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[Display omitted] People have been focusing on how to improve the specific capacity and cycling stability of lithium-sulfur batteries at room temperature, however, on some special occasions such as cold cities and aerospace fields, the operating temperature is low, which dramatically hinders the performance of batteries. Here, we report an iron carbide (Fe 3 C)/rGO composite as electrode host, the Fe 3 C nanoparticles in the composite have strong adsorption and high catalytic ability for polysulfide. The rGO makes the distribution of Fe 3 C nanoparticles more disperse, and this specific structure makes the deposition of Li 2 S more uniform. Therefore, it realizes the rapid transformation and high performance of lithium-sulfur batteries at both room and low temperatures. At room temperature, after 100 cycles at 1C current density, the reversible specific capacity of the battery can be stabilized at 889 ± 7.1 mAh/g. Even at −40 °C, in the first cycle battery still emits 542.9 ± 3.7 mAh/g specific capacity. This broadens the operating temperature for lithium-sulfur batteries and also provides a new idea for the selection of host materials for sulfur in low-temperature lithium-sulfur batteries. [ABSTRACT FROM AUTHOR]

• The formation of Co-N bond in hybrid catalyst can effectively enhance interfacial charge transfer. • Enhanced oxygen catalytic activity using NCNTs/Ni offers excellent electrical conductivity. • The CoS x /NCNTs/Ni exhibits outstanding ORR/OER performance and realizes the potential for application on zinc-air batteries. The slow kinetics of the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) remain the primary problem impeding the commercialization of zinc-air batteries (ZABs). Herein, we demonstrate a hybrid composite consisting of multivalent CoS x nanoparticles and nitrogen-doped carbon nanotubes catalytically active-nickel (NCNTs/Ni) as an advanced ORR/OER electrocatalyst with excellent electrocatalytic activity. The Co-N bonds in the hybrid catalyst effectively enhance interfacial charge transfer, resulting in synergetic effects for enhanced oxygen electrochemistry. The optimized hybrid, CoS x /NCNTs/Ni-2, affords excellent performance in an alkaline ZAB, achieving a high-power density of 131 mW cm−2, and the voltage gap remained at only 0.87 V after 200 h of continuous charge–discharge at 5 mA cm−2. This study provides a facile strategy for the construction of bifunctional hybrids with non-precious metals for potential application in ZABs and other sustainable energy conversion devices. [ABSTRACT FROM AUTHOR]

Abstract In this study, we designed three turbulence promoters using three-dimensional (3D) printing technology for cross-flow microfiltration. Designing turbulence promoters with optimal geometry for microfiltration systems remains a key challenge. The effects of the operating conditions, such as cross-flow velocity, transmembrane pressure and geometry of the turbulence promoter on the filtration flux and cake properties were investigated. The distribution of the fluid velocity was examined using computational fluid dynamics (CFD). For normal microfiltration tests without promoters, the filtration flux merely increased by 10% when the cross-flow velocity increased from 0.1 to 0.5 m/s under a transmembrane pressure of 20 kPa. Therefore, the turbulence promoters were individually added into the channel of the microfiltration device to induce vortices in the flow stream and increase cross-flow velocity. Three turbulence promoters with different configurations (circular, diamond and elliptic) were made with a 3D printer. The elliptic type of promoter with a hydraulic angle of 90° displays the flux enhancement by approximately 30–64% under a transmembrane pressure of 20 kPa compared to the normal type of microfiltration, whereas the diamond type of promoter with a hydraulic angle of 60° shows a lower flux enhancement by approximately 7–16% under the same transmembrane pressure. Overall, adding the turbulence promoter to the microfiltration module shows a great potential to significantly mitigate membrane fouling and enhance filtration flux in cross-flow microfiltration. Graphical abstract fx1 Highlights • Three types of turbulence promoters were designed by using 3D printing technology. • Velocity distributions were examined by using computational fluid dynamics (CFD). • Elliptic type of promoters display a flux enhancement by approximately 30–64%. [ABSTRACT FROM AUTHOR]

Laser annealing of Pb(Zr 0.52 Ti 0.48 )O 3 (PZT) thin films (0.6 μm) prepared by metal-organic decomposition (MOD) process on Pt/SiO 2 /Si substrates were investigated. The annealing of the films is done in two steps; initially the films were annealed at low temperatures (550°C) using conventional furnace and rapid thermal annealing techniques. The films were finally laser annealed at room temperature using KrF excimer laser (248 nm). The RTA processed films, which already contain small proportion of perovskite phase, crystallized into the PZT perovskite structure after laser annealing process. The laser annealing duration increased the grain size of the PZT films. In contrast, the conventionally annealed films containing only pyrochlore phase cannot be converted into perovskite structure by the same laser annealing process. On the other hand, in-situ laser annealing of PZT films, which was heated to 400°C, can directly convert the amorphous to perovskite, which markedly increases the crystallization kinetics. [ABSTRACT FROM AUTHOR]