posted on 2023-12-11, 07:29authored byAnup Kuchipudi, Ankit Das, Krishnendu Bera, Subhendu K. Panda, Gosipathala Sreedhar, Subrata Kundu
Electrocatalytic water splitting
to an anodic oxygen evolution
reaction (OER) and a cathodic hydrogen evolution reaction (HER) is
believed to be the most important application for sustainable hydrogen
generation. Being a four-electron, four-proton transfer process, the
OER plays the main obstacle for the same. Therefore, designing an
effective electrocatalyst to minimize the activation energy barrier
for the OER is a research topic of prime importance. The metal–organic
framework (MOF) with a highly porous network is considered an appropriate
candidate for the OER in alkaline conditions. Apart from several MOFs,
the bimetallic one has an advantageous electrocatalytic performance
due to the synergistic electronic interaction between two metal ions.
However, most bimetallic MOFs have an obstacle to electrocatalytic
application due to their low conductive nature, and therefore, they
possess a barrier for charge transfer kinetics at the interface. Surface
functionalization via various nanoparticles (NPs) is believed to be
the most effective strategy for nullifying the conductive issue. In
this work, we have designed a CoNi-based bimetallic MOF that was surface-functionalized
by Au NPs (Au@CoNi-Bpy-BTC) for the OER under alkaline conditions.
Au@CoNi-Bpy-BTC required an overpotential of just 330 mV, which is
56 mV lower as compared to the pristine MOF. Impedance analysis confirms
an improved conductivity and charge transfer at the interface, where
Au@CoNi-Bpy-BTC possesses a lower Rct value
than CoNi-Bpy-BTC materials. Moreover, the Au-decorated MOF shows
an 8.5 times increase in the TOF value compared to the pristine MOF.
Therefore, this noble strategy toward the surface functionalization
of MOFs via noble metal NPs is believed to be the most effective strategy
for developing effective electrocatalysts for electrocatalytic application
in energy-related fields. Overall, this report displays an exceptional
correlation between the decorated NPs over the MOF surface, which
can regulate the OER activity, as confirmed by experimental analysis.