Crystal-Facet Engineering of Ferric Giniite by Using Ionic-Liquid Precursors and Their Enhanced Photocatalytic Performances under Visible-Light Irradiation

Crystal morphology control of synthetic giniite for enhanced photo-Fenton activity against the emerging pollutant metronidazole

Metronidazole (MNZ) is a recalcitrant antibiotic with toxic and carcinogenic effects in aquatic environments. In this work, Fe₅(PO₄)₄(OH)₃·2H₂O (giniite) particles were synthesised with three different alkaline cations (Li⁺, Na⁺ and K⁺) and used as Fenton catalysts for MNZ removal. It is shown that the addition of different cations during the hydrothermal synthesis process promote different morphologies from asterisk-like to flower-like and branches-like, maintaining the crystalline structure of pure giniite. The photo-Fenton activity of these particles was then evaluated through the degradation of MNZ under sunlight radiation for 9 h. The results indicate that the alkaline cation has a predominant role in the photo-Fenton efficiency, as demonstrated by the superior degradation efficiencies of Na@giniite particles (91.2% and 72.5% with giniite concentration of 0.2 g L^-1 and 0.07 g L^-1, respectively), related with its high surface area (10.7 m² g^-1). Thus, it is demonstrated the suitability of Na@giniite particles as Fenton catalyst for MNZ removal from water.

Solvothermal Synthesis of Three-Dimensional Hierarchical CuS Microspheres from a Cu-Based Ionic Liquid Precursor for High-Performance Asymmetric Supercapacitors

It is meaningful to exploit copper sulfide materials with desired structure as well as potential application due to their cheapness and low toxicity. A low-temperature and facile solvothermal method for preparing three-dimensional (3D) hierarchical covellite (CuS) microspheres from an ionic liquid precursor [Bmim]2Cu2Cl6 (Bmim = 1-butyl-3-methylimidazolium) is reported. The formation of CuS nanostructures was achieved by decomposition of intermediate complex Cu(Tu)3Cl (thiourea = Tu), which produced CuS microspheres with diameters of 2.5-4 μm assembled by nanosheets with thicknesses of 10-15 nm. The ionic liquid, as an "all-in-one" medium, played a key role for the fabrication and self-assembly of CuS nanosheets. The alkylimidazolium rings ([Bmim](+)) were found to adsorb onto the (001) facets of CuS crystals, which inhibited the crystal growth along the [001] direction, while the alkyl chain had influence on the assembly of CuS nanosheets. The CuS microspheres showed enhanced electrochemical performance and high stability for the application in supercapacitors due to intriguing structural design and large specific surface area. When this well-defined CuS electrode was assembled into an asymmetric supercapacitor (ASC) with an activated carbon (AC) electrode, the CuS//AC-ASC demonstrated good cycle performance (∼88% capacitance after 4000 cycles) and high energy density (15.06 W h kg(-1) at a power density of 392.9 W kg(-1)). This work provides new insights into the use of copper sulfide electrode materials for asymmetric supercapacitors and other electrochemical devices.

Ionic liquid-modulated preparation of hexagonal tungsten trioxide mesocrystals for lithium-ion batteries

Hexagonal (h-WO3) mesocrystals with biconical morphology were prepared by a straightforward ionic liquid-assisted hydrothermal route and investigated as anodic materials for lithium-ion batteries. Compared to the alternatives, the biconical tungsten trioxide mesocrystal exhibited excellent lithium insertion with good cyclability and rate capability, making it a promising candidate as the anode material for high-performance lithium-ion batteries.

Ionic liquid-assisted fabrication of copper hydroxyphosphate nanocrystals with exposed {100} facets for enhanced photocatalytic activity

Libethenite Cu2PO4OH nanocrystals with different morphologies were prepared by an ionic liquid-assisted hydrothermal route, and were further investigated as photocatalysts under visible-light irradiation. The Cu2PO4OH elongated truncated bipyramids exposing {100} facets exhibit superior photocatalytic activity compared to other particles, which can be attributed to the presence of 100% Cu5c atoms on {100} facets. It is highly expect this research can provide a useful fundamental understanding of shape-dependent photocatalytic performance of copper hydroxyphosphate.

Exposed facet and crystal phase tuning of hierarchical tungsten oxide nanostructures and their enhanced visible-light-driven photocatalytic performance

Tungsten oxide hierarchical nanostructures controllably assembled with one dimensional nanostructures which exhibit different exposed facets and crystal phases were synthesized via a facile hydrothermal reaction assisted by urea.

Architectures of tavorite LiFe(PO4)(OH)(0.5)F(0.5) hierarchical microspheres and their lithium storage properties

Tavorite LiFe(PO4)(OH)0.5F0.5 microspheres with different morphologies were prepared by a facile solvothermal route, and were further investigated as cathode materials for Li-ion batteries. We highly expect that this research can provide a useful fundamental understanding of the shape-dependent electrochemical performance of tavorite electrode materials.