New Advanced Materials for Photocatalytic Oxidation and Hydrogen Production
Photocatalytic oxidation today is considered as the universal method for air purification from low concentrations of dangerous organic, inorganic and biological species. Main efforts are focusing on the synthesis of highly active photocatalysts which are usually based on the anatase form TiO2. Its modification by acidic treatment or noble metals deposition could result in further enhancement of photoactivity. As it was demonstrated in the static reactor in the case of using mixed TiO2/activated carbon photocatalyst the faster removal of acetone vapor was observed. Using the adsorbent in flow conditions could be effective if substrate inlet concentration increases periodically. In this case adsorbent works as buffer reducing the value of maximum substrate outlet concentration in several times.
Overall water splitting under visible light on semiconductor materials is classified as artificial photosynthetic reaction and has attracted considerable attention in recent years. As a result a lot of semiconductor photocatalysts are developed for H2 production. Unfortunately almost all of them have serious drawbacks like low quantum efficiency and stability. Novel composite photocatalysts Pt/Cd1-xZnxS/ZnO/Zn(OH)2 with a high activity under visible light were proposed. The activation of this kind of the photocatalysts during the photocatalytic hydrogen evolution from alkaline aqueous solutions of ethanol was observed. The problem of activation/deactivation of the photocatalysts during the hydrogen problem is very important and it is required a detailed study, involving a wide range of experimental techniques.
Modern approaches for solving of the problems in the fields of photooxidation and photoreduction as well as application of results in the Russian Federation and worldwide are the subject of lecture.