Photocatalytic H2Evolution from Ammonia Borane: Improvement of Charge Separation and Directional Charge Transmission

Co/(MFe)-Fe-II layered double hydroxide (LDH) LDH photocatalysts have been designed from the aspect of employing stable half-filled Fe(3+)to trap photogenerated electrons, adjusting the M-II-O-Fe oxo-bridged structure to optimize the short-range directional charge transmission and intercalating oxometallate anions into the LDH to further improve light absorption along with electron-hole separation and non-noble metal Co NP loading and reduction to form a heterojunction. These LDH-based photocatalysts are employed for photocatalytic H(2)evolution from ammonia borane in aqueous solution under visible light at 298 K. The photocatalytic H(2)evolution activity is greatly improved through adjustment of the M-II-O-Fe oxo-bridged structure and molybdate intercalation into the LDH. Turnover frequencies of up to 113.2 min(-1)are achieved with Co/CoFe-Mo. Alongside the experimental results and materials characterization, capture experiments and in situ DRIFTS analysis are carried out to study the photocatalytic hydrogen production mechanism.