Flexible supercapacitors are promising energy storage devices in wearable smart electronics. Exploring cost-efficient electrodes with high capacitance would promote the wide-scale application of such capacitors. Herei...Flexible supercapacitors are promising energy storage devices in wearable smart electronics. Exploring cost-efficient electrodes with high capacitance would promote the wide-scale application of such capacitors. Herein, in order to explore a methodology for preparing low cost, flexible, tough, and up-scalable supercapacitor electrodes, silk textile is directly carbonized to make a conductive free-standing textile substrate. Through mildly baking the surfactant-free TiCTflakes suspension loaded on the carbonized silk cloth, a uniform and adhesive coating consisting of nanometer-thick TiCTflakes is well established on the conductive fabric support, forming a MXene-coated flexible textile electrode. The fabricated electrode exhibits a high areal capacitance of 362 m F/cm~2 with excellent cyclability and flexibility. Moreover,capacitance changes neglegibly under the bending deformation mode. This study elucidates the feasibility of using silk-derived carbon cloth from biomss for MXene-based flexible supercapacitor.展开更多
Designing efficient electrocatalysts with low Pt loadings for hydrogen evolution reaction(HER)is urgently required for renewable and sustainable energy conversion.Here,we report a strategy that Pt nanoparticulates are...Designing efficient electrocatalysts with low Pt loadings for hydrogen evolution reaction(HER)is urgently required for renewable and sustainable energy conversion.Here,we report a strategy that Pt nanoparticulates are spontaneously immobilized on porous MXene/MAX monolith as HER catalysts by utilizing the redox reaction between Ti3C2Tx MXene and[PtCl4]2 in H2 PtCl6 aqueous solution.By taking advantage of homogeneously distributed Pt nanoparticulates on highly electrically conductive porous Ti3C2Tx/Ti3AlC2 monolith,the as-prepared electrocatalysts show high catalytic performance for hydrogen evolution.Specifically,the binder-free electrocatalysts have Pt loadings as low as 8.9μg/cm^2,with low overpotential of 43 mV at a curre nt density of 10 mA/cm^2 and low Tafel slope that three times lower than porous Ti3C2Tx/Ti3AlC2 without Pt loading.This strategy offers a new approach to constructing ultra-low Pt-loading HER catalysts on the basis of in situ redox reaction between noble metal ions and MXenes.展开更多
REB_(2)C_(2)(RE=Y and lanthanides)compounds have gained attention for their unique layered crystal structure.However,there have been few reports about Raman spectroscopy of REB_(2)C_(2) compounds up to now.Here,the Ra...REB_(2)C_(2)(RE=Y and lanthanides)compounds have gained attention for their unique layered crystal structure.However,there have been few reports about Raman spectroscopy of REB_(2)C_(2) compounds up to now.Here,the Raman spectrum of YbB_(2)C_(2) is obtained by a micro-Raman spectroscope and the first-principles calculations.Raman active vibrational modes of YbB_(2)C_(2) are confirmed as A_(1g)(627 and 1311 cm^(-1)),B_(1g)(944 and 1172 cm^(-1)),B_(2g)(330 and 885 cm^(-1))and E_(g)(357 and 530 cm^(-1)).Atomic displacements of these modes are different,they can be divided into two groups:A_(1g)’,B_(1g) and B_(2g) correspond to ring breathing(δ_(in),in the plane)of B_(2)C_(2) layer;E_(g) is due to ring deformation(δ_(oop),out of the plane)of B_(2)C_(2) layer.These results are helpful to understand the individual structure of REB_(2)C_(2).展开更多
The authors regret that the printed version of the above article contained some errors.(1)The SEM images of CSC and CSC@Ti3C2Tx electrode in Fig.1 are corrected to reflect the originality of the images.
Objective: We explored the relationship between traditional Chinese constitution and risk factors for cardiovascular disease in subjects with high-normal blood pressure (BP). Methods: The traditional Chinese constitut...Objective: We explored the relationship between traditional Chinese constitution and risk factors for cardiovascular disease in subjects with high-normal blood pressure (BP). Methods: The traditional Chinese constitution of 80 subjects with high-normal BP was judged by questionnaires and interviews. Measurements of cardiovascular and metabolic health in- cluded BP, body weight, body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), 2-hour oral glucose tolerance test (OGTT2h), and waist cir- cumference. Statistical relationships between cardiovascular disease risk factors and specific Chinese constitution were evaluated by univariate and multivariate analyses. Results: Ping He, Tan Shi, and Yin Xu were the dominant constitutions in subjects with high-normal blood pressure. There were significant differences in weight, LDL-C, BMI, OGTT2h, and waist circumference between Tan Shi and Ping He (P P < 0.05), and weight, BMI, waist circumference, SBP, and LDL-C between Tan Shi and Yin Xu constitutions (P < 0.01). Logistic regression found a strong association between the Tan Shi constitution and LDL-C in subjects with high-normal blood pressure. Conclusion: Ping He, Tan Shi, and Yin Xu are the principle traditional Chinese constitutions in subject with high-normal blood pressure. The Tan Shi constitution is associated with multiple risk factors for cardiovascular disease (LDL-C, BMI, body weight, and waist circumference), while OGTT2h is closely related to the Yin Xu constitution.展开更多
基金supported by the Youth Innovation Promotion Association,Chinese Academy of Sciences(CAS)under grant no.2011152Shenyang National Laboratory for Materials Science,Institute of Metal Research,CAS,under grant no.2017RP06
文摘Flexible supercapacitors are promising energy storage devices in wearable smart electronics. Exploring cost-efficient electrodes with high capacitance would promote the wide-scale application of such capacitors. Herein, in order to explore a methodology for preparing low cost, flexible, tough, and up-scalable supercapacitor electrodes, silk textile is directly carbonized to make a conductive free-standing textile substrate. Through mildly baking the surfactant-free TiCTflakes suspension loaded on the carbonized silk cloth, a uniform and adhesive coating consisting of nanometer-thick TiCTflakes is well established on the conductive fabric support, forming a MXene-coated flexible textile electrode. The fabricated electrode exhibits a high areal capacitance of 362 m F/cm~2 with excellent cyclability and flexibility. Moreover,capacitance changes neglegibly under the bending deformation mode. This study elucidates the feasibility of using silk-derived carbon cloth from biomss for MXene-based flexible supercapacitor.
基金supported by the Youth Innovation Promotion Association,Chinese Academy of Sciences(CAS)(No.2011152)Shenyang National Laboratory for Materials Science,Institute of Metal Research,CASby Special Program for Applied Research on Super Computation of the NSFC-Guangdong Joint Fund(the second phase)(No.U1501501)。
文摘Designing efficient electrocatalysts with low Pt loadings for hydrogen evolution reaction(HER)is urgently required for renewable and sustainable energy conversion.Here,we report a strategy that Pt nanoparticulates are spontaneously immobilized on porous MXene/MAX monolith as HER catalysts by utilizing the redox reaction between Ti3C2Tx MXene and[PtCl4]2 in H2 PtCl6 aqueous solution.By taking advantage of homogeneously distributed Pt nanoparticulates on highly electrically conductive porous Ti3C2Tx/Ti3AlC2 monolith,the as-prepared electrocatalysts show high catalytic performance for hydrogen evolution.Specifically,the binder-free electrocatalysts have Pt loadings as low as 8.9μg/cm^2,with low overpotential of 43 mV at a curre nt density of 10 mA/cm^2 and low Tafel slope that three times lower than porous Ti3C2Tx/Ti3AlC2 without Pt loading.This strategy offers a new approach to constructing ultra-low Pt-loading HER catalysts on the basis of in situ redox reaction between noble metal ions and MXenes.
基金financially supported by the National Natural Science Foundation of China under Contract Nos.50802099 and 51072201。
文摘REB_(2)C_(2)(RE=Y and lanthanides)compounds have gained attention for their unique layered crystal structure.However,there have been few reports about Raman spectroscopy of REB_(2)C_(2) compounds up to now.Here,the Raman spectrum of YbB_(2)C_(2) is obtained by a micro-Raman spectroscope and the first-principles calculations.Raman active vibrational modes of YbB_(2)C_(2) are confirmed as A_(1g)(627 and 1311 cm^(-1)),B_(1g)(944 and 1172 cm^(-1)),B_(2g)(330 and 885 cm^(-1))and E_(g)(357 and 530 cm^(-1)).Atomic displacements of these modes are different,they can be divided into two groups:A_(1g)’,B_(1g) and B_(2g) correspond to ring breathing(δ_(in),in the plane)of B_(2)C_(2) layer;E_(g) is due to ring deformation(δ_(oop),out of the plane)of B_(2)C_(2) layer.These results are helpful to understand the individual structure of REB_(2)C_(2).
文摘The authors regret that the printed version of the above article contained some errors.(1)The SEM images of CSC and CSC@Ti3C2Tx electrode in Fig.1 are corrected to reflect the originality of the images.
文摘Objective: We explored the relationship between traditional Chinese constitution and risk factors for cardiovascular disease in subjects with high-normal blood pressure (BP). Methods: The traditional Chinese constitution of 80 subjects with high-normal BP was judged by questionnaires and interviews. Measurements of cardiovascular and metabolic health in- cluded BP, body weight, body mass index (BMI), low-density lipoprotein cholesterol (LDL-C), 2-hour oral glucose tolerance test (OGTT2h), and waist cir- cumference. Statistical relationships between cardiovascular disease risk factors and specific Chinese constitution were evaluated by univariate and multivariate analyses. Results: Ping He, Tan Shi, and Yin Xu were the dominant constitutions in subjects with high-normal blood pressure. There were significant differences in weight, LDL-C, BMI, OGTT2h, and waist circumference between Tan Shi and Ping He (P P < 0.05), and weight, BMI, waist circumference, SBP, and LDL-C between Tan Shi and Yin Xu constitutions (P < 0.01). Logistic regression found a strong association between the Tan Shi constitution and LDL-C in subjects with high-normal blood pressure. Conclusion: Ping He, Tan Shi, and Yin Xu are the principle traditional Chinese constitutions in subject with high-normal blood pressure. The Tan Shi constitution is associated with multiple risk factors for cardiovascular disease (LDL-C, BMI, body weight, and waist circumference), while OGTT2h is closely related to the Yin Xu constitution.
