Guisheng Li

Bio: Guisheng Li is an academic researcher from Shanghai Normal University. The author has contributed to research in topics: Electron transfer & Aqueous solution. The author has an hindex of 2, co-authored 2 publications receiving 125 citations. Previous affiliations of Guisheng Li include University of Florida.

Pt-Enhanced Mesoporous Ti3+/TiO2 with Rapid Bulk to Surface Electron Transfer for Photocatalytic Hydrogen Evolution.

Abstract: Pt-doped mesoporous Ti3+ self-doped TiO2 (Pt–Ti3+/TiO2) is in situ synthesized via an ionothermal route, by treating metallic Ti in an ionic liquid containing LiOAc, HOAc, and a H2PtCl6 aqueous solution under mild ionothermal conditions. Such Ti3+-enriched environment, as well as oxygen vacancies, is proven to be effective for allowing the in situ reduction of Pt4+ ions uniformly located in the framework of the TiO2 bulk. The photocatalytic H2 evolution of Pt–Ti3+/TiO2 is significantly higher than that of the photoreduced Pt loaded on the original TiO2 and commercial P25. Such greatly enhanced activity is due to the various valence states of Pt (Ptn+, n = 0, 2, or 3), forming Pt–O bonds embedded in the framework of TiO2 and ultrafine Pt metal nanoparticles on the surface of TiO2. Such Ptn+–O bonds could act as the bridges for facilitating the photogenerated electron transfer from the bulk to the surface of TiO2 with a higher electron carrier density (3.11 × 1020 cm–3), about 2.5 times that (1.25 × 1020 cm...

Preparation method for visible-light response black titanium dioxide photocatalyst

Abstract: The invention discloses a preparation method for visible-light response black titanium dioxide photocatalyst. Glacial acetic acid and amide are adopted as solvents. Metal lithium salt is adopted as promoter. Titanium sheets are adopted as titanium sources. Ionic liquid is added as a structure-directing agent. A composition is achieved in one step by the adoption of a solvothermal method. The particle diameter of the prepared product is about 100 nm. Compared with other titanium dioxide, the visible-light response black titanium dioxide photocatalyst is black in color. The visible-light response black titanium dioxide photocatalyst displays good performance for degrading organic dyes under visible light. The preparation method for the visible-light response black titanium dioxide photocatalyst has the advantages that the chemical reagents which are used by the preparation method for the visible-light response black titanium dioxide photocatalyst are frequently-used reagents, low in price, easy to achieve, simple in method and technology, and capable of expanding anatase phase titanium dioxide to a visible-light response range. Meanwhile, the photocatalyst can degrade low-concentration dye wastewater under visible-light, and display the same high activity in a system of the low-concentration dye wastewater and phenolic substance.

Cadmium sulfide-based nanomaterials for photocatalytic hydrogen production

Abstract: Solar hydrogen generation via photocatalytic water splitting represents an attractive strategy to address the global energy crisis and environmental pollution issues. CdS-based photocatalysts, including nanosized CdS powder, CdS-based solid solutions and CdS quantum dots, have attracted significant attention for photocatalytic H2 production due to their unique advantages, including strong visible light absorption capacity, suitable band edge levels and excellent electronic charge transfer. This review focuses on recent advances in material design and technological aspects of CdS-based photocatalysts for applications in photocatalytic H2 production. A brief overview of basic concepts and principles of photocatalytic water splitting was given in the Introduction section, followed by the basic properties of CdS. Then, the utilization of three main types of CdS-based semiconductor photocatalysts for solar H2 generation is introduced, and those important factors which can determine the photocatalytic performance were also discussed in detail. Special consideration has been given to the effect of morphology, interfacial junctions, exposing facet and cocatalysts on the photocatalytic performance of CdS-based photocatalysts. Finally, a roadmap of possible future directions to further explore the research field of CdS-based photocatalysts for solar H2 generation is also discussed.

Modifications on reduced titanium dioxide photocatalysts: A review

Abstract: A large variety of reduced titanium dioxide (TiO2-x) materials have been reported recently Reduced TiO2, usually resulting from the removal of oxygen atoms or hydrogen incorporation, is proved to be efficient for achieving highly photocatalytic performance including photodegradation of organic compounds, hydrogen generation from water splitting, CO2 reduction for CH4 evolution, solar cells, etc To further improve the properties and activities of TiO2-x, a combination of the Ti3+ self-doping and other traditional modifications like nonmetals doping has been proposed in the past decades This paper provides a general and critical review on the further modifications on reduced TiO2 samples, including non-metal elements (N, B, S, F and I) doping, noble-metal (Au, Pt, Pd and Ag) and iron-group metal (Fe, Co and Ni) grafting, metal oxide compositing, carbon (nanotubes and graphene) and carbon-based-material compositing, special facets exposure (mainly dual {001}-{101} and {111}-{110} facets) of TiO2-x and ordered structure controlling of TiO2-x These modifications enhance the physical and/or chemical properties of the reduced TiO2, or create new features for the modified TiO2-x samples, which finally leads to the enhancement of photocatalytic performance Key examples such as N-doping, Au grafting and graphene-based compositing are discussed carefully, and the mechanisms for solar light enhancement, electron transfer and charge separation are also investigated Finally, some challenging issues on TiO2-x catalysts are also proposed to encourage new approaches for preparation of TiO2-x catalysts with efficiently photocatalytic performance

The selective deposition of MoS2 nanosheets onto (101) facets of TiO2 nanosheets with exposed (001) facets and their enhanced photocatalytic H2 production

Abstract: One of the challenging issues in photocatalytic hydrogen (H2) production is to efficiently separate the photogenerated electron-hole pairs and require the enrichment of photogenerated electrons on the photocatalyst’s surface. Herein, a novel 2D-2D nanojunction of MoS2 nanosheets (NSs) selectively deposited on the (101) facets of TiO2 NSs with mainly exposed high-active (001) facets is prepared via a hydrothermal/annealing treatment combined with an photoreduction method using carbon fiber (CF) as templates. The obtained MoS2@TiO2 composite (selective deposition) photocatalyst exhibits a greatly enhanced photocatalytic H2 production activity at the optimal weight percentage of MoS2 (15 wt%), exceeding that of pure TiO2 NSs and MoS2@TiO2 composites (random deposition) by 32 and 3 times, respectively. The superior photoactivity of MoS2@TiO2 composites (selective deposition) is attributed to the synergistic promoting effects of the following factors: (i) the mainly exposed (001) facets of TiO2 NSs with higher surface energy in MoS2@TiO2 composites (selective deposition) facilitate the activation of water molecules and the photocatalytic reduction; (ii) the coexposed (101) and (001) facets can form a surface heterojunction within single TiO2 NS, which is beneficial for the transfer and separation of charge carriers; (iii) the MoS2 NSs are selectively deposited on the electrons-rich (101) facets of TiO2 NSs, which can effectively reduce the charge carriers recombination rate by capturing photoelectrons. This study presents an inexpensive photocatalyst for energy conversion to achieve highly efficient H2 evolution without noble metals.

Robust photocatalytic hydrogen evolution over amorphous ruthenium phosphide quantum dots modified g-C3N4 nanosheet

Abstract: The development of materials which meet the needs of both cost-efficiency and high performance for hydrogen evolution reaction is of great importance. However, developing photocatalysts with Pt-like activity still remains as a major challenge. Herein, we utilize ultrafine amorphous ruthenium phosphide (RP) nanoparticles as a high-efficient and robust cocatalyst to enhance the H2 production activity of g-C3N4 (g-CN). The RP/g-CN samples were prepared based on a facile in-situ growth phosphatization method. The optimum H2 evolution rate reached up to 2110 μmol h−1g−1 for 0.1%-RP/g-CN, which was 113.4 times as high as that of pristine g-C3N4 and 2.22 times of Pt-loaded g-C3N4. Furthermore, ruthenium is the cheapest platinum-group metal and its amount in the best RP/g-CN sample is only 0.1%, showing the superiority of competitive price and high activity. The introduction of ultrafine amorphous ruthenium phosphide accelerated the transfer rate of electrons and restrain the recombination of charge carriers. The amorphous ruthenium phosphide ultrafine nanoparticles could also serve as cocatalysts for hydrogen evolution. This work provides a promising alternative to expensive Pt-loaded photocatalyst for excellent hydrogen evolution performance under visible light irradiation.