ABSTRACT
A Ti3C2T x /ZIF-67 nanocomposite with outstanding conductivity has been prepared by loading ZIF-67 onto a two-dimensional Ti3C2T x nanosheet. Ti3C2T x sheets were synthesized by etching Ti3AlC2, and then ZIF-67 was grown in situ on the Ti3C2T x nanosheet. The Ti3C2T x /ZIF-67 nanocomposite exhibits excellent detection performance for glucose, with a low LOD of 3.81 µM and wide linear detection range of 5-7500 µM. This terrific result is contributed by the synergistic effect of the high electrically conductive ability of Ti3C2T x and active catalytic performance of ZIF-67. Moreover, the electrochemical sensor prepared using the Ti3C2T x /ZIF-67 nanocomposite also shows excellent selectivity, stability and repeatability for glucose detection. The Ti3C2T x /ZIF-67 nanocomposite with outstanding performance has potential applications for electrochemical sensors.
ABSTRACT
The copper benzene-1,3,5-tricarboxylate (Cu-BTC) with outstanding chemical and physical properties, is a novel and promising material in the field of electrochemical sensing. However, it has significant limitations for direct application in electrochemical sensing due to the relatively weak conductivity of Cu-BTC. Here, the conductivity of Cu-BTC was improved by loading Cu-BTC onto two-dimensional Ti3C2T x nanosheets with high conductivity. Thanks to the synergistic effect produced by the high conductivity of Ti3C2T x and the unique catalytic activity of Cu-BTC, the Ti3C2T x /Cu-BTC nanocomposite exhibits excellent sensing performance for glyphosate, with a low limit of detection (LOD) of 2.6 × 10-14 M and wider linear sensing range of 1.0 × 10-13 to 1.0 × 10-6 M. Moreover, the electrochemical sensor based on Ti3C2T x /Cu-BTC also shows excellent selectivity, good reproducibility and stability.
ABSTRACT
Although side-chain polyazobenzenes have been extensively studied, main-chain polyazobenzenes (abbreviated MCPABs) are rarely reported due to the challenges associated with difficulty in synthetic chemistry and photoisomerization of azo bonds in MCPABs. Thus, it is highly demanded to develop new mechanisms other than photoisomerization of azo bonds in MCPABs to extend their applications. In this work, we created a new series of N-linked MCPABs via fast NaBH4-mediated reductive coupling polymerization on N-substituted bis(4-nitrophenyl)amines. The structure of MCPABs has been characterized by comprehensive solid-state NMR experiments such as CPMAS 13C NMR with long and short contact times, cross-polarization polarization-inversion (CPPI), and cross-polarization nonquaternary suppressed (CPNQS). The azo bonds in MCPABs were found to be promising for acid vapor sensing, being acidified to form azonium ion with significant color change from red to green. And the azonium of MCPABs turned from green to red when exposed to base vapor, thus suitable for base vapor sensing.
