Carbonaceous functional materials are a rising star in multiple applications, such as environmental remediation, energy storage, and catalytic conversion of chemicals. Specifically, they have shown great potential for the efficient abatement of organic contaminants from the environmental medium by coupling with chemical oxidants (e.g., hydrogen peroxide, persulfates, ferrates, and periodates), where the redox nature and conductivity of carbon catalysts played significant roles. Among others, the advanced oxidation processes based on persulfates (PS-AOPs) attracted considerable attention due to their high efficiencies, low cost, and easy operation. Accordingly, PS-AOPs have been successfully applied in in situ and/or ex situ remediation of organic contaminated water and soil. Nitrogen atoms could be doped/incorporated into the carbon matrix and substitute C atoms to form different N configurations (i.e., graphitic, pyridinic, pyrrolic N), which served as the catalytically active sites for the PS activation. Through further thermal treatment, the incorporated N atoms could be transferred into the N vacancies. Additionally, the doped N atoms could further introduce the highly active single-atom sites by forming metal–N₄ bonds. This paper summarized recent advances in the applications of nitrogen-doped carbon catalysts (NDCs) in PS-AOPs for the removal of organic contaminants and elucidated the underlying mechanisms. First, we briefly introduced the synthetic routes of NDCs and devoted to illustrating the relationship between the N dopants and the synthetic parameters. Second, the roles of different N configurations and N vacancies in PS activation were critically discussed based on experimental and computational evidence. Special attention was paid to the design of single-atom catalysts, and the role of metal–N₄ configuration was introduced. The relationships between structure and activity were particularly focused and comprehensively discussed through statistical analysis. The influences of coexisting substances and the reusability and stability of NDCs were also taken into consideration. Finally, the current challenges and possible future perspectives were outlined based on the above discussion. Overall, this review may shed new light on the NDC induced PS-AOPs towards environmental remediation.

Photocatalytic solar-energy conversion is of great interest because of its tremendous potential to address the global energy crisis and environmental issues. Many strategies have been developed in the past few years to address the serious drawback of sluggish separation and migration kinetics of charge carriers. One of the most useful strategies in recent years has been the introduction of a local interaction field into the system due to its significant capacity toward separating photogenerated electron–hole pairs and some other advantages (i.e., promoting mass transfer, affecting reaction pathways, etc.). This review attempts to summarize the recent progress made in the rational design and construction of the local field in the photocatalysis community, mainly including the electric field, thermal field, magnetic field, ultrasonic field, and multifield coupling. The photocatalytic properties and charge transfer pathways of these systems are presented based on environmental and energy applications, for instance, water splitting, degradation of pollutants, small-molecule activation, and other semiconductor-induced chemical transformations. Finally, we discuss the existing challenges and prospects in utilizing the local field to improve the solar-energy conversion efficiency.