| The increasing world population and rapid urbanization in the world demands more energy and water. With current energy sources and consumption patterns, a significant percentage of the population is projected to lose access to electricity and clean water in near future. Although the utilization of renewable energy source is increasing, the world is far from being independent from greenhouse gas emitting energy sources. In addition, the water used in the production food and other products becomes polluted and this polluted water often discharged to the environment without proper treatments. Continuing this will lead to lack of access to clean water, energy and environmental pollution. In order to meet the increasing energy demand with reduced carbon footprint, and to improve wide adoption of wastewater treatment process, renewable energy sources and economical wastewater treatment are necessary. Photocatalysis is such a process that can produce clean, carbon free fuel from water and can degrade organic pollutants in wastewater by harnessing solar energy. Among several photocatalysts available, titania is widely studied for solar energy conversion. However, rapid charge carrier recombination and poor utilization of solar spectrum are the two major drawbacks of titania and several works have been done to improve the drawbacks. Magnesia-titania mixed oxide is known in literature to improve the efficiency of titania by minimizing recombination. In this work, we have studied the role of MgO as support for titania in several loadings. We have synthesized, and characterized TiO2-MgO with five different loadings of titania and we found that highly dispersed small titana clusters supported on MgO facilitates the photocatalytic activity for water splitting. The photocatalytic degradation of methylene blue goes through dye sensitized photocatalysis and reactive oxygen species are formed by the reaction of dissolved oxygen with excited electron. The as formed reactive oxygen species degrade methylene blue. From this work, we show that the prepared MgO supported TiO2 can be used for photocatalytic energy production in the presence of ultraviolet radiation and it can also be used for the degradation of methylene blue in the presence of visible light and oxygen. |
