One-step laser ablation of Fe clusters supported on Ti3C2Tx nanosheets for enhanced NH3 sensing at room temperature

Supported metal clusters, different from single-atom and large metal-nanoparticle catalysts, possess distinct geometric and electronic structures and effective catalytic sites and thus exhibit unique catalytic activity. Here, an environment-friendly and effective method of using one-step pulsed laser ablation in liquid is reported for synthesizing the emerging gas-sensing materials of the Fe clusters supported on Ti3C2Tx MXene (L-Fe-Ti3C2Tx). Then, the sensors based on the L-Fe-Ti3C2Tx nanosheets are subsequently developed for the real-time detection of ammonia at room temperature. Moreover, it was found that the response of the L-Fe-Ti3C2Tx-232 sensor (in a synthesis condition) toward 10 ppm NH3 is improved to 64.03%, yet remains 39.19%, and exhibits significant repeatability even at high humidity, which makes it become a promising candidate in some special scenarios such as agriculture or human health applications. The excellent NH3-sensing properties can be attributed to the abundance of defective sites with stronger adsorption and the catalysis of the Fe clusters supported on the Ti3C2Tx nanosheets. This work may provide an effective methodology for the confinement of non-noble metal clusters on two-dimensional (2D) materials to further improve the performance of the gas sensors based on 2D materials.