Shuoping Ding

Surfactant-mediated synthesis of single-crystalline Bi3O4Br nanorings with enhanced photocatalytic activity

We present a surfactant-mediated approach to the production of single-crystal Bi3O4Br nanorings via a simple solvothermal method. The ring-like morphology is rare among bismuth oxyhalides, and the reaction pathways are superior to traditional chemical transformations. In detail, Bi3O4Br nanorings are prepared in three stages: (1) the formation of precursors, (2) selective etching and (3) Ostwald ripening. During these steps, the extra usage of templates is avoided and a series of useful intermediates are obtained. Besides, this method can be extended to fabricate other bismuth oxyhalide nanorings. Under visible-light irradiation, all of our samples are photo-activated. The Bi3O4Br nanorings exhibit an efficient oxygen-evolution rate (72.54 μmol h−1) and pollutant degradation rate (4.71 × 10−2 g min−1 m−2), which can be attributed to their unique ring structures and band potentials. Thus, the surfactant-mediated chemical conversion strategy not only paves a new way to enhance the photocatalytic activity of bismuth oxyhalides, but also provides an important large-scale route for designing other nanomaterials with ring-like structures.

Bi metal-modified Bi4O5I2 hierarchical microspheres with oxygen vacancies for improved photocatalytic performance and mechanism insights

In this work, we firstly synthesized metallic Bi-modified Bi4O5I2 nanocomposites with oxygen vacancies via a facile one-pot solvothermal method. The deposited Bi metal and oxygen vacancies endowed the Bi/Bi4O5I2 samples with dramatically enhanced photocatalytic performance for degradation of bisphenol A (BPA) and methyl orange (MO) under visible light irradiation. In particular, the improved photocatalytic activity can be ascribed to the synergistic effect of Bi metal and oxygen vacancies, which resulted in their efficient light harvesting properties and excellent charge separation ability. The photocatalytic mechanism of Bi/Bi4O5I2 for organics degradation was demonstrated. This work could shed light on exploring high photocatalytic performance materials and stimulating the development of non-noble metal/BixOyIz photocatalysts, which would also contribute to advancement in environmental remediation and energy exploitation.

Synthesis and characterization of single-crystalline Bi2O2SiO3 nanosheets with exposed {001} facets

Bismuth oxide silicate (Bi2O2SiO3) single-crystalline nanosheets with exposed {001} facets were synthesized for the first time via a facile one-step CTAB-assisted hydrothermal method in the presence of NaOH. Control experiments were carried out to investigate various factors that affect the formation, morphology and exposed planes of the products systematically. The results revealed that the pH and the amount of CTAB play vital roles in the reaction. Bi2O2SiO3 nanosheets could not be obtained without the addition of sodium hydroxide solution in the synthesis process, and CTAB not only promotes the exposure of {001} facets, but also modulates the size and thickness of these Bi2O2SiO3 nanosheets in a wide range. It was shown that the as-prepared Bi2O2SiO3 nanosheets synthesized under the conditions that the amount of CTAB was 4 mmol and the pH value was 12 exhibited higher photocatalytic activities toward RhB and BPA degradation under simulated sunlight irradiation than all the other samples in our experiment, which might give the main credit to the highly exposed {001} facets and considerable number of oxygen vacancies. The present work provides a new reference for the synthesis of Bi2O2SiO3 nanosheets and other manipulation of facet-dependent photoreactivity of semiconductors.

Generalized Synthesis of Ternary Sulfide Hollow Structures with Enhanced Photocatalytic Performance for Degradation and Hydrogen Evolution

A series of ternary sulfide hollow structures have been successfully prepared by a facile glutathione (GSH)-assisted one-step hydrothermal route, where GSH acts as the source of sulfur and bubble template. We demonstrate the feasibility and versatility of this in situ gas-bubble template strategy by the fabrication of novel hollow structures of MIn2S4 (M = Cd, Zn, Ca, Mg, and Mn). Interestingly, with the reaction time varying, the hierarchical CdIn2S4 microspheres with controlled internal structures can be regulated from yolk-shell, smaller yolk-shell (yolk-shell with shrunk yolk), hollow, to solid. Under visible-light irradiation, all of our prepared CdIn2S4 samples with different morphologies were photoactivated. In virtue of the appealing hierarchical hollow structure, the yolk-shell-structured CdIn2S4 microspheres exhibited the optimal photocatalytic activity and excellent durability for both the X3B degradation and H2 evolution, which can be ascribed to the synergy-promoting effect of the small crystallite size together with the unique structural advantages of the yolk-shell structure. Thus, we hypothesize that this proof-of-concept strategy paves an example of rational design of hollow structured ternary or multinary sulfides with superior photochemical performance, holding great potential for future multifunctional applications.

Synthesis and characterization of single-crystalline Bi19Cl3S27 nanorods

Single-crystalline Bi19Cl3S27 nanorods have been synthesized for the first time via a facile solvothermal route. The Bi19Cl3S27 nanorods showed high activity for the photocatalytic removal of Cr(VI). In addition, the growth of the nanorods and the generation of active species in the catalysis system were proposed.

Construction of Hierarchical MoSe2 Hollow Structures and Its Effect on Electrochemical Energy Storage and Conversion

Metal selenides have attracted increased attention as promising electrode materials for electrochemical energy storage and conversion systems including metal-ion batteries and water splitting. However, their practical application is greatly hindered by collapse of the microstructure, thus leading to performance fading. Tuning the structure at nanoscale of these materials is an effective strategy to address the issue. Herein, we craft MoSe2 with hierarchical hollow structures via a facile bubble-assisted solvothermal method. The temperature-related variations of the hollow interiors are studied, which can be presented as solid, yolk-shell, and hollow spheres, respectively. Under the simultaneous action of the distinctive hollow structures and interconnections among the nanosheets, more intimate contacts between MoSe2 and electrolyte can be achieved, thereby leading to superior electrochemical properties. Consequently, the MoSe2 hollow nanospheres prepared under optimum conditions exhibit optimal electrochemical activities, which hold an initial specific capacity of 1287 mA h g-1 and maintain great capacity even after 100 cycles as anode for Li-ion battery. Moreover, the Tafel slope of 58.9 mV dec-1 for hydrogen evolution reaction is also attained.