Pb contamination in aquatic environments causes severe pollution;therefore,harmless absorbents are required.In this study,we report a novel synthesis of whitlockite(WH,Ca_(18)Mg_(2)(HPO_(4))_(2)(PO_(4))_(12)),which is...Pb contamination in aquatic environments causes severe pollution;therefore,harmless absorbents are required.In this study,we report a novel synthesis of whitlockite(WH,Ca_(18)Mg_(2)(HPO_(4))_(2)(PO_(4))_(12)),which is the second most abundant biomineral in human bone,and its application as a high-performing Pb^(2+)absorbent.Hydroxyapatite(HAP)and WH are prepared via a simple precipitation method.The Pb2+absorption performance and mechanism of the synthesized biominerals are investigated in aqueous solutions at neutral pH.The results demonstrate that WH exhibits an excellent Pb2+absorption capacity of 2339 mg g^(−1),which is 1.68 times higher than the recorded value for HAP.Furthermore,the absorbed Pb^(2+) ions are recycled into high-purity PbI_(2).This is employed as a precursor for the fabrication of perovskite solar cells(PSCs),resulting in a conversion efficiency of 19.00%comparable to that of commercial PbI2 powder(99.99%purity).Our approach provides an efficient way to remove Pb^(2+)ions from water and reuse them in the recycling of PSCs.展开更多
Efficient and cost-effective electrocatalysts that can operate across a wide range of pH conditions are essential for green hydrogen production.Inspired by biological systems,Fe_(7)S_(8)nanoparticles incorporated on p...Efficient and cost-effective electrocatalysts that can operate across a wide range of pH conditions are essential for green hydrogen production.Inspired by biological systems,Fe_(7)S_(8)nanoparticles incorporated on polydopamine matrix electrocatalyst were synthesized by co-precipitation and annealing process.The resulting Fe_(7)S_(8)/C electrocatalyst possesses a three-dimensional structure and exhibits enhanced electrocatalytic performance for hydrogen production across various pH conditions.Notably,the Fe_(7)S_(8)/C electrocatalyst demonstrates exceptional activity,achieving low overpotentials of 90.6,45.9,and 107.4 mV in acidic,neutral,and alkaline environments,respectively.Electrochemical impedance spectroscopy reveals that Fe_(7)S_(8)/C exhibits the lowest charge transfer resistance under neutral conditions,indicating an improved proton-coupled electron transfer process.Continuous-wave electron paramagnetic resonance results confirm a change in the valence state of Fe from 3+to 1+during the hydrogen evolution reaction(HER).These findings closely resemble the behavior of natural[FeFe]-hydrogenase,known for its superior hydrogen production in neutral conditions.The remarkable performance of our Fe_(7)S_(8)/C electrocatalyst opens up new possibilities for utilizing bioinspired materials as catalysts for the HER.展开更多
The fourth industrial revolution indispensably brings explosive data processing and storage;thus,a new computing paradigm based on artificial intelligence-enabling device structure is urgently required.Memristors have...The fourth industrial revolution indispensably brings explosive data processing and storage;thus,a new computing paradigm based on artificial intelligence-enabling device structure is urgently required.Memristors have received considerable attention in this regard because of their ability to process and store data at the same location.However,fundamental problems with abrupt switching characteristics limit their practical application.To address this problem,we utilized the concept of metaplasticity inspired by biosystems and observed gradual switching in the peptide-based memristor at high proton conductivity.An unexpectedly high slope value>1.7 in the logI–V curve at low voltage(≤400 mV)was considered the main origin,and it might arise from the modulatory response of proton ions on the threshold of Ag ion migration in the peptide film.With the obtained gradual switching property at high proton conductivity,the device showed significantly increased accuracy of image recognition(~82.5%).We believe that such a demonstration not only contributes to the practical application of neuromorphic devices but also expands the bioinspired functional synthetic platform.展开更多
Neuromorphic devices inspired by the human brain have attracted significant attention because of their excellent ability for cognitive and parallel computing.This study presents ZnO-based artificial synapses with pept...Neuromorphic devices inspired by the human brain have attracted significant attention because of their excellent ability for cognitive and parallel computing.This study presents ZnO-based artificial synapses with peptide insulators for the electrical emulation of biological synapses.We demonstrated the dynamic responses of the device under various environmental conditions.The proton-conducting property of the tyrosine-rich peptide enables time-dependent responses under ambient conditions such that various aspects of synaptic behaviors are emulated by the devices.The transition from short-term memory to longterm memory is achieved via electrochemical doping of ZnO by protons.Furthermore,we demonstrate an image classification simulation using a multi-layer perceptron model to evaluate the potential of the device for use in neuromorphic computing.The neural network based on our device achieved a recognition accuracy of 87.47% for the MNIST handwritten digit images.This work proposes a novel device platform inspired by biosystems for brain-mimetic hardware systems.展开更多
基金supported by the National Research Foundation of Korea(NRF)grant funded by the Korea Government(MSIT)(NRF-2018M3C1B7021994)the Technology Development Program to Solve Climate Changes(2018M1A2A2058207)+3 种基金Institute of Information&Communications Technology Planning&Evaluation(IITP)grant funded by the Korea Government(MSIT)(No.2020-0-00541,Flexible Photovoltaic Device Module with Autonomous Power Supply for Smart Farm Wireless Composite IoT Sensor)Korea Institute of Energy Technology Evaluation and Planning(KETEP)grant funded by the Korea government(MOTIE)(20203040010320)the Korea Evaluation Institute of Industrial Technology(KEIT)(20016588)funded by the Korea Governmentsupported by the Research Institute of Advanced Materials(RIAM)and National Center for Inter-university Research Facilities(NCIRF)at Seoul National University.
文摘Pb contamination in aquatic environments causes severe pollution;therefore,harmless absorbents are required.In this study,we report a novel synthesis of whitlockite(WH,Ca_(18)Mg_(2)(HPO_(4))_(2)(PO_(4))_(12)),which is the second most abundant biomineral in human bone,and its application as a high-performing Pb^(2+)absorbent.Hydroxyapatite(HAP)and WH are prepared via a simple precipitation method.The Pb2+absorption performance and mechanism of the synthesized biominerals are investigated in aqueous solutions at neutral pH.The results demonstrate that WH exhibits an excellent Pb2+absorption capacity of 2339 mg g^(−1),which is 1.68 times higher than the recorded value for HAP.Furthermore,the absorbed Pb^(2+) ions are recycled into high-purity PbI_(2).This is employed as a precursor for the fabrication of perovskite solar cells(PSCs),resulting in a conversion efficiency of 19.00%comparable to that of commercial PbI2 powder(99.99%purity).Our approach provides an efficient way to remove Pb^(2+)ions from water and reuse them in the recycling of PSCs.
基金Outsourced R&D Project of Korea Electric Power Corporation(KEPCO),Grant/Award Number:R23XO04National Research Foundation of Korea(NRF)+7 种基金Korean government(MSIT),Grant/Award Numbers:NRF-2021M3H4A6A01045764,2020M3H4A3106313,2021R1C1C1004264,2021R1A4A1032114Korea Institute for Advancement of Technology(KIAT)Ministry of Trade,Industry,and Energy(MOTIE),Korea,Grant/Award Number:P0025273Korea Institute of Energy Technology Evaluation and Planning(KETEP)and the Ministry of Trade,Industry&Energy(MOTIE)of the Republic of Korea,Grant/Award Number:20224000000320KENTECH Research GrantKorea Institute of Energy Technology,Republic of Korea,Grant/Award Number:KRG2022-01-016Regional Innovation Strategy(RIS)through the National Research Foundation of Korea(NRF)Ministry of Education(MOE),Grant/Award Number:2021RIS-002。
文摘Efficient and cost-effective electrocatalysts that can operate across a wide range of pH conditions are essential for green hydrogen production.Inspired by biological systems,Fe_(7)S_(8)nanoparticles incorporated on polydopamine matrix electrocatalyst were synthesized by co-precipitation and annealing process.The resulting Fe_(7)S_(8)/C electrocatalyst possesses a three-dimensional structure and exhibits enhanced electrocatalytic performance for hydrogen production across various pH conditions.Notably,the Fe_(7)S_(8)/C electrocatalyst demonstrates exceptional activity,achieving low overpotentials of 90.6,45.9,and 107.4 mV in acidic,neutral,and alkaline environments,respectively.Electrochemical impedance spectroscopy reveals that Fe_(7)S_(8)/C exhibits the lowest charge transfer resistance under neutral conditions,indicating an improved proton-coupled electron transfer process.Continuous-wave electron paramagnetic resonance results confirm a change in the valence state of Fe from 3+to 1+during the hydrogen evolution reaction(HER).These findings closely resemble the behavior of natural[FeFe]-hydrogenase,known for its superior hydrogen production in neutral conditions.The remarkable performance of our Fe_(7)S_(8)/C electrocatalyst opens up new possibilities for utilizing bioinspired materials as catalysts for the HER.
基金This work was funded by a National Research Foundation of Korea(NRF)grant from the Korean government(MSIT)(No.2020R1A2C2004864)S.D.N.acknowledges the support by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute(KHIDI),funded by the Ministry of Health&Welfare,Republic of Korea(No.HI19C1234).
文摘The fourth industrial revolution indispensably brings explosive data processing and storage;thus,a new computing paradigm based on artificial intelligence-enabling device structure is urgently required.Memristors have received considerable attention in this regard because of their ability to process and store data at the same location.However,fundamental problems with abrupt switching characteristics limit their practical application.To address this problem,we utilized the concept of metaplasticity inspired by biosystems and observed gradual switching in the peptide-based memristor at high proton conductivity.An unexpectedly high slope value>1.7 in the logI–V curve at low voltage(≤400 mV)was considered the main origin,and it might arise from the modulatory response of proton ions on the threshold of Ag ion migration in the peptide film.With the obtained gradual switching property at high proton conductivity,the device showed significantly increased accuracy of image recognition(~82.5%).We believe that such a demonstration not only contributes to the practical application of neuromorphic devices but also expands the bioinspired functional synthetic platform.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2020R1A2C2004864)。
文摘Neuromorphic devices inspired by the human brain have attracted significant attention because of their excellent ability for cognitive and parallel computing.This study presents ZnO-based artificial synapses with peptide insulators for the electrical emulation of biological synapses.We demonstrated the dynamic responses of the device under various environmental conditions.The proton-conducting property of the tyrosine-rich peptide enables time-dependent responses under ambient conditions such that various aspects of synaptic behaviors are emulated by the devices.The transition from short-term memory to longterm memory is achieved via electrochemical doping of ZnO by protons.Furthermore,we demonstrate an image classification simulation using a multi-layer perceptron model to evaluate the potential of the device for use in neuromorphic computing.The neural network based on our device achieved a recognition accuracy of 87.47% for the MNIST handwritten digit images.This work proposes a novel device platform inspired by biosystems for brain-mimetic hardware systems.