Plasmonic S-scheme heterojunction with catalytic synergistic effect of Zn metal-Se vacancy dual active sites for boosted photocatalytic hydrogen production

The efficient synergy of Zn‑metal/Se‑vacancy dual active sites facilitates surface catalytic reactions. • The localized surface plasmon resonance effect of CuCo 2 O 4  broadens the spectral absorption range to near-infrared light. • The formation of S-Scheme heterojunction and its mechanism of photogenerated electron migration have been deeply studied. The synergistic effect of metal-vacancy dual active sites plays a pivotal role in surface catalytic reactions, yet its underlying microscopic mechanism remains poorly understood. Herein, a Zn-ZnSe photocatalyst containing Se vacancies is prepared through solvothermal synthesis followed by thermal reduction methods. The resulting Zn-ZnSe photocatalyst with Se vacancy (V Se ) is then coupled with the plasmonic catalyst CuCo 2 O 4 to construct a CuCo 2 O 4 /Zn-ZnSe S-scheme heterojunction. Owing to the localized surface plasmon resonance (LSPR) effect, the as-prepared CuCo 2 O 4 /Zn-ZnSe exhibits intense near-infrared light response. Experimental characterization and theoretical calculations indicate that the synergistic effect of Zn metal and Se vacancies (Zn-V Se ) promotes surface photocatalytic reactions. Specifically, H 2 O activation (*H 2 O → *OH*H) occurs primarily at Se vacancy sites, whereas Zn metal facilitates H 2 formation and desorption (*H → * + 1/2H 2 ). This work elucidates the synergistic catalysis of Zn-V Se dual active sites, and provides a strategy for converting full-spectrum solar energy into hydrogen. Download: Download high-res image (151KB) Download: Download full-size image