Thin films of the metal-organic framework (MOF) NU-1000 were grown on conducting glass substrates. The films uniformly cover the conducting glass substrates and are composed of free-standing sub-micrometer rods. Subsequently, atomic layer deposition (ALD) was utilized to deposit Co2+ ions throughout the entire MOF film via self-limiting surface mediated reaction chemistry. The Co ions bind at aqua and hydroxo sites lining the channels of NU-1000, resulting in the three-dimensional arrays of separated Co ions in the MOF thin film. The Co modified MOF thin films demonstrate promising electrocatalytic ability for water oxidation.