Ultra-low hydrogen sulfide gas detection of metal-organic framework derived hollowed-out rod-shaped copper oxide nanostructures

Abstract

Highly selective detection of hydrogen sulfide (H₂S) at low temperatures has broad applications in industries, agriculture, and the healthcare sector. However, the practical application of metal oxide semiconductor (MOS) resistive gas sensors is greatly limited by their inherent high operating temperature, low response, and low selectivity. To further enhance the detection performance of H₂S gas, this study proposes and investigates an efficient hydrogen sulfide (H₂S) gas sensor based on hollowed-out rod-shaped copper oxide (CuO) derived from metal-organic frameworks (MOF). The sensor material was synthesized using a solvothermal method to prepare the precursor copper terephthalate metal–organic frameworks (CuBDC) and then calcinated under high temperatures. The sensor prepared at 500 °C exhibits the most outstanding gas sensitivity, with a response as high as 330 (Rg/Ra) to 1 ppm H₂S at room temperature (20 °C) and theoretical detection limits at the ppt level, excellent selectivity and stability. The gas sensing mechanism is briefly explained through an oxygen adsorption model. The research results underscore the potential application prospects of this sensor in H₂S detection, providing a new direction for developing high-performance, low-cost, and highly efficient gas sensors.