Effects from Surface Structures of Manganese Phosphate on Electrocatalytic Water Oxidation

Abstract

In heterogeneous electrocatalysts, the effect of the surface structure on water oxidation is hardly fairly compared. Herein, two manganese phosphates with identical bulk structures but different surface properties are designed to form an appealing platform to investigate the effect of the surface structure on water oxidation. The uniform MnO6 site and similar physical properties avoid unfair comparisons of water oxidation performance. In situ Raman and X-ray absorption spectral results demonstrate that the flexibility of the catalyst surface structure and proton-accepting sites is favorable to water oxidation. The results from surface spectroscopic studies provide insights into evaluating the surface influencing factors of electrocatalytic water oxidation.

Avoid Using Phosphate Buffered Saline (PBS) as an Electrolyte for Accurate OER Studies

“…The composition of “1×” PBS is shown in Table S2, with “saline” alluding to the major component, sodium chloride (NaCl). Recently, it has gained popularity as an electrolyte in assessing the performance of newly developed OER catalysts under neutral condition. − A standard 1× PBS solution has a reasonably good ionic strength of 0.156 M, providing adequate ionic conductivity for electrochemical reactions. The presence of phosphate buffer provides a fast reactant supply (OH – ) and reduces local pH shift during OER, better revealing the intrinsic catalytic properties.…”

“…The prevalent use of “0.1/1 M PBS” in the water electrolysis community often lacks composition details, − with “PBS” sometimes being used without specifying its full name. − This leads to misinformation within the water electrolysis community, as it could either denote pure phosphate buffer solution − or phosphate buffered saline, − which have different salt compositions, ionic strengths and ionic conductivities. Such lack of clarity poses complication and misinformation during cross-referencing among researchers. , Furthermore, denoting concentration using molarity is only correct for pure phosphate buffer solution, but not for phosphate buffered saline.…”