Homogeneous Zn Se nanocrystals were prepared via surfactant-assisted hydrothermal method.Surfactants agent CTAB was used to control the particle morphology and the growth rate.The structure,morphology and optical prop...Homogeneous Zn Se nanocrystals were prepared via surfactant-assisted hydrothermal method.Surfactants agent CTAB was used to control the particle morphology and the growth rate.The structure,morphology and optical properties of Zn Se nanocrystals have been investigated by XRD,TEM and luminescence spectroscopy.The results indicated that the size of Zn Se nanocrystals ranged from 3.0 nm to 5.0 nm with cubic zinc blende structure.Zn Se nanocrystals coated by CTAB were revealed high dispersibility and distribution under TEM.Compared to the bulk Zn Se,the absorption edges and photoluminescence peaks of Zn Se nanocrystals were blue shifted to higher energies due to the quantum confinement effect.The emission intensity was strengthened after coated CTAB compared to bare sample.This was mainly due to the surface passivation.Meanwhile,we simply explored the formation mechanism of Zn Se nanocrystal in hydrothermal system.展开更多
Recently,cyclic(alkyl)(amino)carbenes(CAACs)have been widely used as ligands to enhance the catalytic reactivity of center metal,but the problem of recycling this expensive ligand remains to be solved.In this work,the...Recently,cyclic(alkyl)(amino)carbenes(CAACs)have been widely used as ligands to enhance the catalytic reactivity of center metal,but the problem of recycling this expensive ligand remains to be solved.In this work,the heterogeneous SBA-15-CAAC-Ir catalyst was prepared by a covalent attachment method.and using SBA-15 as the carrier.It shows high reactivity for the hydrogenation of CO_(2) to formate.After immobilization,the ordered mesoporous structure and the overall rod-like morphology of the original SBA-15 have been preserved very well.Using SBA-15-CAAC-Ir as catalyst,up to 21050 TON can be obtained at 60℃.In addition,the catalyst can be separated easily by centrifugation,and the catalytic activity of SBA-15-CAAC-Ir can still remain very high after multiple cycles.展开更多
WO_(3) photoanodes have been widely utilized for the oxygen evolution reaction(OER)in the photoelectrochemical water splitting system.Herein,the effects of hydrazine hydrate modification and In^(3+)-doping on the phys...WO_(3) photoanodes have been widely utilized for the oxygen evolution reaction(OER)in the photoelectrochemical water splitting system.Herein,the effects of hydrazine hydrate modification and In^(3+)-doping on the physicochemical properties and photocurrent density of the WO_(3) photoanode prepared by hydrothermally treating at 160℃followed by calcining at 500℃are investigated.Among them,the hydrazine hydrate in the hydrothermal solution can serve as a texture regulator,resulting in the formation of WO_(3) films with the layered architecture stacked by nanosheets dominantly exposed(020)facets,which allows the WO_(3) films to have faster charge separation and larger specific surface area for OER according to the characterization results of microstructures and photoelectrochemcial behaviors;while the In^(3+)-doping can optimize the energy band structure of WO_(3) and adjust the work function to increase the driving force of OER based on the ultraviolet photoelectron spectroscopy,Mott–Schottky and open-circuit photovoltage plots.Under the simulated sunlight(AM1.5G)illumination,the designed In^(3+)–WO_(3)(N_2H_4)photoanode in Na_2SO_4 solution delivers amaximum incident photon-to-current efficiency of 38.6%at 410 nm and a photocurrent density of 1.93 mA cm^(-2)at 1.23 V vs.RHE,which is 2.8 and 3.0 times higher than the pristine WO_(3) photoanode,respectively.This study provides a promising strategy to improve the water splitting performance of nanostructured WO_(3) photoanodes by altering the architecture and introducing heteroatoms.展开更多
Selective separation of CO_(2) and H_(2)S from CH_(4) is of importance to the natural gas upgrading because of its cor-rosivity. As is well known, amine group can recognize reversibly CO_(2) and H_(2)S with a moderate...Selective separation of CO_(2) and H_(2)S from CH_(4) is of importance to the natural gas upgrading because of its cor-rosivity. As is well known, amine group can recognize reversibly CO_(2) and H_(2)S with a moderate interaction. Withthis in mind, this work prepared a series of amine-functionalized supported-protic-ionic-liquid membranes(SPILMs) for the selective separation of CO_(2) and H_(2)S from CH_(4) . For comparison, aprotic ionic liquid membranewas also prepared for natural gas sweetening. The effect of temperature and transmembrane pressure differenceon the permeability of single gas and ideal selectivity of CO_(2)/CH_(4) and H_(2)S/CO_(2) were studied. Facilitated transportmechanism was studied by NMR spectra. The permeability of CO_(2) in primary amine functionalized [DMPDAH][Tf_(2)N]-based membrane decreases with the increasing transmembrane pressure, indicating a typical feature offacilitated transport membrane. The permeability of CO_(2) and the ideal selective of CO_(2)/CH_(4) are as high as 2000 barrers and 53.2 at 313.2 K in [DMPDAH][Tf_(2)N] membrane, significantly higher than those in conventional ILsmembrane. It is anticipated that these amine-functionalized SPILMs can provide alternative insight for the se-lective separation of CO_(2) and H_(2)S from CH_(4) .展开更多
基金supported by the National Natural Science Foundation of China (10874061)Research Fund for the Doctoral Program of Higher Education (200807300010)the National Science Foundation for Distinguished Young Scholars (50925206)
文摘Homogeneous Zn Se nanocrystals were prepared via surfactant-assisted hydrothermal method.Surfactants agent CTAB was used to control the particle morphology and the growth rate.The structure,morphology and optical properties of Zn Se nanocrystals have been investigated by XRD,TEM and luminescence spectroscopy.The results indicated that the size of Zn Se nanocrystals ranged from 3.0 nm to 5.0 nm with cubic zinc blende structure.Zn Se nanocrystals coated by CTAB were revealed high dispersibility and distribution under TEM.Compared to the bulk Zn Se,the absorption edges and photoluminescence peaks of Zn Se nanocrystals were blue shifted to higher energies due to the quantum confinement effect.The emission intensity was strengthened after coated CTAB compared to bare sample.This was mainly due to the surface passivation.Meanwhile,we simply explored the formation mechanism of Zn Se nanocrystal in hydrothermal system.
基金supported by the National Natural Science Foundation of China(Nos.22178159,21878141)Key Research&Development Plan of Jiangsu Province(BE2019095)。
文摘Recently,cyclic(alkyl)(amino)carbenes(CAACs)have been widely used as ligands to enhance the catalytic reactivity of center metal,but the problem of recycling this expensive ligand remains to be solved.In this work,the heterogeneous SBA-15-CAAC-Ir catalyst was prepared by a covalent attachment method.and using SBA-15 as the carrier.It shows high reactivity for the hydrogenation of CO_(2) to formate.After immobilization,the ordered mesoporous structure and the overall rod-like morphology of the original SBA-15 have been preserved very well.Using SBA-15-CAAC-Ir as catalyst,up to 21050 TON can be obtained at 60℃.In addition,the catalyst can be separated easily by centrifugation,and the catalytic activity of SBA-15-CAAC-Ir can still remain very high after multiple cycles.
基金supported by the National Natural Science Foundation of China(21975190 and 25173166)the Science and Technology Planning Project of Shenzhen Municipality(JCYJ20180302153921190)+2 种基金the Characteristic Innovation Project of Colleges and Universities of Guangdong Province(2022KTSCX149)the Research Fund Project of Zhaoqing University(KY202136)the College Students’Innovative Project of Guangdong Province(pdjh2022b0556,X202210580144),China。
文摘WO_(3) photoanodes have been widely utilized for the oxygen evolution reaction(OER)in the photoelectrochemical water splitting system.Herein,the effects of hydrazine hydrate modification and In^(3+)-doping on the physicochemical properties and photocurrent density of the WO_(3) photoanode prepared by hydrothermally treating at 160℃followed by calcining at 500℃are investigated.Among them,the hydrazine hydrate in the hydrothermal solution can serve as a texture regulator,resulting in the formation of WO_(3) films with the layered architecture stacked by nanosheets dominantly exposed(020)facets,which allows the WO_(3) films to have faster charge separation and larger specific surface area for OER according to the characterization results of microstructures and photoelectrochemcial behaviors;while the In^(3+)-doping can optimize the energy band structure of WO_(3) and adjust the work function to increase the driving force of OER based on the ultraviolet photoelectron spectroscopy,Mott–Schottky and open-circuit photovoltage plots.Under the simulated sunlight(AM1.5G)illumination,the designed In^(3+)–WO_(3)(N_2H_4)photoanode in Na_2SO_4 solution delivers amaximum incident photon-to-current efficiency of 38.6%at 410 nm and a photocurrent density of 1.93 mA cm^(-2)at 1.23 V vs.RHE,which is 2.8 and 3.0 times higher than the pristine WO_(3) photoanode,respectively.This study provides a promising strategy to improve the water splitting performance of nanostructured WO_(3) photoanodes by altering the architecture and introducing heteroatoms.
基金This work was sponsored by the Natural Science Foundation of Jiangsu Province(BK20190310)China Postdoctoral Science Foundation(2021M691515)+1 种基金the Postdoctoral Science Foundation of Jiangsu Province(2021K211B)the National Natural Science Foundation of China(Nos.22078145 and 21878141)。
文摘Selective separation of CO_(2) and H_(2)S from CH_(4) is of importance to the natural gas upgrading because of its cor-rosivity. As is well known, amine group can recognize reversibly CO_(2) and H_(2)S with a moderate interaction. Withthis in mind, this work prepared a series of amine-functionalized supported-protic-ionic-liquid membranes(SPILMs) for the selective separation of CO_(2) and H_(2)S from CH_(4) . For comparison, aprotic ionic liquid membranewas also prepared for natural gas sweetening. The effect of temperature and transmembrane pressure differenceon the permeability of single gas and ideal selectivity of CO_(2)/CH_(4) and H_(2)S/CO_(2) were studied. Facilitated transportmechanism was studied by NMR spectra. The permeability of CO_(2) in primary amine functionalized [DMPDAH][Tf_(2)N]-based membrane decreases with the increasing transmembrane pressure, indicating a typical feature offacilitated transport membrane. The permeability of CO_(2) and the ideal selective of CO_(2)/CH_(4) are as high as 2000 barrers and 53.2 at 313.2 K in [DMPDAH][Tf_(2)N] membrane, significantly higher than those in conventional ILsmembrane. It is anticipated that these amine-functionalized SPILMs can provide alternative insight for the se-lective separation of CO_(2) and H_(2)S from CH_(4) .
