Constructing highly active Co sites in Prussian blue analogues for boosting electrocatalytic water oxidation

Abstract

High valence cobalt sites are considered as highly active centers for oxygen evolution reaction (OER) and their corresponding construction is thus of primary importance to pursue outstanding performance. Herein, we...

Co–Fe–P Nanosheet Arrays as a Highly Synergistic and Efficient Electrocatalyst for Oxygen Evolution Reaction

“…With so many high-valence Co 3+ as the active sites, the Co-Fe-P/CC is therefore able to drive the OER process at very low overpotential and Tafel slope. [22,26] This result clearly demonstrates the great significance and advantage of synergistic effect for the design and synthesis of highly efficient OER electrocatalysts.…”

“…Figure 5a and the related discussion therein) and thus is expected to induced better OER performance when using Co−Fe−P for electrocatalytic water splitting, since high-valence-state Co (particularly, Co 3+ and/or Co 4+ ) has been demonstrated to be the catalytic species of OER. 33,35,39 The electrocatalytic OER activity of Co−Fe−P/CC was evaluated in a three-electrode electrochemical cell with alkaline electrolyte (aqueous solution of 1.0 M KOH) and all the LSV curves were calibrated with 90% iR compensation (see Figure S9 for the curves without iR compensation). The polarization curves obtained from LSV in Figure 4a reveal the excellent electrocatalytic activity of Co−Fe−P/CC, which needs only an overpotential of 240 mV to reach a current density of 10 mA cm −2 .…”

“…[17][18][19][20][21] When serving as OER catalysts, bimetallic catalysts often show better performance than their monometallic counterparts due to their optimized electronic structure and synergistic effect. [22][23][24][25][26][27] For example, Co can be coupled with Fe, Zn, or Ni to enhance its electrocatalytic activity, since the coupling of a second metal facilitates the generation of abundant high-valence Co species (Co 3+ and/or Co 4+ ), the highly active sites for electrocatalytic OER. [22,23,26,28,29] In this regard, bimetallic TMPs, especially those derived from MOFs, are of particular interest to construct highly active OER electrocatalyst, since their highly porous structure inherited from MOFs could further facilitate the efficient exposure of catalytic sites with synergistic effects.…”

“…[22][23][24][25][26][27] For example, Co can be coupled with Fe, Zn, or Ni to enhance its electrocatalytic activity, since the coupling of a second metal facilitates the generation of abundant high-valence Co species (Co 3+ and/or Co 4+ ), the highly active sites for electrocatalytic OER. [22,23,26,28,29] In this regard, bimetallic TMPs, especially those derived from MOFs, are of particular interest to construct highly active OER electrocatalyst, since their highly porous structure inherited from MOFs could further facilitate the efficient exposure of catalytic sites with synergistic effects. [30][31][32][33] Here, we design and synthesize a Co-and Fe-based bimetallic phosphide (denoted as Co-Fe-P; Figure 1a), using a two-dimensional Fe-doped Co-MOFs as the precursor.…”

“…29−34 For example, Co can be coupled with Fe, Zn, or Ni to enhance its electrocatalytic activity, since the coupling of a second metal facilitates the generation of abundant high-valence Co species (Co 3+ and/or Co 4+ ), the highly active sites for electrocatalytic OER. 29,30,33,35,36 In this regard, bimetallic TMPs construction of new and efficient OER electrocatalysts, due to their integrated merits of excellent porosity, defect-rich structure, synergistic effect, and enhanced electrical conductivity. 25,37−40 Despite the recent progress, the development of such bimetallic TMP electrocatalysts remain a great challenge.…”