RESUMEN
Under the limitation of the carrier yield and mobility of semiconductor photocatalysts and the reaction domain, it seems that the photocatalytic efficiency cannot be greatly improved. Here, an efficient contact-electro-catalysis (CEC) system based on droplet triboelectric nanogenerator (TENG) is developed. Instead of using traditional semiconductor catalysts, the electric charge transferred during the electrification process of the contact between water droplets and polytetrafluoroethylene (PTFE) is used to participate in catalysis, and the output electrical signal can also monitor the degree of catalysis. The important role of light in the circulation of this CEC system is studied and discussed for the first time. It is proved that the contact electrification at the liquid-solid interface is accompanied by the generation of a large number of strong oxidizing radicals. The efficient transport of charge carriers driven by mechanical force and the active oxygen species distributed in the whole domain greatly improve the degradation rate of dyes. The experimental data show that the degradation efficiency of crystal violet (CV) reaches 90% within 38 s, and the rate constant k is as high as 3.7 min-1. This is a breakthrough in the field of catalysis.
RESUMEN
OBJECTIVE: To study the medicinal plant resources and their diversity in Kangle County, Gansu Province, and to provide scientific basis on utilization and protection of the medicinal plant resources of the county. METHODS: By field survey, sample collection, taxonomic identification and data verification methods. RESULTS: There were 258 species, 65 families in existing medicinal plants, of which 43 species, 39 genera and 24 families were national protection medicinal plants. Dominant families were mainly Asteraceae and Rosaceae. In this area,the plants used whole herbs and roots ( or rhizomes) as medicinal materials represented 40.31% and 25.19% respectively, and antipyretic and rheumatism medicine accounted for 28.68% and 12.79% respectively. 12 medicinal plants were cultivated and the cultivated area was 3,000 hectares. CONCLUSION: However, the reserves of most medicinal plants are less enough and the resources are diminishing increasingly in recent years. So we should accelerate the research progress as well as developing and utilizing rationally on the premise of protection.