Boosting the Faradaic Efficiency of Br-Mediated Photoelectrochemical Epoxidation by Local Acidity on α-FeO.

The redox mediated photoelectrochemical (PEC) or electrochemical (EC) alkene oxidation process is a promising method to produce high value-added epoxides. However, due to the competitive reaction of water oxidation and overoxidation of the mediator, the utilization of the electricity is far below the ideal value, where the loss of epoxidation's faradaic efficiency (FE) is ≈50%. In this study, a Br/HOBr-mediated method is developed to achieve a near-quantitative selectivity and ≈100% FE of styrene oxide on α-FeO, in which low concentration of Br as mediator and locally generated acidic micro-environment work together to produce the higher active HOBr species.

[Characteristics Analysis of the Surface Ozone Concentration of China in 2015].

Surface ozone concentration data from 189 cities in China in 2015 were processed by ArcGIS software in order to obtain the characteristics of the surface ozone concentration, such as time and space, topographical features, temperature, etc. The trend for surface ozone concentration was a decrease followed by an increase in China in 2015. The concentrations during the four seasons followed the order:summer > autumn > spring > winter, and the maximum appeared in July.