The paper presents a comparative approach concerning the properties of SnO2 thin layers obtained via spray pyrolysis deposition (SPD) using precursors with different molar concentrations The photocatalytic efficiency of the samples was tested in the photodegradation of methylene blue The sample obtained from 0 001 M precursor exhibit higher electrical conductivity (current-voltage curves) and photocatalyric properties compared with the samples obtained from precursors with lower molar concentrations Regardless of the molar concentrations the samples present tetragonal structure (X-ray diffraction) and granular morphology (atomic force microscopy) (C) 2010 Elsevier B V All rights reserved