Surface ruthenated tin oxide thin-film as a hydrocarbon sensor

A thin-film sensor based on the surface ruthenated tin oxide capable of good sensitivity and high selectivity towards hydrocarbons is demonstrated. The misfits created at the grain boundaries of tin oxide can affect the adsorbate–substrate interaction leading to unusually high selectivity. The surface ruthenated tin oxide film deposited on the commercially available glass shows a sensitivity of 45 in comparison to 3 of pure tin oxide film at operating temperature between 225–3500°C. A systematic study of the morphology, surface coverage and oxidation state of Ru using different techniques, such as scanning electron microscopy (SEM), energy dispersive analysis of X-rays (EDAX) and X-ray photoelectron spectroscopy (XPS) reveals the reason for the enhanced sensitivity of the surface functionalised tin oxide film.