Triangular network of crystalline submicron rutile TiO2 block assembly:: An alcohol sensor

RF sputtering technique was used to obtain periodic submicron triangular TiO2 blocks on quartz substrates at 500 degrees C. Preferentially oriented XRD patterns exhibiting the strongest line at 2 theta = 27.78 degrees suggested a rutile TiO2 block assembly. X-ray photoelectron spectroscopy confirmed that the surface composition of the particles corresponded to TiO2 with the absence of Ti3+ species at 500 degrees C after sputtering. Analysis of AFM images indicated that the single crystals were triangular in shape, self-assembled across the quartz surface. The sides of the triangular crystal obtained at 500 degrees C were found in the submicron range of 100-225 nm, whereas those sputtered at 300 degrees C were in the range of 250-375 nm. The image Z-range, R-q, R-a of TiO2 single crystal deposits sputtered at 500 degrees C were found to be 19.6, 3.1 and 2.5 nm, respectively, evidencing a smooth surface and regularly assembled single crystals. The crystalline submicron TiO2 film exhibited a sensor signal in the range of 2.3-10.8 to a low concentration (10-50 ppm) of alcohol at 250-500 degrees C. The reversibility of the sensor was also assessed. (C) 2007 Elsevier B.V. All rights reserved.