The strategy of incorporating earth-abundant catalytic centers into light-absorbing architectures is desirable from the viewpoint of low cost,low toxicity,and versatility for activating small molecules to produce sola...The strategy of incorporating earth-abundant catalytic centers into light-absorbing architectures is desirable from the viewpoint of low cost,low toxicity,and versatility for activating small molecules to produce solar-based fuels.Herein,we show that an Fe-quaterpyridine molecular catalyst can be anchored to a light-absorbing,crystalline,carbon nitride(PTI),to yield a molecular-catalyst/material hybrid,Fe-qpy-PTI,capable of facilitating CO_(2)reduction to CO selectively(up to∼97–98%)in aqueous solution under lowintensity light irradiation.This hybrid material leverages the ability of the Fe-qpy catalyst to bind CO_(2)upon a one-electron reduction,as achieved by transfer of excited electrons from the carbon-nitride semiconductor.At a low incident power density of only 50 mW cm^(−2),the catalytic activity of the hybrid material was measured across a range of catalyst loadings from 0.1–3.8 wt%,yielding CO rates of up to 596μmol g^(−1)h^(−1)for a 3.8 wt%loading during a 3 h experiment.Over the course of 8 h,the hybrid material attained a CO evolution rate of 608μmol g^(−1)h^(−1)and 305 turnovers for a TOF of∼38 h^(−1)and an apparent quantum yield of 2.6%.Higher light intensities provided an initial increase in activity but negatively impacted photocatalytic rates with time,with an AQY of 0.6%at 150 mW cm^(−2)and 0.4%at 250 mW cm^(−2).Transient absorption spectroscopy results showed electron survival probabilities consistent with the trends in observed product rates.Computational modeling was also used to evaluate and understand the mechanistic pathway of the high product selectivity for CO versus H2.These results thus help unveil key factors for leveraging the mechanistic understanding of molecular catalysts for CO_(2)reduction for pairing with light absorbing semiconductors and establishing optimal conditions to attain maximal rates in aqueous solution.展开更多
基金supported as part of the Center for Hybrid Approaches in Solar Energy to Liquid Fuels(CHASE),an Energy Innovation Hub funded by the U.SDepartment of Energy,Office of Science,Office of Basic Energy Sciences under Award Number DE-SC0021173+5 种基金Research efforts were performed in part at the Molecular Education,Technology and Research Innovation Center(METRIC)at NC State University and performed in part at the Analytical Instrumentation Facility(AIF)at North Carolina State University,which is supported by the State of North Carolina and the National Science Foundation(award number ECCS-2025064)The AIF is a member of the North Carolina Research Triangle Nanotechnology Network(RTNN),a site in the National Nanotechnology Coordinated Infrastructure(NNCI)This work used the High-Performance Research Computing FASTER cluster at Texas A&M University through allocation CHE240107 from the Advanced Cyberinfrastructure Coordination Ecosystem:Services&Support(ACCESS)program,81 which is supported by U.S.National Science Foundation grants#2138259,#2138286,#2138307,#2137603,and#2138296Additional efforts were performed at the University of North Carolina’s Chapel Hill Analytical and Nanofabrication Laboratory,CHANL,a member of the North Carolina Research Triangle Nanotechnology Network,RTNN,which is supported by the National Science Foundation,Grant ECCS-2025064,as part of the National Nanotechnology Coordinated Infrastructure,NNCIThe authors thank the University of North Carolina’s Department of Chemistry NMR Core Laboratory for the use of their NMR spectrometers,particularly the instrument funded under the National Science Foundation Grant No.CHE-1828183The authors thank the University of North Carolina’s Department of Chemistry Mass Spectrometry Core Laboratory for the use of their mass spectrometer funded by the National Science Foundation under Grant No.CHE-1726291.
文摘The strategy of incorporating earth-abundant catalytic centers into light-absorbing architectures is desirable from the viewpoint of low cost,low toxicity,and versatility for activating small molecules to produce solar-based fuels.Herein,we show that an Fe-quaterpyridine molecular catalyst can be anchored to a light-absorbing,crystalline,carbon nitride(PTI),to yield a molecular-catalyst/material hybrid,Fe-qpy-PTI,capable of facilitating CO_(2)reduction to CO selectively(up to∼97–98%)in aqueous solution under lowintensity light irradiation.This hybrid material leverages the ability of the Fe-qpy catalyst to bind CO_(2)upon a one-electron reduction,as achieved by transfer of excited electrons from the carbon-nitride semiconductor.At a low incident power density of only 50 mW cm^(−2),the catalytic activity of the hybrid material was measured across a range of catalyst loadings from 0.1–3.8 wt%,yielding CO rates of up to 596μmol g^(−1)h^(−1)for a 3.8 wt%loading during a 3 h experiment.Over the course of 8 h,the hybrid material attained a CO evolution rate of 608μmol g^(−1)h^(−1)and 305 turnovers for a TOF of∼38 h^(−1)and an apparent quantum yield of 2.6%.Higher light intensities provided an initial increase in activity but negatively impacted photocatalytic rates with time,with an AQY of 0.6%at 150 mW cm^(−2)and 0.4%at 250 mW cm^(−2).Transient absorption spectroscopy results showed electron survival probabilities consistent with the trends in observed product rates.Computational modeling was also used to evaluate and understand the mechanistic pathway of the high product selectivity for CO versus H2.These results thus help unveil key factors for leveraging the mechanistic understanding of molecular catalysts for CO_(2)reduction for pairing with light absorbing semiconductors and establishing optimal conditions to attain maximal rates in aqueous solution.
