No abstract

A variety of boehmite hollow core/shell and hollow microspheres with high adsorption affinity toward organic pollutants in water were prepared via a facile one-pot hydrothermal method using aluminum sulfate as a precursor and urea and sodium tartrate as precipitating and mediating agents, respectively. These microspheres were characterized by powder X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and nitrogen adsorption. In addition, the aforementioned microspheres were examined as potential adsorbents for Congo red and phenol from aqueous solutions. This study shows that the crystallinity, specific surface area, and pore structure of the resulting microspheres can be controlled by varying the concentration of sodium tartrate and reaction time. The reported experiments allowed us to propose the mechanism of formation of hollow core/shell and hollow microspheres, which involves sodium tartrate-mediated phase transformation, followed by a subsequent self-assembly process. Adsorption performance of the boehmite microspheres studied is gradually enhanced with increasing concentration of sodium tartrate. This enhancement is substantial in comparison to the performance of the microspheres prepared without sodium tartrate and commercial boehmite powders, and it is probably due to several factors, such as high specific surface area, large pore volume, proper crystallite size, and unique core/shell morphology and structure of the aforementioned microspheres. Especially, the hollow core/shell microspheres prepared at 0.01 M concentration of sodium tartrate exhibited the best adsorption performance, which can be easily regenerated without any great loss in the adsorption capacity. This study suggests that the degree of chemical self-transformation of amorphous particles into crystalline shells, followed by their self-assembly into complex higher-order architectures with desirable functionality, can be mediated by simple organic anions.

Electrochemical reduction of CO2 (CO2RR) into valuable hydrocarbons is appealing in alleviating the excessive CO2 level. We present the very first utilization of metallic bismuth–tin (Bi‐Sn) aerogel for CO2RR with selective HCOOH production. A non‐precious bimetallic aerogel of Bi‐Sn is readily prepared at ambient temperature, which exhibits 3D morphology with interconnected channels, abundant interfaces and a hydrophilic surface. Superior to Bi and Sn, the Bi‐Sn aerogel exposes more active sites and it has favorable mass transfer properties, which endow it with a high FEHCOOH of 93.9 %. Moreover, the Bi‐Sn aerogel achieves a FEHCOOH of ca. 90 % that was maintained for 10 h in a flow battery. In situ ATR‐FTIR measurements confirmed that the formation of *HCOO is the rate‐determining step toward formic acid generation. DFT demonstrated the coexistence of Bi and Sn optimized the energy barrier for the production of HCOOH, thereby improving the catalytic activity.

No abstract

An efficient and low‐cost electrocatalyst for reversible oxygen electrocatalysis is crucial for improving the performance of rechargeable metal−air batteries. Herein, a novel oxygen vacancy–rich 2D porous In‐doped CoO/CoP heterostructure (In‐CoO/CoP FNS) is designed and developed by a facile free radicals–induced strategy as an effective bifunctional electrocatalyst for rechargeable Zn–air batteries. The electron spin resonance and X‐ray absorption near edge spectroscopy provide clear evidence that abundant oxygen vacancies are formed in the interface of In‐CoO/CoP FNS. Owing to abundant oxygen vacancies, porous heterostructure, and multiple components, In‐CoO/CoP FNS exhibits excellent oxygen reduction reaction activity with a positive half‐wave potential of 0.81 V and superior oxygen evolution reaction activity with a low overpotential of 365 mV at 10 mA cm−2. Moreover, a home‐made Zn–air battery with In‐CoO/CoP FNS as an air cathode delivers a large power density of 139.4 mW cm−2, a high energy density of 938 Wh kgZn−1, and can be steadily cycled over 130 h at 10 mA cm−2, demonstrating great application potential in rechargeable metal–air batteries.

No abstract

A full set of flexible force field parameters for ZIF-8, applied for its gas adsorption and diffusion, has been presented.

A 'second generation' approach to the provision of Grid middleware is now emerging which is built on service-oriented architecture and web services standards and technologies. However, advanced Grid applications have significant demands that are not addressed by present-day web services platforms. As one prime example, current platforms do not support the rich diversity of communication 'interaction types' that are demanded by advanced applications (e.g. publish-subscribe, media streaming, peer-to-peer interaction). In the paper we describe the Gridkit middleware which augments the basic service-oriented architecture to address this particular deficiency. We particularly focus on the communications infrastructure support required to support multiple interaction types in a unified, principled and extensible manner-which we present in terms of the novel concept of pluggable overlay networks.