Synergistic Structural and Compositional Modulation of Porous Hollow CdS toward Hydrogen Evolution

The fabrication of hollow architectures combined with elemental doping has emerged as a promising strategy to optimize the performance of photocatalysts in hydrogen evolution reactions (HER). In this study, we report the synthesis of porous, hollow CdS nanododecahedrons codoped with Ag and Co via a templated sequential transformation approach. Starting with ZIF-67 as the initial template, a sulfidation process followed by stepwise cation exchange enabled the successful incorporation of Ag and Co dopants into the CdS lattice. The resulting nanostructures exhibit well-defined porosity and hollow morphology, characterized by abundant sulfur vacancies and intrinsic lattice strain, alongside precisely controllable nanoparticle sizes and pore dimensions. These structural characteristics collectively contribute to the enhancement of broadband light absorption and facilitate the effective separation of photogenerated charge carriers. Notably, the hollow and porous Co/Ag codoped CdS demonstrates significantly improved photocatalytic activity for the hydrogen evolution reaction (HER) compared to the as-prepared hollow CoS/CdS hybrid nanostructures. These results highlight that the templated reverse cation exchange methodology offers a versatile platform for the fabrication of three-dimensional confined doped photocatalysts with controlled structural and porous properties.