Solvothermal synthesis of porous Fe₃O₄ nanoparticles for humidity sensor application

Abstract

In this research, the effect of PVP on magnetic properties and morphology of Fe 3 O 4 nanoparticle (Fe 3 O 4 -NP S ) is investigated. Also, the sensitivity of the humidity of the selected Fe 3 O 4 -NP S is studied. X-ray diffraction (XRD), transmission electron microscope (TEM), and vibration sample magnetometer (VSM) were used to characterize the synthesized Fe 3 O 4 -NPs. The XRD and TEM results demonstrated that Fe 3 O 4 -NPs were crystallized in cubic structure with spherical pores morphology. Superparamagnetic behavior was seen in the samples prepared with the maximum saturation of approximately 10 emu g −1 for the sample synthesized using PVP:Fe(ac ac) 3 ratio equal to 4. The outcomes of the humidity sensing of the selected sample revealed that the prepared Fe 3 O 4 -NPs with a porous structure is a good candidate to be used for humidity sensing.

Microwave-Assisted Solvothermal Synthesis of Nanocrystallite-Derived Magnetite Spheres

“…Magnetic particles are highly desirable in many scientific fields, especially biomedical fields [ 1 , 2 ], starting from MRI contrast agents [ 3 , 4 ], drug delivery systems [ 5 , 6 ], magnetic separators [ 7 ] and hyperthermia agents [ 8 ] and followed by the environmental [ 9 ], catalysis [ 10 ] and biosensing [ 11 , 12 ] fields. These nanoparticles capped with a plasmonic silver or gold layer could also be applied in surface-enhanced Raman spectroscopy due to signal enhancement for two reasons: the concentration of the sample using magnet and surface plasmons [ 13 , 14 , 15 ].…”

“…Chemical synthesis, otherwise known as the bottom-up method, is the most widely applied in the synthesis of magnetic structures. This route could be further divided according to the synthesis procedure: hydrothermal [ 16 ], solvothermal [ 12 , 17 ], thermal decomposition [ 18 ], microwave-assisted [ 19 , 20 ], sol-gel [ 21 , 22 ], coprecipitation [ 23 ] and others [ 4 ]. In addition to this, the combination of two methods could be used: microwave-assisted solvothermal [ 24 , 25 , 26 , 27 , 28 , 29 ] or hydrothermal [ 20 , 30 ] methods or microwave assisted thermal decomposition methods [ 31 ].…”