p-/n-Type Switching in the Ag/BTO/TiO Nanocomposite as a Gas Sensor toward Ethanol, Liquefied Petroleum Gas, and Ammonia.

A novel Ag/BTO/TiO nanocomposite was prepared using chemical reduction and sol-gel techniques followed by sintering at ∼950 °C to grow rutile TiO and remove organic materials and hydroxyl groups. The structural, optical, morphological, dielectric, and gas-sensing properties were investigated using X-ray diffraction, Fourier transform infrared spectroscopy, ultraviolet-visible spectroscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy, and inductance, capacitance, and resistance meter, respectively. The surface plasmon resonance peak of Ag was observed at 428 nm, and the absorption edge of the Ag/BTO/TiO nanocomposite was observed at 235 nm, with an energy bandgap of 5.