Synthesis of BaCeO3 nanoneedles and the effect of V, Ag, Au, Pt doping on the visible light hydrogen evolution in the photocatalytic water splitting reaction

Abstract

Barium cerate BaCeO3, with the perovskite-like and 4f electronic structure of its conduction band, is a material that found applications in photocatalytic hydrogen production from water splitting and solid oxide fuel cells. In fine-tuning of the material, one needs to overcome the hurdle of fast recombination of photogenerated electron–hole pairs. This usually is achieved via metal and other atoms doping. In this paper, we report our attempts to increase the efficiency of the water-splitting reaction when using BaCeO3 by doping it with V, Ag, Au, and Pt. Pure BaCeO3 nanoneedles were synthesized employing a sol–gel method. The nanoneedles were then doped with the afore-mentioned elements. Characterization of the material was carried out via XRD, UV–Vis, TEM, PL, photocurrent intensity, and N2-adsorption measurements. Photocatalytic water splitting was set up under conditions that simulate the natural sunlight with the utilization of glycerol as a scavenger. While pure BaCeO3 does not show appreciable activity towards water splitting, Pt–BaCeO3 produced the best results compared with the other three elements used as dopants. The rate of H2 production using BaCeO3, V–BaCeO3, Ag–BaCeO3, Au–BaCeO3, and Pt–BaCeO3 was 28, 500, 900, 1800, and 2400 μmol g−1, respectively. The superior performance of Pt-doped and Au-doped BaCeO3 can be explained by the narrow bandgap (Pt: 2.16 eV, Au: 2.36 eV), high surface area (Pt: 36.0 m2/g, Au: 38.0 m2/g), and the compatible 4f electronic structure of BaCeO3 and Pt and Au.