Wireless gas sensors based on Au nanocluster-sensitized SnO₂ nanosheets for CO-resistant hydrogen detection

Noble metal nanosensitizers such as Pt and Pd are widely employed to enhance the H₂ sensing performance of semiconductor metal oxide gas sensors owing to their superior capability for H₂ adsorption and dissociation; however, they exhibit poor resistance to CO, a gas that commonly coexists with H₂, leading to cross-response and false alarms in real-world application scenarios. In this work, we design a wireless gas sensor based on Au nanocluster-functionalized SnO₂ nanosheets. The sensor exhibits exceptional sensitivity (43.2 ppm⁻¹), a low detection limit (100 ppb), rapid response time (11 s), excellent selectivity, and strong anti-interference capability against CO. Notably, owing to their ultra-small particle size and high catalytic activity, the Au nanocluster-functionalized SnO₂ nanosheets show a response 51.1 and 1.6 times higher than that of pristine SnO₂ and conventional Au nanoparticle-functionalized SnO₂ nanosheets. Moreover, when CO at a concentration 60 times higher than H₂ is introduced into the H₂ stream, the sensor response changes by only 7.8%. Furthermore, a handheld detector is developed for hydrogen leak detection and early warning. This work presents an alternative strategy for the fabrication of high-performance H₂ sensors with superior CO resistance by employing gold nanoclusters as a sensitizer in place of conventional Pd-based materials.