Complex [Fe-11 (H2O)(14)(OH)(2)(W3O10)(2)(alpha-SbW9O33)(6)](27-)(2) has been studied independently under photocatalytic or chemical catalytic or electrocatalytic conditions by our group. (1) Under the optimal photocatalytic conditions (photoirradiation at gimel = 420 nm, [Ru(bpy)(3)](CIO4)(2) as the photosensor, Na2S2O8 as the oxidant in borate buffer (pH = 10.0)], the turnover number (TON) can reach as high as 1815, the initial quantum yield and the initial turnover frequency (TOF) for the first 60 s was 47% and 6.3 s(-1), respectively. (2) We report herein that 2 are highly active homogeneous water oxidation catalysts when [Ru(bpy)(3)](3+) is used as the terminal oxidant, with a turnover number (TON) of higher than 78. (3) The current densities achieved during cyclic voltammetry (CV) show that 2 exhibit no electrocatalytic activity at pH 10.0. This study discusses the catalytic behaviors and mechanism of 2 in different experimental conditions (driving forces) for water oxidation. (C) 2017 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.