A novel
cobalt hydrogen-bonded organic framework (Co-HOF,
C24H14CoN4O8) was synthesized
from a mixed linker, that is, 2,5-pyridinedicarboxylic acid (PDC)
and 2,2′-bipyridyl (BPY) linkers and cobalt ion through a simple,
one-pot, low-cost, and scalable solvothermal method. The Co-HOF was
fully characterized using several analytical and spectroscopic techniques
including single-crystal X-ray diffraction, diffuse reflectance spectroscopy,
Fourier transform infrared spectroscopy, scanning electron microscopy,
energy-dispersive X-ray, and X-ray photoelectron spectroscopy. The
Co-HOF exhibits high thermal and chemical stabilities compared to
previously reported HOF materials. Moreover, Co-HOF shows excellent
photocatalytic activity under visible light irradiation due to its
narrow band gap of 2.05 eV. The cycloaddition reaction of CO2 to variable epoxides was investigated to evaluate the photocatalytic
performance of Co-HOF under visible light radiation and was found
to produce the corresponding cyclic carbonates in yields up to 99.9%.