Enhanced Photoactivity and Hydrogen Generation of LaFeO<inf>3</inf> Photocathode by Plasmonic Silver Nanoparticle Incorporation

A plasmonic LaFeO3-Ag (LFO-Ag) photocathode was synthesized by incorporating Ag nanoparticles to excite surface plasmon resonances (SPRs) for enhanced light harvesting to drive photoelectrochemical (PEC) hydrogen evolution. The Ag nanoparticles were modeled using finite difference time domain (FDTD) simulations, and the results show an optimal dimension of 50-80 nm for SPR enhancement. Nanostructured LFO films were prepared by a novel and inexpensive spray pyrolysis method, and the Ag nanoparticles were dispersed uniformly on to the films by simple spin coating method. The LFO-Ag photocathode exhibited strong light absorption capability and high current density, twice that of its untreated counterpart. This subsequently led to enhanced PEC hydrogen evolution, doubling the volume of hydrogen generated compared to untreated LFO. The enhancement is ascribed to the strong SPR effect and the synergy between the Ag nanoparticles and nanostructured LFO photocathode.