In situ doping brushite on zinc manganese oxide toward enhanced water oxidation performance: Mimicry of an oxygen-evolving complex

We report in situ doping of brushite on zinc manganese oxide (ZMO), fabricated by calcining a Mn(II) oxalate-impregnated metal-organic framework. The doping process was conducted in combination with the photocatalytic water oxidation reaction which was catalyzed by ZMO in neutral phosphate-buffered aqueous solution containing [Ru(bpy) 3 ] 2+ -Na 2 S 2 O 8 and calcium(II) triflate salt, exhibiting greatly enhanced water oxidation performance with optimized turnover frequency of 0.18 mmol O2 mol Mn −1 s −1 . Different analytical techniques indicated that photodeposited calcium-phosphate (CaP) acted as a co-catalyst to promote the O 2 evolution activity of ZMO. This system involved the use of manganese oxide and calcium ion, and the operation was conducted under ambient temperature and neutral conditions, thus, it efficiently mimicked the oxygen-evolving complex in photosystem II.