Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing activity.Herein,we designed a surface oxygen-injection strategy to tune th...Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing activity.Herein,we designed a surface oxygen-injection strategy to tune the electronic structure of SnS_(2) nanosheets,which showed effectively enhanced electrocatalytic activity and selectivity of CO_(2) reduction to formate and syngas(CO and H_(2)).The oxygen-injection SnS_(2) nanosheets exhibit a remarkable Faradaic efficiency of 91.6%for carbonaceous products with a current density of 24.1 mA cm^(−2) at−0.9 V vs RHE,including 83.2%for formate production and 16.5%for syngas with the CO/H_(2) ratio of 1:1.By operando X-ray absorption spectroscopy,we unravel the in situ surface oxygen doping into the matrix during reaction,thereby optimizing the Sn local electronic states.Operando synchrotron radiation infrared spectroscopy along with theoretical calculations further reveals that the surface oxygen doping facilitated the CO_(2) activation and enhanced the affinity for HCOO*species.This result demonstrates the potential strategy of surface oxygen injection for the rational design of advanced catalysts for CO_(2) electroreduction.展开更多
The properties of two-dimensional(2D)materials are highly dependent on their phase and thickness.Various phases exist in tin disulfide(SnS_(2)),resulting in promising electronic and optical properties.Hence,accurately...The properties of two-dimensional(2D)materials are highly dependent on their phase and thickness.Various phases exist in tin disulfide(SnS_(2)),resulting in promising electronic and optical properties.Hence,accurately identifying the phase and thickness of SnS_(2)nanosheets is prior to their optoelectronic applications.Herein,layered 2H-SnS_(2)and 4H-SnS_(2)crystals were grown by chemical vapor transportation and the crystalline phase of SnS_(2)was characterized by X-ray diffraction,ultralow frequency(ULF)Raman spectroscopy and high-resolution transmission electron microscope.As-grown crystals were mechanically exfoliated to single-and few-layer nanosheets,which were investigated by optical microscopy,atomic force microscopy and ULF Raman spectroscopy.Although the 2H-SnS_(2)and 4H-SnS_(2)nanosheets have similar optical contrast on SiO_(2)/Si substrates,their ULF Raman spectra obviously show different shear and breathing modes,which are highly dependent on their phases and thicknesses.Interestingly,the SnS_(2)nanosheets have shown phase-dependent electrical properties.The 4H-SnS_(2)nanosheet shows a current on/off ratio of 2.58×10^(5) and excellent photosensitivity,which are much higher than those of the 2H-SnS_(2)nanosheet.Our work not only offers an accurate method for identifying single-and few-layer SnS_(2)nanosheets with different phases,but also paves the way for the application of SnS_(2)nanosheets in highperformance optoelectronic devices.展开更多
基金This work was supported by National Natural Science Foundation of China(Grants No.12025505)China Ministry of Science and Technology(2017YFA0208300)+2 种基金Youth Innovation Promotion Association CAS(CX2310007007 and CX2310000091)Open Fund Project of State Key Laboratory of Environmentally Friendly Energy Materials(20kfhg08)We would thank NSRL and SSRF for the synchrotron beam time.The calculations were performed on the supercomputing system in the Supercomputing Center of University of Science and Technology of China.
文摘Surface chemistry modification represents a promising strategy to tailor the adsorption and activation of reaction intermediates for enhancing activity.Herein,we designed a surface oxygen-injection strategy to tune the electronic structure of SnS_(2) nanosheets,which showed effectively enhanced electrocatalytic activity and selectivity of CO_(2) reduction to formate and syngas(CO and H_(2)).The oxygen-injection SnS_(2) nanosheets exhibit a remarkable Faradaic efficiency of 91.6%for carbonaceous products with a current density of 24.1 mA cm^(−2) at−0.9 V vs RHE,including 83.2%for formate production and 16.5%for syngas with the CO/H_(2) ratio of 1:1.By operando X-ray absorption spectroscopy,we unravel the in situ surface oxygen doping into the matrix during reaction,thereby optimizing the Sn local electronic states.Operando synchrotron radiation infrared spectroscopy along with theoretical calculations further reveals that the surface oxygen doping facilitated the CO_(2) activation and enhanced the affinity for HCOO*species.This result demonstrates the potential strategy of surface oxygen injection for the rational design of advanced catalysts for CO_(2) electroreduction.
基金supported by the National Natural Science Foun-dation of China(Nos.51832001,21571101 and 51322202)the Natural Science Foundation of Jiangsu Province in China(No.BK20161543)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China(No.15KJB430016).
文摘The properties of two-dimensional(2D)materials are highly dependent on their phase and thickness.Various phases exist in tin disulfide(SnS_(2)),resulting in promising electronic and optical properties.Hence,accurately identifying the phase and thickness of SnS_(2)nanosheets is prior to their optoelectronic applications.Herein,layered 2H-SnS_(2)and 4H-SnS_(2)crystals were grown by chemical vapor transportation and the crystalline phase of SnS_(2)was characterized by X-ray diffraction,ultralow frequency(ULF)Raman spectroscopy and high-resolution transmission electron microscope.As-grown crystals were mechanically exfoliated to single-and few-layer nanosheets,which were investigated by optical microscopy,atomic force microscopy and ULF Raman spectroscopy.Although the 2H-SnS_(2)and 4H-SnS_(2)nanosheets have similar optical contrast on SiO_(2)/Si substrates,their ULF Raman spectra obviously show different shear and breathing modes,which are highly dependent on their phases and thicknesses.Interestingly,the SnS_(2)nanosheets have shown phase-dependent electrical properties.The 4H-SnS_(2)nanosheet shows a current on/off ratio of 2.58×10^(5) and excellent photosensitivity,which are much higher than those of the 2H-SnS_(2)nanosheet.Our work not only offers an accurate method for identifying single-and few-layer SnS_(2)nanosheets with different phases,but also paves the way for the application of SnS_(2)nanosheets in highperformance optoelectronic devices.
基金financially supported by the National Natural Science Foundation of China(NSFC,U21A20500,52072115,51972102)the Natural Science Project of Hubei Province in China(2023AFB758,2022CFB518)。
