Synthesis, characterization, and ethanol vapor sensing characteristics of vanadium-based-MOFs with and without Cu doping

Abstract

Metal-organic frameworks (MOFs) with a highly porous nature have large surface areas (SSAs), both of which are highly beneficial for gas-sensing studies. Herein, we used a chemical method to synthesize a vanadium-based MOF (V-MOF) and a Cu-doped V-MOF (V-MOF(Cu)) for detecting gaseous ethanol. The morphologies, phases, and chemical compositions of the samples were characterized using various techniques. Notably, V-MOF exhibited a large specific surface area (SSA) of 1405 m2.g−1, while that of V-MOF(Cu) was 1388 m2.g−1. Gas-sensing experiments revealed that the V-MOF sensor produced a maximum response of 1.35 toward 10 ppm ethanol gas at 200 °C, whereas the V-MOF(Cu) sensor exhibited a 20 % higher response, reaching 1.62 under the same conditions. The underlying ethanol sensing mechanism is attributed to the large SSA of the sensors, the modulation of the width of the hole-accumulation layer in the presence of ethanol, and the high affinity of Cu centers for ethanol adsorption. This study demonstrates the high potential of V-MOF(Cu) for use in gas-sensing devices.