Optimization of Pt nanoparticles loading in ZnO for highly selective and stable hydrogen gas sensor at reduced working temperature

The aim of the current research is to utilize pure ZnO, and Pt nanoparticles loaded ZnO pencil-like microstructures to develop a highly selective and stable H₂ gas sensor. The microstructures were synthesized using the well-known hydrothermal route and characterized via several techniques such as X-ray diffraction, field emission scanning electron microscopy, X-ray photoelectron spectroscopy, and transmission electron microscopy to investigate the structural, elemental, and morphological properties. Finally, the hydrogen sensing properties of prepared sensors were examined to optimize the Pt content and explore the detection capabilities of the materials toward H₂ gas. The highly selective response was observed for the optimum concentration of 1 at% Pt loaded ZnO microstructures at a relatively reduced working temperature of 150 ℃ with good repeatability and high stability. Additionally, the improved sensing mechanism was thoroughly investigated. Our findings indicate that the inclusion of an optimal amount of noble metals into metal oxide semiconductor-based microstructures improves the gas detection performance with superior selectivity in real-world applications.