One-Pot Crystallization of 2D and 3D Cobalt-Based Metal–Organic Frameworks and Their High-Performance Electrocatalytic Oxygen Evolution

Abstract

Developing highly competent and low-cost earth-plentiful metal-based oxygen evolution reaction (OER) electrocatalysts is critical for future electrochemical conversion technologies and renewable energy systems. Herein, two cobalt-based metal–organic frameworks (Co-MOFs), [Co6(btc)2(DMF)6(HCOO)6] (2D, MOF 1) and [Co3(CHOO)9{DMA}3] (3D, MOF 2), where btc = 1,3,5-benzenetricarboxylic acid, DMF = N,N-dimethylformamide, and DMA = dimethylamine, have been crystallized under hydrothermal conditions, from a single reaction. MOF 1 shows an extraordinary OER performance with 175 mV overpotential to attain 10 mA cm–2 current density with a low Tafel slope value of 80 mV dec–1, whereas MOF 2 achieves 10 mA cm–2 current density at 389 mV overpotential. Two different architecture-based MOFs have been synthesized from a single solution for the very first time. Also, the OER activity of MOF 1 overpowers the commercially used RuO2 and surpasses most of the reported OER electrocatalysts. Post OER characterization of MOF 1 revealed the in situ formation of Co­(OH)2 and CoOOH, acting as active sites for the OER process.

Rapid synthesis of a CuZn-MOF via controlled electrodeposition: manifesting enhanced overall electrocatalytic water splitting

“…The lower potential of CuZn-BTC-250 for overall water splitting reactions may be attributed to the synergistic effect between Cu and Zn. 33 The faradaic efficiency was also evaluated using the water–gas displacement method, 34 in which the amount of H 2 and O 2 gas evolved experimentally was compared with that evolved theoretically, as shown in Fig. 4c.…”

Electronic Redistribution Through the Interface: A Prodigy that Enhances Electrocatalysis

“…As a novel category of porous material, metal-organic frameworks, also known as MOFs, have been studied in depth. [69,70] In particular, polyoxometalate (POM)-based metalorganic frameworks (POMOFs), have received a lot of interest since they inherit the benefits of both POMs and MOFs. [71,72] Because of the benefits of POMOFs, we now believe that it is extremely conceivable and promising to create a porous, closely connected MoÀ Fe-based electrocatalyst with a wide surface area by adopting the synthetic technique of POMOFs.…”

“…Consequently, leading to an improvement in HER performance as a whole. As a novel category of porous material, metal‐organic frameworks, also known as MOFs, have been studied in depth [69,70] . In particular, polyoxometalate (POM)‐based metal‐organic frameworks (POMOFs), have received a lot of interest since they inherit the benefits of both POMs and MOFs [71,72] .…”

Synthesis of Conductive MOFs and Their Electrochemical Application

“…Consequently, this leads to low OER catalytic efficiency. [ 126,127 ] A promising solution has emerged through the application of conductive MOFs as OER catalysts. Conductive MOFs offer explicit active sites and good electrical conductivity, making them attractive candidates.…”