A 2H-MoS2/carbon cloth composite for high-performance all-solid-state supercapacitors derived from a molybdenum dithiocarbamate complex.

A molecular complex Mo2O2(µ-S)2(Et2dtc)2 (dtc = dithiocarbamate) is prepared and loaded onto carbon cloth (CC) through facile solvothermal treatment, followed by subsequent single-source pyrolysis. This results in a highly porous 2H-MoS2/CC composite with a sponge-like stacked lamellar morphology. Due to its high porosity and unique nano/microstructure, the MoS2/CC composite exhibits a specific capacitance of 550.0 F g-1 at 1 A g-1, outperforming some 1T-MoS2 based electrodes. The composite is further assembled into a symmetric all-solid-state supercapacitor, which can be operated stably at a wide potential window and shows a specific capacitance of 127.5 F g-1 at 1 A g-1. In addition, the device delivers a high energy density of 70.8 W h kg-1 at 1 kW kg-1, which still remains 15.0 W h kg-1 at 18.0 kW kg-1. 75% of the performance of the device can be retained after 8000 cycles. Such remarkable electrochemical performance is attributed to its novel nano/microstructures with a large surface area, convenient ion transport pathways, enhanced conductivity, and improved structural stability. Thus, this work demonstrates a highly promising dithiocarbamate-based single-precursor pyrolysis route towards the fabrication of metal sulfides/carbon composites for energy storage applications.

A Hybrid SAR/ISAR Approach for Refocusing Maritime Moving Targets with the GF-3 SAR Satellite.

Due to self-motion and sea waves, moving ships are typically defocused in synthetic aperture radar (SAR) images. To focus non-cooperative targets, the inverse SAR (ISAR) technique is commonly used with motion compensation. The hybrid SAR/ISAR approach allows a long coherent processing interval (CPI), in which SAR targets are processed with ISAR processing, and exploits the advantages of both SAR and ISAR to generate well-focused images of moving targets. In this paper, based on hybrid SAR/ISAR processing, we propose an improved rank-one phase estimation method (IROPE). By using an iterative two-step convergence approach in the IROPE, the proposed method achieves accurate phase error, maintains robustness to noise and performs well in estimating various phase errors. The performance of the proposed method is analyzed by comparing it with other focusing algorithms in terms of processing simulated data and real complex image data acquired by Gaofen-3 (GF-3) in spotlight mode. The results demonstrate the effectiveness of the proposed method.

The photocurrent response in the perovskite device based on coordination polymers: structure, topology, band gap and matched energy levels.

Using a rigid ditopic ligand, 4,5-di(4'-carboxylphenyl)benzene (H2L), three coordination polymers (CPs) formulated as MnL(H2O)2 (1), CdL(H2O) (2) and Mn2L2(DMF)3 (3) have been synthesized and structurally characterized by single-crystal X-ray diffraction. These three CPs display 2D architectures but with different topologies. The experimental data and DFT calculation indicate that CP 2 is a semiconductor, and its CB/VB energy levels match with those of the perovskite CH3NH3PbI3. A FTO/TiO2/CH3NH3PbI3/CP 2 device is fabricated and the CP-based device shows much larger photoresponse under visible light illumination (650 nm > λ > 350 nm, 100 mW cm-2) than the individual CP 2. At 0 V vs. AgCl/Ag, the largest photocurrent density yielded by the CP-based perovskite device is ca. 200 times that of CP 2, which is due to the matched energy levels of all the materials in the device, leading the photogenerated electron-hole pairs to be separated effectively. Meanwhile, the coverage of the insoluble CP on the surface of the perovskite CH3NH3PbI3 can improve the stability of the perovskite against water.