Highly Selective and Sensitive Methanol Sensor Using Rose-Like ZnO Microcube and MoO₃ Micrograss-Based Composite

Rose-like ZnO microcube/MoO₃ micrograss-based composite was synthesized via hydrothermal process followed by solution-based synthesis approach. The crystal structure, chemical state, morphology, and elemental analysis of the obtained rose-like composite were examined by X-ray diffraction, X-ray photoelectron spectroscopy, field emission scanning electron microscopy, and energy dispersive X-ray spectrometer, respectively. The results indicated that rose-like ZnO microcube/MoO₃ micrograss composite was obtained where ZnO microcube pistil and MoO₃ micrograss petal were formed. Furthermore, volatile organic compounds sensing performance of the rose-like composite was examined, where sensors presented outstanding sensing performance toward methanol including high selectivity and sensitivity, low-optimal operating temperature as well as very stable response-recovery characteristics, and long-term stability. Such sensing performance can be ascribed to a combined effect of the unique rose-like structures and band formation between ZnO/MoO₃ n-n heterojunction.