Enhanced photoelectrochemical performance of TiO2 photoanode decorated with Pd-carbon core shell nanoparticles

Abstract

In this work, we report enhancement in photoelectrochemical performance of TiO2 photo-anode on coating it with Palladium carbon (Pd-C) core shell nanoparticles. Transmission electron microscopy images confirmed formation of Pd nanoparticle and Pd-C nanoparticles with Pd core surrounded by carbon shell. X-Ray Diffraction analysis confirmed the pure anatase phase of synthesized TiO2 films. Raman spectroscopy revealed graphitic nature of carbon in Pd-C. In comparison to pristine TiO2, quenching in PL intensity of Pd-TiO2& Pd-C-TiO2 sample was observed which indicates lowering of recombination rate of charge carriers, this effect is explained through surface plasmon resonance (SPR) in Pd and Pd-C nanoparticles. Also, SPR in Pd & Pd-C promoted absorption of photons in visible region thus making both Pd-C-TiO2& Pd-TiO2 active in visible region. Finally, graphitic carbon layer over Pd in Pd-C-TiO2 offered an additional advantage over bare Pd in Pd-TiO2 i.e. reducing the charge transfer resistance between electrode and electrolyte under illumination.