In the present study, we investigated the effect of cerium and erbium doping of the zirconium dioxide matrix. We synthesized doped samples using hydrothermal process. The amounts of dopant used were 0.5%, 1% and 5% mo...In the present study, we investigated the effect of cerium and erbium doping of the zirconium dioxide matrix. We synthesized doped samples using hydrothermal process. The amounts of dopant used were 0.5%, 1% and 5% molar(rare earth oxide over zirconium dioxide) respectively. The samples have been studied via X-ray Diffraction measurements for the structural characterization. UV visible diffuse reflectance was used for the optical analysis, Brunauer-Emmett-Teller(BET) model for the measurement of the surface area. Finally the samples have been analysed via electron paramagnetic resonance(EPR) for the electronic characterization. Then we tested the new synthetized materials to determine their photocatalytic activity in the reaction of degradation of methylene blue performed under irradiation by diodes(LEDs) emitting exclusively visible light.展开更多
Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce（NO3）3·6H2O as precursors by supercritical fluid drying ...Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce（NO3）3·6H2O as precursors by supercritical fluid drying （SCFD） technology. The catalysts were characterized by means of XRD and TEM. The particle size of nanocomposite oxide photocatalysts synthesized by SCFD method is about 6 - 11 nm, which is smaller than those obtained by common drying method （CD）. The phase transformation from anatase to rutile was inhibited by SCFD technology. The peaks of SiO2 and CeO2 in XRD patterns indicate that a SiO2 amorphorous phase exists in all the samples and CeO2 is well dispersed on the surface of TiO2. The orthogonal test was designed to optimize the preparing conditions. It is found that ceria dop;.ng enhances the photocatalyric activity markedly, and the optimum doping of CeO2 is 0.1%. The thermal stability of photocatalyst can be improved ; the growth of particle-size and the decrease of surface area can be prohibited by doping of SlOe. Heat-treatment is a necessary factor to induce chemistry change of Ti-Si surface. The optimum heat-treating temperature is 600℃. A novel and efficient Ti-Ce-Si ternary nanocomposite was prepared by SCFI） method with strong thermal stability and high photoactivity in the photodegratation of phenol.展开更多
针对Bi_(2)MoO_(6)光催化剂在光催化反应过程中电子-空穴对分离效率低的问题,以期通过稀土离子掺杂对其光催化性能进行改性.采用溶剂热法合成了系列稀土离子掺杂的Bi_(2)MoO_(6)光催化剂,即为RE3+/Bi_(2)MoO_(6)(RE3+=Tb3+、Sm3+).通过...针对Bi_(2)MoO_(6)光催化剂在光催化反应过程中电子-空穴对分离效率低的问题,以期通过稀土离子掺杂对其光催化性能进行改性.采用溶剂热法合成了系列稀土离子掺杂的Bi_(2)MoO_(6)光催化剂,即为RE3+/Bi_(2)MoO_(6)(RE3+=Tb3+、Sm3+).通过多种分析手段对RE3+/Bi_(2)MoO_(6)材料的组成、结构和形貌进行了表征,并以有机染料罗丹明B(RhB)为模拟污染物,研究了该材料在可见光下的光催化活性.结果表明:稀土Tb3+、Sm3+离子掺杂改性后,样品的比表面积增大,并且对其能带结构、可见光吸收范围均有所调节,光生电子-空穴对的分离效率提高.在可见光下,样品4%Tb3+/Bi_(2)MoO_(6)和4%Sm3+/Bi_(2)MoO_(6)对50 mL 10 mg/L RhB的光降解率均达95%以上,较纯相Bi_(2)MoO_(6)的光催化效率提升了近2倍.展开更多
Rare earth metals are strategic resources with potential applications in optics,metallurgy and catalysis.In recent years,single-atom site catalysts(SASCs) have attracted increasing attention owing to their 100%atom ef...Rare earth metals are strategic resources with potential applications in optics,metallurgy and catalysis.In recent years,single-atom site catalysts(SASCs) have attracted increasing attention owing to their 100%atom efficiency and unique catalytic performances.Over the past decade,rare earth elements,including rare earth metals and their oxides,have shown great potential in SASCs.However,systematic analyses of data are still handful.In this mini-review,the use of rare earth metals and their oxides in SASCs was summarized and the results are discussed.A particular focus was paid to the synthetic strategies,characterization of rare earth-containing SASCs,and applications as catalysis supports,promoters and active sites.Current issues faced by rare-earth metals and their oxides in SASCs,as well as future prospects were also provided.展开更多
Efficient photocatalysis and electrocatalysis in energy conversion have been important strategies to alleviate energy crises and environmental issues.In recent years,with the rapid development of emerging catalysts,si...Efficient photocatalysis and electrocatalysis in energy conversion have been important strategies to alleviate energy crises and environmental issues.In recent years,with the rapid development of emerging catalysts,significant progress has been made in photocatalysis for converting solar energy into chemical energy and electrocatalysis for converting electrical energy into chemical energy.However,their selectivity and efficiency of the products are poor.Rare earth(RE)can achieve atomic level fine regulation of catalysts and play an crucial role in optimizing catalyst performance by their unique electronic and orbital structures.However,there is a lack of systematic review on the atomic interface regulation mechanism of RE and their role in energy conversion processes.Single atom catalysts(SACs)provide clear active sites and 100%atomic utilization,which is conducive to exploring the regulatory mechanisms of RE.Therefore,this review mainly takes atomic level doped RE as an example to review and discuss the atomic interface regulation role of RE elements in energy conversion.Firstly,a brief introduction was given to the synthesis strategies that can effectively exert the atomic interface regulation effect of RE,with a focus on the atomic interface regulation mechanism of RE.Meanwhile,the regulatory mechanisms of RE atoms have been systematically summarized in various energy conversion applications.Finally,the challenges faced by RE in energy conversion,as well as future research directions and prospects,were pointed out.展开更多
基金supported by the CARIPLO Foundation with the Advanced Materials Grant 2013 "Development of second generation photocatalysts for energy and environment"the Local Funding of the University of Torino call_2014_L2_126
文摘In the present study, we investigated the effect of cerium and erbium doping of the zirconium dioxide matrix. We synthesized doped samples using hydrothermal process. The amounts of dopant used were 0.5%, 1% and 5% molar(rare earth oxide over zirconium dioxide) respectively. The samples have been studied via X-ray Diffraction measurements for the structural characterization. UV visible diffuse reflectance was used for the optical analysis, Brunauer-Emmett-Teller(BET) model for the measurement of the surface area. Finally the samples have been analysed via electron paramagnetic resonance(EPR) for the electronic characterization. Then we tested the new synthetized materials to determine their photocatalytic activity in the reaction of degradation of methylene blue performed under irradiation by diodes(LEDs) emitting exclusively visible light.
文摘Ti-Ce, Ti-Si binary and Ti-Ce-Si ternary novel nanocomposite oxide photocatalysts were prepared with cheap inorganic salts TiCI4, Na2SiO3·9H2O and Ce（NO3）3·6H2O as precursors by supercritical fluid drying （SCFD） technology. The catalysts were characterized by means of XRD and TEM. The particle size of nanocomposite oxide photocatalysts synthesized by SCFD method is about 6 - 11 nm, which is smaller than those obtained by common drying method （CD）. The phase transformation from anatase to rutile was inhibited by SCFD technology. The peaks of SiO2 and CeO2 in XRD patterns indicate that a SiO2 amorphorous phase exists in all the samples and CeO2 is well dispersed on the surface of TiO2. The orthogonal test was designed to optimize the preparing conditions. It is found that ceria dop;.ng enhances the photocatalyric activity markedly, and the optimum doping of CeO2 is 0.1%. The thermal stability of photocatalyst can be improved ; the growth of particle-size and the decrease of surface area can be prohibited by doping of SlOe. Heat-treatment is a necessary factor to induce chemistry change of Ti-Si surface. The optimum heat-treating temperature is 600℃. A novel and efficient Ti-Ce-Si ternary nanocomposite was prepared by SCFI） method with strong thermal stability and high photoactivity in the photodegratation of phenol.
文摘针对Bi_(2)MoO_(6)光催化剂在光催化反应过程中电子-空穴对分离效率低的问题,以期通过稀土离子掺杂对其光催化性能进行改性.采用溶剂热法合成了系列稀土离子掺杂的Bi_(2)MoO_(6)光催化剂,即为RE3+/Bi_(2)MoO_(6)(RE3+=Tb3+、Sm3+).通过多种分析手段对RE3+/Bi_(2)MoO_(6)材料的组成、结构和形貌进行了表征,并以有机染料罗丹明B(RhB)为模拟污染物,研究了该材料在可见光下的光催化活性.结果表明:稀土Tb3+、Sm3+离子掺杂改性后,样品的比表面积增大,并且对其能带结构、可见光吸收范围均有所调节,光生电子-空穴对的分离效率提高.在可见光下,样品4%Tb3+/Bi_(2)MoO_(6)和4%Sm3+/Bi_(2)MoO_(6)对50 mL 10 mg/L RhB的光降解率均达95%以上,较纯相Bi_(2)MoO_(6)的光催化效率提升了近2倍.
基金Project supported by the China Postdoctoral Science Foundation(2020M670355)the National Key R&D Program of China(2016YFC0204305)National Natural Science Foundation of China(21777004)。
文摘Rare earth metals are strategic resources with potential applications in optics,metallurgy and catalysis.In recent years,single-atom site catalysts(SASCs) have attracted increasing attention owing to their 100%atom efficiency and unique catalytic performances.Over the past decade,rare earth elements,including rare earth metals and their oxides,have shown great potential in SASCs.However,systematic analyses of data are still handful.In this mini-review,the use of rare earth metals and their oxides in SASCs was summarized and the results are discussed.A particular focus was paid to the synthetic strategies,characterization of rare earth-containing SASCs,and applications as catalysis supports,promoters and active sites.Current issues faced by rare-earth metals and their oxides in SASCs,as well as future prospects were also provided.
基金support from the National Natural Science Foundation of China(Nos.21875021,22075024)the Beijing Natural Science Foundation(No.2212018).
文摘Efficient photocatalysis and electrocatalysis in energy conversion have been important strategies to alleviate energy crises and environmental issues.In recent years,with the rapid development of emerging catalysts,significant progress has been made in photocatalysis for converting solar energy into chemical energy and electrocatalysis for converting electrical energy into chemical energy.However,their selectivity and efficiency of the products are poor.Rare earth(RE)can achieve atomic level fine regulation of catalysts and play an crucial role in optimizing catalyst performance by their unique electronic and orbital structures.However,there is a lack of systematic review on the atomic interface regulation mechanism of RE and their role in energy conversion processes.Single atom catalysts(SACs)provide clear active sites and 100%atomic utilization,which is conducive to exploring the regulatory mechanisms of RE.Therefore,this review mainly takes atomic level doped RE as an example to review and discuss the atomic interface regulation role of RE elements in energy conversion.Firstly,a brief introduction was given to the synthesis strategies that can effectively exert the atomic interface regulation effect of RE,with a focus on the atomic interface regulation mechanism of RE.Meanwhile,the regulatory mechanisms of RE atoms have been systematically summarized in various energy conversion applications.Finally,the challenges faced by RE in energy conversion,as well as future research directions and prospects,were pointed out.
