Citrate, oxalate, tartrate and malate were added into soils during the growthperiod of ryegrass to study the effect of different organic ligands on the release of variousinorganic P (Pi) fractions in a yellow-brown so...Citrate, oxalate, tartrate and malate were added into soils during the growthperiod of ryegrass to study the effect of different organic ligands on the release of variousinorganic P (Pi) fractions in a yellow-brown soil and a paddy soil. The results showed that oxalatewas most effective in promoting the release of total Pi in the yellow-brown soil and tartrate in thepaddy soil. The dominant Pi fractions released from the yellow-brown soil were calcium phosphate(Ca-P) and aluminum phosphate (Al-P) and those from the paddy soil were iron phosphate (Fe-P) andreductant soluble phosphate (O-P) mobilized by tartrate. Phosphorous-mobilizing capability oforganic acids in the yellow-brown soil revealed the following order: oxalate > citrate > malate >tartrate. In the paddy soil, the order was tartrate > citrate ≈ oxalate > malate. It wasdemonstrated that organic ligands were different in their capabilities of mobilizing Pi and the sameorganic ligand showed also a discrepancy in mobilizing P in different soils. Although the additionof organic ligands into soils could increase the amount of P taken up by ryegrass, the more uptakeof P, however, was not only due to the more release of Pi, but also partly from organic P. In manycases, organic ligands promoted the release of the total Pi, while different fractions showeddifferent trends: some increased and others decreased.展开更多
During the last two decades,porous coordination polymers(PCPs),usually called as metal-organic frameworks(MOFs),have been developed rapidly due to their versatile structural diversities and potential physical and chem...During the last two decades,porous coordination polymers(PCPs),usually called as metal-organic frameworks(MOFs),have been developed rapidly due to their versatile structural diversities and potential physical and chemical functions.This article provides a short review of recent advances in the design and constructions of porous coordination polymers based on three planar rigid ligands,including imidazole-4,5-dicarboxlate(H3IDC),1H-tetrazole(HTz),as well as 1H-tetrazole-5-carboxylate(H2Tzc).Their preparations,crystal structures,and desirable properties have been reviewed.展开更多
All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years,such as light-emitting diodes,photodetectors and solar cells,owing to their sup...All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years,such as light-emitting diodes,photodetectors and solar cells,owing to their superb optoelectronic properties.Still,the stability issue of nanocrystals is a bottleneck for their practical application.Herein,we report a facile method for the synthesis of a series of phosphine ligand modified CsPbBr3 QDs with high PL intensity.By introducing organic phosphine ligands,the tolerance of CsPbBr3 QDs to ethanol,water and UV light was dramatically improved.Moreover,the phosphine ligand modified QD films deposited on the glass subtracts exhibit superior PL intensity and optical stability to those of pristine QD based films.展开更多
The sluggish kinetics of the oxygen reduction reaction(ORR)is the bottleneck for various electrochemical energy conversion devices.Regulating the electronic structure of electrocatalysts by ligands has received partic...The sluggish kinetics of the oxygen reduction reaction(ORR)is the bottleneck for various electrochemical energy conversion devices.Regulating the electronic structure of electrocatalysts by ligands has received particular attention in deriving valid ORR electrocatalysts.Here,the surface electronic structure of Ptbased noble metal aerogels(NMAs)was modulated by various organic ligands,among which the electron-withdrawing ligand of 4-methylphenylene effectively boosted the ORR electrocatalysis.Theoretical calculations suggested the smaller energy barrier for the transformation of O^(*) to OH^(*) and downshift the d-band center of Pt due to the interaction between 4-methylphenylene and the surface metals,thus enhancing the ORR intrinsic activity.Both Pt3Ni and Pt Pd aerogels with 4-methylphenylene decoration performed significant enhancement in ORR activity and durability in different media.Remarkably,the 4-methylphenylene modified Pt Pd aerogel exhibited the higher halfwave potential of 0.952 V and the mass activity of 10.2 times of commercial Pt/C.This work explained the effect of electronic structure on ORR electrocatalytic properties and would promote functionalized NMAs as efficient ORR electrocatalysts.展开更多
Heavy metal contaminated water sources pose serious health risks for humans,animals,and plants.Exposure to and ingestion of heavy metals have been associated to liver,kidney,and brain function.Objective:The aim of thi...Heavy metal contaminated water sources pose serious health risks for humans,animals,and plants.Exposure to and ingestion of heavy metals have been associated to liver,kidney,and brain function.Objective:The aim of this research is to comparatively examine the metal removal efficacy of three solid bidentate chemicals and four plant materials.Study Design&Methods:Standard solutions of zinc(II)and lead(II)ions with concentrations of 1,000 ppm were respectively treated with OA(Oxalic Acid),dibasic bidentate ligands(sodium hydrogen phosphate and sodium carbonate).Then,the solutions were placed on a shaker for 15 h,centrifuged,and the supernatant was analyzed using ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry).Results:All the solid bidentate adsorbents were very effective in removing zinc and lead(>90%).However,more lead than zinc was removed across all adsorbents except for lemon where equal percent of zinc and lead(49%)were removed.OA and Na2HPO4 removed about equal amount of lead(>99%).The plant materials(SP(Spinach),bell pepper and GBP(Green Bell Pepper)),respectively and preferentially removed more lead(98.9%,98.3%,81.5%)than zinc(91.7%,46%,46%).Conclusion:Although plant materials have gained attraction for the remediation of heavy metal,however,some bidentate chemical ligands such as OA,sodium carbonate and sodium hydrogen phosphates are even more effective in removing these metals from contaminated water.Furthermore,heavier metals are preferentially removed than lighter metals.展开更多
Two kinds of Eu-complexes, Eu（TTA）2（Phen）（AA） and Eu（TTA）2（Phen）（MA） （HTTA=2-Thenoyltrifluoroacetone, Phen=1,10- phenanthroline, AA=acrylic acid, MA=Maleic anhydride）, which combined the excellent fluore...Two kinds of Eu-complexes, Eu（TTA）2（Phen）（AA） and Eu（TTA）2（Phen）（MA） （HTTA=2-Thenoyltrifluoroacetone, Phen=1,10- phenanthroline, AA=acrylic acid, MA=Maleic anhydride）, which combined the excellent fluorescence properties of Eu（TTA）2（Phen）（H2O） and the reactivity of acrylic acid and maleic anhydride with radicals, were synthesized. The two complexes were characterized by elemental analysis, infrared （IR） spectra, and X-ray photoelectron spectroscopy （XPS）. Based on the data shown from the fluorescent spectra of the Eu-MA and Eu-AA complexes, the Ωλ （λ=2 and 4） experimental intensity parameters were calculated. The results demonstrated that the Ω2 intensity parameters for the two complexes were smaller than those for the Eu（TTA）2（Phen）（H2O） complex, indicating that a less symmetrical chemical environment existed in the complexes. It implied that the radiative efficiency of the ^5D0 of these two complexes could be enhanced by ligand of MA and AA, respectively. The luminescent lifetime of the Eu-AA （r=-7.26×10^-4 s） or Eu-MA complex （r=-8.12×10^-4 s） was higher than that of the Eu（TTA）2（Phen）（H2O） complex, which was attributed to the substitution of the water molecule （H2O） in Eu（TTA）2（Phen）（H2O） by the MA or AA ligand.展开更多
Deep-level defects and random oriented configuration in perovskite crystallization process would cause the nonradiative recombination and further affect the performance of perovskite solar cells(PSCs).Herein,two metal...Deep-level defects and random oriented configuration in perovskite crystallization process would cause the nonradiative recombination and further affect the performance of perovskite solar cells(PSCs).Herein,two metal-organic frameworks(MOFs)with tunable Lewis-base passivation sites have been constructed(Cd-Httb and Cd-Httb-BDC,Httb=5-(4-(1H-1,2,4-triazole-1-yl)benzyl)-1h-tetrazole,BDC=1,4-dicarboxybenzene)to eliminate deep-level defects and simultaneously as nanostructured heterogeneous nucleation seed to assist the growth of large-grained perovskite films.Compared with the control and Cd-Httb,Cd-Httb-BDC designed with mix-ligands strategy exhibited the enhanced inducted effect on the crystallization and nucleation of high-quality perovskite films during annealing process.Consequently,the resultant Cd-Httb-BDC-modified device achieved higher power conversion efficiency(PCE)(22.18%)than the control(20.89%)and Cd-Httb(21.56%).Meanwhile,the unencapsulated Cd-Httb-BDC-modified device still maintained 90%of initial PCE after 1500 h in ambient conditions and exhibited enhanced thermal stability(85℃ in N_(2) atmosphere).This work presented a successful example of mixligands strategy on construction of high-quality MOF-assisted perovskite films for high-efficient and stable PSCs.展开更多
While common in biological systems,building blocks with low symmetry and flexibility pose numerous problems for synthetic self-assembly,such as the formation of isomers of assemblies that are difficult to distinguish ...While common in biological systems,building blocks with low symmetry and flexibility pose numerous problems for synthetic self-assembly,such as the formation of isomers of assemblies that are difficult to distinguish and purify.In this work,three aromatic amide-based ligands(L1–L3)with a central 1,8-diazatriptycene core were designed and used for selfassembly with Pd^(2+).While hundreds of stereoisomers based on the conformational flexibility around the amides and the unsymmetrical nonplanar structure of the core are possible upon coordination with the metal,the constraints designed into the ligands direct the self-assembly toward only a single Pd_(2)L_(4)cage(L1)or Pd_(4)L_(8)double-walled metallomacrocycle(L2)structure,even in mixtures of the ligands.This structural approach and the modularity of the ligand synthesis affords ready access to deep cavitands with endohedral functionalization(L3).These results highlight the potential of this new design strategy and open the door to selectively functionalized cavity-based architectures for numerous applications.展开更多
基金Project supported by the National Key Basic Research Support Foundation (NKBRSF) of China (No.G1999011806).
文摘Citrate, oxalate, tartrate and malate were added into soils during the growthperiod of ryegrass to study the effect of different organic ligands on the release of variousinorganic P (Pi) fractions in a yellow-brown soil and a paddy soil. The results showed that oxalatewas most effective in promoting the release of total Pi in the yellow-brown soil and tartrate in thepaddy soil. The dominant Pi fractions released from the yellow-brown soil were calcium phosphate(Ca-P) and aluminum phosphate (Al-P) and those from the paddy soil were iron phosphate (Fe-P) andreductant soluble phosphate (O-P) mobilized by tartrate. Phosphorous-mobilizing capability oforganic acids in the yellow-brown soil revealed the following order: oxalate > citrate > malate >tartrate. In the paddy soil, the order was tartrate > citrate ≈ oxalate > malate. It wasdemonstrated that organic ligands were different in their capabilities of mobilizing Pi and the sameorganic ligand showed also a discrepancy in mobilizing P in different soils. Although the additionof organic ligands into soils could increase the amount of P taken up by ryegrass, the more uptakeof P, however, was not only due to the more release of Pi, but also partly from organic P. In manycases, organic ligands promoted the release of the total Pi, while different fractions showeddifferent trends: some increased and others decreased.
文摘During the last two decades,porous coordination polymers(PCPs),usually called as metal-organic frameworks(MOFs),have been developed rapidly due to their versatile structural diversities and potential physical and chemical functions.This article provides a short review of recent advances in the design and constructions of porous coordination polymers based on three planar rigid ligands,including imidazole-4,5-dicarboxlate(H3IDC),1H-tetrazole(HTz),as well as 1H-tetrazole-5-carboxylate(H2Tzc).Their preparations,crystal structures,and desirable properties have been reviewed.
基金National Natural Science Foundation of China (No. 21771063)State Key Research Development Program of China (No. 2016YFA0204200)Fundamental Research Funds for the Central Universities in China (Nos. WJ1714046 and 222201717003).
文摘All-inorganic cesium lead halide perovskite quantum dots (QDs) have been a promising candidate for optoelectronic devices in recent years,such as light-emitting diodes,photodetectors and solar cells,owing to their superb optoelectronic properties.Still,the stability issue of nanocrystals is a bottleneck for their practical application.Herein,we report a facile method for the synthesis of a series of phosphine ligand modified CsPbBr3 QDs with high PL intensity.By introducing organic phosphine ligands,the tolerance of CsPbBr3 QDs to ethanol,water and UV light was dramatically improved.Moreover,the phosphine ligand modified QD films deposited on the glass subtracts exhibit superior PL intensity and optical stability to those of pristine QD based films.
基金supported by the National Natural Science Foundation of China(22374119,21902128)the China Postdoctoral Science Foundation(2021M692620)+1 种基金the Research Fund of the State Key Laboratory of Solidification Processing(NPU),China(2021-QZ-01)the Key Project of Natural Science Fund of Shaanxi Province(2023-JC-ZD-06)。
文摘The sluggish kinetics of the oxygen reduction reaction(ORR)is the bottleneck for various electrochemical energy conversion devices.Regulating the electronic structure of electrocatalysts by ligands has received particular attention in deriving valid ORR electrocatalysts.Here,the surface electronic structure of Ptbased noble metal aerogels(NMAs)was modulated by various organic ligands,among which the electron-withdrawing ligand of 4-methylphenylene effectively boosted the ORR electrocatalysis.Theoretical calculations suggested the smaller energy barrier for the transformation of O^(*) to OH^(*) and downshift the d-band center of Pt due to the interaction between 4-methylphenylene and the surface metals,thus enhancing the ORR intrinsic activity.Both Pt3Ni and Pt Pd aerogels with 4-methylphenylene decoration performed significant enhancement in ORR activity and durability in different media.Remarkably,the 4-methylphenylene modified Pt Pd aerogel exhibited the higher halfwave potential of 0.952 V and the mass activity of 10.2 times of commercial Pt/C.This work explained the effect of electronic structure on ORR electrocatalytic properties and would promote functionalized NMAs as efficient ORR electrocatalysts.
文摘Heavy metal contaminated water sources pose serious health risks for humans,animals,and plants.Exposure to and ingestion of heavy metals have been associated to liver,kidney,and brain function.Objective:The aim of this research is to comparatively examine the metal removal efficacy of three solid bidentate chemicals and four plant materials.Study Design&Methods:Standard solutions of zinc(II)and lead(II)ions with concentrations of 1,000 ppm were respectively treated with OA(Oxalic Acid),dibasic bidentate ligands(sodium hydrogen phosphate and sodium carbonate).Then,the solutions were placed on a shaker for 15 h,centrifuged,and the supernatant was analyzed using ICP-AES(Inductively Coupled Plasma-Atomic Emission Spectrometry).Results:All the solid bidentate adsorbents were very effective in removing zinc and lead(>90%).However,more lead than zinc was removed across all adsorbents except for lemon where equal percent of zinc and lead(49%)were removed.OA and Na2HPO4 removed about equal amount of lead(>99%).The plant materials(SP(Spinach),bell pepper and GBP(Green Bell Pepper)),respectively and preferentially removed more lead(98.9%,98.3%,81.5%)than zinc(91.7%,46%,46%).Conclusion:Although plant materials have gained attraction for the remediation of heavy metal,however,some bidentate chemical ligands such as OA,sodium carbonate and sodium hydrogen phosphates are even more effective in removing these metals from contaminated water.Furthermore,heavier metals are preferentially removed than lighter metals.
基金supported by the National Natural Science Foundation of China, China Energy Conservation Investment Corporation (50173004 and 50503002)Beijing New Star Project (2003A11)+3 种基金the National High-Tech Research Developing Foundation (863) (2003AA324030)Beijing Municipal Commission of Education (JD100100403)National Key Project of Scientific, Technical Supporting Programs Funded by the Ministry of Science & Technology of China (2006BAE03B)Program for New Century Excellent Talentsin University (NCET)
文摘Two kinds of Eu-complexes, Eu（TTA）2（Phen）（AA） and Eu（TTA）2（Phen）（MA） （HTTA=2-Thenoyltrifluoroacetone, Phen=1,10- phenanthroline, AA=acrylic acid, MA=Maleic anhydride）, which combined the excellent fluorescence properties of Eu（TTA）2（Phen）（H2O） and the reactivity of acrylic acid and maleic anhydride with radicals, were synthesized. The two complexes were characterized by elemental analysis, infrared （IR） spectra, and X-ray photoelectron spectroscopy （XPS）. Based on the data shown from the fluorescent spectra of the Eu-MA and Eu-AA complexes, the Ωλ （λ=2 and 4） experimental intensity parameters were calculated. The results demonstrated that the Ω2 intensity parameters for the two complexes were smaller than those for the Eu（TTA）2（Phen）（H2O） complex, indicating that a less symmetrical chemical environment existed in the complexes. It implied that the radiative efficiency of the ^5D0 of these two complexes could be enhanced by ligand of MA and AA, respectively. The luminescent lifetime of the Eu-AA （r=-7.26×10^-4 s） or Eu-MA complex （r=-8.12×10^-4 s） was higher than that of the Eu（TTA）2（Phen）（H2O） complex, which was attributed to the substitution of the water molecule （H2O） in Eu（TTA）2（Phen）（H2O） by the MA or AA ligand.
基金supported by the National Natural Science Foundation of China(22072034,22001050,and 21873025)the China Postdoctoral Science Foundation(2020T130147,2020M681084,and 2022M710949)+1 种基金the Postdoctoral Foundation of Heilongjiang Province(LBH-Z19059)the Natural Science Foundation of Heilongjiang Youth Fund(YQ2021B002).
文摘Deep-level defects and random oriented configuration in perovskite crystallization process would cause the nonradiative recombination and further affect the performance of perovskite solar cells(PSCs).Herein,two metal-organic frameworks(MOFs)with tunable Lewis-base passivation sites have been constructed(Cd-Httb and Cd-Httb-BDC,Httb=5-(4-(1H-1,2,4-triazole-1-yl)benzyl)-1h-tetrazole,BDC=1,4-dicarboxybenzene)to eliminate deep-level defects and simultaneously as nanostructured heterogeneous nucleation seed to assist the growth of large-grained perovskite films.Compared with the control and Cd-Httb,Cd-Httb-BDC designed with mix-ligands strategy exhibited the enhanced inducted effect on the crystallization and nucleation of high-quality perovskite films during annealing process.Consequently,the resultant Cd-Httb-BDC-modified device achieved higher power conversion efficiency(PCE)(22.18%)than the control(20.89%)and Cd-Httb(21.56%).Meanwhile,the unencapsulated Cd-Httb-BDC-modified device still maintained 90%of initial PCE after 1500 h in ambient conditions and exhibited enhanced thermal stability(85℃ in N_(2) atmosphere).This work presented a successful example of mixligands strategy on construction of high-quality MOF-assisted perovskite films for high-efficient and stable PSCs.
基金supported in part through the Concerted Research Action(ARC16/21-074)and the China Scholarship Council(pre-doctoral fellowships for C.-L.L.).
文摘While common in biological systems,building blocks with low symmetry and flexibility pose numerous problems for synthetic self-assembly,such as the formation of isomers of assemblies that are difficult to distinguish and purify.In this work,three aromatic amide-based ligands(L1–L3)with a central 1,8-diazatriptycene core were designed and used for selfassembly with Pd^(2+).While hundreds of stereoisomers based on the conformational flexibility around the amides and the unsymmetrical nonplanar structure of the core are possible upon coordination with the metal,the constraints designed into the ligands direct the self-assembly toward only a single Pd_(2)L_(4)cage(L1)or Pd_(4)L_(8)double-walled metallomacrocycle(L2)structure,even in mixtures of the ligands.This structural approach and the modularity of the ligand synthesis affords ready access to deep cavitands with endohedral functionalization(L3).These results highlight the potential of this new design strategy and open the door to selectively functionalized cavity-based architectures for numerous applications.
