Nanostructured α- and β-cobalt hydroxide thin films

Synthesis of Co3O4 nanosheets via electrodeposition followed by ozone treatment and their application to high-performance supercapacitors

“…The green cobalt hydroxide film was reported to be low-crystalline [18,22], which agrees with our observation. The high concentration of cobalt nitrate in the electrodeposited solution (0.10 M) causes the massive aggregates of cobalt hydroxide, leading to the lowcrystalline cobalt hydroxide film [18]. The partial protonation of the Co(OH) 2 layers happens during the electrodeposition simultaneously, resulting in the incorporation of positive charge on the layers.…”

“…The asprepared thin film, when it is electrodeposited, is known to consist of a-Co(OH) 2 and b-Co(OH) 2 [16,18,20e22]. The green cobalt hydroxide film was reported to be low-crystalline [18,22], which agrees with our observation. The high concentration of cobalt nitrate in the electrodeposited solution (0.10 M) causes the massive aggregates of cobalt hydroxide, leading to the lowcrystalline cobalt hydroxide film [18].…”

Modification of Wide‐Band‐Gap Oxide Semiconductors with Cobalt Hydroxide Nanoclusters for Visible‐Light Water Oxidation

“…[26] X-ray diffraction (XRD) patterns for the as-prepared materials with different Co(OH) 2 contents are shown in the Supporting Information, Figure S1. Briefly,rutile TiO 2 powder was sonicated in an aqueous solution containing Co(NO 3 ) 2 at room temperature for 10 min.…”

“…Note that Co(OH) 2 is thermally stable at temperatures below 343 K, and not transformed into other phases with higher oxidation states, such as Co 3 O 4 . [26] X-ray diffraction (XRD) patterns for the as-prepared materials with different Co(OH) 2 contents are shown in the Supporting Information, Figure S1. From now on, the composition of the materials will be referred to in terms of the weight percentage of the cobalt species.F or example, a3 .0 wt %C o(OH) 2 /TiO 2 sample contains 3.0 wt %o fC o-(OH) 2 .A ll of the synthesized materials exhibited as inglephase diffraction pattern, which was assigned to rutile TiO 2 .…”

Modification of Wide‐Band‐Gap Oxide Semiconductors with Cobalt Hydroxide Nanoclusters for Visible‐Light Water Oxidation

“…An aqueous NH 3 solution (28 vol %) was then added dropwise to the suspension, and the resulting reaction mixture was evaporated and dried in an oven at 343 K overnight to yield a brown solid. Note that Co(OH) 2 is thermally stable at temperatures below 343 K, and not transformed into other phases with higher oxidation states, such as Co 3 O 4 …”