The exploitation of heterogeneous semiconductor (photo)electrocatalysis is a significant avenue to study renewable energy for adapting a commodity chemical supply to satisfy the growing global energy demands. The fund...The exploitation of heterogeneous semiconductor (photo)electrocatalysis is a significant avenue to study renewable energy for adapting a commodity chemical supply to satisfy the growing global energy demands. The fundamental thermodynamics that guided the understanding of electron transfer processes and predictive power of materials design for bulk-semiconductor heterogeneous (photo)electrocatalysis are generally understood within the framework pioneered by Gerischer and Marcus.展开更多
This study was performed to investigate the variables that influence chlorobenzene (CB) degradation in aqueous solution by electro-heterogeneous catalysis.The effects of current density,pH,and electrolyte concentratio...This study was performed to investigate the variables that influence chlorobenzene (CB) degradation in aqueous solution by electro-heterogeneous catalysis.The effects of current density,pH,and electrolyte concentration on CB degradation were determined.The degradation effciency of CB was almost 100% with an initial CB concentration of 50 mg/L,current density 15 mA/cm2,initial pH 10,electrolyte concentration 0.1 mol/L,and temperature 25°C after 90 min of reaction.Under the same conditions,the degradation effciency of CB was only 51% by electrochemical (EC) process,which showed that electro-heterogeneous catalysis was more effcient than EC alone.The analysis results of Purge-and-Trap chromatography-mass spectrometry (P&T/GC/MS) and ion chromatography (IC) indicated that in the reaction process,the initial .OH attack could occur at the C-Cl bond of CB,yielding phenol and biphenyl with the release of Cl-.Further oxidation of phenol and biphenyl produced ρ-Vinylbenzoic acid and hydroquinol.Finally,the compounds were oxidized to butenedioic acid and other small-molecule acids.展开更多
Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes(Fe2+/H2O2,UV/Fe2+/H2O2,and electrolysis/Fe2+/H2O2) in this study. Comparison of these techniques in oxidation efficiency...Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes(Fe2+/H2O2,UV/Fe2+/H2O2,and electrolysis/Fe2+/H2O2) in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore,UV light(photo-Fenton) or electron current(electro-Fenton) was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite,especially the electro-Fenton.展开更多
The photo\|catalytic degradation pathway and degradation products of methylene blue, rhodamine B, methyl orange, and malachite green in aqueous TiO 2 suspension irradiated by high pressure mercury lamp by means of UV\...The photo\|catalytic degradation pathway and degradation products of methylene blue, rhodamine B, methyl orange, and malachite green in aqueous TiO 2 suspension irradiated by high pressure mercury lamp by means of UV\|visible absorption spectra and ion chromatography were investigated. The photo\|catalysis degradation of dye solutions with charges was greatly effected by pH value owing to the electrostatic model. The photo\|degradation rate of dyes anion increased with the decrease of pH value, in contrast, the photo\|degradation rate of dyes cation increased with the increase of pH value. And the absorption peaks diminished with a blue shift. After illuminated for 30 minutes, a part of dye chemicals were completely mineralized and transferred into inorganic species including chloride ion, ammonium ion, nitrate ion, sulfate ion. And the addition of 100 mmol/L H 2O 2 promoted the formation of inorganic species. In this study, the quantity of ammonium ion was much more than that of nitrate ion. That indicated the formation of nitrate is from ammonium. The purification rate of COD in four kinds of dye solution was 71.7%—88.7%. The decrease of COD of dyes solution implies the feasibility of the environmental application of photo\|catalyzed process.展开更多
Carbon nanotubes and graphene are carbon-based materials, which possess not only unique structure but also properties such as high surface area, extraordinary mechanical properties, high electronic conductivity, and c...Carbon nanotubes and graphene are carbon-based materials, which possess not only unique structure but also properties such as high surface area, extraordinary mechanical properties, high electronic conductivity, and chemical stability.Thus, they have been regarded as an important material, especially for exploring a variety of complex catalysts. Considerable efforts have been made to functionalize and fabricate carbon-based composites with metal nanoparticles. In this review,we summarize the recent progress of our research on the decoration of carbon nanotubes/graphene with metal nanoparticles by using polyoxometalates as key agents, and their enhanced photo-electrical catalytic activities in various catalytic reactions. The polyoxometalates play a key role in constructing the nanohybrids and contributing to their photo-electrical catalytic properties.展开更多
Adsorption and photo catalysis are the most popular methods applied for the reduction of amount of pollutants that enter water bodies. The main challenge in the process of adsorption is the demonstration of the experi...Adsorption and photo catalysis are the most popular methods applied for the reduction of amount of pollutants that enter water bodies. The main challenge in the process of adsorption is the demonstration of the experimental data obtained from sorption processes. For many decades most of the researchers used adsorption and kinetic of adsorption as a repetitive work to describe the adsorption data by using common models such as, Langmuir and Freundlich for adsorption isotherms;PFO and PSO models for kinetics. This has been done without careful evaluation of the characteristics of adsorption process. It has been well understood that adsorption does not degrade the pollutant to eco-friendly products and photo catalysis will not degrade without adsorption of the pollutant on the catalyst. Therefore, understanding the detailed mechanism of adsorption, as well as, photo catalysis has been presented in this paper. During photo catalysis: modification towards suppression of electron-hole recombination, improving visible light response, preventing agglomeration, controlling the shape, size, morphology, etc. are the most important steps. This mini review also widely discusses the key points behind adsorption and photo catalysis.展开更多
Wastewater management and energy/resource recycling have been extensively investigated via photo(electro)catalysis.Although both operation processes are driven effectively by the same interfacial charge,each system is...Wastewater management and energy/resource recycling have been extensively investigated via photo(electro)catalysis.Although both operation processes are driven effectively by the same interfacial charge,each system is practiced separately since they require very different reaction conditions.In this review,we showcase the recent advancements in photo(electro)catalytic process that enables the wastewater treatment and simultaneous energy/resource recovery(WT-ERR).Various literatures based on photo(electro)catalysis for wastewater treatment coupled with CO_(2)conversion,H_(2)production and heavy metal recovery are summarized.Besides,the fundamentals of photo(electro)catalysis and the influencing factors in such synergistic process are also presented.The essential feature of the catalysis lies in effectively utilizing hole oxidation for pollutant degradation and electron reduction for energy/resource recovery.Although in its infancy,the reviewed technology provides new avenue for developing next-generation wastewater treatment process.Moreover,we expect that this review can stimulate intensive researches to rationally design photo(electro)catalytic systems for environmental remediation accompanied with energy and resource recovery.展开更多
The gold ion modified TiO 2 was prepared by means of sol\|gel whereas gold deposited TiO\-2 was prepared by means of photo\|reduction. The physical properties were influenced significantly by the presence of gold ion ...The gold ion modified TiO 2 was prepared by means of sol\|gel whereas gold deposited TiO\-2 was prepared by means of photo\|reduction. The physical properties were influenced significantly by the presence of gold ion or gold. The enhanced photo\|activity of gold modified TiO\-2 was quantified in terms of methylene blue degradation. The presence of gold ion in TiO\-2 lattices or gold on TiO\-2 surface enhanced their photo\|activity. The optimum molar content of gold ion doping and gold deposition all was 0.5%. The first\|order rates constants of gold modified TiO\-2 was more than that of pure TiO\-2, and decreased by increasing the content of gold ion and gold when their contents were more than 0.5%. Gold ion doped in TiO\-2 lattices was more effective to enhance the photo\|activity than gold on TiO\-2 surface. Moreover, the relationship between physical properties, chemical properties and photo\|activity has been discussed.展开更多
Electro-oxidation of methanol was studied on titanium supported nanocrystallite Pt and Ptx-Sny catalysts prepared by electrodeposition techniques. Their electro-catalytic activities were studied in 0.5 mol/L H2SO4 and...Electro-oxidation of methanol was studied on titanium supported nanocrystallite Pt and Ptx-Sny catalysts prepared by electrodeposition techniques. Their electro-catalytic activities were studied in 0.5 mol/L H2SO4 and compared to those of a smooth Pt, Pt/Pt and Pt-Sn/Pt electrodes. Platinum was deposited on Ti by galvanostatic and potentiostatic techniques. X-ray diffractometer (XRD) and energy dispersive X-ray (EDX) techniques were applied in order to investigate the chemical composition and the phase structure of the modified electrodes. Scanning electron microscopy (SEM) was used to characterize the surface morphology and to correlate the results obtained from the two electrochemical deposition methods. Results show that modified Pt/Ti electrodes prepared by the two methods have comparable performance and enhanced catalytic activity towards methanol electro-oxidation compared to Pt/Pt and smooth Pt electrodes. Steady state Tafel plots experiments show a higher rate of methanol oxidation on a Pt/Ti catalyst than that on a smooth Pt. Introduction of a small amount of Sn deposited with Pt improves the catalytic activity and the stability of prepared electrode with time as indicated from the cyclic votlammetry and the chronoamperometric experiments. The effect of variations in the composition for binary catalysts of the type Ptx-Sny/Ti towards the methanol oxidation reaction is reported. Consequently, the Ptx-Sny/Ti (x∶y (8∶1), molar ratio) catalyst is a very promising one for methanol oxidation.展开更多
The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a signifi...The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a significant limiting factor in the system's performance. By utilising energy from the sun, through a range of key routes, this limitation can be overcome. In this review, we present a comprehensive and critical overview of the potential routes to harvest the sun's energy, primarily through solar-thermal technologies and plasmonic resonance effects. Focusing on the localised heating approach, this review shortlists and compares viable catalysts for the photo-thermal catalytic conversion of carbon dioxide.Further, the pathways and potential products of different carbon dioxide conversion routes are outlined with the reverse water gas shift,methanation, and methanol synthesis being of key interest. Finally, the challenges in implementing such systems and the outlook to the future are detailed.展开更多
Y 2O 3/TiO 2 samples were prepared by sol-gel process and characterized by means of X-ray diffraction (XRD), laser Raman spectra (LRS), UV-visible diffuse reflectance spectra (DRS), specific surface area (BET), and tr...Y 2O 3/TiO 2 samples were prepared by sol-gel process and characterized by means of X-ray diffraction (XRD), laser Raman spectra (LRS), UV-visible diffuse reflectance spectra (DRS), specific surface area (BET), and transmission electron microscopy (TEM). The results show that the relative intensity of 101 peak of anatase and 002 peak of rutile, the mean crystal diameter and mean particle diameter of Y 2O 3/TiO 2 samples decrease while specific surface area increases owing to doping Y 2O 3. Y 2O 3/TiO 2 samples have a larger specific surface area and higher thermal stability. Owing to quantum size effect, the reflectance of Y 2O 3/TiO 2 samples is larger than that of pure TiO 2 in the range of 380～460 nm and the position of Raman peaks varies slightly. Being a model reaction, the photo-catalytic degradation of methylene blue (MB) with positive charge and methyl orange (MO) with negative charge was investigated in TiO 2 and Y 2O 3/TiO 2 nanopowder suspension irradiated by high-pressure mercury lamp. As a result, the addition of Y 2O 3 to TiO 2 is detrimental to photo-activity of TiO 2 for MB photo-degradation and photo-catalytic behavior is enhanced due to 5%, 10% Y 2O 3 deposited on TiO 2 for the photo-degradation of MO. And the relationship between photo-physical properties and photo-activity was discussed.展开更多
X-ray diffraction, scanning electron microscopy and transmission electron microscopy were employed to investigate the microstructure and morphology of Au NPs/ZnO NTs, and their photo-catalytic capability was assessed ...X-ray diffraction, scanning electron microscopy and transmission electron microscopy were employed to investigate the microstructure and morphology of Au NPs/ZnO NTs, and their photo-catalytic capability was assessed to a nicety. The results demonstrated that the diameter and the wall thickness of ZnO nanotube were about 200 and 50 nm, respectively. The diameter of Au nanoparticle was about 30 nm. The characterization on the photo-catalytic capability of the Au-ZnO nanotube hybrid indicated that the degradation of methyl orange was 80% within 4 h. Controlled experiments have shown that Au-Zn O nanotube hybrid presents superior photo-catalytic capability to both bare ZnO nanorod and Au-ZnO nanorod hybrid indicated that the degradation procedure of methyl orange.展开更多
We report the synthesis, characterisation and catalytic performance of two nature-inspired biomassderived electro-catalysts for the oxygen reduction reaction in fuel cells. The catalysts were prepared via pyrolysis of...We report the synthesis, characterisation and catalytic performance of two nature-inspired biomassderived electro-catalysts for the oxygen reduction reaction in fuel cells. The catalysts were prepared via pyrolysis of a real food waste(lobster shells) or by mimicking the composition of lobster shells using chitin and CaCO_3 particles followed by acid washing. The simplified model of artificial lobster was prepared for better reproducibility. The calcium carbonate in both samples acts as a pore agent, creating increased surface area and pore volume, though considerably higher in artificial lobster samples due to the better homogeneity of the components. Various characterisation techniques revealed the presence of a considerable amount of hydroxyapatite left in the real lobster samples after acid washing and a low content of carbon(23%), nitrogen and sulphur(<1%), limiting the surface area to 23 m^2/g, and consequently resulting in rather poor catalytic activity. However, artificial lobster samples, with a surface area of ≈200 m^2/g and a nitrogen doping of 2%, showed a promising onset potential, very similar to a commercially available platinum catalyst, with better methanol tolerance, though with lower stability in long time testing over 10,000 s.展开更多
文摘The exploitation of heterogeneous semiconductor (photo)electrocatalysis is a significant avenue to study renewable energy for adapting a commodity chemical supply to satisfy the growing global energy demands. The fundamental thermodynamics that guided the understanding of electron transfer processes and predictive power of materials design for bulk-semiconductor heterogeneous (photo)electrocatalysis are generally understood within the framework pioneered by Gerischer and Marcus.
基金the Science and Technology Department of Zhejiang Province (No.2006C13120).
文摘This study was performed to investigate the variables that influence chlorobenzene (CB) degradation in aqueous solution by electro-heterogeneous catalysis.The effects of current density,pH,and electrolyte concentration on CB degradation were determined.The degradation effciency of CB was almost 100% with an initial CB concentration of 50 mg/L,current density 15 mA/cm2,initial pH 10,electrolyte concentration 0.1 mol/L,and temperature 25°C after 90 min of reaction.Under the same conditions,the degradation effciency of CB was only 51% by electrochemical (EC) process,which showed that electro-heterogeneous catalysis was more effcient than EC alone.The analysis results of Purge-and-Trap chromatography-mass spectrometry (P&T/GC/MS) and ion chromatography (IC) indicated that in the reaction process,the initial .OH attack could occur at the C-Cl bond of CB,yielding phenol and biphenyl with the release of Cl-.Further oxidation of phenol and biphenyl produced ρ-Vinylbenzoic acid and hydroquinol.Finally,the compounds were oxidized to butenedioic acid and other small-molecule acids.
基金The authors thank the "National" Science Council, Taiwan, China for financially supporting (No. NSC95- 2211-E-006-032).
文摘Both citrate and hypophosphite in aqueous solution were degraded by advanced oxidation processes(Fe2+/H2O2,UV/Fe2+/H2O2,and electrolysis/Fe2+/H2O2) in this study. Comparison of these techniques in oxidation efficiency was undertaken. It was found that Fenton process could not completely degrade citrate in the presence of hypophosphite since it caused a series inhibition. Therefore,UV light(photo-Fenton) or electron current(electro-Fenton) was applied to improve the degradation efficiency of the Fenton process. Results showed that both photo-Fenton and electro-Fenton processes could overcome the inhibition of hypophosphite,especially the electro-Fenton.
文摘The photo\|catalytic degradation pathway and degradation products of methylene blue, rhodamine B, methyl orange, and malachite green in aqueous TiO 2 suspension irradiated by high pressure mercury lamp by means of UV\|visible absorption spectra and ion chromatography were investigated. The photo\|catalysis degradation of dye solutions with charges was greatly effected by pH value owing to the electrostatic model. The photo\|degradation rate of dyes anion increased with the decrease of pH value, in contrast, the photo\|degradation rate of dyes cation increased with the increase of pH value. And the absorption peaks diminished with a blue shift. After illuminated for 30 minutes, a part of dye chemicals were completely mineralized and transferred into inorganic species including chloride ion, ammonium ion, nitrate ion, sulfate ion. And the addition of 100 mmol/L H 2O 2 promoted the formation of inorganic species. In this study, the quantity of ammonium ion was much more than that of nitrate ion. That indicated the formation of nitrate is from ammonium. The purification rate of COD in four kinds of dye solution was 71.7%—88.7%. The decrease of COD of dyes solution implies the feasibility of the environmental application of photo\|catalyzed process.
基金Project supported by the National Natural Science Foundation of China(Grant No.21371173)the National Basic Research Program of China(973 Program)(Grant No.2012CB932504)
文摘Carbon nanotubes and graphene are carbon-based materials, which possess not only unique structure but also properties such as high surface area, extraordinary mechanical properties, high electronic conductivity, and chemical stability.Thus, they have been regarded as an important material, especially for exploring a variety of complex catalysts. Considerable efforts have been made to functionalize and fabricate carbon-based composites with metal nanoparticles. In this review,we summarize the recent progress of our research on the decoration of carbon nanotubes/graphene with metal nanoparticles by using polyoxometalates as key agents, and their enhanced photo-electrical catalytic activities in various catalytic reactions. The polyoxometalates play a key role in constructing the nanohybrids and contributing to their photo-electrical catalytic properties.
文摘Adsorption and photo catalysis are the most popular methods applied for the reduction of amount of pollutants that enter water bodies. The main challenge in the process of adsorption is the demonstration of the experimental data obtained from sorption processes. For many decades most of the researchers used adsorption and kinetic of adsorption as a repetitive work to describe the adsorption data by using common models such as, Langmuir and Freundlich for adsorption isotherms;PFO and PSO models for kinetics. This has been done without careful evaluation of the characteristics of adsorption process. It has been well understood that adsorption does not degrade the pollutant to eco-friendly products and photo catalysis will not degrade without adsorption of the pollutant on the catalyst. Therefore, understanding the detailed mechanism of adsorption, as well as, photo catalysis has been presented in this paper. During photo catalysis: modification towards suppression of electron-hole recombination, improving visible light response, preventing agglomeration, controlling the shape, size, morphology, etc. are the most important steps. This mini review also widely discusses the key points behind adsorption and photo catalysis.
基金financially supported by the National Natural Science Foundation of China(Nos.52000097,51878325,51868050 and 51938007)the Natural Science Foundation of Jiangxi Province(Nos.20192BAB213011 and 20192ACBL21046)+1 种基金the Ph.D.research startup foundation of Nanchang Hangkong University(No.EA201802367)the Open Project Program of the State Key Laboratory of Photocatalysis on Energy and Environment(No.SKLPEE-KF202106),Fuzhou University。
文摘Wastewater management and energy/resource recycling have been extensively investigated via photo(electro)catalysis.Although both operation processes are driven effectively by the same interfacial charge,each system is practiced separately since they require very different reaction conditions.In this review,we showcase the recent advancements in photo(electro)catalytic process that enables the wastewater treatment and simultaneous energy/resource recovery(WT-ERR).Various literatures based on photo(electro)catalysis for wastewater treatment coupled with CO_(2)conversion,H_(2)production and heavy metal recovery are summarized.Besides,the fundamentals of photo(electro)catalysis and the influencing factors in such synergistic process are also presented.The essential feature of the catalysis lies in effectively utilizing hole oxidation for pollutant degradation and electron reduction for energy/resource recovery.Although in its infancy,the reviewed technology provides new avenue for developing next-generation wastewater treatment process.Moreover,we expect that this review can stimulate intensive researches to rationally design photo(electro)catalytic systems for environmental remediation accompanied with energy and resource recovery.
基金Guangdong Natural Science Foundation (No .980 0 12 )
文摘The gold ion modified TiO 2 was prepared by means of sol\|gel whereas gold deposited TiO\-2 was prepared by means of photo\|reduction. The physical properties were influenced significantly by the presence of gold ion or gold. The enhanced photo\|activity of gold modified TiO\-2 was quantified in terms of methylene blue degradation. The presence of gold ion in TiO\-2 lattices or gold on TiO\-2 surface enhanced their photo\|activity. The optimum molar content of gold ion doping and gold deposition all was 0.5%. The first\|order rates constants of gold modified TiO\-2 was more than that of pure TiO\-2, and decreased by increasing the content of gold ion and gold when their contents were more than 0.5%. Gold ion doped in TiO\-2 lattices was more effective to enhance the photo\|activity than gold on TiO\-2 surface. Moreover, the relationship between physical properties, chemical properties and photo\|activity has been discussed.
文摘Electro-oxidation of methanol was studied on titanium supported nanocrystallite Pt and Ptx-Sny catalysts prepared by electrodeposition techniques. Their electro-catalytic activities were studied in 0.5 mol/L H2SO4 and compared to those of a smooth Pt, Pt/Pt and Pt-Sn/Pt electrodes. Platinum was deposited on Ti by galvanostatic and potentiostatic techniques. X-ray diffractometer (XRD) and energy dispersive X-ray (EDX) techniques were applied in order to investigate the chemical composition and the phase structure of the modified electrodes. Scanning electron microscopy (SEM) was used to characterize the surface morphology and to correlate the results obtained from the two electrochemical deposition methods. Results show that modified Pt/Ti electrodes prepared by the two methods have comparable performance and enhanced catalytic activity towards methanol electro-oxidation compared to Pt/Pt and smooth Pt electrodes. Steady state Tafel plots experiments show a higher rate of methanol oxidation on a Pt/Ti catalyst than that on a smooth Pt. Introduction of a small amount of Sn deposited with Pt improves the catalytic activity and the stability of prepared electrode with time as indicated from the cyclic votlammetry and the chronoamperometric experiments. The effect of variations in the composition for binary catalysts of the type Ptx-Sny/Ti towards the methanol oxidation reaction is reported. Consequently, the Ptx-Sny/Ti (x∶y (8∶1), molar ratio) catalyst is a very promising one for methanol oxidation.
文摘The conversion of carbon dioxide into value-added products is of great industrial and environmental interest. However, as carbon dioxide is relatively stable, the input energy required for this conversion is a significant limiting factor in the system's performance. By utilising energy from the sun, through a range of key routes, this limitation can be overcome. In this review, we present a comprehensive and critical overview of the potential routes to harvest the sun's energy, primarily through solar-thermal technologies and plasmonic resonance effects. Focusing on the localised heating approach, this review shortlists and compares viable catalysts for the photo-thermal catalytic conversion of carbon dioxide.Further, the pathways and potential products of different carbon dioxide conversion routes are outlined with the reverse water gas shift,methanation, and methanol synthesis being of key interest. Finally, the challenges in implementing such systems and the outlook to the future are detailed.
文摘Y 2O 3/TiO 2 samples were prepared by sol-gel process and characterized by means of X-ray diffraction (XRD), laser Raman spectra (LRS), UV-visible diffuse reflectance spectra (DRS), specific surface area (BET), and transmission electron microscopy (TEM). The results show that the relative intensity of 101 peak of anatase and 002 peak of rutile, the mean crystal diameter and mean particle diameter of Y 2O 3/TiO 2 samples decrease while specific surface area increases owing to doping Y 2O 3. Y 2O 3/TiO 2 samples have a larger specific surface area and higher thermal stability. Owing to quantum size effect, the reflectance of Y 2O 3/TiO 2 samples is larger than that of pure TiO 2 in the range of 380～460 nm and the position of Raman peaks varies slightly. Being a model reaction, the photo-catalytic degradation of methylene blue (MB) with positive charge and methyl orange (MO) with negative charge was investigated in TiO 2 and Y 2O 3/TiO 2 nanopowder suspension irradiated by high-pressure mercury lamp. As a result, the addition of Y 2O 3 to TiO 2 is detrimental to photo-activity of TiO 2 for MB photo-degradation and photo-catalytic behavior is enhanced due to 5%, 10% Y 2O 3 deposited on TiO 2 for the photo-degradation of MO. And the relationship between photo-physical properties and photo-activity was discussed.
基金Funded by the National Natural Science Foundation of China(No.11404229)Sichuan Province Science&Technology Supporting Program(No.2013GZX0145)
文摘X-ray diffraction, scanning electron microscopy and transmission electron microscopy were employed to investigate the microstructure and morphology of Au NPs/ZnO NTs, and their photo-catalytic capability was assessed to a nicety. The results demonstrated that the diameter and the wall thickness of ZnO nanotube were about 200 and 50 nm, respectively. The diameter of Au nanoparticle was about 30 nm. The characterization on the photo-catalytic capability of the Au-ZnO nanotube hybrid indicated that the degradation of methyl orange was 80% within 4 h. Controlled experiments have shown that Au-Zn O nanotube hybrid presents superior photo-catalytic capability to both bare ZnO nanorod and Au-ZnO nanorod hybrid indicated that the degradation procedure of methyl orange.
基金the EU for the Intra European Marie Curie Research Fellowship (PIEFGA-2013-623227)
文摘We report the synthesis, characterisation and catalytic performance of two nature-inspired biomassderived electro-catalysts for the oxygen reduction reaction in fuel cells. The catalysts were prepared via pyrolysis of a real food waste(lobster shells) or by mimicking the composition of lobster shells using chitin and CaCO_3 particles followed by acid washing. The simplified model of artificial lobster was prepared for better reproducibility. The calcium carbonate in both samples acts as a pore agent, creating increased surface area and pore volume, though considerably higher in artificial lobster samples due to the better homogeneity of the components. Various characterisation techniques revealed the presence of a considerable amount of hydroxyapatite left in the real lobster samples after acid washing and a low content of carbon(23%), nitrogen and sulphur(<1%), limiting the surface area to 23 m^2/g, and consequently resulting in rather poor catalytic activity. However, artificial lobster samples, with a surface area of ≈200 m^2/g and a nitrogen doping of 2%, showed a promising onset potential, very similar to a commercially available platinum catalyst, with better methanol tolerance, though with lower stability in long time testing over 10,000 s.
