Fine Control of the Chemistry of Nitrogen Doping in TiO₂: A Joint Experimental and Theoretical Study

Abstract

N-doped TiO 2 materials have recently attracted a considerable amount of interest due to their enhanced photoelectrochemical properties compared to pristine TiO 2 . However, this improvement is still not clearly correlated to the N chemistry because the attribution of the observed components in the N 1s X-ray photoelectron spectra is strongly disputed. In this context, this joint experimental and theoretical study aims at clearly distinguishing the different N atomic species and positions that can be encountered upon N-doping of titania by the N 2 + ion implantation method. Core-level binding energy shifts (CLS) calculated at a quantum-chemical level for N 1s orbitals with different chemical environments nicely match the components obtained by the fitting of the N 1s XPS experimental regions and allow for its detailed interpretation. We also monitored the N atom positions as a function of the dose used for implantation. Based on classical simulations of ion/surface interactions achieved with the help of the TRIDYN software, we show that oxygen vacancies play a key role in defining the nitrogen doping type (i.e., nitrogen position in the TiO 2 lattice), as further supported by DFT calculations.

A Facile Strategy for the Preparation of N-Doped TiO2 with Oxygen Vacancy via the Annealing Treatment with Urea

“…proves that the annealing treatment with urea extends the photoresponse range of TiO2 to the visible light range [18,40]. The photocatalytic performance of N-TiO2 is comparable to the reported results (Table S2) which may be ascribed to the formation of Vo and the increased specific surface area [33,39,41,42].…”

“…With N-TiO 2 as the photocatalyst, the photocatalytic degradation of MO is feasible and among the samples N-TiO 2 (2:1) presents the best photocatalytic performance. The photocatalytic performance of N-TiO 2 proves that the annealing treatment with urea extends the photoresponse range of TiO 2 to the visible light range [18,40]. The photocatalytic performance of N-TiO 2 is comparable to the reported results (Table S2) which may be ascribed to the formation of Vo and the increased specific surface area [33,39,41,42].…”

Ion‐Implantation in Titania‐Based Plasmonic Photo‐anodes: A Review

“…[69,73] In the current times, ion beam technology has been demonstrated to be a potential method for material modification. [60,61,[74][75][76][77][78][79][80][81][82][83][84][85][86][87][88][89][90] This method has substituted the diffusion [5,74,[91][92][93] process when compared to the conventional doing strategies and has been widely used in the synthesis of nanomaterials [74,75,84,86,89,91] for photo-catalysis, [5,6,28,94,95] photo-electrochemical water-splitting, [3,36,96,97] and photo-voltaic [35,[98][99][100] applications. Significant advances have been made in the synthesis of plasmonic nanocomposites by this method in the last couple of years.…”

Deposition of TiOx and N-TiOx by dielectric barrier discharge at atmospheric pressure

“…Nevertheless, when increasing T sub , the nitrate compound disappears since they are unstable under heating and tends to decompose in NO. Then a second component at 401.7 eV could be assigned to N 2 [42,44]. This component is present for all deposition conditions and decreases when increasing T sub .…”