Hebei University

About: Hebei University is a education organization based out in Baoding, China. It is known for research contribution in the topics: Catalysis & Fuzzy logic. The organization has 16480 authors who have published 12558 publications receiving 129715 citations. The organization is also known as: HBU.

Rechargeable Aqueous Zn–V2O5 Battery with High Energy Density and Long Cycle Life

Abstract: We report an aqueous Zn–V2O5 battery chemistry employing commercial V2O5 cathode, Zn anode, and 3 M Zn(CF3SO3)2 electrolyte. We elucidate the Zn-storage mechanism in the V2O5 cathode to be that hydrated Zn2+ can reversibly (de)intercalate through the layered structure. The function of the co-intercalated H2O is revealed to be shielding the electrostatic interactions between Zn2+ and the host framework, accounting for the enhanced kinetics. In addition, the pristine bulk V2O5 gradually evolves into porous nanosheets upon cycling, providing more active sites for Zn2+ storage and thus rendering an initial capacity increase. As a consequence, a reversible capacity of 470 mAh g–1 at 0.2 A g–1 and a long-term cyclability with 91.1% capacity rentention over 4000 cycles at 5 A g–1 are achieved. The combination of the good battery performance, safety, scalable materials synthesis, and facile cell assembly indicates this aqueous Zn–V2O5 system is promising for stationary grid storage applications.

The parameterization reduction of soft sets and its applications

Abstract: In this paper, we focus our discussion on the parameterization reduction of soft sets and its applications. First we point out that the results of soft set reductions offered in [1] are incorrect. We also observe that the algorithms used to first compute the reduct-soft-set and then to compute the choice value to select the optimal objects for the decision problems in [1] are not reasonable and we illustrate this with an example. Finally, we propose a reasonable definition of parameterization reduction of soft sets and compare it with the concept of attributes reduction in rough sets theory. By using this new definition of parameterization reduction, we improve the application of a soft set in a decision making problem found in [1].

Materials chemistry for rechargeable zinc-ion batteries

Abstract: Rechargeable zinc-ion batteries (ZIBs) are promising for large scale energy storage and portable electronic applications due to their low cost, material abundance, high safety, acceptable energy density and environmental friendliness. This tutorial review presents an introduction to the fundamentals, challenges, recent advances and prospects related to ZIBs. Firstly, the intrinsic chemical properties, challenges and strategies of metallic zinc anodes are underscored. Then, the multiple types of cathode materials are classified and comparatively discussed in terms of their structural and electrochemical properties, issues and remedies. Specific attention is paid to the mechanistic understanding and structural transformation of cathode materials based on Zn ion-(de)intercalation chemistry. After that, the widely investigated electrolytes are elaborated by discussing their effect on Zn plating/stripping behaviours, reaction kinetics, electrode/electrolyte interface chemistries, and cell performances. Finally, the remaining challenges and future perspectives are outlined for the development of ZIBs.

A superior Ce-W-Ti mixed oxide catalyst for the selective catalytic reduction of NOx with NH3

Abstract: A superior Ce-W-Ti mixed oxide catalyst prepared by a facile homogeneous precipitation method showed excellent NH3-SCR activity and 100% N2 selectivity with broad operation temperature window and extremely high resistance to space velocity, which is a very promising catalyst for NOx abatement from diesel engine exhaust. The excellent catalytic performance is associated with the highly dispersed active Ce and promotive W species on TiO2. The introduction of W species could increase the amount of active sites, oxygen vacancies, and Bronsted and Lewis acid sites over the catalyst, which is also beneficial to improve the low temperature activity by facilitating “fast SCR” reaction and enhance both of the high temperature activity and N2 selectivity simultaneously by inhibiting the unselective oxidation of NH3 at high temperatures.

Facile assembled biochar-based nanocomposite with improved graphitization for efficient photocatalytic activity driven by visible light

Abstract: The preparation processes of efficient photocatalyst containing defect regulation and heterostructure construction are usually complicated and difficult to control at present, besides, the catalyst agglomeration in solution further limits their application. There is an urgent need for designing a potentially cheap, efficient, sustainable and easy-prepared nanocomposite to improve photocatalytic performance. In present study, the facile synthesized porous graphitic carbon with microtubular structure, high graphitization degree and abundant porosity demonstrates an outstanding advantage of excellent conductivity and facilitated mass transport. Such porous graphite biochar (PGBC) self-assembled with g-MoS2 nanosheets is observed by the optimized band gap, enhanced visible light harvesting, accelerated charge transfer and efficient photo-generated carrier’s separation. Considering the favorable specific surface area and pore distribution of PGBC for avoiding nanosheet agglomeration, the as-prepared composites display quite high efficiency for tetracycline hydrochloride (TC) removal based on the synergistic action of the desirable absorption and photocatalytic capability. Mechanism exploration indicates that surface adsorption is mainly dominated by electrostatic interaction, hydrogen bonding, π-π stacking and pore-filling, and hole (h+) and hydroxyl radical (·OH) are the predominant active species responsible for TC degradation. Furthermore, the nanocomposites possess advisable stability performance for TC removal in contaminated river water, further providing an underlying insight for establishing high-efficient and easy-prepared photocatalysts in practical contaminated water remediation.