posted on 2024-03-01, 15:35authored bySonadia, Zoya Iqbal, Waheed Miran, Anwar Ul-Hamid, Khurram Shehzad Ayub, Fahad Azad
Developing cost-effective and highly efficient electrocatalysts
for water splitting has remained a significant challenge in recent
research. In this study, we report a facile approach to synthesize
nickel–1,2-benzenedicarboxylic acid (H2BDC) metal–organic
frameworks (Ni–BDC MOFs) and rare-earth erbium (Er) ion-incorporated
Ni–BDC MOFs. These MOFs are employed as electrocatalysts for
oxygen evolution reactions (OERs) and hydrogen evolution reactions
(HERs). Remarkably, a lower concentration of Er demonstrated excellent
OER performance, while a higher Er incorporation was conducive to
HER performance. For OER, a current density of 100 mA cm–2 was achieved at an overpotential of 420 mV in the case of Er0.5Ni–BDC MOF. Meanwhile, Er–Ni–BDC MOF
exhibited a current density of 10 mA cm–2 at 270
mV for HER. The Er-incorporated Ni–BDC MOFs exhibited prolonged
electrochemical durability with a retention rate of 87% for OER and
90% for HER. The electrocatalytic performance of Er-incorporated Ni–BDC
MOFs was found to be higher than that of the pure Ni–BDC and
Er–BDC MOFs. The improvement in the electrocatalytic performance
of Ni–BDC MOFs upon Er incorporation was attributed to the
synergistic effects of the Ni and Er sites, where Er contributes to
modifying the electronic states of the Ni sites, thereby enhancing
the OER and HER activity. The demonstrated strategy of augmenting
HER and OER activity in Ni-MOF through the incorporation of rare-earth
ions opens up new avenues for designing MOF catalysts tailored for
industrial OER and HER applications.