MXene is a rising star of two-dimensional(2D)materials for energy relative applications,however,the traditional synthesis of MXene etched by hazard HF acid or LiF+HCl mixed solution is highly dangerous with the risk o...MXene is a rising star of two-dimensional(2D)materials for energy relative applications,however,the traditional synthesis of MXene etched by hazard HF acid or LiF+HCl mixed solution is highly dangerous with the risk of splashing or pouring liquid solutions.In this work,we developed a water-free ionothermal synthesis of 2D Ti3C2 MXene via etching pristine Ti3AlC2 MAX in low-cost choline chloride and oxalic acid based deep eutectic solvents(DES)with the presence of NH4F,thus it was highly safe and convenient to operate solid precursor and product materials at room temperature.Benefited from the low vapor pressure and solvating properties of DES,the prepared Ti3C2(denoted as DES-Ti3C2)possessed a high purity up to 98% compared with 95% for HF etched Ti3C2(denoted as HF-Ti3C2).Notably,an expanded interlayer spacing of 1.35 nm could be achieved due to the intercalation of choline cations in DES-Ti3C2,larger than that of HF-Ti3C2(0.98 nm).As a result,the DES-Ti3C2 anodes exhibited enhanced lithium storage performance,such as high reversible capacity of 208 m Ah g-1at 0.5 A g-1,and long cycle life over 400 times,outperforming most reported pure MXene anodes.The ionothermal synthesis of MXene developed here may pave a new way to safely prepare other MXene for various energy relating applications.展开更多
Nanozymes based on metal-organic frameworks (MOFs) have been concentrated on due to their naturally high-disperse metal active sites and the adjustable coordination chemistry. In this work, an N-rich melamine (Mel) wa...Nanozymes based on metal-organic frameworks (MOFs) have been concentrated on due to their naturally high-disperse metal active sites and the adjustable coordination chemistry. In this work, an N-rich melamine (Mel) was introduced into the Cu-MOF composed of copper(II) nitrate and 2-aminoterephthalic acid (Cu-NH_(2)-BDC-Mel) to mimic the laccase, which enzyme-like activities were assessed and applied in sensing analyses toward several phenols and amines. Compared to unmodified Cu-NH_(2)-BDC, the resulting Cu-NH_(2)-BDC-Mel exhibits enhanced laccase-like activity, superior stability and catalytic kinetics. It is demonstrated that melamine-doping has increased nitrogen content as well as the surface area, as a result, exhibits a lower Michaelis–Menten constant (K m) (0.1877 mM) and higher maximum reaction rate (V max) (1.7933 × 10^(−3) mM·min^(−1)) in comparison with that of natural laccase. Based on that, an efficient colorimetric sensing strategy for several phenols and amines was built up with excellent selectivity and anti-interference by using the laccase-like Cu-NH_(2)-BDC-Mel, the detection limits are 3.51 µM of adrenaline and 4.41 µM of dopamine. The work broadens the prospect development of bio-colorimetric sensing based on the ligand-modified Cu-MOFs nanozymes catalysis.展开更多
基金financially supported by the National Natural Science Foundation of China (Nos.21601029, 21601030)the Open Project Program of the State Key Laboratory of Inorganic Synthesis and Preparative Chemistry (Nos.2017-33, 2017-26)the Fundamental Research Funds for the Central Universities of China (No.N180503012)。
文摘MXene is a rising star of two-dimensional(2D)materials for energy relative applications,however,the traditional synthesis of MXene etched by hazard HF acid or LiF+HCl mixed solution is highly dangerous with the risk of splashing or pouring liquid solutions.In this work,we developed a water-free ionothermal synthesis of 2D Ti3C2 MXene via etching pristine Ti3AlC2 MAX in low-cost choline chloride and oxalic acid based deep eutectic solvents(DES)with the presence of NH4F,thus it was highly safe and convenient to operate solid precursor and product materials at room temperature.Benefited from the low vapor pressure and solvating properties of DES,the prepared Ti3C2(denoted as DES-Ti3C2)possessed a high purity up to 98% compared with 95% for HF etched Ti3C2(denoted as HF-Ti3C2).Notably,an expanded interlayer spacing of 1.35 nm could be achieved due to the intercalation of choline cations in DES-Ti3C2,larger than that of HF-Ti3C2(0.98 nm).As a result,the DES-Ti3C2 anodes exhibited enhanced lithium storage performance,such as high reversible capacity of 208 m Ah g-1at 0.5 A g-1,and long cycle life over 400 times,outperforming most reported pure MXene anodes.The ionothermal synthesis of MXene developed here may pave a new way to safely prepare other MXene for various energy relating applications.
基金financial support of Liaoning Science and Technology Development Foundation Guided by Central Government(No.2021JH6/10500141)Fundamental Research Funds for the Central Universities(No.N232410019).
文摘Nanozymes based on metal-organic frameworks (MOFs) have been concentrated on due to their naturally high-disperse metal active sites and the adjustable coordination chemistry. In this work, an N-rich melamine (Mel) was introduced into the Cu-MOF composed of copper(II) nitrate and 2-aminoterephthalic acid (Cu-NH_(2)-BDC-Mel) to mimic the laccase, which enzyme-like activities were assessed and applied in sensing analyses toward several phenols and amines. Compared to unmodified Cu-NH_(2)-BDC, the resulting Cu-NH_(2)-BDC-Mel exhibits enhanced laccase-like activity, superior stability and catalytic kinetics. It is demonstrated that melamine-doping has increased nitrogen content as well as the surface area, as a result, exhibits a lower Michaelis–Menten constant (K m) (0.1877 mM) and higher maximum reaction rate (V max) (1.7933 × 10^(−3) mM·min^(−1)) in comparison with that of natural laccase. Based on that, an efficient colorimetric sensing strategy for several phenols and amines was built up with excellent selectivity and anti-interference by using the laccase-like Cu-NH_(2)-BDC-Mel, the detection limits are 3.51 µM of adrenaline and 4.41 µM of dopamine. The work broadens the prospect development of bio-colorimetric sensing based on the ligand-modified Cu-MOFs nanozymes catalysis.
