Room-temperature hydrogen gas sensing properties of the networked Cr2O3-functionalized Nb2O5 nanostructured sensor

Abstract

Cr2O3-functionalized Nb2O5 nanoparticles were synthesized via a facile hydrothermal route. The multiple-networked Cr2O3-functionalized Nb2O5 nanostructured sensor showed enhanced H-2 gas sensing performance compared to its pristine Nb2O5 nanostructure counterpart. The Cr2O3-functionalized Nb2O5 nanostructure sensor showed responses of 5.24 to 2 ppm of H-2 at room temperature, whereas the pristine Nb2O5 nanoparticle sensors showed responses of 2.29. The former also exhibited a faster response to H-2. The multiple-networked pristine and Cr2O3-functionalized Nb2O5 nanostructured sensors were stronger and much shorter, respectively, than other nanomaterial-based Schottky diode-type sensors and Nb2O5-based Schottky diode-type sensors. The underlying mechanism for the enhanced sensing performance of the Cr2O3-functionalized Nb2O5 nanostructured sensor towards H-2 gas is discussed in detail. Particular emphasis is placed on the role of the Cr2O3-Nb2O5 p-n junction in the Cr2O3-functionalized Nb2O5 nanostructure sensor.