Visible-light-stimulated Alkalis-triggered Platinum Cocatalyst with Electron Deficient Interface for Hydrogen Evolution

Solid-liquid interface engineering has recently emerged as a promising technique to optimize the activity. Here, the cation identity and induced interfacial electronic structure of Pt have been shown to have a particularly significant impact on the activity of desired photocatalytic hydrogen evolution. The behavior of Pt aggregation synergistically induced by photo-electron accumulation on Pt surface and the ionic potential of alkalis was logically elucidated. X-ray photoelectron spectroscopy (XPS) and photoconductive atomic force microscopy (pcAFM) results revealed that the surface of alkali-triggered Pt nanoparticles (Pt NPs) aggregates are electron-deficient, which favors photo-induced charge separation, leading to improved reaction kinetics. Based on the density functional theory (DFT) calculation, alkalis-triggered Pt NPs has lower Gibbs free energy and potential energy surface of H-2 formation for hydrogen evolution in thermodynamics. As a result, K+ triggered Pt cocatalyst displays the highest activity (3306.6 mu mol h(-1) g(-1)) on pure CN, almost 4-fold increase compared to the reference without the addition of alkalis, showing high utilization efficiency of Pt.