Facile One-Pot Synthesis of Au–Pd Core–Shell Nanoparticles with Enhanced Catalytic Performance

Abstract Bimetallic nanoparticles offer catalytic properties arising from electronic exchange between their constituent metals, which is highly sensitive to structural configuration. In particular, this electronic interplay modulates the metal-support interaction, a key factor controlling catalytic performance. Core–shell architectures provide an effective platform to tailor these effects with atomic precision. Here, we demonstrate that Au(core)–Pd(shell) nanoparticles supported on TiO2, synthesized through a simple one-pot ball-milling approach, exhibit markedly enhanced photocatalytic hydrogen evolution compared with both AuPd-alloy and a physical mixture of monometallic counterparts. Density functional theory calculations reveal that the core–shell structure weakens metal-support interactions relative to the alloy, thereby promoting higher surface reactivity. These findings demonstrate how mechanochemistry can attain precise structural control in supported bimetallic systems, optimize electronic coupling, and boost photocatalytic activity for hydrogen production.