Abstract:
Developing cost-effective and highly efficient electrocatalysts for water splitting remains a
significant challenge in recent research. In this study, we report a facile approach to synthesize Ni BDC MOF and rare-earth erbium (Er) ions-incorporated Ni-BDC MOFs. These MOFs are
employed as electrocatalysts for oxygen evolution reactions (OER) and hydrogen evolution
reactions (HER). Remarkably, the lower concentration of Er demonstrated excellent OER
performance, while 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 displayed 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 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.
