title: Morphology of hydrothermally synthesized ZnO nanoparticles tethered to carbon nanotubes affects electrocatalytic activity for H2O2detection.
abstract: We describe the synthesis of zinc oxide (ZnO) nanoparticles and demonstrate their attachment to multiwalled carbon tubes, resulting in a composite with a unique synergistic effect. Morphology and size of ZnO nanostructures were controlled using hydrothermal synthesis, varying the hydrothermal treatment temperature, prior to attachment to carboxylic acid functionalized multi-walled carbon nanotubes for sensing applications. A strong dependence of electrocatalytic activity on nanosized ZnO shape was shown. High activity for H2O2reduction was achieved when nanocomposite precursors with a roughly semi-spherical morphology (no needle-like particles present) formed at 90 °C. A 2.4-fold increase in cyclic voltammetry current accompanied by decrease in overpotential from the composites made from the nanosized, needle-like-free ZnO shapes was observed as compared to those composites produced from needle-like shaped ZnO. Electrocatalytic activity varied with pH, maximizing at pH 7.4. A stable, linear response for H2O2concentrations was observed in the 1-20 mM concentration range.
authors: Chemistry Department, Middle Tennessee State University, Murfreesboro, TN 37132, United States.
authors: Mulugeta B
authors: MB
authors: Wayu
authors: Chemistry Department, Missouri State University, Springfield, MO 65897, United States.
authors: Ryan T
authors: RT
authors: Spidle
authors: Chemistry Department, Middle Tennessee State University, Murfreesboro, TN 37132, United States.
authors: Tuphan
authors: T
authors: Devkota
authors: Chemistry Department, Middle Tennessee State University, Murfreesboro, TN 37132, United States.
authors: Anup K
authors: AK
authors: Deb
authors: Biomedical Science Department, Missouri State University, Springfield, MO 65897, United States.
authors: Robert K
authors: RK
authors: Delong
authors: Physics, Astronomy and Materials Science Department, Missouri State University, Springfield, MO 65897, United States.
authors: Kartik C
authors: KC
authors: Ghosh
authors: Chemistry Department, Missouri State University, Springfield, MO 65897, United States.
authors: Adam K
authors: AK
authors: Wanekaya
authors: Chemistry Department, Middle Tennessee State University, Murfreesboro, TN 37132, United States.
authors: Charles C
authors: CC
authors: Chusuei
keywords: Cyclic voltammetry; Electrocatalysis; Hydrothermal synthesis; Multiwalled carbon nanotubes; Nanostructure morphology; Zinc oxide