Structural Relationship between CoO₆Cluster and Phosphate Species in a Cobalt–Phosphate Water Oxidation Catalyst Investigated by Co and P K-edge XAFS

Highly Durable Oxygen Evolution Reaction Catalyst: Amorphous Oxyhydroxide Derived from Brownmillerite-Type Ca2FeCoO5

“…The in situ formation of an OER electrocatalytically active CoOOH phase has been also reported in other systems. − Zhou et al reported that catalysts based on the simple Prussian blue analog Na x CoFe­(CN) 6 form a CoOOH active phase with the replacement of oxygen vacancies by the hydroxyl groups driven by an applied electric field . Kanan and Nocera reported that the amorphous cobalt phosphate precipitates formed by the electrolysis in potassium phosphate solution show pronounced OER activity in neutral media .…”

“…Kanan and Nocera reported that the amorphous cobalt phosphate precipitates formed by the electrolysis in potassium phosphate solution show pronounced OER activity in neutral media . In this case, the active phase has been assigned to γ-CoOOH clusters embedded in phosphate glass matrices by Yoshida et al Enman et al found that Fe species in CoOOH avoid the oxidation of Co species and proposed the different OER mechanism in CoOOH and Fe-doped CoOOH . Most of the above-mentioned studies show that catalyst might undergo modification through clusters formation and/or surface modification under standard OER conditions.…”

Red phosphorus decorated and doped TiO2 nanofibers for efficient photocatalytic hydrogen evolution from pure water

“…The predominant peak at about 1.5Å was attributable to the first shell Ti-O ), oxygen has the highest ability to attract the electrons, and therefore electrons at P site may migrate to O site. The P K-edge had two main features associated with P 0 and P 5+ states [58,59]. It is clear that RP exhibited mostly the P 0 states.…”

In Situ Observations of Oxygen Evolution Cocatalysts on Photoelectrodes by X-ray Absorption Spectroscopy: Comparison between Cobalt-Phosphate and Cobalt-Borate

“…34 The Teflon electrochemical cell for XAFS measurements was equipped with a Pt wire counter electrode, a Ag/AgCl (saturated KCl) reference electrode, and a sample working electrode, and was covered with a 6 µm polymer film, as previously reported. [42][43][44] The X-ray beam was applied through this film at an incident angle of 4°. In situ Co K-edge XAFS spectra were obtained at 1.0 V in 0.1 M K-P i and K-B i buffer solutions containing 0.3 mM Co(NO 3 ) 2 under UV irradiation by a Xe lamp equipped with an IR cut-off filter.…”

“…43 This prior work determined that the phosphate species binds to the Co edge of the CoO 6 clusters in the Co-P i cocatalyst, most likely stabilizing the CoO 6 clusters to promote efficient oxygen evolution activity. 43 Thus, this spectroscopic technique is a useful means of assessing the reaction mechanisms of OER catalysts. In the present work, we focused on the differences in the reaction activities of Co-P i and Co-B i cocatalysts on photoelectrodes.…”