2 research outputs found
Fe<sub>3</sub>O<sub>4</sub>@MoS<sub>2</sub> Core–Shell Composites: Preparation, Characterization, and Catalytic Application
Molybdenum
disulfide (MoS<sub>2</sub>) has received tremendous attention due
to the earth-abundant composition and high catalytic activity. However,
the catalytic activity of MoS<sub>2</sub> except electro- and photocatalytic
has seldom been explored. Herein, Fe<sub>3</sub>O<sub>4</sub>@MoS<sub>2</sub> core–shell composites were prepared for the first
time by <i>in situ</i> growth of MoS<sub>2</sub> nanosheets
on the surfaces of Fe<sub>3</sub>O<sub>4</sub> nanoparticles under
different temperature, and the catalytic performance of the resulting
composites was evaluated by using the catalytic reduction of 4-nitrophenol
to 4-aminophenol. FE-SEM, TEM, XRD, and XPS analyses verified the
core–shell structure with MoS<sub>2</sub> nanosheets of defect-rich
and oxygen incorporation on the surfaces of Fe<sub>3</sub>O<sub>4</sub> nanoparticles. Fe<sub>3</sub>O<sub>4</sub>@MoS<sub>2</sub> composites
were found to exhibit a high catalytic activity for the reduction
of 4-nitrophenol with the highest activity factor <i>k</i> = 3773 min<sup>–1</sup> g<sup>–1</sup>. A plausible
catalytic mechanism for the reduction of 4-nitrophenol was also proposed.
This study presents an inexpensive, reusable, fast, and highly efficient
catalyst for the reduction of 4-nitrophenol without noble metals
Visual Monitoring of Food Spoilage Based on Hydrolysis-Induced Silver Metallization of Au Nanorods
Colorimetric detection
of biogenic amines, well-known indicators
of food spoilage, plays an important role for monitoring of food safety.
However, common colorimetric sensors for biogenic amines suffer from
low color resolution or complicated design and intricate output for
the end-users. Herein, we explored a simple but effective strategy
for visual monitoring of biogenic amines with multiple color change
based on hydrolysis-induced silver metallization reaction to tune
the localized surface plasmon resonance (LSPR) adsorption of Au nanorods
(NRs). The color change and blue shift of longitudinal LSPR peak of
Au NRs were closely related to the concentration of biogenic amines.
This strategy provided a simple, sensitive, robust, nondestructive,
cost-effective, and user-friendly platform for in situ evaluating
the freshness of foodstuffs