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Exfoliated graphite (EG) blocks are prepared from the ultra-large flakes of graphite by intercalation of H 2 SO 4 using a large amount of H 2 O 2 at 5 °C and following exfoliation at 30 °C. By the exfoliation in a closed container, EG blocks with the bulk densities of 0.008-0.024 g/cm 3 are successfully prepared. The resultant EG blocks have high sorption capacities for a diesel oil, up to 45 g/g. The EG blocks after oil sorption can get certain resilience for compressive stress with high reproducibility by compression-release cycles, which allows us to apply the compression-releasing for the oil sorption-desorption of the EG blocks. The performance of cyclic oil sorption-desorption by compression-releasing of EG block is compared with those of filtration and distillation. Since the resultant EG blocks had sufficient mechanical strength, the continuous removal of oil floating on the water surface is possible, exporting oil through a catheter inserted into the block and connected to a peristaltic pump. By warming up by Joule heating, even a crude oil having high viscosity can be continuously removed from the water with sufficient rate. The high hydrophobicity and lipophilicity of EG make selective removal of oil from water possible., (Copyright © 2021. Published by Elsevier B.V.)

Waterborne epoxy (WEP) coatings with enhanced corrosion resistance were prepared using graphene oxide (GO) that was obtained from kish graphite, and amino-functionalized graphene oxide (AGO) was modified by 2-aminomalonamide. The structural characteristics of the GO and AGO were analyzed using X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). And the anti-corrosive performance of waterborne epoxy-cased composite coatings with different addition amounts of AGO was investigated using electrochemical measurements, pull-off adhesion tests, and salt spray tests. The results indicate that AGO15/WEP with 0.15 wt.% of AGO has the best anti-corrosive performance, and the lowest frequency impedance modulus increased from 1.03 × 108 to 1.63 × 1010 ohm·cm−2 compared to that of WEP. Furthermore, AGO15/WEP also demonstrates the minimal corrosion products or bubbles in the salt spray test for 200 h, affirming its exceptional long-term corrosion protection capability. [ABSTRACT FROM AUTHOR]

[Display omitted] · C@p-Si/ESG composite anode material with "sandwich" structure was obtained. · Electrostatic modification enhances the stability of the loading of nano-silicon. · The "sandwich" structure alleviates the volume expansion effect of silicon. · SEI film reduces the occurrence of side reactions. · C@p-Si/ESG exhibits an excellent long-term cycle stability. Silicon-based materials have a high theoretical specific capacity and a low discharge potential, whereas the significant capacity fading owing to weak conductivity and volume exfoliation effect. The co-utilization of silicon and graphite has become a feasible method for realizing high-performance lithium-ion batteries (LIBs). Herein, the C@p-Si/ESG composite anode material with "sandwich" structure was obtained by electrostatic assembly of mildly-exfoliated graphite and electrostatic modified nano silicon, and subsequent coated with amorphous carbon on the surface of the material. The carbon coating and the mildly-exfoliated graphite form a buffer space, which alleviates the volume expansion effect of silicon in the process of lithium alloying. In addition, the SEI film is generated outside the carbon layer, reducing the consumption of the electrolyte and the occurrence of side reactions. C@p-Si/ESG exhibits a high charge–discharge rate and an excellent long-term cycle stability. [ABSTRACT FROM AUTHOR]

SnO 2 -based materials have been widely studied because of their high theoretical specific capacity, whereas the significant capacity fading is caused by the low reversibility conversion reaction and volume expansion. In this work, we proposed a precipitation-polymerization-thermal treatment method to construct SnO 2 -based composites by precipitation reaction of SnCl 2 with moderately exfoliated graphite (MEG), subsequent dopamine (DA) polymerization and thermal treatment to fulfill nitrogen-doped-carbon (NC) coating and part transformation of SnO 2 to Sn. Finally, we can obtain the SnO 2 /Sn/MEG@NC composites for high-performance lithium-ion batteries (LIBs). The conductive NC coating and MEG matrix have the function in facilitating electron transportation, restraining aggregation, and adapting to volume change of SnO 2 /Sn particles. Micron-sized Sn is broken during the cycles and forms nano-sized distribution with ultrafine SnO 2 , the hybrid SnO 2 /Sn allows highly effective reversibility conversion and alloying/de-alloying reactions upon cycles. As a result, the SnO 2 /Sn/MEG@NC electrode exhibits outstanding cycling stability (837.2 mAh g−1 at 1 A g−1 after 800 cycles), displaying outstanding performance for being LIBs. [ABSTRACT FROM AUTHOR]