Promotion of the Photocatalytic Mechanism of Carbon Nitride for Environmental Applications

Abstract

Abstract This dissertation focuses on designing and synthesizing modified carbon nitride materials and promoting their photocatalysis for various environmental applications. As an emerging class of metal-free semiconductors with remarkable properties, polymeric carbon nitride (CN) has enabled unprecedented visible light-catalytic performance for various environmental and energy applications. However, its photocatalytic oxidation (PCO) is still hindered by several shortcomings such as fast charge recombination, weak visible light absorption, low electrical conductivity and the limited reactive oxygen species (ROS) generation. This dissertation presents several strategies such as surface alkalinization, band engineering, functional groups modification, and solvothermal treatment to overcome the shortcomings mentioned above and demonstrates the successful performance of the modified carbon nitride materials for various environmental photocatalytic applications. Both the reduction and oxidation paths on carbon nitride were investigated and utilized to achieve a significantly enhanced photocatalysis. The mechanism insights were also provided from the molecular level and by the theoretical simulation. More importantly, this dissertation involves the conceptualization of a carbon nitride photocatalyst and may offer valuable insights for understanding and developing carbon nitride-based photocatalytic system.