Porous NiTiO3/TiO2 nanostructures for photocatatalytic hydrogen evolution

Abstract

We present a strategy to produce porous NiTiO₃/TiO₂ nanostructures with excellent photocatalytic activity toward hydrogen generation. In a first step, nickel-doped TiO₂ needle bundles were synthesized by a hydrothermal procedure. Through the sintering in air of these nanostructures, porous NiTiO₃/TiO₂ heterostructured rods were obtained. Alternatively, the annealing in argon of the nickel-doped TiO₂ needle bundles resulted in NiO_x/TiO₂ elongated nanostructures. Porous NiTiO₃/TiO₂ structures were tested for hydrogen evolution in the presence of ethanol. Such porous heterostructures exhibited superior photocatalytic activity toward hydrogen generation, with hydrogen production rates up to 11.5 mmol h⁻¹ g⁻¹ at room temperature. This excellent performance is related here to the optoelectronic properties and geometric parameters of the material.