To cope up with the sustainable energy storage goals for supercapacitors(SCs),the self-discharge in SC electrodes is a significant hurdle,and thereby,nickel sulfide(NS)with high conductivity is adopted as a test vehic...To cope up with the sustainable energy storage goals for supercapacitors(SCs),the self-discharge in SC electrodes is a significant hurdle,and thereby,nickel sulfide(NS)with high conductivity is adopted as a test vehicle for understanding the morphological evolution effects for long-life SCs.Herein,honeycomb-like NS is hierarchically formed over hydrothermally grown nickel oxide(NO)via successive ionic layer adsorption reaction(SILAR)method.Their heterostructure shows a fivefold improvement in specific capacitance from 348 F g^(−1) to 2077 F g^(−1)at 1 mV s^(−1) over bare NO.Furthermore,the remarkable upliftment of capacitance retention is achieved from 60.7%to 92.3%even after 3000 cycles via morphological control of NS/NO hetero-structure with the help of highly conductive NS.More importantly,the self-discharge behaviors and synergistic role of leakage current associated with morphological evolution via NS overcoating are studied in detail.In particular,the self-discharge mitigation from 45%(NO)to 35%(NS20/NO)due to the NS/NO heterostructure and the behind mechanism are ascribed to the activated-controlled Faradaic reaction coupled with a charge redistribution.This study emphasizes the potential importance of composite heterostructure by tuning the electrical conductivity and morphological adjustment NO via consecutive overcoating of NS through SILAR as a novel strategy.This enhances charge storage,redox kinetics,and the mitigation of self-discharge properties of the active electrode materials.For practical validation on sustainable energy storage,NS20/NO supercapacitors illuminate the LED for 35%longer than NO after one-time charging,potentially beneficial for the next generation SCs.展开更多
The catalytic oxidation of carbon monoxide(CO)to carbon dioxide(CO_(2))is an effective way to eliminate the harmful effects of CO,with catalysts playing a crucial role in this process.Although Pt-based catalysts have ...The catalytic oxidation of carbon monoxide(CO)to carbon dioxide(CO_(2))is an effective way to eliminate the harmful effects of CO,with catalysts playing a crucial role in this process.Although Pt-based catalysts have been widely used for CO oxidation,the low-temperature activity and thermal stability still need to be improved.In this study,a Pt/ZnO@SiO_(2) composite structure was constructed by coating Pt/ZnO cat-alysts with a thin SiO_(2) layer.The influence of SiO_(2) overcoating layer on the sintering behavior of Pt nanoparticles(NPs)and on the catalytic performance of the Pt catalyst for CO oxidation was investigated in detail.And the results were compared with those without SiO_(2) overcoating layer.Investigations found that the SiO_(2) coating layer effectively inhibited the sintering of Pt NPs at high temperatures,enhancing the thermal stability.In addition,the SiO_(2) overcoating layer improved the catalytic activity of the Pt-based catalyst by inducing higher concentration of oxygen vacancies on the catalyst surface as well as weakening the CO adsorption,which could enhance the adsorption and activation ability of oxygen.Meanwhile,the presence of SiO_(2) overcoating layer improved the catalytic stability during CO oxidation reaction.This work provides an important reference for the design and development of supported Pt-based catalysts with excellent thermal stability and catalytic activity for CO oxidation.展开更多
基金supported by the National Research Founda-tion of Korea(NRF)funded by the Ministry of Science,ICT and Fu-ture Planning(NRF-2021R1A2C1012593)in part by the Prior-ity Research Centers Program through the National Research Foun-dation of Korea(NRF)funded by the Ministry of Education(NRF-2020R1A6A1A03041954).
文摘To cope up with the sustainable energy storage goals for supercapacitors(SCs),the self-discharge in SC electrodes is a significant hurdle,and thereby,nickel sulfide(NS)with high conductivity is adopted as a test vehicle for understanding the morphological evolution effects for long-life SCs.Herein,honeycomb-like NS is hierarchically formed over hydrothermally grown nickel oxide(NO)via successive ionic layer adsorption reaction(SILAR)method.Their heterostructure shows a fivefold improvement in specific capacitance from 348 F g^(−1) to 2077 F g^(−1)at 1 mV s^(−1) over bare NO.Furthermore,the remarkable upliftment of capacitance retention is achieved from 60.7%to 92.3%even after 3000 cycles via morphological control of NS/NO hetero-structure with the help of highly conductive NS.More importantly,the self-discharge behaviors and synergistic role of leakage current associated with morphological evolution via NS overcoating are studied in detail.In particular,the self-discharge mitigation from 45%(NO)to 35%(NS20/NO)due to the NS/NO heterostructure and the behind mechanism are ascribed to the activated-controlled Faradaic reaction coupled with a charge redistribution.This study emphasizes the potential importance of composite heterostructure by tuning the electrical conductivity and morphological adjustment NO via consecutive overcoating of NS through SILAR as a novel strategy.This enhances charge storage,redox kinetics,and the mitigation of self-discharge properties of the active electrode materials.For practical validation on sustainable energy storage,NS20/NO supercapacitors illuminate the LED for 35%longer than NO after one-time charging,potentially beneficial for the next generation SCs.
基金support provided by the National Natural Science Foundation of China(grant No.22072164)the Research Fund of Shenyang National Laboratory for Materials Science.
文摘The catalytic oxidation of carbon monoxide(CO)to carbon dioxide(CO_(2))is an effective way to eliminate the harmful effects of CO,with catalysts playing a crucial role in this process.Although Pt-based catalysts have been widely used for CO oxidation,the low-temperature activity and thermal stability still need to be improved.In this study,a Pt/ZnO@SiO_(2) composite structure was constructed by coating Pt/ZnO cat-alysts with a thin SiO_(2) layer.The influence of SiO_(2) overcoating layer on the sintering behavior of Pt nanoparticles(NPs)and on the catalytic performance of the Pt catalyst for CO oxidation was investigated in detail.And the results were compared with those without SiO_(2) overcoating layer.Investigations found that the SiO_(2) coating layer effectively inhibited the sintering of Pt NPs at high temperatures,enhancing the thermal stability.In addition,the SiO_(2) overcoating layer improved the catalytic activity of the Pt-based catalyst by inducing higher concentration of oxygen vacancies on the catalyst surface as well as weakening the CO adsorption,which could enhance the adsorption and activation ability of oxygen.Meanwhile,the presence of SiO_(2) overcoating layer improved the catalytic stability during CO oxidation reaction.This work provides an important reference for the design and development of supported Pt-based catalysts with excellent thermal stability and catalytic activity for CO oxidation.
