Water splitting is an effective technique for utilizing abundant renewable solar energy. The versatile platform of the metal–organic frameworks (MOFs) has recently emerged for the development of MOF‐based water oxidation catalysts (WOCs). Here, we report new WOCs with Ru(R‐tpy)(inc) 2 (H 2 O) 2+ scaffold (R = –H ( 1 ) and –EtO ( 2 ) , inc = isonicotinic acid and tpy = 2,2′:6′,2′‐terpyridine) active in chemical water oxidation with first‐order kinetics and rates of 16.83 and 19.38 μM s −1 for ( 1) and ( 2) . The kinetics of photocatalytic O 2 evolution were first‐order with k hν obs = 60.6 and 83.52 μM s −1 for catalysts (1) and ( 2) . We have incorporated a more active catalyst (2) into the MOF Fe‐MIL 101 (prepared with 50% BDC/50% inc linkers, where BDC = terephthalic acid), in which Fe 3 O nodes absorb visible light, leading to charge separation. Materials were characterized by a range of structural and spectroscopic techniques. New, Ru(EtO‐tpy)(inc) 2 (H 2 O) 2+ ‐doped MIL 101 achieved a photocurrent (~7 × 10 −4 A cm −2 ) in photoelectrocatalytic water splitting at pH ≈ 1. These results further advance the area of MOF‐based assemblies for light‐driven water‐splitting by providing a synthetic approach for incorporating a variety of WOCs into simple Fe‐MIL 101. The produced MOF utilizes minimal amounts of precious Ru metal and features Fe‐based photosensitizer nodes.
Patel et al. (Wed,) studied this question.