A noble metal-free photocatalytic system based on a novel cobalt tetrapyridyl catalyst for hydrogen production in fully aqueous medium

International audience; The new cobalt tetrapyridyl complex 1(BF4)(2) was characterized and assessed for hydrogen production in fully aqueous solution. Mechanistic information was gained thanks to a fast screening method, using chemical reductants and a Clark microelectrode. Optimal hydrogen production (443 TONs - 3 mL of H-2) was achieved under visible light-driven conditions, in the presence of a noble metal-free photosensitizer, the water soluble porphyrin 2Cl(4), and the ascorbate/tris-(2-carboxyethyl)phosphine (TCEP) sacrificial electron donor system.