Bimetallic Pd/Co Embedded in Two-Dimensional Carbon-Nitride for Z-Scheme Photocatalytic Water Splitting

Two-dimensional s-triazine-based graphitic carbon nitride (g-CN) material with a band gap of 3.18 eV has emerged as a promising photocatalyst for water splitting. Here, we propose a Z-scheme photocatalyst by embedding Pd(OH)(2)- and Co(OH)(2)-groups in different parts of g-CN simultaneously. Density functional theory calculations show that it extends solar light absorption of g-CN into visible and infrared regions, realizes efficient charge separation, and can catalyze water splitting to produce O-2 and H-2, respectively. The staggered band alignment meets the requirement of the Z-scheme. Importantly, ab initio nonadiabatic molecular dynamics simulations suggest that the photogenerated hole evolution accords with anticipation for subsequent water-splitting reactions. The computed Gibbs-free energy and overpotentials confirm the feasibility of hydrogen evolution reactions on the Co-centered fragment and oxygen evolution reactions on the Pd-centered fragment, respectively. It is expected that this new Z-scheme model designed on a single material platform may provide an alternative way for achieving efficient photodriven water splitting.