Thin Films of an Ultrastable Metal-Organic Framework for Formic Acid Sensing with High Selectivity and Excellent Reproducibility

Formic acid, which is an important volatile organic acid that has been widely used in many fields, is highly corrosive and pungent. The effective detection of formic acid is of great significance for determining the leakage source and monitoring air quality in the industry and the environment. In this work, for the first time, we present the thin films of metal-organic frameworks (MOFs) utilized as sensing materials for the detection of formic acid at room temperature. The zirconium-based MOF-802 featured high chemical resistance to water and acid, and the crystalline thin films of MOF-802 grown via the solvothermal method displayed dense packing and uniformity. Remarkably, the sensor fabricated using MOF-802 film showed high selectivity, excellent long-term stability, and reproducibility for detecting formic acid at room temperature. This study suggests that MOF thin films may act as high-performance sensing materials for the detection of formic acid.