Robust MOF-on-MOF heterostructures as efficient cathode candidates for next-generation supercapacitors

• Published in: Materials advances Vol. 4; no. 24; pp. 6627 - 6637
• Main Authors: Deka, Rakesh, Kumar, Viresh, Mobin, Shaikh M
• Format: Journal Article
• Language: English
• Published: 11-12-2023
• ISSN: 2633-5409; 2633-5409
• DOI: 10.1039/d3ma00578j

Metal-organic frameworks (MOFs) have shown great potential as cathode in supercapacitor applications. However, they can also be used as a platform for designing a new class of materials. Herein, a MOF-on-MOF heterostructure,
Ni-BTC@ZIF-67
, has been synthesized
via
a solvothermal method followed by the
in situ
growth of ZIF-67 on Ni-BTC and was well-characterized through various techniques (PXRD, FT-IR, BET, SEM, TEM, and XPS). From SEM, TEM, and XPS analysis, it is clear that ZIF-67 was successfully deposited over the Ni-BTC surface
via
N-O bonding interaction. One potential application of
Ni-BTC@ZIF-67
is as an electro-active material in the construction of supercapacitors. This material demonstrated an impressive specific capacitance of 1063 F g
−1
when subjected to a 4 A g
−1
current. The robust nature of both MOFs helped attain a cyclic retention capacity of about ∼98% after 5500 cycles. Moreover, an asymmetric supercapacitor was assembled with activated carbon and
Ni-BTC@ZIF-67
in an aqueous system, which delivered an energy density of 22 W h Kg
−1
at a power density of 1075 W Kg
−1
with a cyclic retention of ∼83% after 1000 cycles. Thus, the MOF-on-MOF architecture can be a new pathway for supercapacitor applications in the future.
The
Ni-BTC@ZIF-67
heterostructure is shown to enhance the supercapacitor performance. Investigated in both three- and two-electrode setups; this approach unveils exciting prospects in materials chemistry for advanced supercapacitor applications.