Study of the (photo)catalytic properties of tin oxides modified with graphene and/or noble metals for the elucidation of the degradation mechanisms of organic contaminants

Abstract

Conventional water and wastewater treatments, and even sophisticated systems such as reverse osmosis utilized to produce water for hemodialysis are not able to prevent the contamination by organic compounds. This poses serious risks for the environment and/or human health, therefore it is necessary to develop supplementary techniques for water purification. Photocatalysis and photoelectrocatalysis have presented promising results in this aspect. They make use of semiconducting materials activated by illumination to photodegrade organic compounds in aqueous media, thus mineralizing them, and TiO2 has been the most studied material for this application. Strategies to enhance photocatalysts have also been reported. Among them, their combination with graphene and noble metals has shown to be a very efficient approach. Currently, tin oxides of the types SnO and Sn3O4 have attracted attention in applications as chemical sensors and transistors due to their band-gaps in the visible region. This project aims to combine tin oxides with graphene and/or noble metals in hybrid/composite materials, to characterize them in depth and to apply them in the degradation of organic compounds in water (the azo-dyes methyl orange and disperse red 1, as well as the endocrine disruptor bisphenol A). Their degradation mechanisms will also be investigated and correlated to the structural and photocatalytic properties of the composites/hybrids.