文章采用有机分子焊接方法,将苝-3,4,9,10-四羧酸二酐(PTCDA)分子通过酰胺键焊接于Ti_(3)CN层间,制备了PTCDA分子焊接插层的Ti_(3)CN(Ti_(3)CN-PTCDA)。PTCDA分子焊接不仅扩大了Ti_(3)CN层状结构的层间距,而且提升了其层结构稳定性,从...文章采用有机分子焊接方法,将苝-3,4,9,10-四羧酸二酐(PTCDA)分子通过酰胺键焊接于Ti_(3)CN层间,制备了PTCDA分子焊接插层的Ti_(3)CN(Ti_(3)CN-PTCDA)。PTCDA分子焊接不仅扩大了Ti_(3)CN层状结构的层间距,而且提升了其层结构稳定性,从而显著提高了储钠倍率性能和循环稳定性。在0.1Ag^(-1)电流密度下,Ti_(3)CN-PTCDA材料的比容量经过895次循环后可达127.9 mAh g^(-1),当电流密度提升至5.0Ag^(-1)时仍可保持51.8 mAh g^(-1)。本研究证明,二维储钠材料的层结构对其储钠倍率和循环稳定性有重要影响,该结论为设计高倍率二维储钠材料提供了新思路。展开更多
3D-printed Ti_(3)C_(2)T_(x) MXene-based interdigital micro-supercapacitors(MSCs)have great potential as energy supply devices in the field of microelectronics due to their short ion diffusion path,high conductivity,ex...3D-printed Ti_(3)C_(2)T_(x) MXene-based interdigital micro-supercapacitors(MSCs)have great potential as energy supply devices in the field of microelectronics due to their short ion diffusion path,high conductivity,excellent pseudocapacitance,and fast charging capabilities.However,searching for eco-friendly aqueous Ti_(3)C_(2)T_(x) MXene-based inks without additives and preventing severe restack of MXene nanosheets in high-concentration inks are significantly challenging.This study develops an additive-free,highly printable,viscosity adjustable,and environmentally friendly MXene/carbon nanotube(CNT)hybrid aqueous inks,in which the CNT can not only adjust the viscosity of Ti_(3)C_(2)T_(x) MXene inks but also widen the interlayer spacing of adjacent Ti_(3)C_(2)T_(x) MXene nanosheets effectively.The optimized MXene/CNT composite inks are successfully adopted to construct various configurations of MSCs with remarkable shape fidelity and geometric accuracy,together with enhanced surface area accessibility for electrons and ions diffusion.As a result,the constructed interdigital symmetrical MSCs demonstrate outstanding areal capacitance(1249.3 mF cm^(-2)),superior energy density(111μWh cm^(-2) at 0.4mWcm^(-2)),and high power density(8mWcm^(-2) at 47.1μWh cm^(-2)).Furthermore,a self-powered modular system of solar cells integrated with MXene/CNT-MSCs and pressure sensors is successfully tailored,simultaneously achieving efficient solar energy collection and real-time human activities monitoring.This work offers insight into the understanding of the role of CNTs in MXene/CNT ink.Moreover,it provides a new approach for preparing environmentally friendly MXene-based inks for the 3D printing of high-performance MSCs,contributing to the development of miniaturized,flexible,and self-powered printable electronic microsystems.展开更多
Developing an efficient electrocatalyst for superior electrochemical water splitting(EWS)is crucial for achieving comprehensive hydrogen production.A heterostructured electrocatalyst,free of noble metals,Ti_(3)C_(2)MX...Developing an efficient electrocatalyst for superior electrochemical water splitting(EWS)is crucial for achieving comprehensive hydrogen production.A heterostructured electrocatalyst,free of noble metals,Ti_(3)C_(2)MXene nanosheet-integrated cobalt-doped nickel hydroxide(NHCoMX)composite was synthesized via a hydrothermal method.The abundant pores in the Ti_(3)C_(2)MXene nanosheet(MX)-integrated microarchitecture increased the number of active sites and facilitated charge transfer,thus enhancing electrocatalysis.Specifically,the MXenhanced charge transfer considerably transformed the microelectronic structure of cobalt-doped Ni(OH)2(NHCo),which promoted its hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Hence,as an EWS catalyst,NHCoMX exhibited an exceptional electrocatalytic activity,demonstrating OER and HER overpotentials of 310 mV and 73 mV,respectively,with low Tafel slopes of 65 mV dec^(-1)and 85 mV dec^(-1),respectively;it exhibited a current density of 10 mV cm^(-2)in 1.0 mol L^(-1)KOH,representing the closest efficiency to the noble state-of-the-art RuO2 and Pt/C catalyst.Furthermore,the developed electrocatalyst improved the activities of both HER and OER,leading to an overall EWS current density of 10 mA cm^(-2)at 1.72 V in an alkaline electrolyte with two electrodes.This study describes an efficient heterostructured NHCoMX composite electrocatalyst.It is significantly comparable to the noble state-of-the-art electrocatalysts and can be extended to fabricate resourceful catalysts for large-scale EWS applications.展开更多
Thermally chargeable supercapacitors(TCSCs)have unique advantages in the collection,conversion,and storage of thermal energy,contributing to the development of new strategies for thermal energy utilization.2D MXene ma...Thermally chargeable supercapacitors(TCSCs)have unique advantages in the collection,conversion,and storage of thermal energy,contributing to the development of new strategies for thermal energy utilization.2D MXene materials are predicted to be highly promising new thermoelectric materials.Here,we report a self-assembled flexible Ti_(3)C_(2)T_(x) MXenebased TCSC device,using prepared Ti_(3)C_(2)T_(x) MXene as the capacitor electrode and a NaClO_(4)/PEO gel as the electrolyte.We also explore the working mechanism of the TCSCs.The fabricated Ti_(3)C_(2)T_(x)-based TCSCs exhibit an excellent Seebeck coefficient of 11.8 mV∙K^(−1) on average and maintain good cycling stability under various temperature differences.Demonstrations of multiple practical applications show that Ti_(3)C_(2)T_(x) MXene-based TCSC devices are excellent candidates for self-powered integrated electronic devices.展开更多
文摘文章采用有机分子焊接方法,将苝-3,4,9,10-四羧酸二酐(PTCDA)分子通过酰胺键焊接于Ti_(3)CN层间,制备了PTCDA分子焊接插层的Ti_(3)CN(Ti_(3)CN-PTCDA)。PTCDA分子焊接不仅扩大了Ti_(3)CN层状结构的层间距,而且提升了其层结构稳定性,从而显著提高了储钠倍率性能和循环稳定性。在0.1Ag^(-1)电流密度下,Ti_(3)CN-PTCDA材料的比容量经过895次循环后可达127.9 mAh g^(-1),当电流密度提升至5.0Ag^(-1)时仍可保持51.8 mAh g^(-1)。本研究证明,二维储钠材料的层结构对其储钠倍率和循环稳定性有重要影响,该结论为设计高倍率二维储钠材料提供了新思路。
基金supported by the National Natural Science Foundation of China(52174247,52477213,52401244 and 22302066)Science and Technology Innovation Program of Hunan Province(No.2022RC1088)+2 种基金Natural Science Foundation of Hunan Province(2023JJ40255)Zhejiang Provincial Natural Science Foundation of China(No.LQ24B020005)Scientific Research Foundation of Hunan Provincial Education Department(22B0599 and 23A0442).
文摘3D-printed Ti_(3)C_(2)T_(x) MXene-based interdigital micro-supercapacitors(MSCs)have great potential as energy supply devices in the field of microelectronics due to their short ion diffusion path,high conductivity,excellent pseudocapacitance,and fast charging capabilities.However,searching for eco-friendly aqueous Ti_(3)C_(2)T_(x) MXene-based inks without additives and preventing severe restack of MXene nanosheets in high-concentration inks are significantly challenging.This study develops an additive-free,highly printable,viscosity adjustable,and environmentally friendly MXene/carbon nanotube(CNT)hybrid aqueous inks,in which the CNT can not only adjust the viscosity of Ti_(3)C_(2)T_(x) MXene inks but also widen the interlayer spacing of adjacent Ti_(3)C_(2)T_(x) MXene nanosheets effectively.The optimized MXene/CNT composite inks are successfully adopted to construct various configurations of MSCs with remarkable shape fidelity and geometric accuracy,together with enhanced surface area accessibility for electrons and ions diffusion.As a result,the constructed interdigital symmetrical MSCs demonstrate outstanding areal capacitance(1249.3 mF cm^(-2)),superior energy density(111μWh cm^(-2) at 0.4mWcm^(-2)),and high power density(8mWcm^(-2) at 47.1μWh cm^(-2)).Furthermore,a self-powered modular system of solar cells integrated with MXene/CNT-MSCs and pressure sensors is successfully tailored,simultaneously achieving efficient solar energy collection and real-time human activities monitoring.This work offers insight into the understanding of the role of CNTs in MXene/CNT ink.Moreover,it provides a new approach for preparing environmentally friendly MXene-based inks for the 3D printing of high-performance MSCs,contributing to the development of miniaturized,flexible,and self-powered printable electronic microsystems.
基金supported by the Basic Science Research Program through the National Research Foundation of Korea(NRF),funded by the Ministry of Education(NRF-2018R1A6A1A03024962)the Ministry of Science and ICT(NRF-2020R1A2C2100746).
文摘Developing an efficient electrocatalyst for superior electrochemical water splitting(EWS)is crucial for achieving comprehensive hydrogen production.A heterostructured electrocatalyst,free of noble metals,Ti_(3)C_(2)MXene nanosheet-integrated cobalt-doped nickel hydroxide(NHCoMX)composite was synthesized via a hydrothermal method.The abundant pores in the Ti_(3)C_(2)MXene nanosheet(MX)-integrated microarchitecture increased the number of active sites and facilitated charge transfer,thus enhancing electrocatalysis.Specifically,the MXenhanced charge transfer considerably transformed the microelectronic structure of cobalt-doped Ni(OH)2(NHCo),which promoted its hydrogen evolution reaction(HER)and oxygen evolution reaction(OER).Hence,as an EWS catalyst,NHCoMX exhibited an exceptional electrocatalytic activity,demonstrating OER and HER overpotentials of 310 mV and 73 mV,respectively,with low Tafel slopes of 65 mV dec^(-1)and 85 mV dec^(-1),respectively;it exhibited a current density of 10 mV cm^(-2)in 1.0 mol L^(-1)KOH,representing the closest efficiency to the noble state-of-the-art RuO2 and Pt/C catalyst.Furthermore,the developed electrocatalyst improved the activities of both HER and OER,leading to an overall EWS current density of 10 mA cm^(-2)at 1.72 V in an alkaline electrolyte with two electrodes.This study describes an efficient heterostructured NHCoMX composite electrocatalyst.It is significantly comparable to the noble state-of-the-art electrocatalysts and can be extended to fabricate resourceful catalysts for large-scale EWS applications.
基金supported by National Natural Science Foundation of China(62474019)Beijing Natural Science Foundation(L223006).
文摘Thermally chargeable supercapacitors(TCSCs)have unique advantages in the collection,conversion,and storage of thermal energy,contributing to the development of new strategies for thermal energy utilization.2D MXene materials are predicted to be highly promising new thermoelectric materials.Here,we report a self-assembled flexible Ti_(3)C_(2)T_(x) MXenebased TCSC device,using prepared Ti_(3)C_(2)T_(x) MXene as the capacitor electrode and a NaClO_(4)/PEO gel as the electrolyte.We also explore the working mechanism of the TCSCs.The fabricated Ti_(3)C_(2)T_(x)-based TCSCs exhibit an excellent Seebeck coefficient of 11.8 mV∙K^(−1) on average and maintain good cycling stability under various temperature differences.Demonstrations of multiple practical applications show that Ti_(3)C_(2)T_(x) MXene-based TCSC devices are excellent candidates for self-powered integrated electronic devices.
