The catalytic enhancement of the hydrogen evolution reaction facilitated by Pd coating on SrTiO3

The wide bandgap structure of 3.2 eV has made SrTiO3 (STO) well-known for its exclusive responsiveness to ultraviolet (UV) light. By anchoring Pd to the surface oxygen atoms of STO, we have successfully reduced the forbidden bandwidth of STO to 2.75 V, thereby extending its light absorption range to visible light. Simultaneously, trace amounts of low-valent Pd were distributed on the surface, significantly enhancing the photocatalytic hydrogen precipitation rate to 7366.07 μmol·g-1·h-1. This innovative approach led to the development of a novel nanocatalyst with numerous tailored active sites specifically designed for efficient photocatalytic hydrogen evolution. X-ray fine spectroscopy confirms Pd was successfully anchored to the STO surface and coordinated with surface O and the occurrence of Pd and Pd coordination at 2.0 Å from the Pd center in the R-space. Density functional theory (DFT) calculations further validate that anchoring Pd onto the STO surface reduces the free energy of adsorption for H* on these active sites. This discovery presents a promising strategy for immobilizing metal catalysts at perovskite STO’s unit sites. [Display omitted] •Adjusting Pd salt reduction time thus regulating the HER reaction on SrTiO3 surface.•Pd and PdO synergize to promote H2 generation.•Ti in SrTiO3 becomes a new active site due to Pd doping becomes a new active.