Photocharging-activated photocatalysis for hydrogen production in CdS@Cd_xPb_1−xS core-shell nanoparticles

The CdS@Cd_xPb_1−xS core–shell photocatalyst was synthesized through cation exchange and demonstrated significant photocatalytic hydrogen production. Initially, the catalyst was inactive due to the formation of an unfavourable Type I heterojunction. However, under continued illumination, electron accumulation in the Cd_xPb_1−xS shell led to electron repulsion, triggering a structural transition from a film-like morphology to quantum dots (QDs). This transition resulted in the formation of a Type II heterojunction between the CdS and PbS components, boosting hydrogen production by 400% compared to CdS nanoparticles. The reversible structural transformation and stable performance over multiple cycles highlight the potential of CdS@Cd_xPb_1−xS nanoparticles as a highly efficient photocatalyst for hydrogen evolution.