Metal oxide photoanodes for solar hydrogen production

The development of sustainable hydrogen production is a key target in the further facilitation of a hydrogen economy. Solar hydrogen generation through the photolytic splitting of water sensitised by semiconductor materials is attractive as it is both renewable and does not lead to problematic by-products, unlike current hydrogen sources such as natural gas. Consequently, the development of these semiconductor materials has undergone considerable research since their discovery over 30 years ago and it would seem prescient to review the more practical results of this research. Among the critical factors influencing the choice of semiconductor material for photoelectrolysis of water are the band-gap energies, flat band potentials and stability towards photocorrosion; the latter of these points directs us to focus on metal oxides. Careful design of thin films of photocatalyst material can eliminate potential routes of losses in performance, i.e., recombination at grain boundaries. Methods to overcome these problems are discussed such as coupling a photoanode for photolysis of water to a photovoltaic cell in a 'tandem cell' device.

Putting down routes: an examination of local government cultural policy shaping the development of heritage trails

This paper explores the significance of trails within local government cultural strategies by presenting the results of an audit of 1000 trails, content analysis of local cultural strategies and a series of interviews with local government cultural officers. It highlights the growing sophistication of trails as flexible and multi-faceted products promising an array of social, environmental, cultural and economic benefits. However, key issues emerge as challenges for local government cultural officers. These include the need for a realistic assessment of the relative importance of competing rationales, the design of methodologies to enable evidence-based policy making and more effective engagement with commercial organisations.