Deciphering Ligand Controlled Structural Evolution of Prussian Blue Analogues and Their Electrochemical Activation during Alkaline Water Oxidation

Abstract

Herein, we have demonstrated the control over the structure of precatalysts to tune the properties of the active catalysts and their water oxidation activity. The reaction of K 3 [Fe(CN) 6 ] and Na 2 [Fe(CN) 5 (NO)] with Co(OH) 2 @CC produced precatalysts PC-1 and PC-2, respectively, with distinct structural and electronic features. The replacement of the À CN group with strong π-acceptor À NO modulates the electronic and atomic structure of PC-2. As a result, a facile electrochemical transformation of PC-2 into active catalyst FeÀ Co-(OH) 2 -Co(O)OH (AC-2) has been attained only in 15 CV cycles while 600 CV cycles are required for the electrochemical activation of PC-1 into AC-1. The X-ray absorption studies reveal the contraction of the CoÀ O and FeÀ O bond in AC-2 because of the presence of a higher amount of Co 3 + and Fe 3 + than in AC-1. The high valent Co 3 + and Fe 3 + modulates the electronic properties of AC-2 and assists in the OÀ O bond formation, leading to the improved water oxidation activity.

A first principles study of the electronic structure and optical response of heterobimetallic M–dicyanoaurate-based coordination polymers (M = Mn, Co, Ni, Zn and Cd)

“…3,[16][17][18] In this sense, the dicyanoaurate ion (DAu), as a building block, is an ideal unit to explore the use of aurophilicity as a supramolecular design element in the synthesis of heterobimetallic coordination complexes with physical properties of interest for technological goals. 3 Furthermore, this study is a contribution to understanding the impact that the different metal (Au and M) have on electronic structure modulation and derived applications, [19][20][21][22][23][24] a Centro de Investigacio ´n en Ciencia Aplicada y Tecnologı ´a Avanzada, Unidad specifically, in this case for dicyanides and dicyanoaurate derived materials.…”