Order–Disorder Engineering of Carbon Nitride for Photocatalytic H<sub>2</sub>O<sub>2</sub> Generation Coupled with Pollutant Removal
Qing Xu, Jiaqi Wu, Yangzhu Qian, Xiya Chen, Yi Han, Xiaofei Zeng, Bocheng Qiu, Qiaohong Zhu
Abstract
Highly crystalline carbon nitride (CCN), benefiting from the reduced structural imperfections, enables improved electron–hole separation. Yet, the crystalline phase with insufficient inherent defects suffers from a poor performance toward the reaction intermediate adsorption with respect to the amorphous phase. Herein, a crystalline–amorphous carbon nitride (CACN) with an isotype structure was constructed via a two-step adjacent calcination strategy. Through specific oxygen etching and crystallization, the formation of a built-in electric field at the interface could drive charge transfer and separation, thus promoting photoredox reaction. As expected, the optimized CACN exhibited a H 2 O 2 generation efficiency as high as 2.15 mM g cat –1 h –1, paired with a promoted pollutant degradation efficiency, which outperform its crystalline (CCN) and amorphous [amorphous carbon nitride (ACN)] counterparts. The detailed electron/hole transportation via a built-in electronic field and free radical formation based on the enhanced adsorption of oxygen were considered, and the synchronous reaction pathway was carried out. This work paves a novel pathway for the synthesis of carbon nitride with an isotype structure from the perspective of interfacial engineering.