Electronic Tuning of Metal Nanoparticles for Highly Efficient Photocatalytic Hydrogen Peroxide Production

We here present an innovative approach to increase the electron density of metallic Pd nanoparticles loaded on TiO 2 photocatalysts by coordinating Pd with surface-anchored organic ligands. X-ray photoelectron spectroscopy and X-ray absorption near edge structure measurements confirm the negative charge on the Pd nanoparticle induced by electron donation from amine groups of the ligands. The electronically modified Pd on TiO 2 exhibits unprecedentedly high photocatalytic H 2 O 2 production from O 2 reduction. Mechanistic investigations suggest that the enhanced performance results from electronic tuning of Pd nanoparticles, leading to enhanced charge separation on the TiO 2 support, improved activity of Pd nanoparticles as an oxygen reduction center, and improved selectivity for O 2 reduction to produce H 2 O 2 .