CaMg(CO3)2microspheres were prepared and used as hard templates to fabricate a series of CaMg(CO3)2@Ag2CO3composite microspheres via a fast and low‐cost ion exchange process.The effects of ion exchange time and tempe...CaMg(CO3)2microspheres were prepared and used as hard templates to fabricate a series of CaMg(CO3)2@Ag2CO3composite microspheres via a fast and low‐cost ion exchange process.The effects of ion exchange time and temperature on the physicochemical properties and photocatalytic activities of the composite microspheres were studied through photocatalytic degradation of Acid Orange II under xenon lamp irradiation.The obtained samples were analyzed by X‐ray diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,UV‐vis diffuse reflectance spectroscopy,N2physical adsorption,and photocurrent tests.The CaMg(CO3)2@Ag2CO3sample with the highest activity was obtained with an ion exchange time of4h and temperature of40°C.The degradation rate of Acid Orange II by this sample reached83.3%after15min of light irradiation,and the sample also performed well in phenol degradation.The CaMg(CO3)2@Ag2CO3produced under these ion exchange conditions showed a well‐ordered hierarchical morphology with small particle sizes,which was beneficial to light absorption and the transfer of photoelectrons(e-)and holes(h+)to the catalyst surface.Moreover,the separation of photogenerated carriers over the composites was greatly improved relative to bare CaMg(CO3)2.Despite the very low content of Ag2CO3(2.56%),excellent photocatalytic performance was obtained over the CaMg(CO3)2@Ag2CO3microspheres.展开更多
As sustainable energy becomes a major concern for modern society,renewable and clean energy systems need highly active,stable,and low-cost catalysts for the oxygen evolution reaction(OER).Mesoporous materials offer an...As sustainable energy becomes a major concern for modern society,renewable and clean energy systems need highly active,stable,and low-cost catalysts for the oxygen evolution reaction(OER).Mesoporous materials offer an attractive route for generating efficient electrocatalysts with high mass transport capabilities.Herein,we report an efficient hard templating pathway to design and synthesize three-dimensional(3-D)mesoporous ternary nickel iron nitride(Ni3FeN).The as-synthesized electrocatalyst shows good OER performance in an alkaline solution with low overpotential(259 mV)and a small Tafel slope(54 mV dec?1),giving superior performance to IrO2 and RuO2 catalysts.The highly active contact area,the hierarchical porosity,and the synergistic effect of bimetal atoms contributed to the improved electrocatalytic performance toward OER.In a practical rechargeable Zn–air battery,mesoporous Ni3FeN is also shown to deliver a lower charging voltage and longer lifetime than RuO2.This work opens up a new promising approach to synthesize active OER electrocatalysts for energy-related devices.展开更多
Highly ordered 2D and 3D-Co3O4 catalysts were prepared using SBA-15 and KIT-6 as templates. Na- no-Co304 catalyst was obtained by calcination of cobalt nitrate as a comparison. The BET surface area of nano- CO304, 2D-...Highly ordered 2D and 3D-Co3O4 catalysts were prepared using SBA-15 and KIT-6 as templates. Na- no-Co304 catalyst was obtained by calcination of cobalt nitrate as a comparison. The BET surface area of nano- CO304, 2D-Co3O4 and 3D-Co3O4 catalysts was 16.2, 63.9 and 75.1 mE/g, respectively. All the catalysts were tested for the total combustion of methane and their catalytic performance was in the order of 3D-Co3O4（T90=355℃）〉 2D-CoaO4（T90=383℃）〉nano-Co3O4（T90=455℃）. It was also found that the order of the areal specific reaction rates for the combustion of methane followed the same order of total activity. The characterization result demonstrates that enhanced catalytic performance of methane of the 2D-Co3O4 and 3D-Co3O4 catalysts is due to their pronounced reducibility and abundant active Co3O4 species, which was caused by the preferential exposure of {220} crystal planes in 3D-Co3O4 and 2D-Co3O4 catalysts compared to the nano-Co3O4.展开更多
基金supported by the National Natural Science Foundation of China(21567008,21607064,21707055,21763011)Program of Qingjiang Excellent Young Talents,Jiangxi University of Science and Technology+2 种基金Program of 5511 Talents in Scientific Technological Innovation of Jiangxi Province(20165BCB18014)Academic and Technical Leaders of the Main Disciplines in Jiangxi Province(20172BCB22018)Jiangxi Province Natural Science Foundation China(20161BAB203090,20161BAB213083,20171ACB21041)~~
文摘CaMg(CO3)2microspheres were prepared and used as hard templates to fabricate a series of CaMg(CO3)2@Ag2CO3composite microspheres via a fast and low‐cost ion exchange process.The effects of ion exchange time and temperature on the physicochemical properties and photocatalytic activities of the composite microspheres were studied through photocatalytic degradation of Acid Orange II under xenon lamp irradiation.The obtained samples were analyzed by X‐ray diffraction,scanning electron microscopy,Fourier transform infrared spectroscopy,UV‐vis diffuse reflectance spectroscopy,N2physical adsorption,and photocurrent tests.The CaMg(CO3)2@Ag2CO3sample with the highest activity was obtained with an ion exchange time of4h and temperature of40°C.The degradation rate of Acid Orange II by this sample reached83.3%after15min of light irradiation,and the sample also performed well in phenol degradation.The CaMg(CO3)2@Ag2CO3produced under these ion exchange conditions showed a well‐ordered hierarchical morphology with small particle sizes,which was beneficial to light absorption and the transfer of photoelectrons(e-)and holes(h+)to the catalyst surface.Moreover,the separation of photogenerated carriers over the composites was greatly improved relative to bare CaMg(CO3)2.Despite the very low content of Ag2CO3(2.56%),excellent photocatalytic performance was obtained over the CaMg(CO3)2@Ag2CO3microspheres.
基金supported by Chinese Academy of Sciences(Grant No.2018PS0011)100 Talent Plan of Chinese Academy of Sciences+4 种基金Natural Science Foundation of China(Grant No.61971405)the Department of Science and Technology(GoI)for support through the Project Nos.DST FILE NO.YSS/2015/001712,DST 11-IFAPH-07 and DST FILE NO.DST/TMD/SERI/HUBthe financial support from Equipment Research Program(Grant No.6140721050215)the Ontario Ministry of Research and Innovation(ER15-11-123)the Natural Science and Engineering Council of Canada(RGPIN-2019-05994).
文摘As sustainable energy becomes a major concern for modern society,renewable and clean energy systems need highly active,stable,and low-cost catalysts for the oxygen evolution reaction(OER).Mesoporous materials offer an attractive route for generating efficient electrocatalysts with high mass transport capabilities.Herein,we report an efficient hard templating pathway to design and synthesize three-dimensional(3-D)mesoporous ternary nickel iron nitride(Ni3FeN).The as-synthesized electrocatalyst shows good OER performance in an alkaline solution with low overpotential(259 mV)and a small Tafel slope(54 mV dec?1),giving superior performance to IrO2 and RuO2 catalysts.The highly active contact area,the hierarchical porosity,and the synergistic effect of bimetal atoms contributed to the improved electrocatalytic performance toward OER.In a practical rechargeable Zn–air battery,mesoporous Ni3FeN is also shown to deliver a lower charging voltage and longer lifetime than RuO2.This work opens up a new promising approach to synthesize active OER electrocatalysts for energy-related devices.
基金Supported by the National Natural Science Foundation of China（No.21373186）.
文摘Highly ordered 2D and 3D-Co3O4 catalysts were prepared using SBA-15 and KIT-6 as templates. Na- no-Co304 catalyst was obtained by calcination of cobalt nitrate as a comparison. The BET surface area of nano- CO304, 2D-Co3O4 and 3D-Co3O4 catalysts was 16.2, 63.9 and 75.1 mE/g, respectively. All the catalysts were tested for the total combustion of methane and their catalytic performance was in the order of 3D-Co3O4（T90=355℃）〉 2D-CoaO4（T90=383℃）〉nano-Co3O4（T90=455℃）. It was also found that the order of the areal specific reaction rates for the combustion of methane followed the same order of total activity. The characterization result demonstrates that enhanced catalytic performance of methane of the 2D-Co3O4 and 3D-Co3O4 catalysts is due to their pronounced reducibility and abundant active Co3O4 species, which was caused by the preferential exposure of {220} crystal planes in 3D-Co3O4 and 2D-Co3O4 catalysts compared to the nano-Co3O4.
