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Potassium-ion batteries (PIBs) are promising next-generation energy storage candidates due to abundant resources and low cost. Sb-based materials with high theoretical capacity (660 mAh·g−1) and low working potential are considered as promising anode for PIBs. The remaining challenge is poor stability and slow kinetics. In this work, FeSb@N-doped carbon quantum dots anchored in three-dimensional (3D) porous N-doped carbon (FeSb@C/N⊂3DC/N), a Sb-based material with a particular structure, is designed and constructed by a green salt-template method. As an anode for PIBs, it exhibits extraordinarily high-rate and long-cycle stability (a capacity of 245 mAh·g−1 at 3,080 mA·g−1 after 1,000 cycles). The pseudocapacitance contribution (83%) is demonstrated as the origin of high-rate performance of the FeSb@C/N⊂3DC/N electrode. Furthermore, the potassium storage mechanism in the electrode is systematically investigated through ex-situ characterization techniques including ex-situ transmission electron microscopy (TEM) and X-ray photoelectron spectroscopy (XPS). Overall, this study could provide a useful guidance for future design of high-performance electrode materials for PIBs.

In TiO2 both advantages (stability and low cost) and disadvantages (large bandgap) coexist, so how to optimize a bare TiO2 electrode is a continuous hot topic for the construction of suitable photoelectrochemical (PEC) devices based on TiO2 for water splitting. This paper reports a facile and simple fabrication of a TiO2/RGO/C3N4 photoelectrode for PEC splitting of water. Its heterostructure configuration has been characterized and confirmed by XRD, Raman spectroscopy, XPS, TEM and STEM. The introduction of both RGO and C3N4 film onto the surface of TiO2 is mainly due to the fact that C3N4 has a strong photoelectric ability to respond to visible light and RGO plays an important role in the fast transfer of photogenerated charges across interfaces. Photocurrent and monochromatic incident photon-to-photocurrent efficiency (IPCE) of the titled heterostructure have been obviously improved, and the IPCE value (0.5 V vs. AgCl/Ag) of TiO2/RGO/C3N4 was estimated to be up to 28% at a wavelength of 400 nm.

This paper presents a facile one-step approach for the syntheses of MoS2/GC (GC = graphitic carbon) with sodium alginate as the biomass carbon source. The MoS2/GC composites showed enhanced photocatalytic activity for degradation of methylene blue under visible light irradiation. The MoS2/GC (2 : 1) composite shows the best performance and 99.2% methylene blue can be removed in 100 minutes. GC plays an important role in the fast separation and transfer of photogenerated charges across interfaces. The activity and stability performances suggest that the MoS2/GC composite has great potential for practical industrial wastewater treatment.

This study reports a novel Au@CdS/RGO/TiO2 heterostructure as a photoelectrode for photoelectrochemical (PEC) hydrogen generation via water splitting. The unique heterostructures of the Au@CdS/RGO/TiO2 photoelectrode were confirmed by scanning electron microscopy (SEM), transmission electron microscopy (TEM), Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). Au@CdS nanoparticles with a core–shell structure were introduced into the TiO2 photoelectrode for the first time, and the Au@CdS nanoparticles could endow the TiO2 photoelectrode with both visible light response ability and the plasmonic property. Moreover, the RGO thin film sandwiched between TiO2 nanorod and Au@CdS core–shell nanoparticles played an important role in the fast transport of photogenerated charges, due to its excellent electrical conductivity. Clear enhancements of photocurrent and monochromatic incident photon-to-photocurrent efficiency were observed, resulting from the synergistic effect between Au@CdS core–shell nanoparticles and the RGO thin film. More importantly, Au@CdS/RGO/TiO2 photoelectrode achieved a considerable hydrogen evolution rate (4.821 mmol h−1 m−2) under full spectrum illumination (47 mW cm−2).

International audience; MoS2, a kind of two-dimensional material with unique performances, has been widely used in many fields. However, an in-depth understanding of its toxicity is still needed, let alone its effects on the environmental microorganism. Herein, we used different methods, including metabolomics technology, to investigate the influence of bulk MoS2 (BMS) on yeast cells. The results indicated that high concentrations (1 mg/L and more) of BMS could destroy cell membrane and induce ROS accumulation. When exposed to a low concentration of BMS (0.1 mg/L), the intracellular concentrations of many metabolites (e.g., fumaric acid, lysine) increased. However, most of their concentrations descended significantly as the yeast cells were treated with BMS of high concentrations (1 mg/L and more). Metabolomics analysis further revealed that exposure to high concentrations of BMS could significantly affect some metabolic pathways such as amino acid and citrate cycle related metabolism. These findings will be beneficial for MoS2 toxicity assessment and further applications.

In this work, we successfully fabricated a novel stable photoanode, which was built from ZnO nanosheets in situ decorated with carbon film (ZnO/carbon). The thin carbon film, as a passivation layer, can not only improve the photoelectrochemical (PEC) performance, but also significantly depress the photocorrosion of ZnO. Compared with bare ZnO photoanode, the photocurrent density of ZnO/carbon has been increased nearly five times, and its IPCE value can be up to 27% (0.5[Formula: see text]V versus Ag/AgCl). Moreover, the XRD, SEM and TEM data further demonstrate the crystal and microscopic structure of ZnO/carbon in detail.