CoS nanoparticles and CoS/reduced graphene oxide (CoS/rGO) nanohybrids were fabricated by a unique single-mode microwave-assisted hydrothermal method. The microwave absorption properties of CoS/rGO composites with different rGO proportions were investigated. Morphology analysis indicated that the CoS nanoparticles were uniformly embedded into rGO without aggregation. The complex permittivity of CoS/rGO nanohybrids could be artificially tuned with the rGO proportions. For the CoS/rGO 1:2 composite, the minimum reflection loss (RL) of -56.9 dB was achieved at 10.9 GHz for the thickness of 2.2 mm; meanwhile, the RL exceeding -10 dB were obtained in the frequency range of 9.1-13.2 GHz. Compared with other rGO-based materials, CoS/rGO composite exhibited superior microwave absorption ability at a rather thin thickness and it has great potential to be used as a high-efficiency and tunable microwave absorber.

Graphene nanosheets (GNSs) were prepared by an efficient liquid-phase exfoliation method, and then the NiCo/GNS nanohybrids were fabricated using the single-mode microwave-assisted hydrothermal technique. The NiCo/GNS composites with different GNS proportions were investigated as microwave absorbers. Morphology investigation suggested that NiCo nanocrystals were uniformly anchored on the GNS without aggregation. The electromagnetic parameters of NiCo/GNS nanohybrids could be artificially adjusted by changing the GNS proportion, which led to an exceptional microwave-absorbing performance. A reflection loss (RL) exceeding -20 dB was obtained in the frequency range of 5.3-16.4 GHz for the absorber thicknesses of 1.2-3.2 mm, while an optimal RL of -30 dB was achieved at 11.7 GHz for a thickness of 1.6 mm. The enhanced microwave-absorbing performance indicated that the NiCo/10 wt % GNS composite has great potential for use as an excellent microwave absorber.

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In this paper, we report CoP nanowires supported on carbon cloth (CC) (CoP/CC) as a bifunctional electrode for hydrogen evolution reaction (HER) and supercapacitor. CoP/CC possess an excellent electrocatalytic performance for HER, with a Tafel slope of 56 mV/dec and a low overpotential of 68 mV to achieve a current density of 10 mA cm −2 . Remarkably, the bifunctional CoP/CC used as electrode for supercapacitor exhibit a higher specific capacitance of 674 F g −1 at a scan rate of 5 mV s −1 and maintains long-life cycling stability, retaining 86% of the initial capacitance after 10,000 cycles. CoP/CC will be a promising candidate as electrode for HER and supercapacitor.