Generation and transformation of ROS on g-C3N4 for efficient photocatalytic NO removal: A combined in situ DRIFTS and DFT investigation

Understanding the performance of reactive oxygen species (ROS) in photocatalysis is pivotal for advancing their application in environmental remediation. However, techniques for investigating the generation and transformation mechanism of ROS have been largely overlooked. In this study, considering g-C3N4 to be a model photocatalyst, we have focused on the ROS generation and transformation for efficient photocatalytic NO removal. It was found that the key to improving the photocatalysis performance was to enhance the ROS transformation from •O2− to •OH, elevating the production of •OH. The ROS directly participate in the photocatalytic NO removal and tailor the rate-determining step, which is required to overcome the high activation energy of the intermediate conversion. Using a closely combined experimental and theoretical method, this work provides a new protocol to investigate the ROS behavior on g-C3N4 for effective NO removal and clarifies the reaction mechanism at the atomic level, which enriches the understanding of ROS in photocatalytic environmental remediation.