The adsorptive properties and selectivity of dyes and water molecules to cellulosic sheet, dependence of adsorptive properties of dyes on the concentration of dye solution, and discoloration of the dye solution due to...The adsorptive properties and selectivity of dyes and water molecules to cellulosic sheet, dependence of adsorptive properties of dyes on the concentration of dye solution, and discoloration of the dye solution due to the UV-ray irradiation were determined for 18 kinds of commercial dyes. The results are as follows： 1） the adsorptive properties of dyes to cellulose sheet differed greatly, but did not depend on the dye types such as acidic, basic and so on; 2） adsorptive properties of dyes to cellulosic sheet de- pended on the concentration of dye solution and were classified into 4 types： concentration-independent, increasing or decreasing with dye concentration, and having a maximum. This classification was irrelevant to the dye types; 3） the irradiation of UV-ray did not cause significant discoloration of dye solution itself, which suggested that wood components as well as dye molecules influence the discoloration of wood.展开更多
The adsorption properties of atomic and molecular species on Ir4/MgO and Ir4/γ-Al2O3 have been systematically studied by means of planewave density functional theory（DFT）calculations using the periodic boundary con...The adsorption properties of atomic and molecular species on Ir4/MgO and Ir4/γ-Al2O3 have been systematically studied by means of planewave density functional theory（DFT）calculations using the periodic boundary conditions.The binding energies of these species were ordered as follows：H2O〈C2H4〈H〈OH〈S〈N〈O〈C.The adsorption energies of adatoms on Ir4/MgO were larger than those on Ir4/γ-Al2O3 except hydrogen atom,but were in reverse for the molecules calculated.In addition,the difference of adsorption energies on MgO and γ-Al2O3 supports has been elucidated by analyzing the electronic properties.A detailed investigation on state density clarifies the nature of the magnitude of adsorption energy.These calculated results are consistent well with the available experimental and theoretical results.展开更多
Three kinds of activated carbons were prepared using coconut-shells as carbon precursors and characterized by XRD, FT-IR and texture property test. The results indicate that the prepared activated carbons were mainly ...Three kinds of activated carbons were prepared using coconut-shells as carbon precursors and characterized by XRD, FT-IR and texture property test. The results indicate that the prepared activated carbons were mainly amorphous and only a few impurity groups were adsorbed on their surfaces. The texture property test reveals that the activated carbons displayed different texture properties, especially the micropore size distribution. The adsorption capacities of the activated carbons were investigated by adsorbing CH4, CO2, N2 and O2 at 25 ？C in the pressure range of 0-200 kPa. The results reveal that all the activated carbons had high CO2 adsorption capacity, one of which had the highest CO2 adsorption value of 2.55 mmol/g at 200 kPa. And the highest adsorption capacity for CH4 of the activated carbons can reach 1.93 mmol/g at 200 kPa. In the pressure range of 0-200 kPa, the adsorption capacities for N2 and O2 were increased linearly with the change of pressure and K-AC is an excellent adsorbent towards the adsorption separation of greenhouse gases.展开更多
This paper studies the small molybdenum clusters of Mon （n=2 8） and their adsorption of N2 molecule by using the density functional theory （DFT） with the generalized gradient approximation. The optimized structure...This paper studies the small molybdenum clusters of Mon （n=2 8） and their adsorption of N2 molecule by using the density functional theory （DFT） with the generalized gradient approximation. The optimized structures of Mon clusters show the onset of a structural transition from a close-packed structure towards a body-centred cubic structure occurred at n = 7. An analysis of adsorption energies suggests that the Mo2 is of high inertness and Mo6 cluster is of high activity against the adsorption of N2. Calculated results indicate that the N2 molecule prefers end-on mode by forming a linear or quasi-linear structure Mo-N-N, and the adsorption of nitrogen on molybdenum clusters is molecular adsorption with slightly elongated N-N bond. The electron density of highest occupied molecular orbital and lowest unoccupied molecular orbital, and the partial density of states of representative cluster are also used to characterize the adsorption properties of N2 on the sized Mon clusters.展开更多
Adsorption and desorption of methane by activated carbon （AC） at constant temperature and at various pressures were investigated. The effect of moisture was also studied. A volumetric method was used, up to 40 bar, ...Adsorption and desorption of methane by activated carbon （AC） at constant temperature and at various pressures were investigated. The effect of moisture was also studied. A volumetric method was used, up to 40 bar, at a temperature of 273.5 K. Results of a dry AC sample were compared with those obtained from a moist sample and two different ACs with different physical and surface properties were used. As expected, the results showed that the existence of moisture, trapped in the AC pores, could lead to a decrease in the amount of methane adsorbed and a decrease in the amount of methane delivered during desorption. To model the experimental results, a large variety of adsorption isotherms were used. The regressed parameters for the adsorption isotherms were obtained using the experimental data generated in the present study. The accuracy of the results obtained from the different adsorption isotherms was favorably compared.展开更多
MFI molecular sieve with high specific surface area,adjustable pore size and low production cost have been recognized as an effective adsorbent for VOCs removal.In this paper,NaOH solution was used to etch ZSM-5 to in...MFI molecular sieve with high specific surface area,adjustable pore size and low production cost have been recognized as an effective adsorbent for VOCs removal.In this paper,NaOH solution was used to etch ZSM-5 to increase specific surface area and micro-mesoporous content.Graphene oxide(GO)was loaded on ZSM-5 by ultrasonic-assisted heating immersion method,and largeπ-bond structure and oxygen-containing functional groups were added to ZSM-5 for improving the composite adsorption performance.In addition,the properties of OH-ZSM-5 and ZSM-5@GO composites for toluene adsorption under different factors were also studied.It was positively correlated with initial concentration and adsorbent mass,but was negatively correlated with temperature.Meanwhile,the results showed that the saturated adsorption capacity of OH-ZSM-5(107.3 mg/g)was 1.34 times higher than that of ZG-15%(80.2 mg/g).The pseudo-first-order and pseudo-second-order kinetic model can well describe the adsorption behavior of toluene on the OH-ZSM-5 and ZG-15%,respectively.The adsorption mechanism of OH-ZSM-5 was mainly pore-filled adsorption.However,the adsorption mechanisms of ZSM-5@GO composite were pore-filled adsorption,π-πinteraction,and H-bond interaction.This study will help to design a new strategy for enhancing the performance of traditional adsorbent ZSM-5 in VOCs removal.展开更多
Adsorption properties of dibenzothiophene (DBT) on a CNT (carbon nanotube) support as well as on CoMoS/CNT and CoMoO/CNT catalysts have been studied. Consecutive desorption of adsorbates was measured by TGA. The commo...Adsorption properties of dibenzothiophene (DBT) on a CNT (carbon nanotube) support as well as on CoMoS/CNT and CoMoO/CNT catalysts have been studied. Consecutive desorption of adsorbates was measured by TGA. The commonly used carriers AC (activated carbon), γ-Al_2O_3, and their supported catalysts (CoMoO/AC, CoMoS/AC, CoMoO/γ-Al_2O_3, CoMoS/γ-Al_2O_3)were also subjected to analysis for comparison. The acidic properties of the samples were characterized using the NH_3-TPD technique. Correlation between the adsorption of DBT and the acidic properties of the catalysts has been established. It was found that the Co-Mo catalysts in the sulfide state adsorbed much more DBT molecules than the corresponding Co-Mo catalysts in the oxide state. The CoMoS/CNT catalyst exhibited very high HDS activity and selectivity, as compared with the CoMoS/γ-Al)_2O_3 catalysts. Based on the BET data and the high hydrogenolysis/hydrogenation selectivity of the CoMoS/CNT, it was deduced that more than 90% of the DBT molecules adsorbed on the CoMoS/CNT with an end-on mode, and the surface of the CoMoS/CNT catalyst was almost fully covered with DBT molecules. Although the AC support had very high surface area and high loading ability, the AC supported CoMoS catalyst showed lower HDS activity, as compared with the CoMoS/γ-Al_2O_3 catalyst.展开更多
The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence...The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed. Experimental results show that the concentration, the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption. Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption.展开更多
As the lightest two-dimensional material,monolayer borophene exhibits great potential as electrode materials,but it suffers from stability issues in the free-standing form.Here,the striped-borophene and graphene bilay...As the lightest two-dimensional material,monolayer borophene exhibits great potential as electrode materials,but it suffers from stability issues in the free-standing form.Here,the striped-borophene and graphene bilayer(sB/Gr)is found to be a high-performance anode material for rechargeable alkali-metal ion batteries.The first-principles results show that all the three alkali-metal atoms,Li,Na,and K,can be strongly adsorbed on sB/Gr with ultra-low diffusion barriers than that on pristine borophene/graphene,indicating good charge-discharge rates.Remarkably,high storage capacities are proposed for LIBs(1880 mA·h/g),NIBs(1648 mA·h/g),and KIBs(470 m A·h/g)with relatively small lattice change rate(<2.9%)in the process of alkali-metal atoms intercalations.These intriguing features of sB/Gr make it an excellent choice for batteries.展开更多
By using first-principles calculations within the framework of density functional theory,the electronic and magnetic properties of 3d transitional metal（TM） atoms（from Sc to Zn） adsorbed monolayer Ga As nanosheets...By using first-principles calculations within the framework of density functional theory,the electronic and magnetic properties of 3d transitional metal（TM） atoms（from Sc to Zn） adsorbed monolayer Ga As nanosheets（Ga As NSs） are systematically investigated.Upon TM atom adsorption,Ga As NS,which is a nonmagnetic semiconductor,can be tuned into a magnetic semiconductor（Sc,V,and Fe adsorption）,a half-metal（Mn adsorption）,or a metal（Co and Cu adsorption）.Our calculations show that the strong p–d hybridization between the 3d orbit of TM atoms and the 4p orbit of neighboring As atoms is responsible for the formation of chemical bonds and the origin of magnetism in the Ga As NSs with Sc,V,and Fe adsorption.However,the Mn 3d orbit with more unpaired electrons hybridizes not only with the As 4p orbit but also with the Ga 4p orbit,resulting in a stronger exchange interaction.Our results may be useful for electronic and magnetic applications of Ga As NS-based materials.展开更多
The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence...The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed. Experimental results show that the concentration, the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption. Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption.展开更多
基金Supported by the Research Planning of Japan-China Cooperation Project (The Research Project on Timber from Man-made Forests in China: JICA Project)
文摘The adsorptive properties and selectivity of dyes and water molecules to cellulosic sheet, dependence of adsorptive properties of dyes on the concentration of dye solution, and discoloration of the dye solution due to the UV-ray irradiation were determined for 18 kinds of commercial dyes. The results are as follows： 1） the adsorptive properties of dyes to cellulose sheet differed greatly, but did not depend on the dye types such as acidic, basic and so on; 2） adsorptive properties of dyes to cellulosic sheet de- pended on the concentration of dye solution and were classified into 4 types： concentration-independent, increasing or decreasing with dye concentration, and having a maximum. This classification was irrelevant to the dye types; 3） the irradiation of UV-ray did not cause significant discoloration of dye solution itself, which suggested that wood components as well as dye molecules influence the discoloration of wood.
文摘The adsorption properties of atomic and molecular species on Ir4/MgO and Ir4/γ-Al2O3 have been systematically studied by means of planewave density functional theory（DFT）calculations using the periodic boundary conditions.The binding energies of these species were ordered as follows：H2O〈C2H4〈H〈OH〈S〈N〈O〈C.The adsorption energies of adatoms on Ir4/MgO were larger than those on Ir4/γ-Al2O3 except hydrogen atom,but were in reverse for the molecules calculated.In addition,the difference of adsorption energies on MgO and γ-Al2O3 supports has been elucidated by analyzing the electronic properties.A detailed investigation on state density clarifies the nature of the magnitude of adsorption energy.These calculated results are consistent well with the available experimental and theoretical results.
基金supported by the National Natural Science Foundation of China(Grant 20773090)the Specialized Research Fund for the Doctoral Program of Higher Education(Grant 200806100009)
文摘Three kinds of activated carbons were prepared using coconut-shells as carbon precursors and characterized by XRD, FT-IR and texture property test. The results indicate that the prepared activated carbons were mainly amorphous and only a few impurity groups were adsorbed on their surfaces. The texture property test reveals that the activated carbons displayed different texture properties, especially the micropore size distribution. The adsorption capacities of the activated carbons were investigated by adsorbing CH4, CO2, N2 and O2 at 25 ？C in the pressure range of 0-200 kPa. The results reveal that all the activated carbons had high CO2 adsorption capacity, one of which had the highest CO2 adsorption value of 2.55 mmol/g at 200 kPa. And the highest adsorption capacity for CH4 of the activated carbons can reach 1.93 mmol/g at 200 kPa. In the pressure range of 0-200 kPa, the adsorption capacities for N2 and O2 were increased linearly with the change of pressure and K-AC is an excellent adsorbent towards the adsorption separation of greenhouse gases.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10964012)the Prior Developing Subject Foundation of Xinjiang Normal University
文摘This paper studies the small molybdenum clusters of Mon （n=2 8） and their adsorption of N2 molecule by using the density functional theory （DFT） with the generalized gradient approximation. The optimized structures of Mon clusters show the onset of a structural transition from a close-packed structure towards a body-centred cubic structure occurred at n = 7. An analysis of adsorption energies suggests that the Mo2 is of high inertness and Mo6 cluster is of high activity against the adsorption of N2. Calculated results indicate that the N2 molecule prefers end-on mode by forming a linear or quasi-linear structure Mo-N-N, and the adsorption of nitrogen on molybdenum clusters is molecular adsorption with slightly elongated N-N bond. The electron density of highest occupied molecular orbital and lowest unoccupied molecular orbital, and the partial density of states of representative cluster are also used to characterize the adsorption properties of N2 on the sized Mon clusters.
文摘Adsorption and desorption of methane by activated carbon （AC） at constant temperature and at various pressures were investigated. The effect of moisture was also studied. A volumetric method was used, up to 40 bar, at a temperature of 273.5 K. Results of a dry AC sample were compared with those obtained from a moist sample and two different ACs with different physical and surface properties were used. As expected, the results showed that the existence of moisture, trapped in the AC pores, could lead to a decrease in the amount of methane adsorbed and a decrease in the amount of methane delivered during desorption. To model the experimental results, a large variety of adsorption isotherms were used. The regressed parameters for the adsorption isotherms were obtained using the experimental data generated in the present study. The accuracy of the results obtained from the different adsorption isotherms was favorably compared.
基金This research is financially supported by the Open Project Program of State Key Laboratory of Petroleum Pollution Control(No.PPCIP2017005).
文摘MFI molecular sieve with high specific surface area,adjustable pore size and low production cost have been recognized as an effective adsorbent for VOCs removal.In this paper,NaOH solution was used to etch ZSM-5 to increase specific surface area and micro-mesoporous content.Graphene oxide(GO)was loaded on ZSM-5 by ultrasonic-assisted heating immersion method,and largeπ-bond structure and oxygen-containing functional groups were added to ZSM-5 for improving the composite adsorption performance.In addition,the properties of OH-ZSM-5 and ZSM-5@GO composites for toluene adsorption under different factors were also studied.It was positively correlated with initial concentration and adsorbent mass,but was negatively correlated with temperature.Meanwhile,the results showed that the saturated adsorption capacity of OH-ZSM-5(107.3 mg/g)was 1.34 times higher than that of ZG-15%(80.2 mg/g).The pseudo-first-order and pseudo-second-order kinetic model can well describe the adsorption behavior of toluene on the OH-ZSM-5 and ZG-15%,respectively.The adsorption mechanism of OH-ZSM-5 was mainly pore-filled adsorption.However,the adsorption mechanisms of ZSM-5@GO composite were pore-filled adsorption,π-πinteraction,and H-bond interaction.This study will help to design a new strategy for enhancing the performance of traditional adsorbent ZSM-5 in VOCs removal.
文摘Adsorption properties of dibenzothiophene (DBT) on a CNT (carbon nanotube) support as well as on CoMoS/CNT and CoMoO/CNT catalysts have been studied. Consecutive desorption of adsorbates was measured by TGA. The commonly used carriers AC (activated carbon), γ-Al_2O_3, and their supported catalysts (CoMoO/AC, CoMoS/AC, CoMoO/γ-Al_2O_3, CoMoS/γ-Al_2O_3)were also subjected to analysis for comparison. The acidic properties of the samples were characterized using the NH_3-TPD technique. Correlation between the adsorption of DBT and the acidic properties of the catalysts has been established. It was found that the Co-Mo catalysts in the sulfide state adsorbed much more DBT molecules than the corresponding Co-Mo catalysts in the oxide state. The CoMoS/CNT catalyst exhibited very high HDS activity and selectivity, as compared with the CoMoS/γ-Al)_2O_3 catalysts. Based on the BET data and the high hydrogenolysis/hydrogenation selectivity of the CoMoS/CNT, it was deduced that more than 90% of the DBT molecules adsorbed on the CoMoS/CNT with an end-on mode, and the surface of the CoMoS/CNT catalyst was almost fully covered with DBT molecules. Although the AC support had very high surface area and high loading ability, the AC supported CoMoS catalyst showed lower HDS activity, as compared with the CoMoS/γ-Al_2O_3 catalyst.
基金This work was supported by the National Key Project of China for Basic Research on Photovoltaic cell No.2000028200 and the CAS Knowledge Innovation Project No.KGCX2-303
文摘The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed. Experimental results show that the concentration, the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption. Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption.
基金Project supported by the National Natural Science Foundation of China(Grant No.12174084)the Scientific and Technological Research Foundation of Hebei Province,China(Grant No.ZD2021065)the Key Program of Natural Science Foundation of Hebei Province,China(Grant No.A2021205024)。
文摘As the lightest two-dimensional material,monolayer borophene exhibits great potential as electrode materials,but it suffers from stability issues in the free-standing form.Here,the striped-borophene and graphene bilayer(sB/Gr)is found to be a high-performance anode material for rechargeable alkali-metal ion batteries.The first-principles results show that all the three alkali-metal atoms,Li,Na,and K,can be strongly adsorbed on sB/Gr with ultra-low diffusion barriers than that on pristine borophene/graphene,indicating good charge-discharge rates.Remarkably,high storage capacities are proposed for LIBs(1880 mA·h/g),NIBs(1648 mA·h/g),and KIBs(470 m A·h/g)with relatively small lattice change rate(<2.9%)in the process of alkali-metal atoms intercalations.These intriguing features of sB/Gr make it an excellent choice for batteries.
基金Project supported by the National Natural Science Foundation of China(Grant No.11174212)
文摘By using first-principles calculations within the framework of density functional theory,the electronic and magnetic properties of 3d transitional metal（TM） atoms（from Sc to Zn） adsorbed monolayer Ga As nanosheets（Ga As NSs） are systematically investigated.Upon TM atom adsorption,Ga As NS,which is a nonmagnetic semiconductor,can be tuned into a magnetic semiconductor（Sc,V,and Fe adsorption）,a half-metal（Mn adsorption）,or a metal（Co and Cu adsorption）.Our calculations show that the strong p–d hybridization between the 3d orbit of TM atoms and the 4p orbit of neighboring As atoms is responsible for the formation of chemical bonds and the origin of magnetism in the Ga As NSs with Sc,V,and Fe adsorption.However,the Mn 3d orbit with more unpaired electrons hybridizes not only with the As 4p orbit but also with the Ga 4p orbit,resulting in a stronger exchange interaction.Our results may be useful for electronic and magnetic applications of Ga As NS-based materials.
基金This work was supported by the National Key Project of China for Basic Research on Photovoltaic cell No.2000028200 and the CAS Knowledge Innovation Project No.KGCX2-303
文摘The dye-sensitized TiO2 complex films were prepared by the dye coat onto TiO2 surfaces, and the sensitizing mechanism and adsorption properties of the dye-sensitized TiO2 complex films were investigated. The influence of the application conditions of dye adsorbed on TiO2 films on the amount of dye adsorption was discussed. Experimental results show that the concentration, the temperature of dye solutions and the dipping time of TiO2 films in the dye solutions have a significant influence on the amount of dye adsorption. Cell test indicates that the conversion efficiency of light to electricity increases with the amount of dye adsorption.
