jp8b10521_si_001.pdf (652.09 kB)

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

Download (652.09 kB)
journal contribution
posted on 28.12.2018, 00:00 by Liyan Xie, Xiyu Li, Xijun Wang, Wanying Ge, Jinxiao Zhang, Jun Jiang, Guozhen Zhang
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 O2 and H2, 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.