Metal–organic
frameworks (MOFs) have been widely used as
supporting materials to load or encapsulate metal nanoparticles for
electrochemical sensing. Herein, the influences of morphology on the
electrocatalytic activity of Co-containing zeolite imidazolate framework-67
(ZIF-67) as supporting materials were studied. Three types of morphologies
of MOF ZIF-67 were facilely synthesized by changing the solvent because
of the influence of the polar solvent on the nucleation and preferential
crystal growth. Two-dimensional (2D) ZIF-67 with microplate morphology
and 2D ultrathin ZIF-67 nanosheets were obtained from pure H2O (H-ZIF-67) and a mixed solution of dimethylformamide and H2O (D-ZIF-67), respectively. Three-dimensional ZIF-67 with
rhombic dodecahedron morphology was obtained from pure methanol (M-ZIF-67).
Then, one-step electrodeposition of silver nanostructures on ZIF-67-modified
glassy carbon electrode (Ag/ZIF-67/GCE) was performed for the reduction
of hydrogen peroxide (H2O2). Cyclic voltammetry
can be used to investigate the electrocatalytic activity of Ag/ZIF-67/GCE,
and Ag/H-ZIF-67/GCE displayed the best electrocatalytic property than
Ag/D-ZIF-67/GCE and Ag/M-ZIF-67/GCE. The electrochemical H2O2 sensor showed two wide linear ranges of 5 μM
to 7 mM and 7 to 67 mM with the sensitivities of 421.4 and 337.7 μA
mM–1 cm–2 and a low detection
limit of 1.1 μM. In addition, the sensor exhibited good selectivity,
high reproducibility, and stability. Furthermore, it has been utilized
for real-time detection of H2O2 from HepG2 human
liver cancer cells. This work provides a novel strategy for enhancing
the detection performance of electrochemical sensors by changing the
crystalline morphologies of supporting materials.
Over the past decade,
the use of metal–organic framework
derived materials has emerged as a novel direction to prepare high
performance polymer composites. In this work, nickel based metal–organic
framework (Ni-MOF) was synthesized via a cost-effective and environmentally
acceptable approach. Ni-MOF derived hierarchically mesoporous nickel
phosphate was prepared via a facile hydrothermal method. Morphological
evolution from Ni-MOF to nickel phosphate during the synthesis was
clearly revealed. The microsized rod-like nickel phosphate was evaluated
in both smoke suppression and mechanical enhancement of intumescent
flame retardant wood fiber/poly(lactic acid) system. The cone calorimeter
test showed a 43% reduction in total smoke production when 5 wt %
ammonium polyphosphate was substituted by nickel phosphate. More importantly,
both tensile and impact strength of the composites were improved with
the addition of nickel phosphate. The as-synthesized nickel phosphate
proved to be a promising substitution for ammonium polyphosphate in
wood fiber/poly(lactic acid) composites.
SnO2 and SnO2@C have been successfully synthesized with a simple hydrothermal procedure combined with heat treatment, and their performance as cathode catalysts of Li-air batteries has been comparatively evaluated and discussed. The results show that both SnO2 and SnO2@C are capable of catalyzing oxygen reduction reactions (ORR) and oxygen evolution reactions (OER) at the cathode of Li-air batteries, but the battery with SnO2@C displays better performance due to its unique higher conductivity, larger surface area, complex pore distribution, and huge internal space.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.