Plasmonic Enhancement in BiVO4 Photonic Crystals for Efficient Water Splitting

• Published in: Small (Weinheim an der Bergstrasse, Germany) Germany), 2014-10, Vol.10 (19), p.3970-3978
• Main Authors: Zhang, Liwu, Lin, Chia-Yu, Valev, Ventsislav K., Reisner, Erwin, Steiner, Ullrich, Baumberg, Jeremy J.
• Format: Article
• Language: English
• Subjects: BiVO4; Nanotechnology; photonic crystals; plasmonic; water splitting
• ISSN: 1613-6810; 1613-6829
• DOI: 10.1002/smll.201400970

Photo‐electrochemical water splitting is a very promising and environmentally friendly route for the conversion of solar energy into hydrogen. However, the solar‐to‐H2 conversion efficiency is still very low due to rapid bulk recombination of charge carriers. Here, a photonic nano‐architecture is developed to improve charge carrier generation and separation by manipulating and confining light absorption in a visible‐light‐active photoanode constructed from BiVO4 photonic crystal and plasmonic nanostructures. Synergistic effects of photonic crystal stop bands and plasmonic absorption are observed to operate in this photonic nanostructure. Within the scaffold of an inverse opal photonic crystal, the surface plasmon resonance is significantly enhanced by the photonic Bragg resonance. Nanophotonic photoanodes show AM 1.5 photocurrent densities of 3.1 ± 0.1 mA cm−2 at 1.23 V versus RHE, which is among the highest for oxide‐based photoanodes and over 4 times higher than the unstructured planar photoanode. A photonic nano‐architecture is designed to enhance solar water splitting efficiency by manipulating and confining light absorption. Coupling of an inverse opal photonic crystal and localized surface plasmons from Au nanoparticles is observed in this photonic architecture. Within the scaffold of an inverse opal photonic crystal, the surface plasmon resonance is significantly enhanced by the photonic Bragg resonance.