Nanosized N-doped TiO2 and gold modified semiconductors — photocatalysts for combined UV–visible light destruction of oxalic acid in aqueous solution

One step synthesis of N-doped and Au-loaded TiO2 nanoparticles by laser pyrolysis: Application in photocatalysis

“…FA adsorption decreases with increasing Au amount. These results may indicate that some adsorption sites are blocked by gold as suggested in the literature [33,35].…”

“…Deposition of Au on TiO 2 and NTiO 2 is an effective way to improve photoactivity for the photodegradation of methyl orange and methylene blue under UV irradiation [32,33]. In the same manner, Daous [54] and Iliev [35] show an increased activity under UV for the destruction of TNT and oxalic acid respectively when Au is added to TiO 2 or N-TiO 2 but does not compare their samples to P25. Figure 10B shows the results concerning the disappearance of formic acid concentration under visible light irradiation for 6h over the most active sample (0.16-Au-TiO 2 ), N-TiO 2 and Au/N-TiO 2 compared to the P25 sample.…”

“…Theoretical calculations [34] report that Au adsorption on TiO 2 surfaces significantly increase the amount of N implanted in the oxide and made it more active for the dissociation of water. A higher rate degradation of oxalic acid under UV-Visible irradiation with gold modified N-TiO 2 photocatalysts was also reported [35]. Generally, most of the synthesis methods in the literature are made by the same methods, which need several steps, such as sol-gel process.…”

“…This observed lower photoactivity is often interpreted in terms of recombination centers especially surface states [53] associated to the presence of Nitrogen. However, few studies concern the degradation of organic compounds under UV light using N-TiO 2 materials and the photocatalytic results are rather dispersed related to the very different photocatalysts materials (various elaboration methods, N amount) as well as choice of pollutants (dye or organic molecule such as TNT (trinitrotoluene)) [54] or oxalic acid [35]. The co-doped Au/N sample shows better activity compared to N-TiO 2 , illustrating again the beneficial effect of metallic Au introduction in the samples.…”

A review on plasmonic metal⿿TiO2 composite for generation, trapping, storing and dynamic vectorial transfer of photogenerated electrons across the Schottky junction in a photocatalytic system

“…The observed hydrogen production enhancement was further confirmed by transient photocurrent response and electrochemical impedance spectroscopy (EIS) experiments [104]. Au/N-TiO 2 showed better photocatalytic degradation of oxalic acid under various light sources like only UV, only visible and the mixture of UV-visible light irradiation compared to N-TiO 2 , Au/TiO 2 and TiO 2 due to the dominating influence of charge separation [109]. The longer lifetime of the photoexcited electron in the TiO 2 CB results in the accumulation of electrons on Au nanoparticles and to the formation of new quasi-Fermi level favoring the formation of hydroxyl radical and superoxide radicals [110].…”