Construction of hierarchical trimetallic organic framework leaf-like nanostructures derived from carbon nanotubes for gas-sensing applications

Abstract

Unique trimetallic organic material (TMOM)-based nanostructures combined with the new architectures of metal-organic frameworks (MOFs) are promising candidates for gas-sensing applications. This work is the first to successfully convert MOF nanomaterials into nano-porous carbon through carbon nanotubes (CNT) catalytic reaction via a simple and facile hydrothermal method. The leaf-like nanostructures exhibit a high surface-to-volume ratio of 363 m² g^-1. The TMOM nanostructures were subsequently exposed to different types of target gases for a wide range of gas concentrations at different operating temperatures. The carbon nanotubes (TMOM-CNT) hybrid nanocomposites were characterized using X-ray powder diffraction, X-ray photoelectron spectroscopy, Brunauer-Emmett-Teller, scanning electron microscopy, energy dispersion spectrum analysis, thermo-gravimetric analysis, and transmission electron microscopy. The fabricated Zn-Co-Ni MOF@CNT sensors exhibit high selectivity and gas-sensing response toward H₂S gas at an optimal temperature of 325 °C for 100 ppm. These superior gas-sensing performances reveal that the Zn-Co-Ni MOF@CNT sensors with a unique leaf shape exhibit potential applications for the environment applications in gas sensor industry.

Keywords: Gas sensing; H(2)S; MOFs/CNTs; Nanoleaves; Tri-metallic.