Development of Nano‑SnO_2 and SnO_2: V_2O_5 Thin Films for Selective Gas Sensor Devices

摘要

Pure and doped SnO_2with V_2O_5nanopowders were synthesized via sol–gel method using different V_2O_5ratios. Novel thinfilms of SnO_2:V_2O_5 were thermally vacuum deposited from the nanopowders and utilized for gas sensor devices to detectvolatile organic compounds hazardous gases. The morphological and crystalline structure, textural properties, functionalgroups, optical properties and thermal behavior were investigated by FESEM, XRD, HRTEM, surface area BET, FTIR andUV–Visible spectroscopy, respectively, for both the nanopowders, and thin films. From XRD patterns, the average calculatedcrystallite sizes decreased from 7.8 nm to 4.5 nm as the V_2O_5concentration was varied from 0 to 10%. FESEM andHRTEM show that all the synthesized nanomaterials composed of mesoporous networks of aggregated nanoparticles thatalmost spherical. Thus, V_2O_5doped SnO_2nanopowders synthesized by sol–gel method exhibited the structural and texturalfeatures required to be used as an active area for gas sensor devices. The effect of various doping weight amounts (1, 5 and10 wt%) of V_2O_5as the dopant element enhanced the gas response time and sensitivity. The electrical behavior of the sensorswas determined by measuring the resistance of two deposited platinum electrodes for sensor’s devices for different kinds ofgases (LPG, H_2, NH_3 and acetone) at different temperatures.