Volatile Organic Compounds (VOCs) Response Characteristics of the Hydrothermally Synthesized SnO2 Nanocapsules

摘要

Tin oxide (SnO2) powders were synthesized by hydrothermal route using tin (IV) chloride pentahydrate (SnCl4 center dot 5H(2)O), potassium hydroxide (KOH) and ethanol. XRD studies confirm a pure tetragonal phase of SnO2 with lattice parameters (a = b = 4.708 angstrom and c = 3.154 angstrom). TEM image shows several SnO2 nanocapsules with a uniform diameter of similar to 29 nm in the prepared sample. Gas sensing performance to VOCs (methanol, ethanol, propan-2-ol and acetone) has been carried out in the temperature range: 125-250 degrees C for varying concentration (10-50 ppm). Among all the VOCs examined, the response has been observed to be maximum at the operating temperature of 250 degrees C for 50 ppm concentration of propan-2-ol, which is due to have maximum number of -CH2-groups in the propan-2-ol. The sensing mechanism has been explained based on chemisorption of oxygen on the oxide surface and the subsequent reaction between the adsorbed oxygen species and the VOCs molecules.