摘要
Photocatalytic CO_(2)reduction into value-added chemicals holds significant promise for carbon-neutral recycling and solar-to-fuel conversion.Enhancing reaction efficiency by manipulating charge transfer is a key approach to unlocking this potential.In this work,we construct a two-dimensional/twodimensional(2D/2D)FeSe_(2)/protonated carbon nitride(FeSe_(2)/PCN)heterostructure to promote the interfacial charge transfer dynamics,leading to a four-fold improved conversion efficiency of photocatalytic CO_(2)reduction with near 100%CO selectivity.Combining in situ X-ray photoelectron spectroscopy,in situ soft X-ray absorption spectroscopy,and femtosecond transient absorption spectroscopy,it is revealed that FeSe_(2)acts as an electron acceptor upon photoexcitation,introducing an additional electron transfer pathway from PCN to FeSe_(2)that suppresses radiative recombination and promotes charge transfer.In situ X-ray absorption fine structure spectroscopy,in situ diffuse reflectance infrared Fourier transform spectroscopy,and density functional theory calculation further unravel that the electron-enriched FeSe_(2)functions as the active sites for CO_(2)activation and significantly reduces the energy barrier of key intermediate COOH*formation,which is the rate-determined step for CO generation.This work underscores the importance of regulating photocarrier relaxation pathways to achieve effective spatial charge separation for promoted photocatalytic CO_(2)reduction and demonstrates the powerful functions of in situ spectroscopies in in-depth understanding of the photocatalytic mechanism.
基金
supported by the National Natural Science Foundation of China(12241502,92045301)
Fundamental Research Funds for the Central Universities(20720220010)
USTC Research Funds of the Double First-Class Initiative(YD2310002012)
the Launching Special Funds of Scientific Research for Introduced Talents from University of Science and Technology of China(KY2310000060)
National Key Research and Development Program of China(2019YFA0405602)
Anhui Provincial Natural Science Foundation(2408085QB049)
the Instruments Center for Physical Science and USTC Center for Micro and Nanoscale Research and Fabrication,University of Science and Technology of China
the solid supports from the BL03U,BL10B,and BL12B beamlines of the National Synchrotron Radiation Laboratory(NSRL,Hefei)
the Shanghai Synchrotron Radiation Facility(SSRF,Shanghai)of BL11B(https://cstr.cn/31124.02.SSRF.BL11B)and BL14W1(https://cstr.cn/31124.02.SSRF.BL14W1)beamlines for the assistance on XAFS measurements
Anhui Chuangpu Instruments Co.,Ltd.for the assistance in the test of Table XAFS。
