Electrostatically assembling 2D hierarchical Nb2CTx and zifs-derivatives into Zn-Co-NC nanocage for the electrochemical detection of 4-nitrophenol

Construction of high-sensitive analytical platform to monitor organic pollutants in the environment is of significance. Nitrophenol is toxic organic pollutant, causing serious damage to biosphere. Herein, a simple self-assembled method was proposed to design a novel heterostructure (MXene/ZIF) composed of Nb2CTX and Zn-Co-ZIFs derived bimetallic Zn, Co embedded N-doped carbon (Zn-Co-NC) nanocage. The Nb2CTX/Zn-Co-NC composite modified electrodes were applied for the electrochemical detection of 4-nitrophenols (4-NP). SEM images revealed that the insertion of Zn-Co-NC can effectively avoid Nb2CTx from restacking. EDS and XPS demonstrated the successful synthesis of bimetallic Zn, Co embedded N-doped carbon nanocage. Excellent conductivity and large specific surface area of Nb2CTx as well as superior catalytic activity of Zn-Co-NC nanocage enhance the electrochemical performance of Nb2CTx/Zn-Co-NC sensor. Under optimal conditions, the achieved wide linear range was 1 mu M to 500 mu M. The low detection limit of 0.070 mu M with high sensitivity of 4.65 mu A mu M-1 cm(-2) was obtained. Furthermore, the Nb2CTx/Zn-Co-NC sensor holds outstanding selectivity and stability. Therefore, the innovative structure and excellent properties of MXene/ ZIF make them alternative materials for various electrochemical sensors for the detection of other toxic organic pollutants.

Automated summary

A novel heterostructure was designed for monitoring nitrophenol in the environment, showing wide linear range, low detection limit, high sensitivity, excellent selectivity, and stability. The innovative structure and superior properties make the MXene/ZIF alternative materials for various electrochemical sensors.