Environmental photocatalysis and photochemistry for a sustainable world : a big challenge

During the two last decades, advanced oxidation processes and especially photocatalysis have caused enormous considerations and have been demonstrated to be the green and effective methods for water and air purification, water disinfection, hazardous waste remediation, antibacterial, and selfcleaning and more recently a technology for energy storage (e.g. hydrogen production from photocatalytic water splitting). However, owing to low photocatalytic efficiency, the environmental applications of various photocatalytic materials and technologies are still very limited. Thus, more improvement and investigations are highly required from the viewpointof practical use. The present issue includes 20 articles mainly dealing with materials and devices for water and air purification. It is a collection of key articles presented at the 9th European Meeting on Solar Chemistry and Photocatalysis: Environmental Applications—SPEA9, held at the Convention Center in Strasbourg, France, between 13th and 17th of June, 2016.