Environmentally benign carbon dioxide offers significant potential in its supercritical fluid phase to replace current reliance on a range of hazardous, relatively expensive and environmentally damaging organic solven...Environmentally benign carbon dioxide offers significant potential in its supercritical fluid phase to replace current reliance on a range of hazardous, relatively expensive and environmentally damaging organic solvents that are used on an extensive global basis. The unique combination of the physical properties of supercritical fluids are being exploited and further researched to continue the development and establishment of high efficiency, compact plant to provide energy and water efficient manufacturing processes. This mini-review is focused on the use and potential applications of supercritical fluid carbon dioxide for a selected range of key and emerging industrial processes as a sustainable alternative to totally eliminate or greatly reduce the requirement of numerous conventional organic solvents. Examples of the industries include： chemical extraction and purification, synthetic chemical reactions including polymerization and inorganic catalytic processes. Biochemical reactions involving enzymes, particle size engineering, textile dyeing and advanced material manufacture provide further illustrations of vital industrial activities where supercritical fluid technology processes are being implemented or developed. Some aspects relating to the economics of sustainable supercritical fluid carbon dioxide processes are also considered.展开更多
Zn_(2)SnO_(4)plates,particles and spheres are suc-cessfully prepared via a facile synthesis way by carefully adjusting the solvothermal conditions,which are further applied as photoanodes in dye-sensitized solar cells...Zn_(2)SnO_(4)plates,particles and spheres are suc-cessfully prepared via a facile synthesis way by carefully adjusting the solvothermal conditions,which are further applied as photoanodes in dye-sensitized solar cells(DSSCs)to explore the relationships between the pho-toanode nanostructure and the photovoltaic performances.As a result,the DSSCs based on Zn_(2)SnO_(4)spheres pho-toanode showcased the best power conversion efficiency(PCE,4.85%),compared to Zn_(2)SnO_(4)plates(3.80%)and particles(4.13%).It is found that Zn_(2)SnO_(4)spheres exhibit the highest light-scattering abilities,as evidenced by ultraviolet–visible(UV–Vis)diffuse reflectance spectra.Additionally,investigations on dynamic electron transport and recombination properties via intensity-modulated photovoltage/photocurrent spectroscopy(IMVS/IMPS),and electrochemical impedance spectroscopy(EIS)mea-surements demonstrate that the Zn_(2)SnO_(4)spheres-based DSSCs possess the fastest electron transport rate,the longest electron lifetime,the highest electron collection efficiency(ηc c),and the largest charge recombination resistance,compared with the Zn_(2)SnO_(4)plates and particles,all of which are highly beneficial for the powder conversion efficiency enhancements.展开更多
This study presents a novel nanostructural electrode made of 20-nm-diameter nanoparticles, which orderly decorated with 2-μm TiO2 particles, deposited by a new gel process. The decorated electrode （DE） is better th...This study presents a novel nanostructural electrode made of 20-nm-diameter nanoparticles, which orderly decorated with 2-μm TiO2 particles, deposited by a new gel process. The decorated electrode （DE） is better than the non-decorated electrode （NE） in both light scattering and light harvesting, as confirmed by diffuse reflectance spectroscopy. X-ray diffraction reveals that both electrodes have a mixture of anatase and rutile phases. The dye-sensitized solar cell based on the decorated electrode shows the highest power conversion efficiency of 7.80% as a result of less recombination demonstrated by electrochemical impedance spectroscopy. From internal power conversion efficiency measurement, the external quantum efficiency of DE cell at 530 nm is 89%, which is higher than that of NE cell （77%）.展开更多
In this study, novel core-shell SiO<sub>2</sub>-coated iron nanoparticles (SiO<sub>2</sub>-nZVI) were synthesized using a one-step Stoeber method. The Malachite green degradation abilities of t...In this study, novel core-shell SiO<sub>2</sub>-coated iron nanoparticles (SiO<sub>2</sub>-nZVI) were synthesized using a one-step Stoeber method. The Malachite green degradation abilities of the nanoparticles were investigated. The effects of ethanol/distilled water volume ratio, presence and absence of PEG, tetraethyl orthosilicate (TEOS) dosage, and hydrolysis time used in the nanoparticles preparation process were investigated. The results indicated that the SiO<sub>2</sub>-coated iron nanoparticles had the highest reduction activity when the particles synthesized with ethanol/H<sub>2</sub>O ratio of 2:1, PEG of 0.15 ml, TEOS of 0.5 ml and the reaction time was 4 h. The SiO<sub>2</sub>-nZVI nanoparticles were characterized using Transmission Electron Microscopy (TEM), Energy Dispersive Spectrometry (EDS) and powder X-Ray Diffraction (XRD). The results showed that the average particles diameter of the SiO<sub>2</sub>-nZVI was 20 - 30 nm. The thickness of the outside SiO<sub>2</sub> film is consistent and approximately 10 nm. The results indicated that the nanoparticles coated completely with a transparent SiO<sub>2</sub>-film. Such nanoparticles could have wide applications in dye decolorization.展开更多
In the present work,novel dual-functionalized hollow polymer particles （DF-HPP） with high density of carboxylate and amino dual functional groups have been specially designed and fabricated to serve as high-performa...In the present work,novel dual-functionalized hollow polymer particles （DF-HPP） with high density of carboxylate and amino dual functional groups have been specially designed and fabricated to serve as high-performance adsorbent for selective removal of basic dye （methylene blue,b-MB,as a model dye）.Due to both the high surface area and the extremely high density of carboxylate and amino groups,the DF-HPPs exhibited excellent adsorption property for methylene blue （b-MB）,including high adsorption capacity,fast adsorption/desorption rates,unique pH-sensitivity and easy recovery.The equilibrium adsorption data of b-MB on the DF-HPPs were evaluated using Freundlich and Langmuir isotherm models,and the equilibrium isotherm was better fit with Langmuir model with a maximum adsorption capacity of 538.8 mg/g at pH 12.More interestingly,the DF-HPPs showed a significant pH-dependent equilibrium adsorption capacity,which decreased dramatically from 516.1 mg/g to 24 mg/g as the solution pH decreased from 12 to 3.The dye-adsorbed DF-HPPs can be facilely and rapidly regenerated under mild condition （under weak acidic solution,pH 3,in 30 min） to recover both b-MB and the DF-HPPs,and the regenerated DF-HPPs can be reused for dye removal with high efficiency,indicating the exceptional recyclability of the DF-HPPs.展开更多
Since the prototype of a dye-sensitized solar cell(DSSC)was reported in 1991 by M. Gratzel,it has aroused intensive interest over the past decade due to its low cost and simple preparation procedure.The typical cell c...Since the prototype of a dye-sensitized solar cell(DSSC)was reported in 1991 by M. Gratzel,it has aroused intensive interest over the past decade due to its low cost and simple preparation procedure.The typical cell consists of a dye-coated mesoporous nanocrystalline TiO_2 film sandwiched between two transparent electroldes.A liquid electrolyte,traditionally containing the trioidide/iodide redox couple,fills the pores of the mesoporous nanocrystalline TiO_2 film and contacts the nanoparticles.Photoexcite...展开更多
文摘Environmentally benign carbon dioxide offers significant potential in its supercritical fluid phase to replace current reliance on a range of hazardous, relatively expensive and environmentally damaging organic solvents that are used on an extensive global basis. The unique combination of the physical properties of supercritical fluids are being exploited and further researched to continue the development and establishment of high efficiency, compact plant to provide energy and water efficient manufacturing processes. This mini-review is focused on the use and potential applications of supercritical fluid carbon dioxide for a selected range of key and emerging industrial processes as a sustainable alternative to totally eliminate or greatly reduce the requirement of numerous conventional organic solvents. Examples of the industries include： chemical extraction and purification, synthetic chemical reactions including polymerization and inorganic catalytic processes. Biochemical reactions involving enzymes, particle size engineering, textile dyeing and advanced material manufacture provide further illustrations of vital industrial activities where supercritical fluid technology processes are being implemented or developed. Some aspects relating to the economics of sustainable supercritical fluid carbon dioxide processes are also considered.
基金financially supported by the Application Development Foundation of Guangzhou Lu Chao Science and Technology Company (No. 53H19044)the National Natural Science Foundation of China (No. U20A20238)+1 种基金the Talents Project of Beijing Municipal Committee Organization Department (No. 2018000021223ZK21)the Key Research & Development and Transformation Projects in Qinghai Province (No. 2021-HZ-808)。
文摘Zn_(2)SnO_(4)plates,particles and spheres are suc-cessfully prepared via a facile synthesis way by carefully adjusting the solvothermal conditions,which are further applied as photoanodes in dye-sensitized solar cells(DSSCs)to explore the relationships between the pho-toanode nanostructure and the photovoltaic performances.As a result,the DSSCs based on Zn_(2)SnO_(4)spheres pho-toanode showcased the best power conversion efficiency(PCE,4.85%),compared to Zn_(2)SnO_(4)plates(3.80%)and particles(4.13%).It is found that Zn_(2)SnO_(4)spheres exhibit the highest light-scattering abilities,as evidenced by ultraviolet–visible(UV–Vis)diffuse reflectance spectra.Additionally,investigations on dynamic electron transport and recombination properties via intensity-modulated photovoltage/photocurrent spectroscopy(IMVS/IMPS),and electrochemical impedance spectroscopy(EIS)mea-surements demonstrate that the Zn_(2)SnO_(4)spheres-based DSSCs possess the fastest electron transport rate,the longest electron lifetime,the highest electron collection efficiency(ηc c),and the largest charge recombination resistance,compared with the Zn_(2)SnO_(4)plates and particles,all of which are highly beneficial for the powder conversion efficiency enhancements.
文摘This study presents a novel nanostructural electrode made of 20-nm-diameter nanoparticles, which orderly decorated with 2-μm TiO2 particles, deposited by a new gel process. The decorated electrode （DE） is better than the non-decorated electrode （NE） in both light scattering and light harvesting, as confirmed by diffuse reflectance spectroscopy. X-ray diffraction reveals that both electrodes have a mixture of anatase and rutile phases. The dye-sensitized solar cell based on the decorated electrode shows the highest power conversion efficiency of 7.80% as a result of less recombination demonstrated by electrochemical impedance spectroscopy. From internal power conversion efficiency measurement, the external quantum efficiency of DE cell at 530 nm is 89%, which is higher than that of NE cell （77%）.
文摘In this study, novel core-shell SiO<sub>2</sub>-coated iron nanoparticles (SiO<sub>2</sub>-nZVI) were synthesized using a one-step Stoeber method. The Malachite green degradation abilities of the nanoparticles were investigated. The effects of ethanol/distilled water volume ratio, presence and absence of PEG, tetraethyl orthosilicate (TEOS) dosage, and hydrolysis time used in the nanoparticles preparation process were investigated. The results indicated that the SiO<sub>2</sub>-coated iron nanoparticles had the highest reduction activity when the particles synthesized with ethanol/H<sub>2</sub>O ratio of 2:1, PEG of 0.15 ml, TEOS of 0.5 ml and the reaction time was 4 h. The SiO<sub>2</sub>-nZVI nanoparticles were characterized using Transmission Electron Microscopy (TEM), Energy Dispersive Spectrometry (EDS) and powder X-Ray Diffraction (XRD). The results showed that the average particles diameter of the SiO<sub>2</sub>-nZVI was 20 - 30 nm. The thickness of the outside SiO<sub>2</sub> film is consistent and approximately 10 nm. The results indicated that the nanoparticles coated completely with a transparent SiO<sub>2</sub>-film. Such nanoparticles could have wide applications in dye decolorization.
文摘In the present work,novel dual-functionalized hollow polymer particles （DF-HPP） with high density of carboxylate and amino dual functional groups have been specially designed and fabricated to serve as high-performance adsorbent for selective removal of basic dye （methylene blue,b-MB,as a model dye）.Due to both the high surface area and the extremely high density of carboxylate and amino groups,the DF-HPPs exhibited excellent adsorption property for methylene blue （b-MB）,including high adsorption capacity,fast adsorption/desorption rates,unique pH-sensitivity and easy recovery.The equilibrium adsorption data of b-MB on the DF-HPPs were evaluated using Freundlich and Langmuir isotherm models,and the equilibrium isotherm was better fit with Langmuir model with a maximum adsorption capacity of 538.8 mg/g at pH 12.More interestingly,the DF-HPPs showed a significant pH-dependent equilibrium adsorption capacity,which decreased dramatically from 516.1 mg/g to 24 mg/g as the solution pH decreased from 12 to 3.The dye-adsorbed DF-HPPs can be facilely and rapidly regenerated under mild condition （under weak acidic solution,pH 3,in 30 min） to recover both b-MB and the DF-HPPs,and the regenerated DF-HPPs can be reused for dye removal with high efficiency,indicating the exceptional recyclability of the DF-HPPs.
文摘Since the prototype of a dye-sensitized solar cell(DSSC)was reported in 1991 by M. Gratzel,it has aroused intensive interest over the past decade due to its low cost and simple preparation procedure.The typical cell consists of a dye-coated mesoporous nanocrystalline TiO_2 film sandwiched between two transparent electroldes.A liquid electrolyte,traditionally containing the trioidide/iodide redox couple,fills the pores of the mesoporous nanocrystalline TiO_2 film and contacts the nanoparticles.Photoexcite...
