Yuting Xiao

Cubic quantum dot/hexagonal microsphere ZnIn2S4 heterophase junctions for exceptional visible-light-driven photocatalytic H2 evolution

The fabrication of heterophase junctions is an efficient approach to improve photocatalytic performance, as heterophase junctions have the potential to inhibit the recombination of photoinduced charge carriers. Herein, cubic quantum dot/hexagonal microsphere ZnIn2S4 heterophase junctions were constructed by a two-step process. First, hexagonal ZnIn2S4 microspheres with abundant sulfur vacancies were prepared to act as ideal matrixes via a solvothermal process. Then cubic ZnIn2S4 quantum dots were decorated on the surface of the hexagonal ZnIn2S4 microspheres to form heterophase junctions using a hydrothermal growth method. The characterization of valence band X-ray photoelectron spectra and UV-vis diffuse reflectance spectra proves that the cubic quantum dot/hexagonal microsphere ZnIn2S4 phase junction establishes a type-II band alignment with nanosized interfaces, which accounts for the efficient transfer and separation of photogenerated carriers. Meanwhile, the existing sulfur vacancies in the heterophase junctions can provide more electron trapping sites for proton reduction. Thus the optimal cubic quantum dot/hexagonal microsphere ZnIn2S4 heterophase junction exhibits exceptional visible light photocatalytic performance for H2 production (114.2 μmol h−1) without any cocatalyst, which is 7.3 and 3.2 times higher than that of cubic and hexagonal ZnIn2S4, respectively. This study provides a simple route for the synthesis of heterophase junction catalysts for photocatalytic applications.

Hierarchical Ag/Ag2S/CuS Ternary Heterostructure Composite as an Efficient Visible‐Light Photocatalyst

A hierarchical Ag/Ag2S/CuS ternary heterostructure composite has been obtained through cation exchange between as‐prepared CuS nanoflowers and AgNO3 (synthesized under solvothermal conditions) and subsequent in situ UV‐light reduction. The prepared CuS nanoflowers not only provide reactive sites for in situ ion exchange with Ag+ but also perform as clapboards to prevent the excess aggregation of Ag2S nanoparticles. After exposure to UV light, a uniform Ag/Ag2S/CuS ternary heterostructure composite was obtained. In the composite, both Ag and Ag2S are grown on the surface of CuS nanoflowers. The prepared ternary heterostructure composite exhibited a significant ability for the elimination of some hazardous pollutants under visible‐light irradiation, which is much higher than that of either CuS or Ag2S/CuS. Moreover, the resultant ternary composite possesses excellent stability.

Single-crystalline Bi19Br3S27 nanorods with an efficiently improved photocatalytic activity

Recently, there has been much interest in the design and development of affordable and highly efficient visible-light photocatalysts that can resolve the pivotal issues concerning environmental treatment. Herein, we present the synthesis and application of single-crystalline Bi19Br3S27 nanorods as highly efficient photocatalysts. The Bi19Br3S27 nanorods were prepared through a general and facile one-pot solvothermal method. The obtained Bi19Br3S27 nanorods were characterized using X-ray diffraction, transmission electron microscopy, field emission scanning electron microscopy, and X-ray photo-electron spectroscopy. The use of cetyltrimethylammonium bromide contributed to the formation of 1D nanorod-like superstructures. The visible light photocatalytic performance and stability of the Bi19Br3S27 nanorods outperformed that of the corresponding Bi2S3 material prepared without the introduction of bromine.