWB. The adsorption capacities of both SWB and PWB improved with increasing contact time and temperature and decreased with higher salt concentration in solution. The pH is shown to have insignificant effect on the adsorption of MB onto SWB and PWB</span><span style="font-family:Verdana;">.</span><span style="font-family:Verdana;"> This result is quite meaningful in the adsorption process application since it makes pH complicated adjustment of the discharged contaminated water before treatment unnecessary. The Kinetic study expressed that the pseudo-second-order model described the adsorption process better than the pseudo first order. The experimental isotherm data were found to fit the Langmuir model compared to the Freundlich model with a maximum adsorption capacity 277.78 mg/g and 113.6 for PWB and SWB respectively. The thermodynamic parameters illustrated that the adsorption process was favorable, spontaneous and endothermic.
基金financially supported by the Fundamental Research Funds for the Central Universities(No.2232018A3-04,No.2232018-02,and No.2232018G-043)the Program of Introducing Talents of Discipline to Universities(No.105-07-005735)
文摘In this work,an amino-modified cellulose nanofiber sponge was prepared and used as a support for polyoxometalate(POM)catalysts with a high loading efficiency.Fourier transform infrared spectroscopy,thermogravimetric analysis,and energy-dispersive X-ray spectroscopy revealed that an Anderson-type POM,(NH4)4[CuMo6O18(OH)6]·5H2O was successfully immobilized on the sponge based on electrostatic interactions.Morphological analysis indicated that the POM-loaded sponge retained its porous structure and that the POM was homogeneously distributed on the sponge walls.The POM-loaded sponge exhibited excellent mechanical properties by recovering 79.9%of its original thickness following a 60%compression strain.The POM-loaded sponge was found to effectively catalyze the hydroboration of phenylacetylenes,yielding excellent conversion and regioselectivity of up to 96%and 99%,respectively.Its catalytic activity remained unchanged after five reuse cycles.These findings represent a scalable strategy for immobilizing POMs on porous supports.
基金financially supported by the National Natural Science Foundation of China(Nos.21871025 and 21831001)the Recruitment Program of Global Experts(Young Talents)BIT Excellent Young Scholars Research Fund。
文摘The design and syntheses of metal-organic cages(MOCs)based on polyoxometalates(POMs)building blocks have attracted increasing attention due to their intriguing molecular architectures and physicochemical properties.In this work,we have successfully synthesized and systematically characterized a tetrahedral polyoxometalate-based organic cage(POC),K_(3)Na_(17)H_(12)[(C_(4)H_(6)O_(6))_(6)[Ni_(4)(OH)_(3)(A-α-SiW_(9)O_(34))]_(4)]·96H_(2)O(Ni_(16)L_(6)(SiW_(9))_(4)),using tritopic Ni_(4)-substituted Keggin cluster(Ni_(4)SiW_(9))as nodes and flexible L-(+)-tartaric acid ligands as linkers.The resulting POC tetrahedron has been firstly investigated as efficient catalyst for visible-light-driven hydrogen production,achieving a turnover number of 15,500 after 96-h photocatalysis.Such high catalytic performance of Ni_(16)L_(6)(SiW_(9))_(4)POC catalyst could be attributed to its unique cage structure,thereby offering more efficient catalytic component accessibility.In addition,spectroscopic analyses illustrated the photocatalytic mechanism and the structural stability of the TBA-Ni_(16)L_(6)(SiW_(9))_(4)catalyst during the photocatalytic process.