J. Mater. Chem. A, Advance Article (2024)
Xuanhao Wu, Mengmeng Niu, Xin Tian, Xiaoyan Peng, Pio John S. Buenconsej, Xu Wu, Yeliang Wang, Wei Ji, Yi Li, Jingsi Qiao, Jifang Tao, Mingming Zhang, Song Xiaof and Hongye Yuan
Abstract:
Developing sensitive metal–organic framework (MOF) systems to overcome the ubiquitous trade-off between porosity and conductivity remains a formidable yet sought-after endeavor. This pursuit is of great significance for the development of MOF-based chemiresistive sensors with enhanced sensitivity and selectivity. Herein, we present an innovative template assisted strategy that utilizes the two-dimensional properties and good conductivity of MXene nanosheets, as well as lattice matching between MXene (Nb2C) and selected Ni3(HITP)2, to achieve controllable self-assembly of Ni3(HITP)2 on MXene sheets. This results in Ni3(HITP)2/MXene (HITP: 2,3,6,7,10,11-hexaaminotriphenylene) heterostructures with considerable conductivity, porosity, and solution processability. The powder and film electrical conductivity are 4.8 × 103 and 5.3 × 105 S m−1, respectively, and the BET specific surface area can reach 797.8 m2 g−1. It is worth noting that excellent solution processability helps to prepare large-area films (23 cm × 9 cm) with good uniformity. Gas sensors based on Ni3(HITP)2/MXene heterostructures exhibit high sensitivity (LOD ∼ 5 ppb) and selectivity towards ultratrace ethanol at room temperature, setting a new benchmark. Such sensing behavior stems from the strong coupling of Ni3(HITP)2/MXene heterostructures and their enhanced interaction with ethanol, evidenced by experimental results and theoretical calculations. Real-time respiratory sensing assessments underscore their practicality in healthcare monitoring. This straightforward approach simplifies the integration of MOF-related materials on miniaturized devices with outstanding performance.
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