Author
Huogen Yu
Other affiliations: University of Tokyo, China University of Geosciences (Wuhan), Zhengzhou University ...read more
Bio: Huogen Yu is an academic researcher from Wuhan University of Technology. The author has contributed to research in topics: Photocatalysis & Materials science. The author has an hindex of 57, co-authored 170 publications receiving 10436 citations. Previous affiliations of Huogen Yu include University of Tokyo & China University of Geosciences (Wuhan).
Topics: Photocatalysis, Materials science, Anatase, Catalysis, Cognitive radio
Papers published on a yearly basis
Papers
More filters
TL;DR: In this article, a localized Ostwald ripening mechanism was proposed to account for the formation of CuO/Cu2O composite hollow microspheres with controlled diameter and composition using Cu(CH3COO)2·H2O as a precursor.
Abstract: CuO/Cu2O composite hollow microspheres with controlled diameter and composition were prepared without the addition of templates and additives by hydrothermal synthesis using Cu(CH3COO)2·H2O as a precursor. Increasing the precursor concentration from 0.02 to 0.2 M increased the diameter of the composite hollow microspheres from 500 nm to 5 μm. Moreover, the content of Cu2O in the composite hollow microspheres increased with increasing the reaction time or/and precursor concentration to produce a range of composite hollow microspheres with Cu2O contents from 20 to 80 wt %. A localized Ostwald ripening mechanism was proposed to account for the formation of CuO/Cu2O composite hollow microspheres. The photocatalytic activity experiment indicated that the prepared CuO/Cu2O composite hollow microspheres exhibited a higher photocatalytic activity for the photocatalytic decolorization of methyl orange aqueous solution under the visible-light illumination than the single phase CuO or Cu2O samples.
455 citations
421 citations
TL;DR: In this paper, a one-step green hydrothermal method for the fabrication of easily recycled TiO2-rGO composites, based on the initial formation of strong-coupling TiO 2-GO nanocomposite and the subsequent in situ reduction of reduced graphene oxide (rGO) during hydro-thermal treatment, was developed in the pure water without using any reductant and surfactant.
Abstract: The addition of reduced graphene oxide (rGO) in the TiO2 has been demonstrated to be one of the effective methods to improve the photocatalytic performance of TiO2 photocatalyst. Despite tremendous efforts, developing facile and green synthetic method of TiO2-rGO nanocomposites still remains a great challenge. In this study, a one-step green hydrothermal method for the fabrication of easily recycled TiO2-rGO composites, based on the initial formation of strong-coupling TiO2-GO nanocomposite and the subsequent in situ reduction of GO to rGO during hydrothermal treatment, was developed in the pure water without using any reductant and surfactant. It is found that the TiO2 nanoparticles with a clean surface and a good dispersion are highly required for the formation of the easy-recycling TiO2-rGO composite photocatalyst. Photocatalytic experimental results indicated that compared with the high-efficiency P25 TiO2 precursor, the photocatalytic performance could be obviously improved (about 23%) for the decomposition of phenol after coupling 1-wt% rGO. The enhanced photocatalytic performance can be attributed the cooperation effect of the effective separation of charge carriers via rGO cocatalyst, the enrichment of phenol molecular on the rGO, and the strong coupling interaction between TiO2 nanoparticles and rGO nanosheets. Considering its completely green and facile preparation and recyclable feature from an aqueous solution, the present TiO2-rGO nanocomposite photocatalyst can be regards as one of the ideal photocatalysts for various potential applications.
385 citations
TL;DR: In this article, the hierarchical mesopores exhibit peak intra-aggregated mesopore sizes of 3-10 nm and peak interaggregation sizes of 30-50 nm, depending on the specific molar ratio of fluoride to titanium.
365 citations
TL;DR: In this paper, the photocatalytic activity of as-prepared titanate nanotubes was evaluated by photocatalysis oxidation of acetone in air, and the effects of calcination temperature on the phase structure, crystallite size, morphology, specific surface area and pore structures of the titanate nano-blocks were investigated.
Abstract: Titanate nanotubes were prepared via a hydrothermal treatment of TiO2 powders (P25) in a 10 M NaOH solution at 150 °C for 48 h and then calcined at various temperatures. The as-prepared titanate nanotubes before and after calcination were characterized with XRD, TEM, HRTEM, SEM, FESEM, and nitrogen adsorption–desorption isotherms. The photocatalytic activity of the as-prepared samples was evaluated by photocatalytic oxidation of acetone in air. The effects of calcination temperature on the phase structure, crystallite size, morphology, specific surface area, pore structures and photocatalytic activity of the titanate nanotubes were investigated. The results indicated that at 400 to 600 °C, the calcined nanotube samples showed a higher photocatalytic activity than Degussa P25. Especially, at 400 and 500 °C, the photocatalytic activity of the calcined nanotubes exceeded that of P25 by a factor of about 3.0 times. This could be attributed to the fact that the former had a larger specific surface area and pore volume. With further increase in the calcination temperature from 700 to 900 °C, the photocatalytic activity of the calcined nanotube samples greatly decreased due to the formation of rutile phase, the sintering and growth of TiO2 crystallites and the decrease of specific surface area and pore volume.
354 citations
Cited by
More filters
TL;DR: Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting and its Applications d0 Metal Oxide Photocatalysts 6518 4.4.1.
Abstract: 2.3. Evaluation of Photocatalytic Water Splitting 6507 2.3.1. Photocatalytic Activity 6507 2.3.2. Photocatalytic Stability 6507 3. UV-Active Photocatalysts for Water Splitting 6507 3.1. d0 Metal Oxide Photocatalyts 6507 3.1.1. Ti-, Zr-Based Oxides 6507 3.1.2. Nb-, Ta-Based Oxides 6514 3.1.3. W-, Mo-Based Oxides 6517 3.1.4. Other d0 Metal Oxides 6518 3.2. d10 Metal Oxide Photocatalyts 6518 3.3. f0 Metal Oxide Photocatalysts 6518 3.4. Nonoxide Photocatalysts 6518 4. Approaches to Modifying the Electronic Band Structure for Visible-Light Harvesting 6519
6,332 citations
TL;DR: It is anticipated that this review can stimulate a new research doorway to facilitate the next generation of g-C3N4-based photocatalysts with ameliorated performances by harnessing the outstanding structural, electronic, and optical properties for the development of a sustainable future without environmental detriment.
Abstract: As a fascinating conjugated polymer, graphitic carbon nitride (g-C3N4) has become a new research hotspot and drawn broad interdisciplinary attention as a metal-free and visible-light-responsive photocatalyst in the arena of solar energy conversion and environmental remediation. This is due to its appealing electronic band structure, high physicochemical stability, and “earth-abundant” nature. This critical review summarizes a panorama of the latest progress related to the design and construction of pristine g-C3N4 and g-C3N4-based nanocomposites, including (1) nanoarchitecture design of bare g-C3N4, such as hard and soft templating approaches, supramolecular preorganization assembly, exfoliation, and template-free synthesis routes, (2) functionalization of g-C3N4 at an atomic level (elemental doping) and molecular level (copolymerization), and (3) modification of g-C3N4 with well-matched energy levels of another semiconductor or a metal as a cocatalyst to form heterojunction nanostructures. The constructi...
5,054 citations
2,970 citations
TL;DR: Hollow micro-/nanostructures are of great interest in many current and emerging areas of technology as discussed by the authors, and a comprehensive overview of synthetic strategies for hollow structures is presented.
Abstract: Hollow micro-/nanostructures are of great interest in many current and emerging areas of technology. Perhaps the best-known example of the former is the use of fly-ash hollow particles generated from coal power plants as partial replacement for Portland cement, to produce concrete with enhanced strength and durability. This review is devoted to the progress made in the last decade in synthesis and applications of hollow micro-/nanostructures. We present a comprehensive overview of synthetic strategies for hollow structures. These strategies are broadly categorized into four themes, which include well-established approaches, such as conventional hard-templating and soft-templating methods, as well as newly emerging methods based on sacrificial templating and template-free synthesis. Success in each has inspired multiple variations that continue to drive the rapid evolution of the field. The Review therefore focuses on the fundamentals of each process, pointing out advantages and disadvantages where appropriate. Strategies for generating more complex hollow structures, such as rattle-type and nonspherical hollow structures, are also discussed. Applications of hollow structures in lithium batteries, catalysis and sensing, and biomedical applications are reviewed.
2,767 citations
TL;DR: High photocatalytic H(2)-production activity is attributed predominantly to the presence of graphene, which serves as an electron collector and transporter to efficiently lengthen the lifetime of the photogenerated charge carriers from CdS nanoparticles.
Abstract: The production of clean and renewable hydrogen through water splitting using photocatalysts has received much attention due to the increasing global energy crises. In this study, a high efficiency of the photocatalytic H2 production was achieved using graphene nanosheets decorated with CdS clusters as visible-light-driven photocatalysts. The materials were prepared by a solvothermal method in which graphene oxide (GO) served as the support and cadmium acetate (Cd(Ac)2) as the CdS precursor. These nanosized composites reach a high H2-production rate of 1.12 mmol h–1 (about 4.87 times higher than that of pure CdS nanoparticles) at graphene content of 1.0 wt % and Pt 0.5 wt % under visible-light irradiation and an apparent quantum efficiency (QE) of 22.5% at wavelength of 420 nm. This high photocatalytic H2-production activity is attributed predominantly to the presence of graphene, which serves as an electron collector and transporter to efficiently lengthen the lifetime of the photogenerated charge carrier...
2,212 citations