Metal organic frameworks(MOFs)is a research hotspot in the solar fuel production and photo-degradation of pollutants field due to high surface area,rich metal/organic species,large pore volume,and adjustability of str...Metal organic frameworks(MOFs)is a research hotspot in the solar fuel production and photo-degradation of pollutants field due to high surface area,rich metal/organic species,large pore volume,and adjustability of structures and compositions.Therefore,in this review,we first summarized the design factors of photocatalytic materials based on MOF from the perspective of"star"MOF.The modification strategies of MOFs-based photocatalysts were discussed to improve its photocatalytic activity and specific applications were summarized as well,including photocatalytic CO_(2)reduction,photocatalytic water splitting and photo-degradation of pollutants.Finally,the advantages and disadvantages of MOFs-based photocatalysts were discussed,the current challenges were highlighted,and suggestions for future research directions were proposed.展开更多
The characteristics of electric charge and molecular weight distribution,oxidation-reduction regimes,e.g.Eh and amounts of organic reducing substances produced by milk vetch during anaerobic decomposition process,were...The characteristics of electric charge and molecular weight distribution,oxidation-reduction regimes,e.g.Eh and amounts of organic reducing substances produced by milk vetch during anaerobic decomposition process,were studied by using electrochemical methods.Interaction between soils and organic reducing substances was also observed.The results indicate that the organic reducing substances were mainly the organic compounds with negative and amphoteric charges,which were distributed in two groups at anodic peak potentials of 0.25 and 0.69 volt in differential pulse voltammograms,respectively.Their apparent molecular weights are all less than 700 daltons,in which those active in oxidation-reducion reaction were distributed in the fraction with apparent molecular weight less than 200 daltons.The organic reduction substances can be oxidized by manganese oxides in their interaction with soils.展开更多
Some electrochemical properties,such as PH,Eh,and voltammetric behavior,of the decomposition products of rice straw and the in eractions of these products with soils were studied.The PH,Eh,and amounts of organic reduc...Some electrochemical properties,such as PH,Eh,and voltammetric behavior,of the decomposition products of rice straw and the in eractions of these products with soils were studied.The PH,Eh,and amounts of organic reducing substances changed markedly during the 60-day anaerobic decomposition.pH decreased sharply to pH 5 on the tenth day and then increased gradually to 7 on the 45th day.The amouats of organic reducing substances increased almost synchronously with the fall of redox potential during the first 15 days.The differential pulse voltammetric(dpv) behavior changed not only in the peak current but also in the peak potential.The fractions with apparent molecular weights lower than 200 dations appeared to be active in dpv behavior.The electric charge of organic reducing substances was closely related to the decomposition stage.The 6th day of incubation was the crucial time before and after which the major part of the components was negatively charged and positively charged, respectively.The group with a low apparent molecular weight and a negative charge was the main components responsible for the lower anodic peak potentials.They were oxidized first during the interactions of the organic reducing substances with soils.展开更多
Photoelectrocatalysis(PEC)is a promising approach that can convert renewable solar energy into chemical energy,while most concern is concentrated on PEC water splitting to obtain high‐value‐added fuel—hydrogen.In p...Photoelectrocatalysis(PEC)is a promising approach that can convert renewable solar energy into chemical energy,while most concern is concentrated on PEC water splitting to obtain high‐value‐added fuel—hydrogen.In practice,more economic benefits can be produced based on PEC technique,such as H_(2)O oxidative H_(2)O_(2) synthesis,organic selective oxidation,organic pollutants degradation and CO_(2) reduction.Although there are plenty of excellent reviews focusing on the PEC water splitting system,the production of various high‐value‐added chemicals in PEC systems has not been discussed synthetically.This Account will focus on the production process of various high‐value‐added chemicals through PEC technology.The photoelectrode design,reaction environment and working mechanisms of PEC systems are also discussed in detail.We believe that this comprehensive Account of the expanded application of photoelectrocatalysis can add an inestimable impetus to the follow‐up development of this technology.展开更多
A general method is developed to prepare durable hybrid nanocatalysts by nanostructuring the surface of gold wires via simple alloying and dealloying. The resulting nanoporous gold/Au （NPG/Au） wire catalysts possess...A general method is developed to prepare durable hybrid nanocatalysts by nanostructuring the surface of gold wires via simple alloying and dealloying. The resulting nanoporous gold/Au （NPG/Au） wire catalysts possess nanoporous skins with their thicknesses on robust metal wires specified in a highly controllable manner. As a demonstration, the as-obtained NPG/Au was shown to be a highly active, chemo-selective, and recyclable catalyst for the reduction of nitro com- pounds and azides using organosilanes as reducing agents.展开更多
The design and preparation of non-precious metal and carbon-based nanocomposites are critical to the development of efficient catalysts for technologies ranging from water splitting to fuel cell. Here, we present a co...The design and preparation of non-precious metal and carbon-based nanocomposites are critical to the development of efficient catalysts for technologies ranging from water splitting to fuel cell. Here, we present a constrained-volume self-assembly process for the one-step continuous precipitation-induced formation of soft colloidal particles, in which hydrophobic organoferrous compound,（Ph3P）2Fe（CO）3, is encapsulated within poly（styrene-co-acrylonitrile） nanoparticles（NPs）. The protective and confining polymer matrix ensures uniform carbonization and dispersion of（Ph3P）2Fe（CO）3 within a carbon matrix after a pyrolysis process. The obtained carbon NPs are successfully co-doped with Fe, P and N with a relatively high surface area of-380 m^2 g^（-1）. The Fe-P-N-doped carbon catalyst exhibits high catalytic performance and stability toward oxygen reduction reaction in both alkaline and acidic electrolytes via a favorable four-electron pathway. Meanwhile, the catalytic capability of Fe-P-N-doped carbon can be tailored by the tunable nanostructures.展开更多
Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures c...Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures can be well applied in optoelectronics.To achieve high optoelectronic performance,usually the design and synthesis of CTFs based on appropriate building blocks is critical.Here we report the synthesis of two fluorescent CTFs based on typical fluorescent building blocks,in which CTF-Py constructed from a pyrene(Py)building block was reported for the first time,showing prospective applications in the sensing of nitroaromatics with high sensitivity,and photocatalytic water splitting and carbon dioxide reduction with high performance in comparison with other porous organic materials.展开更多
Quantum dots sensitized nanocrystalline Tit2 solar cells （QDSSCs） are promising third-generation pbotovoltalc devices. In comparison with conventional dye-sensitized solar cells （DSSCs）, the efficiency of QDSSCs i...Quantum dots sensitized nanocrystalline Tit2 solar cells （QDSSCs） are promising third-generation pbotovoltalc devices. In comparison with conventional dye-sensitized solar cells （DSSCs）, the efficiency of QDSSCs is still very low （about 3%）. In this paper, the electrochemical impedance spectroscopy technology has been adopted to investigate the quasi-Fermi level and the cartier dynamics of the colloidal CdSe QDs sensitized Tit2 eletrode with S2-/Sf redox electrolytes and the series resistance of the QDSSCs. In comparison with the conventional DSSCs with I^-3/Г as redox electrolytes, the energy difference between the conduction band edge and the quasi-Fermi levels of the Tit2 films （or the Fermi levels of the redox electrolytes） in QDSSCs has been decreased by about 0.3 V, resulting in the decrease of Voc by this value. The increases of the electrolyte dif- fussion resistance and the charge transfer resistance between Pt counter electrodes and S2-/Sx redox electrolytes were attributed to the decrease of the fill factors. However, the electron lifetime and electron diffussion length for QDSSCs are longer than those for DSSCs due to the retardation of the electron recombination by the adsorbed cysteine at the surfaces of the TiO2 films. It is indicated that electron recombination at the TiO2/electrolyte interface is not the main reason for the lower Jsc of the colloidal QDs sensitized QDSSCs. Improving light harvesting efficiency and photoelectron injection efficiency should be considered in the future for such kind of QDSSCs.展开更多
文摘Metal organic frameworks(MOFs)is a research hotspot in the solar fuel production and photo-degradation of pollutants field due to high surface area,rich metal/organic species,large pore volume,and adjustability of structures and compositions.Therefore,in this review,we first summarized the design factors of photocatalytic materials based on MOF from the perspective of"star"MOF.The modification strategies of MOFs-based photocatalysts were discussed to improve its photocatalytic activity and specific applications were summarized as well,including photocatalytic CO_(2)reduction,photocatalytic water splitting and photo-degradation of pollutants.Finally,the advantages and disadvantages of MOFs-based photocatalysts were discussed,the current challenges were highlighted,and suggestions for future research directions were proposed.
文摘The characteristics of electric charge and molecular weight distribution,oxidation-reduction regimes,e.g.Eh and amounts of organic reducing substances produced by milk vetch during anaerobic decomposition process,were studied by using electrochemical methods.Interaction between soils and organic reducing substances was also observed.The results indicate that the organic reducing substances were mainly the organic compounds with negative and amphoteric charges,which were distributed in two groups at anodic peak potentials of 0.25 and 0.69 volt in differential pulse voltammograms,respectively.Their apparent molecular weights are all less than 700 daltons,in which those active in oxidation-reducion reaction were distributed in the fraction with apparent molecular weight less than 200 daltons.The organic reduction substances can be oxidized by manganese oxides in their interaction with soils.
文摘Some electrochemical properties,such as PH,Eh,and voltammetric behavior,of the decomposition products of rice straw and the in eractions of these products with soils were studied.The PH,Eh,and amounts of organic reducing substances changed markedly during the 60-day anaerobic decomposition.pH decreased sharply to pH 5 on the tenth day and then increased gradually to 7 on the 45th day.The amouats of organic reducing substances increased almost synchronously with the fall of redox potential during the first 15 days.The differential pulse voltammetric(dpv) behavior changed not only in the peak current but also in the peak potential.The fractions with apparent molecular weights lower than 200 dations appeared to be active in dpv behavior.The electric charge of organic reducing substances was closely related to the decomposition stage.The 6th day of incubation was the crucial time before and after which the major part of the components was negatively charged and positively charged, respectively.The group with a low apparent molecular weight and a negative charge was the main components responsible for the lower anodic peak potentials.They were oxidized first during the interactions of the organic reducing substances with soils.
文摘Photoelectrocatalysis(PEC)is a promising approach that can convert renewable solar energy into chemical energy,while most concern is concentrated on PEC water splitting to obtain high‐value‐added fuel—hydrogen.In practice,more economic benefits can be produced based on PEC technique,such as H_(2)O oxidative H_(2)O_(2) synthesis,organic selective oxidation,organic pollutants degradation and CO_(2) reduction.Although there are plenty of excellent reviews focusing on the PEC water splitting system,the production of various high‐value‐added chemicals in PEC systems has not been discussed synthetically.This Account will focus on the production process of various high‐value‐added chemicals through PEC technology.The photoelectrode design,reaction environment and working mechanisms of PEC systems are also discussed in detail.We believe that this comprehensive Account of the expanded application of photoelectrocatalysis can add an inestimable impetus to the follow‐up development of this technology.
文摘A general method is developed to prepare durable hybrid nanocatalysts by nanostructuring the surface of gold wires via simple alloying and dealloying. The resulting nanoporous gold/Au （NPG/Au） wire catalysts possess nanoporous skins with their thicknesses on robust metal wires specified in a highly controllable manner. As a demonstration, the as-obtained NPG/Au was shown to be a highly active, chemo-selective, and recyclable catalyst for the reduction of nitro com- pounds and azides using organosilanes as reducing agents.
基金supported by the National Natural Science Foundation of China (21774095)Shanghai Municipal Natural Science Foundation (17ZR1432200)+2 种基金the Fundamental Research Funds for the Central Universities (0400219376)the start-up funding from Tongji Universitythe Young Thousand Talented Program
文摘The design and preparation of non-precious metal and carbon-based nanocomposites are critical to the development of efficient catalysts for technologies ranging from water splitting to fuel cell. Here, we present a constrained-volume self-assembly process for the one-step continuous precipitation-induced formation of soft colloidal particles, in which hydrophobic organoferrous compound,（Ph3P）2Fe（CO）3, is encapsulated within poly（styrene-co-acrylonitrile） nanoparticles（NPs）. The protective and confining polymer matrix ensures uniform carbonization and dispersion of（Ph3P）2Fe（CO）3 within a carbon matrix after a pyrolysis process. The obtained carbon NPs are successfully co-doped with Fe, P and N with a relatively high surface area of-380 m^2 g^（-1）. The Fe-P-N-doped carbon catalyst exhibits high catalytic performance and stability toward oxygen reduction reaction in both alkaline and acidic electrolytes via a favorable four-electron pathway. Meanwhile, the catalytic capability of Fe-P-N-doped carbon can be tailored by the tunable nanostructures.
基金supported by the National Natural Science Foundation of China(21875078 and 21975146)。
文摘Porous organic polymers(POPs)are an emerging class of porous materials,having many promising applications in a variety of areas.Among them,covalent triazine frameworks(CTFs)featuring conjugated and porous structures can be well applied in optoelectronics.To achieve high optoelectronic performance,usually the design and synthesis of CTFs based on appropriate building blocks is critical.Here we report the synthesis of two fluorescent CTFs based on typical fluorescent building blocks,in which CTF-Py constructed from a pyrene(Py)building block was reported for the first time,showing prospective applications in the sensing of nitroaromatics with high sensitivity,and photocatalytic water splitting and carbon dioxide reduction with high performance in comparison with other porous organic materials.
基金supported by the Study Abroad Project of Chinese Academy of Sciences in 2007Foundation of Renewable Energy, Gas Hydrate Key Laboratory of Chinese Academy of Sciences in 2007the National Natural Science Foundation of China (21073193)
文摘Quantum dots sensitized nanocrystalline Tit2 solar cells （QDSSCs） are promising third-generation pbotovoltalc devices. In comparison with conventional dye-sensitized solar cells （DSSCs）, the efficiency of QDSSCs is still very low （about 3%）. In this paper, the electrochemical impedance spectroscopy technology has been adopted to investigate the quasi-Fermi level and the cartier dynamics of the colloidal CdSe QDs sensitized Tit2 eletrode with S2-/Sf redox electrolytes and the series resistance of the QDSSCs. In comparison with the conventional DSSCs with I^-3/Г as redox electrolytes, the energy difference between the conduction band edge and the quasi-Fermi levels of the Tit2 films （or the Fermi levels of the redox electrolytes） in QDSSCs has been decreased by about 0.3 V, resulting in the decrease of Voc by this value. The increases of the electrolyte dif- fussion resistance and the charge transfer resistance between Pt counter electrodes and S2-/Sx redox electrolytes were attributed to the decrease of the fill factors. However, the electron lifetime and electron diffussion length for QDSSCs are longer than those for DSSCs due to the retardation of the electron recombination by the adsorbed cysteine at the surfaces of the TiO2 films. It is indicated that electron recombination at the TiO2/electrolyte interface is not the main reason for the lower Jsc of the colloidal QDs sensitized QDSSCs. Improving light harvesting efficiency and photoelectron injection efficiency should be considered in the future for such kind of QDSSCs.
