Effect of Nature and Location of Defects on Bandgap Narrowing in Black TiO₂Nanoparticles

Abstract

The increasing need for new materials capable of solar fuel generation is central in the development of a green energy economy. In this contribution, we demonstrate that black TiO(2) nanoparticles obtained through a one-step reduction/crystallization process exhibit a bandgap of only 1.85 eV, which matches well with visible light absorption. The electronic structure of black TiO(2) nanoparticles is determined by the unique crystalline and defective core/disordered shell morphology. We introduce new insights that will be useful for the design of nanostructured photocatalysts for energy applications.

Engineering oxygen vacancy on rutile TiO2 for efficient electron-hole separation and high solar-driven photocatalytic hydrogen evolution

“…The peak at 239 cm −1 is attributed to the multi-proton scattering process [38]. Moreover, compared with sample i, the broadening of these peaks for sample ii-iv further demonstrates that surface oxygen vacancies break down the symmetry of rutile TiO 2 lattice after the in-situ solid-state chemical reduction process [39,40], consistent well with the XRD results. Obviously, a disordered thin layer is formed on the sample surface after hydrogenation, which proved that the reduction reaction occurred on the surface of TiO 2 .…”

Selective isolation of the electron or hole in photocatalysis: ZnO–TiO2 and TiO2–ZnO core–shell structured heterojunction nanofibers via electrospinning and atomic layer deposition

“…43,44 The lattice parameters were calculated for tetragonal TiO 2 (a ¼ b ¼ 3.7847Å, and c ¼ 9.5173Å) and yielded a crystal volume of 136.33Å 3 , which is comparable to the standard value of 135.25Å 3 . 43 However, in the literature lattice contraction is evidenced under the inuence of V O s. 45 In the case of TiO 2 when an O atom is removed, the three nearest Ti atoms tend to relax away from the vacancy in the process of strengthening their bonding with the rest of the lattice. 45,46 In the present case, most probably because of the low density of V O s, a negligible effect on the bond lengths/cell volume is seen.…”

“…43 However, in the literature lattice contraction is evidenced under the inuence of V O s. 45 In the case of TiO 2 when an O atom is removed, the three nearest Ti atoms tend to relax away from the vacancy in the process of strengthening their bonding with the rest of the lattice. 45,46 In the present case, most probably because of the low density of V O s, a negligible effect on the bond lengths/cell volume is seen. Moving onto the XRD pattern of the TiO 2 -ZnO CSHJ sample, we have identied reections of the hexagonal (wurtzite) ZnO and annotated the corresponding Miller indices on Fig.…”

“Black” TiO2 Nanotubes Formed by High-Energy Proton Implantation Show Noble-Metal-co-Catalyst Free Photocatalytic H2-Evolution

“…[12][13][14][15][16]) -such material was reported to cause a similar effect on the Pt-co-catalyzed photocatalytic H 2 -production or when used in a range of other electrochemical applications [17][18][19].…”