Photocatalytic Degradation of Methylene Blue: Performance, Mechanism, and Perspectives

Abstract

Toxic and environmentally-hazardous dye removal from the aquatic environment is a challenging task. Various types of dyes are contaminated in water sources that eventually create health issues to biological species including humans. As per the sustainable development goals (SDGs) put forward by the United Nations' to rectify this issue and to make our green planet earth live long, particularly SDG-3 (Good Health and Well-Being), SGD-6 (Clean Water and Sanitation), and SDG-14 (Life Below Water) proclaims necessary actions to the various nations to protect their aquatic environments. Nanostructured materials such as graphitic carbon nitride (g-C3N4) is a potential material which is used as a catalyst to remove dyes from water sources. Herein, we discuss the applications g-C3N4 in methylene blue (MB) degradation. Initial section discusses the salient features of g-C3N4 including their properties and synthesis methods and further we review the preparation of various g-C3N4-based catalysts for application in the removal of MB from the water. These include the preparation of g-C3N4/metal oxide composites, g-C3N4/polymer nanocomposites, g-C3N4/chalcogenide composites, etc. Furthermore, we detail the potential challenges faced by these catalysts to remove the MB from water and also their future perspectives.