Nanometric and surface properties of semiconductors correlated to photocatalysis and photoelectrocatalysis applied to organic pollutants – A review

This review study summarizes relevant topics about the photoelectrocatalytic semiconductors for the degradation of organic pollutants. Among the topics are A) the basic concepts of photocatalysis and photoelectrocatalysis for the advanced oxidation of organics in water. B) The band theory about heterojunctions, Schottky barriers, and doping of these semiconductors being photocatalysts. C) Proposing the outlook for photocatalysts, as those systems arranging doped semiconductors with heterojunctions and having Schottky junctions, a set of tables and sections show reported cases that complement the semiconductor characteristics providing the percentage of degradation attained, such as photoanodes of Boron-doped TiO2 nanotubes, TiO2 - Sb2S3 composites, and so forth. D) The novel characteristics of graphene-based materials for improving photoelectrocatalytic systems. E) A systematic way of classifying and understanding photoelectrocatalytic semiconductors based on their relevant characteristics and photoelectrochemical mechanisms. Moreover, this work shows the photoelectrocatalytic properties of the recently reported graphene oxide - reduced graphene oxide (GO-rGO) nanohybrids, which can also be used for the degradation of organic pollutants. Finally, based on all the previously gathered and summarized information, some inferences are made about the photoelectrocatalytic properties of some GO-rGO based heterojunctions for the degradation of organic pollutants.