Highly Crystalline and Nanostructured Molybdenum Trioxide (α‐MoO₃) with Metal–Organic Decomposition on Laser‐Induced Graphene for Volatile Organic Compound Gas Sensing

Abstract Gas sensors with metal oxide semiconductors (MOS) are demonstrated high sensitivity, selectivity, and rapid response to volatile organic compounds (VOC) gases due to their redox reactions. However, MOS typically imposes a significant electrical burden on devices due to its low carrier mobility and high electric resistivity. Recently, hybridization of laser‐induced graphene (LIG) with MOS is a promising approach to overcome the inherent limitations of MOS and enhance device performance. In this study, molybdenum oxide (MoO_x) is synthesized on LIG using metal–organic decomposition (MOD) for VOC gas sensing. Highly crystalline α‐MoO₃ is demonstrated to grow densely on the LIG by analysis with field emission scanning electron microscopy, X‐ray diffraction, X‐ray photoelectron spectroscopy, and Raman spectroscopy. Additionally, the gas sensing test revealed that LIG/α‐MoO₃ hybrid gas sensor can selectively detect various VOC gases (methanol, ethanol, 1‐propanol, and 2‐propanol) and stably detected low concentrations of methanolat 44.7 ppm with low electrical resistivity (6.94 × 10⁵ Ω). This work demonstrates that the MOD method enables the synthesis of high‐density, highly crystalline, nanostructured α‐MoO₃, thereby enhancing the performance of conventional gas sensors. Furthermore, the LIG and MOS hybrid process with the MOD method can be applied to other MOS and is expected to enhance the performance of semiconductor devices and manufacturing efficiency and reduce processing costs.