Fe-doped MoO3 nanoribbons for high-performance hydrogen sensor at room temperature

A series of novel ribbon-like Fe-doped orthorhombic MoO3 (α-MoO3) nanoribbons was synthesized using a facile hydrothermal method. The results showed that the size of the prepared α-MoO3 nanoribbons was inversely related to the concentration of the Fe dopant. The hydrogen sensing performance of the modified nanoribbons improved after increasing the content of the Fe dopant from 2 at% to 6 at% but deteriorated at higher concentrations. The α-MoO3 doped with 6 at% Fe exhibited promising gas sensing performance to 500 ppm H2 at room temperature, with a high sensor response of 19.7 s and a short response time of 21.4 s. The sensor based on Fe-doped α-MoO3 nanoribbons was sensitive to 10–1500 ppm H2 and showed outstanding repeatability, response stability, and selectivity to H2. The experimental results and first-principles DFT calculations indicated that the high specific surface area and Fe dopant atoms were the main factors responsible for the promising hydrogen sensing performance of the modified MoO3. Our study indicates that Fe-doped α-MoO3 nanoribbons can be applied as a gas sensor with excellent hydrogen gas sensing properties at room temperature.