Graphdiyne(GDY)is emerging as a promising material for various applications owing to its unique structure and fascinating properties.However,the application of GDY in electronics and optoelectronics are still in its i...Graphdiyne(GDY)is emerging as a promising material for various applications owing to its unique structure and fascinating properties.However,the application of GDY in electronics and optoelectronics are still in its infancy,primarily owing to the huge challenge in the synthesis of large-area and uniform GDY film for scalable applications.Here a modified van der Waals epitaxy strategy is proposed to synthesize wafer-scale GDY film with high uniformity and controllable thickness directly on graphene(Gr)surface,providing an ideal platform to construct large-scale GDY/Gr-based optoelectronic synapse array.Essential synaptic behaviors have been realized,and the linear and symmetric conductance-update characteristics facilitate the implementation of neuromorphic computing for image recognition with high accuracy and strong fault tolerance.Logic functions including“NAND”and“NOR”are integrated into the synapse which can be executed in an optical pathway.Moreover,a visible information sensing-memory-processing system is constructed to execute real-time image acquisition,in situ image memorization and distinction tasks,avoiding the time latency and energy consumption caused by data conversion and transmission in conventional visual systems.These results highlight the potential of GDY in applications of neuromorphic computing and artificial visual systems.展开更多
Reducing the size of heterogeneous nanocatalysts is generally conducive to improving their atomic utilization and activities in various catalytic reactions.However,this strategy has proven less effective for Cu-based ...Reducing the size of heterogeneous nanocatalysts is generally conducive to improving their atomic utilization and activities in various catalytic reactions.However,this strategy has proven less effective for Cu-based electrocatalysts for the reduction of CO_(2) to multicarbon(O2+)products,owing to the overly strong binding of intermediates on small-sized(<15 nm)Cu nanoparticles(NPs).Herein,by incorporating pyreny-graphdiyne(Pyr-GDY),we successfully endowed ultrafine(〜2 nm)Cu NPs with a significantly elevated selectivity for CO_(2)-to-C_(2+)conversion.The Pyr-GDY can not only help to relax the overly strong binding between adsorbed H*and CO*intermediates on Cu NPs by tailoring the d-band center of the catalyst,but also stabilize the ultrafine Cu NPs through the high affinity between alkyne moieties and Cu NPs.The resulting Pyr-GDY-Cu composite catalyst gave a Faradic efficiency(FE)for C2+products up to 74%,significantly higher than those of support-free Cu NPs(C2+FE.〜2%),carbon nanotube-supported Cu NPs(CNT-Cu,C_(2+)FE,〜18%),graphene oxide-supported Cu NPs(GO-Cu,C_(2+)FE,〜8%),and other reported ultrafine Cu NPs.Our results demonstrate the critical influence of graphdiyne on the selectivity of Cu-catalyzed CO_(2) electroreduction,and showcase the prospect for ultrafine Cu NPs catalysts to convert CO_(2) into value-added C_(2+)products.展开更多
基金This work was supported by the National Natural Science Foundation of China(Nos.21790052 and 51802220)Natural Science Foundation of Tianjin City(No.19JCYBJC17300).
文摘Graphdiyne(GDY)is emerging as a promising material for various applications owing to its unique structure and fascinating properties.However,the application of GDY in electronics and optoelectronics are still in its infancy,primarily owing to the huge challenge in the synthesis of large-area and uniform GDY film for scalable applications.Here a modified van der Waals epitaxy strategy is proposed to synthesize wafer-scale GDY film with high uniformity and controllable thickness directly on graphene(Gr)surface,providing an ideal platform to construct large-scale GDY/Gr-based optoelectronic synapse array.Essential synaptic behaviors have been realized,and the linear and symmetric conductance-update characteristics facilitate the implementation of neuromorphic computing for image recognition with high accuracy and strong fault tolerance.Logic functions including“NAND”and“NOR”are integrated into the synapse which can be executed in an optical pathway.Moreover,a visible information sensing-memory-processing system is constructed to execute real-time image acquisition,in situ image memorization and distinction tasks,avoiding the time latency and energy consumption caused by data conversion and transmission in conventional visual systems.These results highlight the potential of GDY in applications of neuromorphic computing and artificial visual systems.
基金supported by the National Natural Science Foundation of China(Nos.21702146,21805207,21790052,and 21931007)the National Key Technology R&D Program of China(No.2017YFA0700104)+1 种基金111 Project of China(No.D17003)the Natural Science Foundation of Tianjin(No.19JCQNJC05500).
文摘Reducing the size of heterogeneous nanocatalysts is generally conducive to improving their atomic utilization and activities in various catalytic reactions.However,this strategy has proven less effective for Cu-based electrocatalysts for the reduction of CO_(2) to multicarbon(O2+)products,owing to the overly strong binding of intermediates on small-sized(<15 nm)Cu nanoparticles(NPs).Herein,by incorporating pyreny-graphdiyne(Pyr-GDY),we successfully endowed ultrafine(〜2 nm)Cu NPs with a significantly elevated selectivity for CO_(2)-to-C_(2+)conversion.The Pyr-GDY can not only help to relax the overly strong binding between adsorbed H*and CO*intermediates on Cu NPs by tailoring the d-band center of the catalyst,but also stabilize the ultrafine Cu NPs through the high affinity between alkyne moieties and Cu NPs.The resulting Pyr-GDY-Cu composite catalyst gave a Faradic efficiency(FE)for C2+products up to 74%,significantly higher than those of support-free Cu NPs(C2+FE.〜2%),carbon nanotube-supported Cu NPs(CNT-Cu,C_(2+)FE,〜18%),graphene oxide-supported Cu NPs(GO-Cu,C_(2+)FE,〜8%),and other reported ultrafine Cu NPs.Our results demonstrate the critical influence of graphdiyne on the selectivity of Cu-catalyzed CO_(2) electroreduction,and showcase the prospect for ultrafine Cu NPs catalysts to convert CO_(2) into value-added C_(2+)products.
