Photocatalytic Properties of Titanium Dioxide Thin Films Doped with Noble Metals (Ag, Au, Pd, and Pt)

Abstract

Sol-gel grown TiO 2 thin films are deposited on glass substrates by spincoating, using noble metals (M ¼ Ag, Au, Pd, and Pt) for doping. The films are thermally treated at 500 C, to obtain the anatase phase. The film properties are characterized by field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDX), X-ray diffraction (XRD), Raman spectroscopy, profilometry, and UV/VIS/NIR spectroscopy. FE-SEM images and EDX measurements show the presence of dopant elements in the metallic form. XRD and Raman measurements show the presence of the anatase phase for pure and doped samples. Optical measurements show the optical band gap decreases for Au and Pt doping, while it shows little change for Ag and Pd doping, compared to pure TiO 2 . The photocatalytic activity of all films is evaluated by measuring the rate of decolorization of methylene blue (MB) under UV irradiation. The normalization of the rate of degradation of MB according to the film thickness shows significant photocatalytic activity of all films with the following order Pt-TiO 2 > Pd-TiO 2 >

Bimetal–organic framework derived multi-heterostructured TiO2/CuxO/C nanocomposites with superior photocatalytic H2generation performance

“…14 Although doping of such species in pure TiO 2 results in enhanced visible light absorption, a serious challenge of low performance for such single metal oxide based photocatalysts is the recombination of photogenerated electrons and holes. [15][16][17][18][19] Therefore, it is important to improve charge separation and charge migration in the photocatalyst particles for an enhanced quantum yield.…”

Photocatalytic Hydrogen Production Under Near-UV Using Pd-Doped Mesoporous TiO2 and Ethanol as Organic Scavenger

“…Doping noble metals on TiO 2 allows (a) increasing the efficiency of the hydrogen evolution reaction, (b) narrowing the band gaps, and (c) improving the optoelectronic semiconductor properties [14]. Furthermore, doping TiO 2 with noble metals such as Pd helps to promote energy levels near the band edges or mid-gap states, which may reduce the effective bandgap energy [15]. Therefore, the effect of Pd on TiO 2 can be attributed to the shift of Fermi levels in the composite material [16][17][18][19][20].…”

Visible-Light-Driven g-C3N4/TiO2 Based Heterojunction Nanocomposites for Photocatalytic Degradation of Organic Dyes in Wastewater: A Review

“…For instance, Moslah et al used a sol-gel/spin-coating method for preparing nanocrystalline pure and noble metal (Ag, Au, Pd, and Pt)-doped TiO 2 thin films. The order of photocatalytic activity is most probably related to the work function order, Pt-TiO 2 > Pd-TiO 2 > Au-TiO 2 > Ag-TiO 2 >pure TiO 2 (Moslah et al, 2018).…”