Strong Synergy between Pd Single Atom and Zn Vacancy Boosts Photocatalytic Pure Water Splitting

Single‐atom and vacancy‐engineered photocatalysts have shown their remarkable strengths in improving carrier transfer dynamics, yet constructing the integration of single atoms and vacancies as the active site is still challenging. Herein, an icing‐assisted photochemical strategy has been employed to anchor Pd single atoms in Zn vacancies on CdxZn1−xS nanorods to form a Pd–S4 tetrahedron coordination structure, enabling exceptional photocatalytic water splitting performance in the absence of any sacrificial agents. Under visible light irradiation, the H2 evolution rate of Pd/Cd0.1Zn0.9S reaches 608.2 μmol g−1 h−1, which is around 229, 6.7, 6.1, and 2 times to that of ZnS, Cd0.1Zn0.9S, Pd/ZnS, and Pd NPs/Cd0.1Zn0.9S, respectively. Detailed experimental and theoretical analyses confirm that Pd–S hybridized electronic states and Pd single atoms are beneficial for enhancing the charge separation/transfer, accelerating the formation of H* and the release of H2. On Pd/CdxZn1−xS nanorods, Pd single atoms are trapped in Zn vacancies to form the Pd–S4 configuration as active sites to achieve efficient H2 productivity in photocatalytic pure water spitting. The synergy between Pd single atoms and Zn vacancies is beneficial for the formation of H* and the release of H2 molecule.