ABSTRACT
Mo2C demonstrates excellent performance in catalysis, and it has been found to possess excellent hydrogen evolution reaction (HER) catalytic activity and highly efficient nitrogen fixation. The catalytic activity of Mo2C is greatly influenced and restricted by the preparation method. Sintering and carbon deposition, which affect the catalytic activity of Mo2C, are inevitable in the traditional vapor-solid-solid (VSS) process. In this study, we report the controllable synthesis of α-Mo2C micron flowers by adjusting the growth temperature via a vapor-liquid-solid (VLS) process. The density of the Mo2C micron flowers is closely related to the concentration of Na2MoO4 aqueous solution. The as-grown Mo2C micron flowers dispersed with Pt are validated to be an enhanced collaborative electrocatalyst for HER against Pt/VSS-Mo2C.
ABSTRACT
Micro-nanoplastics have become a new type of pollutant worldwide and have attracted widespread attention for their potential toxicity. However, the toxicity of polystyrene nanoplastics (PS-NPs) under continuous exposure of multi-generations is still unclear. In the present study, Drosophila melanogaster was selected as an in vivo biological model to investigate the reproductive toxicity and underlying mechanism induced by PS-NPs (100 nm; 1, 10, 50, and 100 mg L-1) after continuous exposure of five generations. The results showed that PS-NPs accumulated in the crop, gut and ovaries after 5 d of exposure. It was also observed that the number of egg production and eclosion rate decreased significantly (P < 0.05) accompanied by delayed development during continuous exposure PS-NPs of multi-generations. Further analysis revealed that the degree of apoptosis and necrosis of oocytes in the F5 generation increased with the increasing exposure dose. To elucidate the underlying toxicity mechanism mediated by PS-NPs, transcriptomic analysis was performed on the ovaries of the F5 generation. The results showed that there were 102 and 208 differentially expressed genes (DEGs) in the 1 mg L-1 and 100 mg L-1 PS-NPs treatment groups, respectively, compared with the control group. The transcriptome analysis further detected the KEGG pathway with significant enrichment of DEGs, revealing obvious reproductive toxicity at the molecular level. In conclusion, this research not only highlighted the negative physiological effects of multi-generational exposure to PS-NPs on Drosophila melanogaster, but also explored potential mechanisms by transcriptomic analysis to better understand reproductive toxicity induced by multi-generational exposure.
