Hydrogen plasma treated iron vanadate nanoparticles for efficient ammonia sensing

Abstract

In this study, we investigate the impact of hydrogen plasma treatment on the gas-sensing properties of iron vanadate (FeVO4) nanostructures. The FeVO4 nanoparticles were synthesized via a sol–gel method, followed by surface modification using hydrogen plasma. Both hydrogen plasma-treated (hp-FeVO4) and untreated (FeVO4) samples were systematically characterized using X-ray diffraction (XRD), scanning electron microscopy (SEM), and X-ray photoelectron spectroscopy (XPS) techniques. Gas sensing experiments revealed that hp-FeVO4 nanostructures exhibited a response to 50 ppm NH3 that was twice as high as that of untreated FeVO4 samples, highlighting the significant enhancement achieved through plasma surface engineering. Notably, the hp-FeVO4 sensor exhibited a response time of 72 s and a recovery time of 292 s, operating at a reduced temperature of 380 °C, possibly due to increased band bending on the plasma-treated surface. Moreover, the sensor exhibited promising repeatability, selectivity, and long-term stability without the need to incorporate noble metals. These findings highlight the strong potential of hydrogen plasma-modified iron vanadate for advanced gas sensing applications.