6 - Recent advancement in the development of metal oxide heterostructures for environmental remediation

Abstract

This chapter discusses the advancements in the fabrication of heterostructured metal oxides for photocatalytic environmental remediation applications. In particular, it focuses on highlighting the interplay effect relationship of the structure features and photocatalytic performances of the heterostructured photocatalysts constituting interfaces formed from combinations of multicomponents of semiconductor metal oxides. These semiconductor multicomponent composites present unique synergistic structure–activity enhancement effects driven by the nanoscale design that endows appreciable high-performance photocatalytic applications in environmental remediation. The photoactivity of these materials is elaborated specifically with respect to the influence of their structure design effect in the photocatalytic removal of both organic molecules and inorganic heavy metal pollutants. The concept strategies aimed to achieve desirable materials design structure properties that can be amenable to superior photocatalytic performances are discussed with relation to applications in remediating the efficient removal of organic and inorganic waste pollutants. The discussion elaborates on the influence of key interface structure characteristics spanning from morphology dimensions, crystal facets, redox, electronic properties, point defects such as oxygen vacancies with respect to their effect on the photocatalytic surface processes, such as photo-light absorption, photocarriers generation of electrons/holes, separation, and transfer efficiency for their utilization in the redox photocatalysis reactions. It continues to find the balance to understand the interplay of these heterostructures interfaced metal oxide semiconductors effect with the mechanistic photodegradation or photoreduction pathways to convert pollutants into less harmful products. Finally, the discussion aims to provide a systematic understanding of the specific key heterostructure interfaces properties that deem challenging; hence, vital insights on approaches for further photocatalytic material design and development with desirable potential applications for sustainable environmental remediation purposes.