Studies on gas sensing behavior of ZnNb2O6 nano composite towards hydrogen

Abstract In the present study, semiconductor gas sensor based on nanoporous Zinc Niobate (ZnNb 2 O 6 ) synthesized via Sol-Gel protocol followed by impregnation and calcined at different temperatures i.e., from 400 °C to 800 °C (coded as ZNb 4 to ZNb 8 ) and its formation is demonstrated. We systematically monitored the formation of ZnNb 2 O 6 through diverse characterization techniques such as Energy Dispersive X-Ray Analysis (EDX), X-Ray Diffraction (XRD), Particle Size Analyzer (PSA) and Transmission Electron Microscope (TEM). The XRD studies confirmed the formation of single phase ZnNb 2 O 6 for the samples ZNb 7 & ZNb 8 . The TEM images revealed the particles morphology of single phase ZnNb 2 O 6 samples which exhibited considerably high sensing response of S = 0.7 & selectivity towards H 2 gas compared to LPG and NH 3 gas. The gas sensing characteristics towards the H 2 gas was carried out and it’s resistance was measured in air (R a ) & in presence of gas (R g ) and the sensitivity was calculated as S = R a  − R g /R a . Plausible gas sensing mechanism is proposed based on the gas sensing studies carried out with our materials. The achieved features make the sample ZNb 7 a potential candidate for development of H 2 gas sensor.