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 & Photocatalysis. The organization has 40384 authors who have published 36724 publications receiving 575695 citations. The organization is also known as: WUT.

Lattice Softening Significantly Reduces Thermal Conductivity and Leads to High Thermoelectric Efficiency.

Abstract: The influence of micro/nanostructure on thermal conductivity is a topic of great scientific interest, particularly to thermoelectrics. The current understanding is that structural defects decrease thermal conductivity through phonon scattering where the phonon dispersion and speed of sound are assumed to remain constant. Experimental work on a PbTe model system is presented, which shows that the speed of sound linearly decreases with increased internal strain. This softening of the materials lattice completely accounts for the reduction in lattice thermal conductivity, without the introduction of additional phonon scattering mechanisms. Additionally, it is shown that a major contribution to the improvement in the thermoelectric figure of merit (zT > 2) of high-efficiency Na-doped PbTe can be attributed to lattice softening. While inhomogeneous internal strain fields are known to introduce phonon scattering centers, this study demonstrates that internal strain can modify phonon propagation speed as well. This presents new avenues to control lattice thermal conductivity, beyond phonon scattering. In practice, many engineering materials will exhibit both softening and scattering effects, as is shown in silicon. This work shines new light on studies of thermal conductivity in fields of energy materials, microelectronics, and nanoscale heat transfer.

Promoting the interfacial H2-evolution reaction of metallic Ag by Ag2S cocatalyst: A case study of TiO2/Ag-Ag2S photocatalyst

Abstract: Metallic Ag has been widely demonstrated to be an excellent oxygen-reduction cocatalyst to significantly improve the photocatalytic decomposition performance of various organic substances. However, as a H2-evolution cocatalyst, the improved photocatalytic performance by metallic Ag is quite limited due to its low H2-evolution rate. In this study, for the well-known TiO2/Ag photocatalyst, Ag2S as the efficient H2-evolution active sites was selectively loaded on the metallic Ag surface to greatly promote the interfacial H2-evolution reaction rate. In this case, the TiO2/Ag-Ag2S sample was synthesized by a two-step process including the simple photoinduced deposition of metallic Ag on the TiO2 surface and the following in situ sulfidation of partial Ag into Ag2S. Photocatalytic experimental results indicated that the TiO2/Ag-Ag2S(40uL) photocatalysts clearly exhibited a significantly higher UV-light photocatalytic H2-evolution activity (119.11 μmol h−1) than the pure TiO2, TiO2/Ag and TiO2/Ag2S photocatalysts by a factor of 51.8, 3.9 and 3.6 times, respectively. On the basis of the present results, a synergistic effect of dual electron-cocatalyst (metallic Ag and Ag2S) is proposed for the improved photocatalytic H2-evolution activity, namely, the Ag-nanoparticle cocatalyst can steadily capture and transfer the photogenerated electrons from TiO2 surface, while the Ag2S cocatalyst is considered to be the interfacial active sites to promote the rapid H2-evolution reaction. This research may provide new strategies for the development of highly efficient photocatalytic materials used in various fields.

Environmental Kuznets Curve and Pakistan: An Empirical Analysis

Abstract: In this study, the Environmental Kuznets Curve (EKC) is hypothesized to investigate the relationship between CO2 emission, economic growth, energy consumption, trade liberalization and population density in Pakistan with yearly data from 1971 to 2008. The cointegration analysis using Auto Regressive Distributed Lag (ARDL) bounds testing approach is incorporated. The results support the hypothesis both in short-run and long-run and inverted U-shaped relationship is found between CO2 emission and growth. Interestingly we found trade support the environment positively and population contributes to environmental degradation in Pakistan. The energy consumption and growth are the major explanatory variables which contribute to environmental pollution in Pakistan. Moreover, the time series data analysis is used and the stability of variables in estimated model is also assessed.