Highly Active Amino-Fullerene Derivative-Modified TiO2 for Enhancing Formaldehyde Degradation Efficiency under Solar-Light Irradiation

Formaldehyde (HCHO) is a ubiquitous indoor pollutant that seriously endangers human health. The removal of formaldehyde effectively at room temperature has always been a challenging problem. Here, a kind of amino-fullerene derivative (C60-EDA)-modified titanium dioxide (C60-EDA/TiO2) was prepared by one-step hydrothermal method, which could degrade the formaldehyde under solar light irradiation at room temperature with high efficiency and stability. Importantly, the introduction of C60-EDA not only increases the adsorption of the free formaldehyde molecules but also improves the utilization of sunlight and suppresses photoelectron-hole recombination. The experimental results indicated that the C60-EDA/TiO2 nanoparticles exhibit much higher formaldehyde removal efficiency than carboxyl-fullerene-modified TiO2, pristine TiO2 nanoparticles, and almost all other reported formaldehyde catalysts especially in the aspect of the quality of formaldehyde that is treated by catalyst with unit mass (mHCHO/mcatalyst = 40.85 mg/g), and the removal efficiency has kept more than 96% after 12 cycles. Finally, a potential formaldehyde degradation pathway was deduced based on the situ diffuse reflectance infrared Fourier transform spectrometry (DRIFTS) and reaction intermediates. This work provides some indications into the design and fabrication of the catalysts with excellent catalytic performances for HCHO removal at room temperature

IRSDT: A Framework for Infrared Small Target Tracking with Enhanced Detection

Currently, infrared small target detection and tracking under complex backgrounds remains challenging because of the low resolution of infrared images and the lack of shape and texture features in these small targets. This study proposes a framework for infrared vehicle small target detection and tracking, comprising three components: full-image object detection, cropped-image object detection and tracking, and object trajectory prediction. We designed a CNN-based real-time detection model with a high recall rate for the first component to detect potential object regions in the entire image. The KCF algorithm and the designed lightweight CNN-based target detection model, which parallelly lock on the target more precisely in the target potential area, were used in the second component. In the final component, we designed an optimized Kalman filter to estimate the target’s trajectory. We validated our method on a public dataset. The results show that the proposed real-time detection and tracking framework for infrared vehicle small targets could steadily track vehicle targets and adapt well in situations such as the temporary disappearance of targets and interference from other vehicles

Rational design of sulfur-containing composites for high-performance lithium-sulfur batteries

Sulfur has received considerable attention as a cathode material for lithium-sulfur (Li-S) batteries due to its high theoretical energy density (2567 W h kg(-1)), high earth abundance, and environmental benignity. However, the insulating nature of sulfur and the shuttle effect of soluble lithium polysulfides result in serious technical issues, such as low utilization rate of sulfur, reduced columbic efficiency, and poor cycling stability, which compromise the high theoretical performance of Li-S batteries. In the past years, various attempts have been made to achieve high specific capacity and reliable cycling stability of Li-S batteries. Incorporation of sulfur into functional host materials has been demonstrated to be effective to improve the electrochemical performance of sulfur-based cathodes via enhancing the electron and Li ion conductivities, immobilizing sulfur/lithium polysulfides in cathodes, and accommodating the volume changes in sulfur-based cathodes. Therefore, the rational design of sulfur-containing composites needs to be emphasized as key strategies to develop high-performance cathodes for Li-S batteries. In this perspective, after reviewing the achievements obtained in the design of sulfur-containing composites as cathodes for Li-S batteries, we propose the new issues that should be overcome to facilitate the practical application of Li-S batteries.

Covalent Confinement of Sulfur Copolymers onto Graphene Sheets Affords Ultrastable Lithium-Sulfur Batteries with Fast Cathode Kinetics

Lithium-sulfur (Li-S) batteries have received significant attention due to the high theoretical specific capacity of sulfur (1675 mA h g(-1)). However, the practical applications are often handicapped by sluggish electrochemical kinetics and the "shuttle effect" of electrochemical intermediate polysulfides. Herein, we propose an in-situ copolymerization strategy for covalently confining a sulfur-containing copolymer onto reduced graphene oxide (RGO) to overcome the aforementioned challenges. The copolymerization was performed by heating elemental sulfur and isopropenylphenyl-functionalized RGO to afford a sulfur-containing copolymer, that is, RGO-g-poly(S-r-IDBI), which is featured by a high sulfur content and uniform distribution of the poly(S-r-IDBI) on RGO sheets. The covalent confinement of poly(S-r-IDBI) onto RGO sheets not only enhances the Li+ diffusion coefficients by nearly 1 order of magnitude, but also improves the mechanical properties of the cathodes and suppresses the shuttle effect of polysulfides. As a result, the RGO-g-poly(S-r-IDBI) cathode exhibits an enhanced sulfur utilization rate (10% higher than that of an elemental sulfur cathode at 0.1C), an improved rate capacity (688 mA h g(-1) for the RGO-g-poly(S-r-IDBI) cathode vs 400 mA h g(-1) for an elemental sulfur cathode at 1C), and a high cycling stability (a capacity decay of 0.021% per cycle, less than one-tenth of that measured for an elemental sulfur cathode)