Photo-induced self-formation of dual-cocatalysts on semiconductor surface

Cocatalyst plays key roles in photogenerated charge separation and surface catalytic reactions in photocatalysis. However, it is not clear if the chemical states of cocatalysts changed or remains unchanged under photocatalytic reaction conditions. Herein, taking NaTaO3 as an example, we systemically investigated the chemical states of nickel-based cocatalysts during photocatalytic water splitting reaction. It was found that photo-induced self-formation of Ni and NiO cocatalyst species take place on the surface of NaTaO3 nanocrystals. The self-formation of dual-cocatalysts not only occurs on 26-facet NaTaO3, but also takes place on a more general 6-facet NaTaO3. Our work clarified that the chemical states of cocatalysts are changing and the redox dual-cocatalysts are redistributed on the semiconductor surface owing to the reaction induced by photogenerated charges under the condition of photocatalytic reactions. (C) 2018, Dalian Institute of Chemical Physics, Chinese Academy of Sciences. Published by Elsevier B.V. All rights reserved.