Rich electron delocalization structure in carbon nitride inducing radical transfer for high-performance photocatalytic uranyl reduction

Abstract

Investigating the activation of the persulfate process through heterogeneous carbonaceous catalysts to expedite the reduction of uranyl ions (U(VI)) is imperative. The primary hurdle involves understanding the transfer and distribution of photogenerated carriers during the reduction process in this intricate system and deciphering the role of activated groups in promoting reduction efficiency. In this study, we strategically regulate the structure of polymeric carbon nitride to promote the N-doped state, thereby facilitating delocalization electron enrichment. The resulting active sites effectively activate peroxyl disulfate (PDS), generating radicals that expedite the selective reduction of U(VI). This strategic approach mitigates the inherent disadvantage of the short half-life of free radicals in persulfate-based advanced oxidation processes. As a consequence of our endeavors and with the simultaneous presence of PDS and hydrogen peroxide, we achieve an exceptional photoreduction efficiency of 100% within a remarkably short period of 20 min. This breakthrough presents a high-efficiency application with significant potential for addressing the pollution associated with uranyl-containing wastewater. Our findings not only contribute to the fundamental understanding of AOPs but also offer a practical solution with implications for environmental remediation.

Keywords

persulfate activation / photocatalytic / polymerized carbon nitride / reduction uranium (VI) / rich electron delocalization structure