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Abstract: The enhancement of O2 evolution via the oxidation of water on {102} facet dominant nitrogen-doped TiO2 (N-TiO2) nanorods is described. N-doped TiO2 nanosphere and nanorod were synthesized and subsequent NH3 treatment. 3 atomic% of nitrogen was incorporated into both anatase TiO2 nanocrystals. They show same band gap energies of 2.8eV and similar lifetime of photo-exciton. The surface of N-doped TiO2 nanorod, however, presents much more dominant amount of {102} facets than that of nanosphere. The low overpotential of the {102} facets results in the selective generation of O2, with the simultaneous suppression of the photocatalytic formation of ·OH. [Copyright &y& Elsevier]

Highlights: [•] Carbon-doped TiO2 was wrapped with nanographene controlling the surface charge. [•] The interfacial charge-transfer rate was measured by time-resolved photoluminescence. [•] Hydroxyl radical was quantified by a colorimetric probe-assisted spectrometric method. [•] The charge-transfer resistance was measured by electrochemical impedance spectroscopy. [•] Graphene-modified nanoparticles showed outstanding oxidizing power under visible light. [ABSTRACT FROM AUTHOR]

Highlights: [•] N-doped TiO2 were used for production of O2 via the oxidation of water by visible light. [•] The migration of h+ to the surface leads to the evolution of O2 and the formation of OH radicals. [•] E g for TiO2−x N x is optimized to 2.8eV for the evolution of O2 under the irradiation by visible light. [ABSTRACT FROM AUTHOR]

Abstract: We describe a method tuning the band-gap energy (E g) of visible light sensitive TiO2-x C x nanoparticle. E g tends to become smaller with the increase in the amount of carbon dopant in TiO2-x C x nanoparticle due to the increase in excess electrons. Photo-catalytic oxidative activity, however, did not depend on only the value of E g, but also the energy level of valence band. TiO1.96C0.04 nanoparticle having E g of 2.6eV showed outstanding performance in oxidative decomposition of phenol under the irradiation of visible light. [Copyright &y& Elsevier]

Abstract: Since the conversion of solar energy to electric or chemical forms is essential for achieving a sustainable society, the development of novel photo-catalytic materials is a subject of considerable interest. Here we report on the facile synthesis of a visible light sensitive photo-catalyst by doping a large amount of carbon into TiO2 nanoparticles. The findings show that carbon is clearly incorporated into the TiO2 framework, as evidenced by TPO, XANES, and EXAFS. The photo-catalytic activity of the carbon-doped TiO2 is increased by more than 4 times, compared to commercial TiO2 P25 for the degradation of phenol under irradiation by white light. Additionally, we observed for the first time that the carbon-doped TiO2 shows catalytic activity under irradiation by visible light at wavelengths longer than 600nm. The synthetic method developed in this study is very simple, and doping level of carbon can be easily controlled by changing the synthetic conditions used. [Copyright &y& Elsevier]