Shanghai University

About: Shanghai University is a education organization based out in Shanghai, Shanghai, China. It is known for research contribution in the topics: Microstructure & Catalysis. The organization has 59583 authors who have published 56840 publications receiving 753549 citations. The organization is also known as: Shànghǎi Dàxué.

Valence band engineering and thermoelectric performance optimization in SnTe by Mn-alloying via a zone-melting method

Abstract: Tin telluride (SnTe) has recently attracted lots of interest due to its potential thermoelectric application as a lead-free rock-salt analogue of PbTe. However, pristine SnTe samples have high hole concentration due to the presence of intrinsic Sn vacancies, and shows a low Seebeck coefficient and high electrical thermal conductivity, resulting in poor thermoelectric performance. In this report, we show that zone-melted SnTe systems with additional Mn (1–7 mol%) can control the hole concentration by reducing the Sn vacancies, and modulate the electronic band structure by increasing the band gap and decreasing the energy separation between the light and heavy hole valence bands. Therefore, alloying with additional Mn enhances the contribution of the heavy hole valence band and significantly improves the Seebeck coefficient in SnMnxTe with the highest value of ∼270 μV K−1. A record power factor of 31.9 μW cm−1 K−2 has been obtained at 820 K. The maximum thermoelectric figure of merit ZT of ∼1.25 is found at 920 K for the high quality crystalline ingot of p-type SnMn0.07Te.

Promotional effects of zirconium doped CeVO4 for the low-temperature selective catalytic reduction of NOx with NH3

Abstract: In this work, we developed a novel zirconium doped CeVO 4 to form Ce 1− x Zr x VO 4 ( x = 0.05, 0.10, 0.15, 0.20, 0.30, 0.50, 0.70, 0.80) solid solution as a low-temperature catalyst for the selective catalytic reduction (SCR) of NO x with NH 3 . The optimized catalysts showed excellent performance at low temperature. The light-off temperature (the temperature at which the conversion of NO reaches 50%) was down to about 125 °C, while the temperature window (the NO conversion is above 80%) ranged from 150 to 375 °C. The selectivity was kept close to 100% during the whole temperature range. Furthermore, the catalysts also exhibited good H 2 O/SO 2 durability and fascinating performance at high gas hourly space velocity of 400,000 h −1 . Hydrogen temperature-programmed reduction, X-ray photoelectron spectroscopy, ammonia and nitrogen oxides temperature-programmed desorption and in-situ diffuse reflectance infrared Fourier transform experiments were performed to study the influence of Zr doping on the SCR performance. It was found that the introduction of Zr in CeVO 4 with a proper amount could significantly increase the surface area, oxidative ability, active oxygen species and especially surface acid sites of the catalysts, which were beneficial to the promotion of SCR performance.

Morphological Effect of Graphene Nanosheets on Ultrathin CoS Nanosheets and Their Applications for High-Performance Li-Ion Batteries and Photocatalysis

Abstract: A unique CoS-graphene sheet-on-sheet nanocomposite has been successfully prepared by anchoring CoS nanosheets on the surface of graphene nanosheets (GNS) with the assistance of the structure-directing agent of ethylenediamine. The shape and size of the introduced CoS nanosheets can be further adjusted by varying the amount of GNS. The unprecedented sheet-like CoS structure is believed to be matched well with GNS basically due to their similar two-dimensional structure with maximum contact areas between two components. The strong interaction between CoS and the underlying highly conductive graphene can facilitate fast electron and ion transport and improve structure stability of the composite. The composite with 26.2% GNS displays excellent electrochemical performance when evaluated as an anode for rechargeable lithium-ion battery. A larger-than-theoretical reversible capacity of 898 mAh/g can be delivered after 80 cycles at 0.1 C along with excellent high-rate cycling performance. The CoS-graphene sheet-o...