(560cj) Plasmonic Perovskite Semiconductor for Photoelectrochemical Water Splitting

Photoelectrochemical (PEC) water splitting, as an environmental-friendly approach for hydrogen generation, has drawn numerous attentions. For practical hydrogen generation, it is imperative to develop efficient photoanodes with low cost. However, the PEC water splitting performance is still far from practice due to their insufficient light absorption and serious charge recombination during the water oxidation and reduction reactions. Herein, great efforts have been put on the development of photoanodes with expanding light absorptions and enhanced charge separations by virtue of localized surface plasmonic resonance (LSPR). In this work, a nonmetallic photocatalyst, namely, reduced SrTiO₃ nanotubes with a crystalline-core and amorphous shell nanostructures, was developed. It exhibits strong LSPR with reversible tunability. Both experimental and theoretical studies illustrate that the abundant oxygen vacancies existing in the amorphous shell induce the high carrier concentration and thus are responsible for LSPR effect. It plays an important role in PEC water splitting. A remarkable photocurrent density of 170.0 μA cm^-2 and a maximum incident photon-to-current conversion efficiency of 4.0 % were achieved under visible light excitation by using the novel plasmonic SrTiO_3. It is comparable to the state-of-the-art noble metal sensitized catalyst with plasmonic effect. Present work, the nonmetallic plasmonic perovskite semiconductor with LSPR properties, opens a novel paradigm for PEC water lighting in the field of solar energy harvesting.