Modification of N-doped TiO 2 photocatalysts using noble metals (Pt, Pd) - a combined XPS and DFT study

• Published in: Physical chemistry chemical physics : PCCP Vol. 19; no. 10; pp. 7062 - 7071
• Main Authors: Batalović, K, Bundaleski, N, Radaković, J, Abazović, N, Mitrić, M, Silva, R A, Savić, M, Belošević-Čavor, J, Rakočević, Z, Rangel, C M
• Format: Journal Article
• Language: English
• Published: England 08.03.2017
• ISSN: 1463-9076; 1463-9084
• DOI: 10.1039/C7CP00188F

Nitrogen-doped TiO (N-TiO ) is considered as one of the most promising materials for various photocatalytic applications, while noble metals Pd and Pt are known as good catalysts for hydrogen evolution. This work focuses on the determination of structural and electronic modifications of N-TiO , achieved by noble metal deposition at the surface, as a starting indicator for potential applications. We focus on the properties of easily synthesized nanocrystalline nitrogen-doped anatase TiO , modified by depositing small amounts of Pd (0.05 wt%) and Pt (0.10 wt%), aiming to demonstrate efficient enhancement of optical properties. The chemical states of dopants are studied in detail, using X-ray photoemission spectroscopy, to address the potential of N-TiO to act as a support for metallic nanoparticles. DFT calculations are used to resolve substitutional from interstitial nitrogen doping of anatase TiO , as well as to study the combined effect of nitrogen doping and oxygen vacancy formation. Based on the binding energies calculated using Slater's transition state theory, dominant contribution to the N 1s binding energy at 399.8 eV is ascribed to interstitially doped nitrogen in anatase TiO . Given that both structure and photocatalytic properties depend greatly on the synthesis procedure, this work contributes further to establishing correlation between the structure and optical properties of the noble metal modified N-TiO system.