A confined strategy towards ZIF-L-derived ZnO nanowires-N-doped carbon@Ti3C2Tx nanosheets for the detection of sunset yellow

The space-confined synthesis methods have highlighted in the field of electrochemical applications, which provides a relatively independent nanospace unlike open space to obtain high-performance nanomaterials. Herein, a novel space-confined pyrolytic process of metal-organic framework (MOF)-derived nanomaterial has been proposed by using few-layer Ti3C2Tx nanosheets to wrap Au nanoparticles@zeolitic imidazole framework-L precursor. Since the coating of Ti3C2Tx provides a special decomposition environment, a uniquely hierarchical Au nanoparticles-ZnO nanowires@N-doped carbon@Ti3C2Tx nanosheets (AuNPs-ZnONWs@NC@Ti3C2Tx) has been obtained for the electrochemical detection of sunset yellow. The establish sensor based on AuNPsZnONWs@NC@Ti3C2Tx shows 1 - 40 mu M and 40 - 170 mu M of two-stage linear ranges, and 6.6 nM of detection limit. More importantly, a series of control experiments demonstrate the compositional and structural advantages of AuNPs-ZnONWs@NC@Ti3C2Tx. First, AuNPs with electrocatalytic activity induce the formation of ZnONWs. Second, ZnONWs with cross-linking structure not only provide more active sites, but also prevent stacking of two-dimensional nanosheets. Third, NC with conductivity and hydrophilia immobilize AuNPs on the surfaces of Ti3C2Tx nanosheets. Fourth, Ti3C2Tx nanosheets with metallic conductivity support AuNPs, ZnONWs and NC, which provide the synergistic effect of platform. Such work provides a new idea for the design of space-confined synthesis based on MOF-derived material towards electrochemical application.