Preparation of Au nanoparticles modified TiO2/C core/shell nanowire array and its catalytic performance for NaBH4 oxidation

• A novel 3D Au nanoparticles electrode with good electron conductivity and high surface area is successfully fabricated.
• Au nanoparticles are uniformly distributed on the surface of C@TiO2 nanowire array.
• The electrode exhibits high performance and good stability for NaBH4 oxidation.

In this work, Au nanoparticles directly grown on the surface of TiO2 core-C shell (Au/C@TiO2) has prepared by a simple electrodeposition method for the first time. The morphology is characterized by scanning electron microscope, and its structure is investigated by X-ray diffraction. Au nanoparticles are uniformly distributed on the surface of C@TiO2 nanowire array. Its catalytic performance for NaBH4 oxidation is evaluated by cyclic voltammetry and chronoamperometry measurement. The results indicate that Au/C@TiO2 shows a good and stable catalytic performance. In 2 mol cm−3 NaOH and 0.2 mol cm−3 NaBH4 the oxidation current density for the electrooxidation of BH4− can reach 475 mA cm−2 at 0 V. The electrons transfer number released by BH4− electrooxidation on Au/C@TiO2 electrode has been found to be a 6-electron process. The high performance is mainly attributed to its 3D structure which can promote the mass transport of NaBH4, electronic conductivity and Au utilization.