Carbon nitride with water soluble ability: Enhanced oxygen species interphase mass transfer for homogenous photocatalytic water purification

Heterogeneous catalysis has been considered a promising way for waste purification, however the catalytic performances of the heterogeneous-based systems are still unsatisfactory, mainly due to the limited active sites exposure and sluggish reactants mass transfer. In this study, we propose a conceptual carbonitride-based quasi-homogeneous catalytic system, exhibiting remarkable photocatalytic activity toward organic pollutants degradation and pathogenic bacteria inactivation. We verify that downsizing carbonitride into nanodot level and modifying the material with hydrophilic groups can endow it with water soluble ability, forming a quasi-homogeneous catalytic system to maximize the active sites exposure and minimize the reactants mass transfer resistance for high-efficient water purification. As a result, the as-established quasi-homogeneous photocatalytic system exhibits abundant surface-active sites and reactants mass transfer efficiencies that allows remarkable O2 reduction for ROS generation. In addition, the treated water containing the functionalized carbonitride is found capable of driving the fast flocculate of suspended substance, which helps to build a well water decontamination and suspended substance removal water purification nexus for practical applications. The work demonstrated here sheds new light in designing high-efficient homogeneous catalytic system for energy and environmental related applications.