Wuhan University of Technology

About: Wuhan University of Technology is a education organization based out in Wuhan, China. It is known for research contribution in the topics: Microstructure & Catalysis. The organization has 40384 authors who have published 36724 publications receiving 575695 citations. The organization is also known as: WUT.

Convergence of conduction bands as a means of enhancing thermoelectric performance of n-type Mg2Si(1-x)Sn(x) solid solutions.

Abstract: Mg(2)Si and Mg(2)Sn are indirect band gap semiconductors with two low-lying conduction bands (the lower mass and higher mass bands) that have their respective band edges reversed in the two compounds. Consequently, for some composition x, Mg(2)Si(1-x)Sn(x) solid solutions must display a convergence in energy of the two conduction bands. Since Mg(2)Si(1-x)Sn(x) solid solutions are among the most prospective of the novel thermoelectric materials, we aim on exploring the influence of such a band convergence (valley degeneracy) on the Seebeck coefficient and thermoelectric properties in a series of Mg(2)Si(1-x)Sn(x) solid solutions uniformly doped with Sb. Transport measurements carried out from 4 to 800 K reveal a progressively increasing Seebeck coefficient that peaks at x=0.7. At this concentration the thermoelectric figure of merit ZT reaches exceptionally large values of 1.3 near 700 K. Our first principles calculations confirm that at the Sn content x≈0.7 the two conduction bands coincide in energy. We explain the high Seebeck coefficient and ZT values as originating from an enhanced density-of-states effective mass brought about by the increased valley degeneracy as the two conduction bands cross over. We corroborate the increase in the density-of-states effective mass by measurements of the low temperature specific heat. The research suggests that striving to achieve band degeneracy by means of compositional variations is an effective strategy for enhancing the thermoelectric properties of these materials.

Sulfur-doped g-C3N4 with enhanced photocatalytic CO2-reduction performance

Abstract: Graphitic carbon nitride (g-C 3 N 4 ) is the most stable phase of all carbon nitride allotropes under ambient conditions. In this study, sulfur-doped g-C 3 N 4 was fabricated by simply calcinating thiourea at 520 °C. Sulfur-doped g-C 3 N 4 (TCN) was found to absorb light up to 475 nm corresponding to a band gap of 2.63 eV, which was narrower than that of un-doped g-C 3 N 4 (MCN) with a band gap of 2.7 eV. First-principle calculations based on spin-polarized density functional theory were utilized to investigate the theoretical partial density of states of the TCN and MCN, indicating that the band gaps of TCN and MCN were the same, but impurities existed in the TCN sample. Consequently, photogenerated electrons could easily jump from the impurity state to the conduction band or from the valence band to the impurity state. Photocatalytic CO 2 reduction was further used to evaluate the photoactivity of samples, and the CH 3 OH yield using TCN and MCN were 1.12 and 0.81 μmol g −1 , respectively. PL spectrum analysis and transient photocurrent responses were also carried out to verify the suggested photocatalysis mechanism.

Hierarchical mnmoo 4 /Comoo 4 heterostructured nanowires with enhanced supercapacitor performance

Abstract: The construction of three-dimensional hierarchical heterostructures can lead to improved electrochemical properties. Mai et al. synthesize a three-dimensional multicomponent oxide, MnMoO4/CoMoO4, which is used to produce a supercapacitor with enhanced performance.

Water-Lubricated Intercalation in V 2 O 5 ·nH 2 O for High-Capacity and High-Rate Aqueous Rechargeable Zinc Batteries.

Abstract: Low-cost, environment-friendly aqueous Zn batteries have great potential for large-scale energy storage, but the intercalation of zinc ions in the cathode materials is challenging and complex. Herein, the critical role of structural H2O on Zn2+ intercalation into bilayer V2O5·nH2O is demonstrated. The results suggest that the H2O-solvated Zn2+ possesses largely reduced effective charge and thus reduced electrostatic interactions with the V2O5 framework, effectively promoting its diffusion. Benefited from the “lubricating” effect, the aqueous Zn battery shows a specific energy of ≈144 Wh kg−1 at 0.3 A g−1. Meanwhile, it can maintain an energy density of 90 Wh kg−1 at a high power density of 6.4 kW kg−1 (based on the cathode and 200% Zn anode), making it a promising candidate for high-performance, low-cost, safe, and environment-friendly energy-storage devices.