Role of rare earth in ZnO photodegradation of aqueous organics

Heterogeneous photocatalysis has been actively studied in recent years due to its great potential in solving both environmental pollution and the continuing energy crisis problems. Undeniably, ZnO as a significant photocatalyst has shown a huge potential in various organic pollutants degradation. The high efficiency of ZnO in photocatalysis needed a suitable modification technique that minimized the electron-hole recombination and maximized the photon absorption. In order to further improve the electron-hole separation during excitation state, doping with rare earth (RE) metals has shown to be a popular method to facilitate the photoactivity of ZnO under visible/solar light. This book focuses on the principles and mechanisms of ZnO photocatalysis as well as the recent achievement in the RE-doped ZnO for aqueous organics photodegradation. An original experimental work, the phenol photodegradation by RE-doped ZnO hierarchical micro/nanospheres (RE/ZnO; RE = cerium (Ce), europium (Eu) and neodymium (Nd)) was comprehensively discussed as a case study that can suggest that RE-doped ZnO were promising visible light-driven photocatalysts in remediation of water contaminated by organics.