Photodetection properties of populated Fe3O4@TiO2 core–shell/Si heterojunction prepared by laser ablation in water

Abstract

In this work, we demonstrated the first study on the preparation and characterization of the populated Fe 3 O 4 @TiO 2 coreshell/Si photodetector by laser ablation in liquid. The structural and optical properties of Fe 3 O 4 nanoparticles and Fe 3 O 4 @ TiO 2 core-shell nanoparticles were studied by X-ray diffraction, transmission electron microscope, and UV-Vis absorption. X-ray diffraction findings suggest the formation of a populated crystalline Fe 3 O 4 @TiO 2 core-shell through the existence of XRD peaks related to TiO 2 and Fe 3 O 4 . The optical properties revealed that the optical energy gap of Fe 3 O 4 @TiO 2 was 3 eV, while the optical energy gap of Fe 3 O 4 was 2.8 eV. Raman studies reveal the presence of vibration modes centered at 91 cm −1 (E g ), 144 cm −1 (E g ), 396 cm −1 (B 1g ), 512 cm −1 (B 1g ), 541 cm −1 (B 1g + A 1g ), and 609 cm −1 (E g ) which are belong to the TiO 2 . The vibration modes related to the magnetite Fe 3 O 4 are observed at 145 -1 (T 2g ), 302 cm −1 (T 2g ), and 554 cm −1 (T 1g ). Transmission electron microscope results suggest the presence of a core-shell morphology with an average size of 60 nm. The current-voltage characteristics of Fe 3 O 4 /p-Si and Fe 3 O 4 @TiO 2 core-shell/p-Si photodetectors are measured in the dark and under illumination conditions. The maximum responsivity of the Fe 3 O 4 @TiO 2 /Si photodetector was 0.5A/W at 400 nm, while the maximum responsivity of Fe 3 O 4 /p-Si photodetector was 0.4A/W at 500 nm. The specific detectivity and external quantum efficiency of the Fe 3 O 4 @TiO 2 /p-Si photodetector are larger than those of Fe 3 O 4 /p-Si photodetector.

Fabrication and Characterization of the PMMA/G/Ag Nanocomposite by Pulsed Laser Ablation (PLAL)

“…These techniques, which include multiple steps and the use of strong reducing agents, are not environmentally friendly. On the other hand, pulsed laser ablation in liquid (PLAL) is another method for producing graphene due to its cleanliness, simplicity, ease of particle synthesis at the nanoscale, and strong tools for controlling the final production of the laser ablation process [15][16][17][18]. Besides, an important way to purify the particle size produced in this way is to use the newest method as in the [19].…”

Photocatalytic CO2 reduction to methanol integrated with the oxidative coupling of thiols for S–X (X = S, C) bond formation over an Fe3O4/BiVO4 composite

“…In Fe 3 O 4 , the band at 301.66 cm −1 is attributed to T 1g mode. 33 In the hybrids (FBV-1, FBV-2, and FBV-3), an intense band at 823.33 cm −1 is assigned to the symmetric V–O stretching mode. 30 The band at 352.5 cm −1 is attributed to the symmetric or anti-symmetric bending modes of vanadate anion (VO 4 3− ) in Fe 3 O 4 /BiVO 4 composites.…”

Hollow Fe3+-Doped Anatase Titanium Dioxide Nanosphere for Photocatalytic Degradation of Organic Dyes

“…However, the low utilization of sunlight, high photogenerated electron–hole complexation rate, and restricted bandwidth of TiO 2 , to a certain extent restrict the application scope and scale of TiO 2 . To overcome these limitations and enhance the photocatalytic activity of TiO 2 , various strategies have been employed, including single doping, − codoping, defect engineering, , surface and interface engineering, , and heterostructure strategies. − Among these strategies, doping has emerged as a potent method to improve the performance of TiO 2 by influencing the crystal and electronic structures of the metal and modifying the semiconductor’s band gap. Me–O–Ti linkages are generated when transition metals are doped into TiO 2 , resulting in a powerful interaction between the metal and TiO 2 .…”