Jing Jiang

Bio: Jing Jiang is an academic researcher from Wuhan University. The author has contributed to research in topics: Irradiation & Positron. The author has an hindex of 8, co-authored 16 publications receiving 587 citations. Previous affiliations of Jing Jiang include National University of Defense Technology.

Characterization of Oxygen Vacancy Associates within Hydrogenated TiO2: A Positron Annihilation Study

Abstract: This paper introduces a novel method for characterizing the oxygen vacancy associates in hydrogenation-modified TiO2 by using a positron annihilation lifetime spectroscopy (PALS). It was found that a huge number of small neutral Ti3+–oxygen vacancy associates, some larger size vacancy clusters, and a few voids of vacancy associates were introduced into hydrogenated TiO2. The defects blurred the atomic lattice high-resolution transmission electron microscopy (HRTEM) images and brought about the emergence of new Raman vibration. X-ray photoelectron spectroscopy (XPS) measurement indicated that the concentration of oxygen vacancies was 3% in the TiO2 lattice. The photoluminescence (PL) spectroscopy, photocurrent, and degradation of methylene blue indicated that the oxygen vacancy associates introduced by hydrogenation retarded the charge recombination and therefore improved the photocatalytic activity remarkably.

Interaction of hydrogen with defects in ZnO nanoparticles – studied by positron annihilation, Raman and photoluminescence spectroscopy

Abstract: The interaction of hydrogen with defects in ZnO nanoparticles under H2–Ar mixed gas was investigated by positron annihilation, Raman and photoluminescence spectroscopy. Two series of experiments were performed, including annealing the samples in pure Ar gas and H2–Ar mixed gas. The thermal stability of hydrogen-related defects was also carried out by subsequent isochronal annealing in air. The positron annihilation results showed that more vacancy clusters were formed in the hydrogenated samples due to the reducing effect of hydrogen when compared to those samples annealed in pure Ar gas, which was consistent with the smaller grain size, and more surface and interfaces observed by X-ray diffraction, scanning electron microscopy and high-resolution transmission electron microscopy. Raman, electron paramagnetic resonance, and photoluminescence spectra indicated that there existed two main forms of hydrogen in the ZnO nanoparticles: hydrogen occupying the oxygen vacancy HO and interstitial hydrogen Hi. Hi diffused out at 150 °C, while HO was completely removed at 700 °C. The results are helpful to understand the role of hydrogen in nanoscale ZnO and the applications in UV optoelectronics.

Defective TiO2 with oxygen vacancies: synthesis, properties and photocatalytic applications

Abstract: Titanium dioxide (TiO2), as an important semiconductor metal oxide, has been widely investigated in the field of photocatalysis. The properties of TiO2, including its light absorption, charge transport and surface adsorption, are closely related to its defect disorder, which in turn plays a significant role in the photocatalytic performance of TiO2. Among all the defects identified in TiO2, oxygen vacancy is one of the most important and is supposed to be the prevalent defect in many metal oxides, which has been widely investigated both by theoretical calculations and experimental characterizations. Here, we give a short review on the existing strategies for the synthesis of defective TiO2 with oxygen vacancies, and the defect related properties of TiO2 including structural, electronic, optical, dissociative adsorption and reductive properties, which are intimately related to the photocatalytic performance of TiO2. In particular, photocatalytic applications with regard to defective TiO2 are outlined. In addition, we offer some perspectives on the challenge and new direction for future research in this field. We hope that this tutorial minireview would provide some useful contribution to the future design and fabrication of defective semiconductor-based nanomaterials for diverse photocatalytic applications.

Black titanium dioxide (TiO2) nanomaterials

Abstract: In the past few decades, there has been a wide research interest in titanium dioxide (TiO2) nanomaterials due to their applications in photocatalytic hydrogen generation and environmental pollution removal. Improving the optical absorption properties of TiO2 nanomaterials has been successfully demonstrated to enhance their photocatalytic activities, especially in the report of black TiO2 nanoparticles. The recent progress in the investigation of black TiO2 nanomaterials has been reviewed here, and special emphasis has been given on their fabrication methods along with their various chemical/physical properties and applications.

Sub-10 nm rutile titanium dioxide nanoparticles for efficient visible-light-driven photocatalytic hydrogen production

Abstract: Titanium dioxide is a promising photocatalyst for water splitting, but it suffers from low visible light activity due to its wide band gap Doping can narrow the band gap of titanium dioxide; however, new charge-carrier recombination centres may be introduced Here we report the design of sub-10 nm rutile titanium dioxide nanoparticles, with an increased amount of surface/sub-surface defects to overcome the negative effects from bulk defects Abundant defects can not only shift the top of the valence band of rutile titanium dioxide upwards for band-gap narrowing but also promote charge-carrier separation The role of titanium(III) is to enhance, rather than initiate, the visible-light-driven water splitting The sub-10 nm rutile nanoparticles exhibit the state-of-the-art activity among titanium dioxide-based semiconductors for visible-light-driven water splitting and the concept of ultra-small nanoparticles with abundant defects may be extended to the design of other robust semiconductor photocatalysts

H‐Doped Black Titania with Very High Solar Absorption and Excellent Photocatalysis Enhanced by Localized Surface Plasmon Resonance

Abstract: Black TiO2 attracts enormous attention due to its large solar absorption and induced excellent photocatalytic activity. Herein, a new approach assisted by hydrogen plasma to synthesize unique H-doped black titania with a core/shell structure (TiO2@TiO2-xHx) is presented, superior to the high H-2-pressure process (under 20 bar for five days). The black titania possesses the largest solar absorption (approximate to 83%), far more than any other reported black titania (the record (high-pressure): approximate to 30%). H doping is favorable to eliminate the recombination centers of light-induced electrons and holes. High absorption and low recombination ensure the excellent photocatalytic activity for the black titania in the photo-oxidation of organic molecules in water and the production of hydrogen. The H-doped amorphous shell is proposed to play the same role as Ag or Pt loading on TiO2 nanocrystals, which induces the localized surface plasma resonance and black coloration. Photocatalytic water splitting and cleaning using TiO2-xHx is believed to have a bright future for sustainable energy sources and cleaning environment.