Multi-Modal X-Ray Probing of Enhanced H3+ Formation on Nanoparticle Surfaces

We demonstrate a novel multi-modal approach combining momentum-resolved ion emission spectroscopy, X-ray photoelectron spectroscopy, and coherent diffraction imaging to investigate enhanced H 3 + formation on nanoparticle surfaces. Using the SQS instrument at European XFEL, we simultaneously captured single-shot 3D ion momentum distributions and diffraction patterns from individual nanoparticles, allowing direct correlation between particle morphology and surface reaction dynamics. Our results reveal enhanced trihydrogen cation formation on water-decorated nanoparticle surfaces through X-ray induced ionization processes. The multi-modal detection scheme provides unprecedented insight into the spatiotemporal evolution of surface chemistry at the nanoscale.