Superior Photocatalytic H2 Production with Cocatalytic Co/Ni Species Anchored on Sulfide Semiconductor

• DOI: 10.1002/adma.201703258
• Publication Date: 2017-08-25T16:14:38Z
• Authors: Guixia Zhao; Yubin Sun; Wei Zhou; Xiangke Wang; Kun Chang; Guigao Liu; Huimin Liu; Tetsuya Kako; Jinhua Ye
• Keywords: 01 natural sciences; 0104 chemical sciences

AbstractDownsizing transition metal‐based cocatalysts on semiconductors to promote photocatalytic efficiency is important for research and industrial applications. This study presents a novel and facile strategy for anchoring well‐dispersed metal species on CdS surface through controlled decarboxylation of the ethylenediaminetetraacetate (EDTA) ligand in the metal–EDTA (M–EDTA) complex and CdS mixture precursor to function as a cocatalyst in the photocatalytic H2 evolution. Microstructure characterization and performance evaluation reveal that under visible light the resulting pentacoordinated Co(II) and hexacoordinated Ni(II) on CdS exhibits a high activity of 3.1 mmol h−1 (with turnover frequency (TOF) of 626 h−1 and apparent quantum efficiency (AQE) of 56.2% at 420 nm) and 4.3 mmol h−1 (with TOF of 864 h−1 and AQE of 67.5% at 420 nm), respectively, toward cocatalytic hydrogen evolution, and the cocatalytic activity of such a hexacoordinated Ni(II) even exceeds that of platinum. Further mechanistic study and theoretical modeling indicate that the fully utilized Co(II)/Ni(II) active sites, efficient charge transfer, and favorable kinetics guarantee the efficient activities. This work introduces a promising precursor, i.e., M–EDTA for planting well‐dispersed transition metal species on the sulfide supports by a facile wet‐chemistry approach, providing new opportunities for photocatalytic H2 production at the atomic/molecular scale.