Yi Liu,Yongjin Ma,Wenwen Liu,Yanyang Shang,Anquan Zhu,Pengfei Tan,Xiang Xiong,Jun Pan
As the highest energy facet of wurtzite CdS, (0 0 2) facet is well worth investigating toward the contribution in photocatalytic hydrogen (H 2 ) evolution. In this study, flower-like CdS with highly preferred (0 0 2) facet was fabricated through a low temperature mixed-solvothermal strategy. The mixted-solvent of diethylenetriamine (DETA) and ethyl alcohol (EtOH) was used to inhibit the growth of (1 0 0) and (1 0 1) facets. For comparison, porous flower-like, belt-like and net-like CdS samples with different preferred degrees of (0 0 2) facet were controllably synthesized by the addition of H 2 O in different proportions. The preferred orientation degrees of (0 0 2) facet were qualitative proved by the mathematical fitting of XRD patterns. As expected, the flower-like CdS exhibited the highest photocatalytic activity on H 2 evolution under visible light without any co-catalyst. Meanwhile, the photocatalytic H 2 production increased with the increasement of exposed (0 0 2) facet, which suggested that (0 0 2) facet of CdS played a critical role in improving the photocatalytic activity. Moreover, the growth mechanisms of CdS with various morphologies were investigated and proposed in detail.
We, herein, report the synthesis of umbrella-like CdS single crystal with exposed high-activity (002) facets first time by using a one-step hydrothermal method with cadmium acetate dihydrate (Cd(CH 3 COO) 2 ·2H 2 O) and ammonium thiocyanate (NH 4 SCN), and its possible growth mechanism was discussed. As a contrast, CdS nanoparticles with different morphologies were also synthesized. The morphology, composition and photocatalytic property of as-synthesized samples were determined by XRD, SEM, TEM, UV–Vis DRS, PL and photocurrent tests, respectively. The results show that umbrella-like CdS under UV (20 min) and visible light (80 min) irradiation, the removal rate of rhodamine B was as high as 99.1% and 99.3%, respectively. Moreover, even though the particle size of umbrella-like CdS particle is larger than as-synthesized CdS nanospheres, it still shows excellent photocatalytic degradation activity due to its exposed high-energy (002) facets. And its excellent application prospects are conceivable. The current work provides a new paradigm in material morphology design, especially in the construction of highly active surfaces for photocatalysis and photoelectric conversion.
Two-dimensional (2D) semiconducting nanomaterials have generated much interest both because of fundamental scientific interest and technological applications arising from the unique properties in two dimensions. However, the colloidal synthesis of 2D quaternary chalcogenide nanomaterials remains a great challenge owing to the lack of intrinsic driving force for its anisotropic growth. 2D wurtzite Cu 2 ZnSnS 4 nanosheets (CZTS-NS) with high-energy (002) facets have been obtained for the first time via a simple one-pot thermal decomposition method. The CZTS-NS exhibits superior photoelectrochemical activity as compared to zero-dimensional CZTS nanospheres and comparable performance to Pt counter electrode for dye sensitized solar cells. The improved catalytic activity can be attributed to additional reactive catalytic sites and higher catalytic reactivity in high-energy (002) facets of 2D CZTS-NS. This is in accordance with the density functional theory (DFT) calculations, which indicates that the (002) facets of wurtzite CZTS-NS possess higher surface energy and exhibits remarkable reducibility for I 3
− ions. The developed synthetic method and findings will be helpful for the design and synthesis of 2D semiconducting nanomaterials, especially eco-friendly copper chalcogenide nanocrystals for energy harvesting and photoelectric applications.
危险品化学品经营许可证（带存储）