Hydrogen (H₂) has attracted lots of attention as a future energy source, especially due to its high energy-density, carbon-free, and pollution-free characteristics^[1,2]. However, H₂ is flammable and has low ignition energy. At room temperature and pressure, H₂ exhibits a wide explosion range for concentrations (4%–75% by volume) coupled with a large flame propagation speed. Furthermore, as a colorless, odorless, extremely volatile gas, it diffuses very fast and easily, so it may eventually leak out of its container due to its small molecular size^[3]. Thus, fast leaks detection equipment for all H₂-related systems is required because of such safety reasons.