Polycyclic Aromatic Hydrocarbon Based Electrical Sensor: Dimethylamine Substituted Alkynylated Anthracene for H2 Detection

The demand for hydrogen is on a continuous rise in view of its application as a clean-burning and alternate carbon-free energy source. It is flammable at concentration above 4 % in air and is odorless. Fabrication of highly sensitive and selective hydrogen sensors based on small organic molecules which operate at room temperature is challenging. This work describes the fabrication of a hydrogen sensor containing -conjugated organic semiconductor based on a N,N-dimethylamine substituted tetraalkynylatedanthracene that can detect H2 at concentrations as low as 150 part per million (ppm) at room temperature. The N,N-dimethyl amine containing tetraalkynylatedanthracene (AnPhNMe2) has been synthesized by tetra-fold Sonogashira reaction employing a catalyst system based on Pd(CH3CN)2Cl2 + cataCXium® A. A precisely con-trolled fabrication is enabled by employing a μ-gridder printing system. The gas sensor shows excellent sensitivity, fast response and high recovery to H2 at room temperature. Moreover, after the interaction with H2, the surface electron of the ANPhNMe2 gets enhanced and shows a decrease in the resistance of the fabricated device. Sensor exhibits a limit of detection of 49 ppb with the highest sensitivity of 19.95% for the detection of 900 ppm of H2, with a response time of 10 to 20 seconds. This work aims to develop a proof-of-concept for enhancing room temperature hydrogen sensing by developing a low cost printed sensor.