Aerosol Spray Assisted Synthesis of Ni Doped BaTiO3 Hollow Porous Spheres/Graphene as Photoanode for Water Splitting

Abstract

A key challenge in photoelectrochemical water splitting is to fabricate nanostructured photoelectrodes with desirable properties. Herein, Ni doped BaTiO3 hollow spheres (HS) supported on reduced graphene oxide (RGO) nanocomposite were successfully synthesized by aerosol spray drying method. Former spheres consisted of small nanoparticles with size 5–20 nm possessing high porosity and large area. Characterizations were done by X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), high-resolution transmission electron microscopy (HRTEM), and field emission scanning electron microscopy (FESEM). Ni doped BaTiO3 HS/RGO nanocomposites as photoanodes exhibited an enhanced photoelectrochemical performance and long-term stability compared to BaTiO3 HS and BaTiO3 HS/RGO. The photocurrent density of Ni doped BaTiO3 HS/RGO photoanode revealed 8.14 μA cm−2 which is 37% more than BaTiO3 HS. From electrochemical impedance spectroscopy (EIS) analysis, Ni doped BaTiO3 HS/RGO exhibited the lowest charge transfer resistance in comparison with BaTiO3 HS and BaTiO3 HS/RGO which leads to enhancement in the electrocatalytic activity. The successful doping of BaTiO3 HS by Ni and its loading over RGO increases the separation rate of photogenerated electrons and holes and improved the light harvesting. Ni doped BaTiO3 HS/RGO as photo-electrocatalyst exhibits excellent activity toward water oxidation capability and presents a new approach for high-efficient future photo-electrocatalysis.