Influence of Mg, Cu, and Ni Dopants on Amorphous TiO2 Thin Films Photocatalytic Activity

Abstract

The present study investigates Mg (0 ÷ 17.5 wt %), Cu (0 ÷ 21 wt %) and Ni (0 ÷ 20.2 wt %) dopants (M-doped) influence on photocatalytic activity of amorphous TiO2 thin films. Magnetron sputtering was used for the deposition of M-doped TiO2 thin films. According to SEM/EDS surface analysis, the magnetron sputtering technique allows making M-doped TiO2 thin films with high uniformity and high dopant dispersion. Photocatalysis efficiency analysis was set in oxalic acid under UV irradiation. In accordance with the TOC (total organic carbon) measurements followed by the apparent rate constant (kapp) results, the dopants’ concentration peak value was dopant-dependent; for Mg/TiO2, it is 0.9% (kapp—0.01866 cm−1), for Cu/TiO2, it is 0.6% (kapp—0.02221 cm−1), and for Ni/TiO2, it is 0.5% (kapp—0.01317 cm−1). The obtained results clearly state that a concentration of dopants in TiO2 between 0.1% and 0.9% results in optimal photocatalytic activity.

Extraction–Pyrolytic Method for TiO2 Polymorphs Production

“…However, TiO 2 is a wide bandgap semiconductor (3.2 and 3.02 eV for the anatase and rutile phases, respectively [20]) that requires UV light (5% in the solar spectrum) for its activation. To reduce the bandgap, TiO 2 should be either doped (e.g., with N, Ta) or used in the form of nanotubes [13,[21][22][23][24][25][26]. Other important studies are related to the applications of TiO 2 as protective coatings in microelectronic and optical devices and as luminescent compounds [27][28][29][30][31][32].…”

TiO2–Ag–NP adhesive photocatalytic films able to disinfect living indoor spaces with a straightforward approach

“…Titania photocatalysts represent promising tools to ensure air cleaning and sanitization in living indoor microclimates with a low cost, feasible and straightforward approach. This approach represents an easy to handle, cost effective, feasible and efficacious approach to reduce microbial pollution in indoor spaces, by simply attaching a TiO 2 -Ag-NP adhesive film on the wall.The use of titanium dioxide with Ag nanoparticulate thin films (TiO 2 -Ag-NP) as a photo-oxidative catalyst to remove chemical pollutants or microbial contamination, dates back to few decades ago, when this approach was appreciated for its cost effectiveness, highest oxidation rate at room temperature, high duct velocities and low pressure drop tolerance [1][2][3][4][5][6] .Different kinds of thin film technologies, such as spin coating 7 , e-beam evaporation, chemical vapor deposition 8 or magnetron sputtering 9 , are able to build up a composed thin film of TiO 2 elements (100 nm) joined and/or complexed with silver (Ag) nanoparticles (usually ≤ 10 nm, range 1-100 nm), via various methods, such as doping 10,11 , heterojunction formation 12 or metal ion implantation or others 13 . The component TiO 2 works as a semiconductor, having an energy gap (EG) = 3-3.3 eV, despite this value depends on the different allotropic forms of titania.…”

“…Different kinds of thin film technologies, such as spin coating 7 , e-beam evaporation, chemical vapor deposition 8 or magnetron sputtering 9 , are able to build up a composed thin film of TiO 2 elements (100 nm) joined and/or complexed with silver (Ag) nanoparticles (usually ≤ 10 nm, range 1-100 nm), via various methods, such as doping 10,11 , heterojunction formation 12 or metal ion implantation or others 13 . The component TiO 2 works as a semiconductor, having an energy gap (EG) = 3-3.3 eV, despite this value depends on the different allotropic forms of titania.…”

Conduction Band Discontinuity in n-type Si/TiO2 Heterojunction Interfaces

“…In the TiO 2 solar-cell HEs, the TiO 2 acts as a hole blocker, which increases their efficiency. In addition to that, much research has been carried out over the past few decades, which focused on TiO 2 modification: metal doping of TiO 2 , [7][8][9][10][11] surface area modification, [12][13][14][15][16][17] and application of high-quality crystal phases or their mixtures. [18][19][20][21][22][23][24][25][26] Furthermore, various deposition methods have been extensively analyzed and compared through decades of research, based on photocatalysis efficiency.…”