One-pot hydrothermal synthesis of CuO-ZnO composite hollow spheres for selective H2S detection

Abstract

Pure ZnO and CuO-ZnO composite hollow spheres were prepared by one-pot, glucose-mediated hydrothermal reaction with subsequent heat treatment. The pure ZnO hollow spheres could selectively detect C2H5OH at 475 degrees C. The CuO-ZnO hollow spheres prepared from the solutions with the compositions of [Cu2+]/([Cu2+] + [Zn2+]) = 0.02 and 0.04 showed high responses to 5 ppm H2S (R-a/R-g = 13.3 and 32.4, R-a: resistance in air, R-g: resistance in gas) with negligible cross responses to 100 ppm C2H5OH, C3H8. CO and H-2 (R-a/R-g =1.4-1.8) at 336 degrees C. They also showed selective C2H5OH detection at 475 degrees C. The dual selective detection of H2S and C2H5OH by the composite particles was due to electrochemical interactions with H2S of nano-scale p(CuO)-n(ZnO) junctions within the hollow spheres. (C) 2012 Elsevier B.V. All rights reserved.