Rong Fu

Bio: Rong Fu is an academic researcher from Xi'an Jiaotong University. The author has contributed to research in topics: Photocatalysis & Visible spectrum. The author has an hindex of 3, co-authored 4 publications receiving 31 citations.

Black TiO 2 synthesized via magnesiothermic reduction for enhanced photocatalytic activity

Abstract: Utilizing solar energy for hydrogen evolution is a great challenge for its insufficient visible-light power conversion. In this paper, we report a facile magnesiothermic reduction of commercial TiO2 nanoparticles under Ar atmosphere and at 550 °C followed by acid treatment to synthesize reduced black TiO2 powders, which possesses a unique crystalline core–amorphous shell structure composed of disordered surface and oxygen vacancies and shows significantly improved optical absorption in the visible region. The unique core–shell structure and high absorption enable the reduced black TiO2 powders to exhibit enhanced photocatalytic activity, including splitting of water in the presence of Pt as a cocatalyst and degradation of methyl blue (MB) under visible light irradiation. Photocatalytic evaluations indicate that the oxygen vacancies play key roles in the catalytic process. The maximum hydrogen production rates are 16.1 and 163 μmol h−1 g−1 under the full solar wavelength range of light and visible light, respectively. This facile and versatile method could be potentially used for large scale production of colored TiO2 with remarkable enhancement in the visible light absorption and solar-driven hydrogen production.

Preparation of core–shell nanostructured black nano-TiO2 by sol–gel method combined with Mg reduction

Abstract: Black nano-TiO2 samples with core–shell nanostructure were successfully prepared by sol–gel method combined with Mg reduction using butyl titanate as titanium source and calcining at 500°C in air atmosphere and at 400–600°C in nitrogen atmosphere. The prepared black TiO2 samples were characterized by X-ray diffraction, high resolution transmission electron microscopy, Raman spectra, photoluminescence emission spectra, N2 adsorption–desorption, and ultraviolet–visible spectroscopy. The results show that the black TiO2 exhibits a crystalline core–disordered shell structure composed of disordered surface and oxygen vacancies, and the thickness of the disordered layer is about 2–3 nm. The optical absorption properties of black nano-TiO2 samples have been remarkably enhanced in visible light region. Compared with the white TiO2, the reduced black TiO2 samples exhibit enhanced photocatalytic hydrogen production under the full solar wavelength range of light, and the sample prepared with the Mg and TiO2 ratio of 9:1 calcined at 500 °C has the maximum hydrogen production rate.

Evolution of mesoporous TiO2 during fast sol–gel synthesis

Abstract: Mesoporous TiO2 nanoparticles were synthesized by a fast sol–gel method using polyethylene glycol (PEG) and polyacrylamide as bi-template followed by two-step calcination under nitrogen and air atmosphere. The effects of factors such as the solvent volume, amount of water, medium pH, and amount and molecular weight of PEG on the sol–gel reaction rate were studied based on analysis of zeta potential measurements. The results showed that lower ethanol volume, lower pH, greater water volume, and higher PEG molecular weight led to faster sol–gel reaction rate with shorter gelation time, with pH and water volume being the most influential amongst these factors. The evolution during the fast sol–gel process was also investigated based on the infrared (IR) spectrum. The results indicated that the fast sol–gel process occurred due to intermolecular hydrogen bonding between hydrolysates of Ti alkoxides and the bi-template. The samples were characterized by X-ray diffraction (XRD) analysis, transmission electron microscopy (TEM), and N2 adsorption–desorption measurements, revealing high crystallinity with small crystallite size and large specific surface area.

Titanium Dioxide: From Engineering to Applications

Abstract: Titanium dioxide (TiO2) nanomaterials have garnered extensive scientific interest since 1972 and have been widely used in many areas, such as sustainable energy generation and the removal of environmental pollutants. Although TiO2 possesses the desired performance in utilizing ultraviolet light, its overall solar activity is still very limited because of a wide bandgap (3.0–3.2 eV) that cannot make use of visible light or light of longer wavelength. This phenomenon is a deficiency for TiO2 with respect to its potential application in visible light photocatalysis and photoelectrochemical devices, as well as photovoltaics and sensors. The high overpotential, sluggish migration, and rapid recombination of photogenerated electron/hole pairs are crucial factors that restrict further application of TiO2. Recently, a broad range of research efforts has been devoted to enhancing the optical and electrical properties of TiO2, resulting in improved photocatalytic activity. This review mainly outlines state-of-the-art modification strategies in optimizing the photocatalytic performance of TiO2, including the introduction of intrinsic defects and foreign species into the TiO2 lattice, morphology and crystal facet control, and the development of unique mesocrystal structures. The band structures, electronic properties, and chemical features of the modified TiO2 nanomaterials are clarified in detail along with details regarding their photocatalytic performance and various applications.

Application of TiO2 and ZnO nanoparticles immobilized on clay in wastewater treatment: a review

Abstract: Increase in industrial and anthropogenic activities leads to a decline in water quality. This necessitates the need for the removal of contaminants from industrial and domestic wastewater. Clay minerals are naturally abundant and non-toxic materials that found to be useful for remediation of emerging contaminants from wastewater. This review paper presents an insight into clay, the simplest material (in solgel techniques) for the synthesis of TiO2 and ZnO, mechanisms of their reactions, analytical techniques used for characterizations, and their nanocomposites for wastewater treatment. Nanomaterials, such as nanoclay, titanium, and zinc oxide, have offered the opportunities of sequestering variety of pollutants in wastewater. TiO2 and ZnO anchored on clay have been found to be good promising sequesters and have been explored for wastewater remediation via nanotechnology. This water treatment method includes adsorption/absorption, photocatalysis, and microbial disinfection. These nanocomposites provide more active surface sites and reduce the agglomeration of the nanoparticles, but leaching has been their shortcomings. To overcome this, the filtration technique may become significant for the removal and avoidance of fouling of wastewater. This can be achieved through the fabrication of nano-based filters using the nanocomposites.

Bandgap engineering via boron and sulphur doped carbon modified anatase TiO2: a visible light stimulated photocatalyst for photo-fixation of N2 and TCH degradation

Abstract: The present research reports the synthesis of two-dimensional (2D) sheet/flake-like nanostructures of crystalline carbon modified TiO2 (CT), B-TiO2 (B-CT), and S-TiO2 (S-CT) using a facile one-pot synthesis method. The crystallinity and phase purity (anatase) of the prepared nano-photocatalyst were characterised using X-ray diffraction, selected area electron diffraction (SAED) and high-resolution transmission electron microscopy (HRTEM) analysis. Furthermore, the morphological details and elemental content of the sample were studied via scanning electron microscopy (SEM) and transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS), respectively. Additionally, the optoelectronic features of all of the prepared specimens were measured via UV-vis diffuse reflectance spectroscopy (DRS), photoluminescence (PL), impedance and Mott–Schottky studies. After successful characterisation, their photocatalytic performance was tested towards dinitrogen photo-fixation and tetracycline hydrochloride (TCH) degradation under visible light illumination. Moreover, the effective charge separation and greater availability of the active surface area led to the robust photocatalytic activity of the fabricated B-CT compared to the CT and S-CT samples, which correlates well with the PL, impedance and surface area analysis. B-CT displays the highest photocatalytic activity, i.e. 32.38 μmol L−1 (conversion efficiency = 0.076%) of ammonia production, and 95% tetracycline hydrochloride (10 ppm) degradation. Here, we have effectively designed a novel and productive pathway towards the enhancement of the photocatalytic performance of visible photon active TiO2-based materials for energy and environmental sustainability.