In the past decade, there have been exciting developments in the field of lithium ion batteries as energy storage devices, resulting in the application of lithium ion batteries in areas ranging from small portable electric devices to large power systems such as hybrid electric vehicles. However, the maximum energy density of current lithium ion batteries having topatactic chemistry is not sufficient to meet the demands of new markets in such areas as electric vehicles. Therefore, new electrochemical systems with higher energy densities are being sought, and metal‐air batteries with conversion chemistry are considered a promising candidate. More recently, promising electrochemical performance has driven much research interest in Li‐air and Zn‐air batteries. This review provides an overview of the fundamentals and recent progress in the area of Li‐air and Zn‐air batteries, with the aim of providing a better understanding of the new electrochemical systems.

Cleaning Solid Oxide Fuel Cells: Solid oxide fuel cells, which operate between 500° and 1000°C, transport oxygen through a ceramic material. At these temperatures, metals that catalyze hydrocarbon reforming reactions can also be incorporated so that conventional fuels such as methane can power the cell. One problem, however, has been rapid deactivation by sulfur impurities and carbon buildup. Yang et al. (p. 126 ; see the Perspective by Selman ) report that doping of a barium zirconate-cerate with the rare-earths Y and Yb creates a material that transports both protons and oxygen ions at 750°C. This material, when used with nickel at the fuel cell anode, resists deactivation even when traces of hydrogen sulfide are present, apparently through enhanced ability to supply or remove water during surface reactions.

Visible light-responsive photocatalytic technology holds great potential in water treatment to enhance purification efficiency, as well as to augment water supply through the safe usage of unconventional water sources. This review summarizes the recent progress in the design and fabrication of visible light-responsive photocatalysts via various synthetic strategies, including the modification of traditional photocatalysts by doping, dye sensitization, or by forming a heterostructure, coupled with π-conjugated architecture, as well as the great efforts made within the exploration of novel visible light-responsive photocatalysts. Background information on the fundamentals of heterogeneous photocatalysis, the pathways of visible light-responsive photocatalysis, and the unique features of visible light-responsive photocatalysts are presented. The photocatalytic properties of the resulting visible light-responsive photocatalysts are also covered in relation to the water treatment, i.e., regarding the photocatalytic degradation of organic compounds and inorganic pollutants, as well as photocatalytic disinfection. Finally, this review concludes with a summary and perspectives on the current challenges faced and new directions in this emerging area of research.