Synthesis Method Effect of CoFe₂O₄ on Its Photocatalytic Properties for H₂ Production from Water and Visible Light

Abstract

Currently, the need for more efficient materials that work in the visible light spectrum for hydrogen production has been increasing. Under this criterion, ferrites are ideal because their energetic properties are favorable to photocatalysis as they have a low band gap (1.5 to 3 ev). In this particular research, ferrite is presented as a hydrogen producer. Cobalt ferrites were synthesized by chemical coprecipitation (CP) and ball milling (BM) for comparison of their performance. The characterization of the materials was carried out with X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), BET surface area, UV-VIS spectroscopy, and water adsorption/desorption tests. Evaluation of the photocatalytic activity under visible light was followed by gas chromatography. The results showed that cobalt ferrite by ball milling had a higher photocatalytic activity; this is attributed to the vacancies generated during the milling process at which the sample was exposed.

Ferrite Materials for Photoassisted Environmental and Solar Fuels Applications

“…CoFe2O4 [162]. They compared two different synthetic methods, namely co-precipitation, followed by a relatively low temperature crystallization, and ball-milling of a stoichiometric mixture of iron metal and Co3O4 previously activated y solid-state reaction at 700 °C.…”

Controlled Synthesis of Hierarchical Nanostructured Metal Ferrite Microspheres for Enhanced Electrocatalytic Oxygen Evolution Reaction

“…From the result, the BET surface area of the CoFe 2 O 4 microspheres is estimated to be 144.52 m 2 /g, whereas that of the NiFe 2 O 4 microspheres is 158.47 m 2 /g. From these data, we can find that the BET surface area of the NiFe 2 O 4 microspheres is slightly higher than that of the CoFe 2 O 4 microspheres and to our surprise, and both of them are larger than most other CoFe 2 O 4 -based (Figure c) and NiFe 2 O 4 -based (Figure d) materials in the papers reported in the past. − The pore size distribution curve (inset of Figure a) of the CoFe 2 O 4 microspheres shows a wide peak in the range of 2–100 nm. Also, the peak at 4 nm may reflect the pores of nanosheets, and another peak at 20 nm may be attributed to the porosity between the nanosheets assembled into the CoFe 2 O 4 microspheres.…”

Ba3(PO4)2 Photocatalyst for Efficient Photocatalytic Application

“…Notably, the bandgap value is known to be highly dependent on particle size, resulting in a decrease in the bandgap with an increase in particle size. [40,41] The structural properties of Ba 3 (PO 4 ) 2 prepared by the solgel and hydrothermal methods were investigated using Fouriertransform infrared (FTIR) spectroscopy, as shown in Figure 3b. The spectrum reveals the band's appearance matching the different vibrations of the PO 4 3− phosphate groups in the frequency scale 500-600 cm −1 and 920-1100 cm −1 .…”

“…Notably, the bandgap value is known to be highly dependent on particle size, resulting in a decrease in the bandgap with an increase in particle size. [ 40,41 ]…”