Highly selective and ultra-sensitive gas sensor based on Fe2O3/Ti3C2Tx MXene heterostructure for ppb-level n-butanol detection

The sensitive and rapid detection of toxic gases, particularly at concentrations as low as parts per billion (ppb), is crucial in preventing explosion and gas leakage accidents. Herein, we have developed a ppb-level n-butanol sensor by constructing a heterojunction structure through in situ growth of n-type oxide semiconductor Fe2O3 nanoparticles on two-dimensional layered carbide materials Ti3C2Tx MXene. The obtained results from that the Fe2O3/MXene-1% sensors display ultra-low detection limit, exhibiting a 1.31 response towards 70 ppb n-butanol. In addition, the Fe2O3/MXene-1% sensors show a remarkable response of 83.7 towards 100 ppm n-butanol at 150 °C, which represents a 22-fold improvement when comparison with the pure Fe2O3 sensors. The sensors also exhibit brilliant selectivity, reproducibility and excellent long-term stability. The remarkable enhancement in gas sensitive performance depends on Schottky heterojunctions formed between metal oxides and Ti3C2Tx MXene and the synergistic effect. The incorporation of MXene decreases materials’ resistance and enhances the carrier transfer rate. The design of this study provides a novel approach for achieving ppb-level n-butanol detection.