For the purpose of effective and economic desulfurization of flue-gas, the predominance area diagram of the Mn-S-O system at different temperatures was constructed based on the thermodynamic data obtained from the lit...For the purpose of effective and economic desulfurization of flue-gas, the predominance area diagram of the Mn-S-O system at different temperatures was constructed based on the thermodynamic data obtained from the literatures. It is seen from this figure that flue-gas desulfurization by manganese oxides is feasible from the thermodynamic point of view. Additionally, the most appropriate temperature range for flue-gas desulfurization is between 600 and 800 K, and the reaction is strongly exothermic to maintain the heat balance. The natural manganese ores encompass large tunnels that exhibit large surface areas and highly chemical activity, which can provide a high enough SO2 removing efficiency. From the superposition of the diagrams of Mn-S-O and Fe-S-O systems, it is found that there is a coexistent stability region of MnSO4 and Fe2O3, which provides the possibility of desulfurization by selective sulfation without ferric sulfate forming. A multi-stage desulfurization system has been discussed briefly.展开更多
A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transf...A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transformed infrared spectroscopy(FT-IR)and thermal gravimetric analysis and differential thermal analysis(DTA-TG).Subsequently,the photocatalytic performances of Bi2S3 microsphere were evaluated by photocatalytic degradation of methyl orange(MO)simulation solution under visible-light irradiation.The results show that,Bi2S3 microsphere could be used as a potential cost-efficient catalysis for eliminating of methyl orange from aqueous solutions,whose degradation rate could reach 91.07%within 180 min.Besides,a tentative photocatalytic reaction mechanism was discussed according to the energy band position.Therefore,this work indicated a simplistic approach for the fabrication of visible-light responsive Bi2S3 microsphere photocatalyst,which can be used as a valuable candidate in solar energy conversion and environment pollution treatment.展开更多
In order to reduce the impact of CdS photogenerated electron-hole recombination on its photocatalytic performance,a narrow band gap semiconductor MoS_(2) and organic macromolecular cucurbit[n]urils(Q[n])were used to m...In order to reduce the impact of CdS photogenerated electron-hole recombination on its photocatalytic performance,a narrow band gap semiconductor MoS_(2) and organic macromolecular cucurbit[n]urils(Q[n])were used to modify CdS.Q[n]/CdS-MoS_(2)(n=6,7,8)composite photocatalysts were synthesized by hydrothermal method.Infrared spectroscopy,X-ray diffraction,X-ray photoelectron spectroscopy,field emission scanning electron microscopy,ultraviolet-visible and photoluminescence spectrum were used to characterize the structure,morphology and optical properties of the products,and the catalytic degradation of the solutions of methylene blue,rhodamine B and crystal violet by Q[n]/CdS-MoS_(2) composite catalyst was investigated.The results showed that the Q[n]played a regulatory role on the growth and crystallization of CdS-MoS_(2) particles,Q[n]/CdS-MoS_(2)(n=6,7,8)formed flower clusters with petal-like leaves,the flower clusters of petal-like leaves increased the surface area and active sites of the catalyst,the Q[n]/CdS-MoS_(2) barrier width decreased,the electron-hole pair separation efficiency was improved in the Q[6]/Cds-MoS_(2).Q[n]makes the electron-hole pair to obtain better separation and migration.The Q[6]/CdS-MoS_(2) and Q[7]/CdS-MoS2 have good photocatalytic activity for methylene blue,and the catalytic process is based on hydroxyl radical principle.展开更多
Micaceous iron oxide （MIO） with a hexagonal flaky shape was prepared by hydrothermal method. The ferric hydroxide used as precursor was obtained by an acidic leaching solution of pyrite cinders reacting with ammonia...Micaceous iron oxide （MIO） with a hexagonal flaky shape was prepared by hydrothermal method. The ferric hydroxide used as precursor was obtained by an acidic leaching solution of pyrite cinders reacting with ammonia solution. The optimal experimental conditions for preparing micaceous iron oxide were investigated by orthogonal experiments. Micaceous iron oxide can be successfully prepared when optimal parameters of total iron concentration of 2.0 mol/L, pH value of 8, n（Fe2＋）/n（Fe3＋） of 0.1, mass of seed crystal of 1 g, reaction temperature of 260 ℃ and reaction time of 30 min are applied. X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and selected area electron diffractometry （SAEM） were adopted to characterize the hydrothermal products prepared under optimal conditions. The results indicate that highly crystallized α-Fe2O3 hexagonal flakes, about 1.0-1.5 μm in diameter and 0.1 μm in thickness, are prepared. Furthermore, the quality of micaceous iron oxide prepared can meet the required characteristics of micaceous iron oxide pigments for paints （ISO 10601--2007）.展开更多
Hydrothermal deposition of antimony selenosulfide(Sb_(2)(S,Se_(3)))has enabled solar cell applications to surpass the 10%efficiency threshold.This deposition process involves the reaction of three precursor materials:...Hydrothermal deposition of antimony selenosulfide(Sb_(2)(S,Se_(3)))has enabled solar cell applications to surpass the 10%efficiency threshold.This deposition process involves the reaction of three precursor materials:Sb,S,and Se.However,this process generates an unfavourable gradient of Se and S anions in the Sb_(2)(S,Se)_(3)film,which limits further efficiency improvements.Herein,we demonstrate how NH_(4)F can be used as an additive to regulate the band gradient of the Sb_(2)(S,Se)_(3)and modify the surface of the CdS electron-transporting layer.On the one hand,NH_(4)F inhibits the decomposition of Na_(2)S_(2)O_(3)and selenourea,which optimizes the deposition process and allows for adjustment of the Se/S ratio and their distribution in the Sb_(2)(S,Se)_(3)film.On the other hand,hydrolysis of NH_(4)F induces dissolution and redeposition of CdS,thereby effectively improving the morphology and crystallinity of the CdS substrate.Finally,the dual effect of NH_(4)F enables improved surface morphology and energy alignment of the Sb_(2)(S,Se)_(3)film,thus yielding a maximum efficiency of 10.28%,a 12%improvement over the control device.This study demonstrates an effective strategy for simultaneously modifying a sulfide-based substrate and regulating the element distribution during the deposition of a metal chalcogenide film for optoelectronic device applications.展开更多
基金Project(51344006)supported by the National Natural Science Foundation of China
文摘For the purpose of effective and economic desulfurization of flue-gas, the predominance area diagram of the Mn-S-O system at different temperatures was constructed based on the thermodynamic data obtained from the literatures. It is seen from this figure that flue-gas desulfurization by manganese oxides is feasible from the thermodynamic point of view. Additionally, the most appropriate temperature range for flue-gas desulfurization is between 600 and 800 K, and the reaction is strongly exothermic to maintain the heat balance. The natural manganese ores encompass large tunnels that exhibit large surface areas and highly chemical activity, which can provide a high enough SO2 removing efficiency. From the superposition of the diagrams of Mn-S-O and Fe-S-O systems, it is found that there is a coexistent stability region of MnSO4 and Fe2O3, which provides the possibility of desulfurization by selective sulfation without ferric sulfate forming. A multi-stage desulfurization system has been discussed briefly.
基金Projects(21476269,21776319) supported by the National Natural Science Foundation of ChinaProject(2016TP1007) supported by Hunan Provincial Science and Technology Plan Project of China+2 种基金Project(2017J01569) supported by the Natural Science Foundation of Fujian Province,ChinaProject(201710533255) supported by National College Students’ Free Exploration Project of ChinaProject(2017zzts777) supported by Fundamental Research Funds for the Central Universities of Central South University,China
文摘A novel Bi2S3 microsphere was fabricated through one-pot urea-assisted solvothermal method.The synthesized Bi2S3 microsphere was characterized by X-ray diffraction(XRD),scanning electron microscopy(SEM),Fourier transformed infrared spectroscopy(FT-IR)and thermal gravimetric analysis and differential thermal analysis(DTA-TG).Subsequently,the photocatalytic performances of Bi2S3 microsphere were evaluated by photocatalytic degradation of methyl orange(MO)simulation solution under visible-light irradiation.The results show that,Bi2S3 microsphere could be used as a potential cost-efficient catalysis for eliminating of methyl orange from aqueous solutions,whose degradation rate could reach 91.07%within 180 min.Besides,a tentative photocatalytic reaction mechanism was discussed according to the energy band position.Therefore,this work indicated a simplistic approach for the fabrication of visible-light responsive Bi2S3 microsphere photocatalyst,which can be used as a valuable candidate in solar energy conversion and environment pollution treatment.
基金This work was supported by the National Natural Science Foundation of China(No.21871064)the National College Students’Innovative Training Program of China(No.2020053)+1 种基金the“Undergraduate Teaching Project”of Guizhou University(No.201936)the Student Research Training Foundation of Guizhou University,China(No.(2019)106).
文摘In order to reduce the impact of CdS photogenerated electron-hole recombination on its photocatalytic performance,a narrow band gap semiconductor MoS_(2) and organic macromolecular cucurbit[n]urils(Q[n])were used to modify CdS.Q[n]/CdS-MoS_(2)(n=6,7,8)composite photocatalysts were synthesized by hydrothermal method.Infrared spectroscopy,X-ray diffraction,X-ray photoelectron spectroscopy,field emission scanning electron microscopy,ultraviolet-visible and photoluminescence spectrum were used to characterize the structure,morphology and optical properties of the products,and the catalytic degradation of the solutions of methylene blue,rhodamine B and crystal violet by Q[n]/CdS-MoS_(2) composite catalyst was investigated.The results showed that the Q[n]played a regulatory role on the growth and crystallization of CdS-MoS_(2) particles,Q[n]/CdS-MoS_(2)(n=6,7,8)formed flower clusters with petal-like leaves,the flower clusters of petal-like leaves increased the surface area and active sites of the catalyst,the Q[n]/CdS-MoS_(2) barrier width decreased,the electron-hole pair separation efficiency was improved in the Q[6]/Cds-MoS_(2).Q[n]makes the electron-hole pair to obtain better separation and migration.The Q[6]/CdS-MoS_(2) and Q[7]/CdS-MoS2 have good photocatalytic activity for methylene blue,and the catalytic process is based on hydroxyl radical principle.
基金Project(2008A090300016) supported by Major Science & Technology Special Program of Guangdong Province,China
文摘Micaceous iron oxide （MIO） with a hexagonal flaky shape was prepared by hydrothermal method. The ferric hydroxide used as precursor was obtained by an acidic leaching solution of pyrite cinders reacting with ammonia solution. The optimal experimental conditions for preparing micaceous iron oxide were investigated by orthogonal experiments. Micaceous iron oxide can be successfully prepared when optimal parameters of total iron concentration of 2.0 mol/L, pH value of 8, n（Fe2＋）/n（Fe3＋） of 0.1, mass of seed crystal of 1 g, reaction temperature of 260 ℃ and reaction time of 30 min are applied. X-ray diffractometry （XRD）, scanning electron microscopy （SEM）, transmission electron microscopy （TEM） and selected area electron diffractometry （SAEM） were adopted to characterize the hydrothermal products prepared under optimal conditions. The results indicate that highly crystallized α-Fe2O3 hexagonal flakes, about 1.0-1.5 μm in diameter and 0.1 μm in thickness, are prepared. Furthermore, the quality of micaceous iron oxide prepared can meet the required characteristics of micaceous iron oxide pigments for paints （ISO 10601--2007）.
基金the National Natural Science Foundation of China(22005293 and U19A2092)the National Key Research and Development Program of China(2019YFA0405600).
文摘Hydrothermal deposition of antimony selenosulfide(Sb_(2)(S,Se_(3)))has enabled solar cell applications to surpass the 10%efficiency threshold.This deposition process involves the reaction of three precursor materials:Sb,S,and Se.However,this process generates an unfavourable gradient of Se and S anions in the Sb_(2)(S,Se)_(3)film,which limits further efficiency improvements.Herein,we demonstrate how NH_(4)F can be used as an additive to regulate the band gradient of the Sb_(2)(S,Se)_(3)and modify the surface of the CdS electron-transporting layer.On the one hand,NH_(4)F inhibits the decomposition of Na_(2)S_(2)O_(3)and selenourea,which optimizes the deposition process and allows for adjustment of the Se/S ratio and their distribution in the Sb_(2)(S,Se)_(3)film.On the other hand,hydrolysis of NH_(4)F induces dissolution and redeposition of CdS,thereby effectively improving the morphology and crystallinity of the CdS substrate.Finally,the dual effect of NH_(4)F enables improved surface morphology and energy alignment of the Sb_(2)(S,Se)_(3)film,thus yielding a maximum efficiency of 10.28%,a 12%improvement over the control device.This study demonstrates an effective strategy for simultaneously modifying a sulfide-based substrate and regulating the element distribution during the deposition of a metal chalcogenide film for optoelectronic device applications.
