In this paper, core–shell quantum dots(QDs) with two polar surface functional groups(ZnSe/ZnS–COOH QDs and ZnSe/ZnS–NH_2 QDs) are synthesized in an aqueous phase. Photoluminescence(PL) and absorption spectra clearl...In this paper, core–shell quantum dots(QDs) with two polar surface functional groups(ZnSe/ZnS–COOH QDs and ZnSe/ZnS–NH_2 QDs) are synthesized in an aqueous phase. Photoluminescence(PL) and absorption spectra clearly indicate luminescence down-shifting(LDS) properties. On the basis of QDs, surface functional group multilayer LDS films(MLDSs) are fabricated through an electrostatic layer-by-layer(LBL) self-assembly method. The PL intensity increases linearly with the number of bilayers, showing a regular and uniform film growth. When the M-LDS is placed on the surface of a Si-based solar cell as an optical conversion layer for the first time, the external quantum efficiency(EQE) and shortcircuit current density(Jsc) notably increases for the LDS process. The EQE response improves in a wavelength region extending from the UV region to the blue region, and its maximum increase reaches more than 15% between 350 nm and 460 nm.展开更多
Dry reforming of ethane(DRE)has received significant attention because of its potential to produce chemical raw materials and reduce carbon emissions.Herein,a composition-induced strong metal-support interaction(SMSI)...Dry reforming of ethane(DRE)has received significant attention because of its potential to produce chemical raw materials and reduce carbon emissions.Herein,a composition-induced strong metal-support interaction(SMSI)effect over FeNi/Al-Ce-O catalysts is revealed via X-ray photoelectron spectroscopy(XPS),H_(2)-temperature programmed reduction(TPR),and energy dispersive X-ray spectroscopy(EDS)elemental mapping.The introduction of Al into Al-Ce-O supports significantly influences the dispersion of surface active components and improves the catalytic performance for DRE over supported FeNi catalysts due to enhancement of the SMSI effect.The catalytic properties,for example,C_(2)H_(6) and CO_(2) conversion,CO selectivity and yield,and turnover frequencies(TOFs),of supported FeNi catalysts first increase and then decrease with increasing Al content,following the same trend as the theoretical effective surface area(TESA)of the corresponding catalysts.The FeNi/Ce-Al_(0.5) catalyst,with 50%Al content,exhibits the best DRE performance under steady-state conditions at 873 K.As observed by with in situ Fourier transform infrared spectroscopy(FTIR)analysis,the introduction of Al not only increases the content of surface Ce3+and oxygen vacancies but also promotes the dispersion of surface active components,which further alters the catalytic properties for DRE over supported FeNi catalysts.展开更多
基金Project supported by the Natural Science Foundation of Shandong Province,China(Grant No.ZR2017PF011)the National Natural Science Foundation of China(Grant No.E020701)the Doctoral Scientific Research Foundation of Binzhou University,China(Grant No.2014Y10)
文摘In this paper, core–shell quantum dots(QDs) with two polar surface functional groups(ZnSe/ZnS–COOH QDs and ZnSe/ZnS–NH_2 QDs) are synthesized in an aqueous phase. Photoluminescence(PL) and absorption spectra clearly indicate luminescence down-shifting(LDS) properties. On the basis of QDs, surface functional group multilayer LDS films(MLDSs) are fabricated through an electrostatic layer-by-layer(LBL) self-assembly method. The PL intensity increases linearly with the number of bilayers, showing a regular and uniform film growth. When the M-LDS is placed on the surface of a Si-based solar cell as an optical conversion layer for the first time, the external quantum efficiency(EQE) and shortcircuit current density(Jsc) notably increases for the LDS process. The EQE response improves in a wavelength region extending from the UV region to the blue region, and its maximum increase reaches more than 15% between 350 nm and 460 nm.
基金support from the National Key Research and Development Program of China(2017YFB0702800)the China Petrochemical Corporation(Sinopec Group)the National Natural Science Foundation of China(91434102 and U1663221)。
文摘Dry reforming of ethane(DRE)has received significant attention because of its potential to produce chemical raw materials and reduce carbon emissions.Herein,a composition-induced strong metal-support interaction(SMSI)effect over FeNi/Al-Ce-O catalysts is revealed via X-ray photoelectron spectroscopy(XPS),H_(2)-temperature programmed reduction(TPR),and energy dispersive X-ray spectroscopy(EDS)elemental mapping.The introduction of Al into Al-Ce-O supports significantly influences the dispersion of surface active components and improves the catalytic performance for DRE over supported FeNi catalysts due to enhancement of the SMSI effect.The catalytic properties,for example,C_(2)H_(6) and CO_(2) conversion,CO selectivity and yield,and turnover frequencies(TOFs),of supported FeNi catalysts first increase and then decrease with increasing Al content,following the same trend as the theoretical effective surface area(TESA)of the corresponding catalysts.The FeNi/Ce-Al_(0.5) catalyst,with 50%Al content,exhibits the best DRE performance under steady-state conditions at 873 K.As observed by with in situ Fourier transform infrared spectroscopy(FTIR)analysis,the introduction of Al not only increases the content of surface Ce3+and oxygen vacancies but also promotes the dispersion of surface active components,which further alters the catalytic properties for DRE over supported FeNi catalysts.
