Facile Elaboration of TiO2-ZnO-Based Low-Cost H2 Gas Sensors

Abstract

This study presents the development of a low-cost H2 gas sensor made from a titanium dioxide–zinc oxide composite by means of a simple, cost-effective screen-printing method. The sensing material was created by mixing titanium dioxide and zinc oxide nanoparticles with an organic binder, which was screen-printed onto a glass substrate containing silver electrodes. These samples were then characterized using X-ray diffraction (XRD) and field-emission scanning electron microscopy (FESEM). The XRD results confirmed that the films boasted well-defined crystallinity, with predominant anatase and hexagonal ZnO phases, as well as uniformity of grains. Sensor performance was evaluated in a custom-built chamber at hydrogen concentrations of 100 to 1000 ppm and at operating temperatures of 100 °C, 200 °C, and 300 °C. The results indicate improved sensor performance as the operating temperature increased to 300 °C, with the best sensitivity values of 0.99, 1.17, and 1.31 at hydrogen concentrations of 100, 500, and 1000 ppm, respectively. The sensor showed stable and reproducible response characteristics, and its responses were retimed after a few hundred seconds. Low-cost fabrication, ease of processing, and reliable sensor performance make titanium oxide–zinc oxide composites promising candidates for hydrogen detection.