Fei-Xiang Ma

Monodisperse SnS2 Nanosheets for High-Performance Photocatalytic Hydrogen Generation

Graphene-like two-dimensional layered materials have attracted quite a lot of interest because of their sizable band gaps and potential applications. In this work, monodisperse tin disulfide (SnS2) nanosheets were successfully prepared by a simple solvothermal procedure in the presence of polyvinylpyrrolidone (PVP). Large PVP molecules absorbing on (001) facets of SnS2 would inhibit crystal growth along [001] orientation and protect the product from agglomeration. The obtained SnS2 nanosheets have diameters of ca. 0.8-1 μm and thicknesses of ca. 22 nm. Different experiment parameters were carried out to investigate the transformation of phase and morphology. The formation mechanism was proposed according to the time-dependent experiments. SnS2 nanosheets exhibit high photocatalytic H2 evolution activity of 1.06 mmol h(-1) g(-1) under simulated sunlight irradiation, much higher than that of SnS2 with different morphologies and P25-TiO2. Moreover, the as-obtained SnS2 nanosheets show excellent photoelectrochemical response performance in visible-light region.

Sulfurizing-Induced Hollowing of Co9S8 Microplates with Nanosheet Units for Highly Efficient Water Oxidation

Transition metal-based compounds are promising alternative nonprecious electrocatalysts for oxygen evolution to noble metals-based materials. Nanosheet-constructed hollow structures can efficiently promote the electrocatalystic activity, mainly because of their largely exposed active sites. Herein, hierarchical Co9S8 hollow microplates with nanosheet building units are fabricated via sulfurization and subsequent calcination of preformed Co-glycolate microplates. Benefiting from the advantages of a hollow structure, nanosheet units and high Co3+ content, Co9S8 hollow microplates exhibit remarkable catalytic property for oxygen evolution reaction (OER) with low overpotential of 278 mV to reach a current density of 10 mA cm-2, a low Tafel slope of 53 mV dec-1, and satisfied stability. This construction method of Co9S8 hierarchical hollow microplates composed of a nanosheet structure is an effective tactic for promoting OER performance of water splitting electrocatalysts.

Synthesis of self-stacked CuFe2O4–Fe2O3 porous nanosheets as a high performance Li-ion battery anode

Self-stacked CuFe2O4–Fe2O3 porous nanosheets were prepared via a facile polyol-mediated route followed by calcination. Because of its highly porous structures and good electrical and ion conductivity of the well-dispersed CuFe2O4 phase in the matrix, the hybrid material exhibits high specific capacity of 910 mA h g−1 at 0.5 C after 200 cycles, superior capacity retention (0.02% capacity loss per cycle) and good rate capability (417 mA h g−1 at 4 C) as a promising anode material for Li-ion batteries.

In situ soft-chemistry synthesis of β-Na0.33V2O5 nanorods as high-performance cathode for lithium-ion batteries

β-Na0.33V2O5 nanorods were prepared via a facile soft-chemistry strategy using Na+ intercalated (NH4)0.5V2O5 nanosheets as precursor. Based on X-ray diffraction, Fourier transform infrared spectra and scanning electron microscope analysis, the formation mechanism of β-Na0.33V2O5 nanorods is proposed, which involves cation co-intercalation and crystal structure slip as well as a phase transformation process induced by cation release. When used as cathode for lithium-ion batteries, β-Na0.33V2O5 nanorods calcined at 600 °C exhibited good stable cycling behaviour with high capacity retention of 81.3% after 50 cycles. Reversible discharge capacities of 237.8, 199.8, 183.5, 151.7 mA h g−1 and 110.5 mA h g−1 can be delivered at 30, 60, 150, 300 and 600 mA g−1, respectively. It is expected that the Na0.33V2O5 nanorods could be employed as a promising cathode material in rechargeable lithium-ion batteries.