Synergistic polarization-crystallinity modulation and interlayer bridging in poly heptazine imide for enhanced piezo-photocatalysis toward uranium removal

Photocatalytic immobilization of U(VI) is an effective means of separating and removing uranium from water bodies. Improving photocatalytic performance is currently a hot topic in photocatalytic research. In light of this, this study proposes a novel strategy based on synergistic polarization-crystallinity modulation and interlayer bridging in poly heptazine imide (PHI) to achieve efficient U(VI) removal. The obtained potassium poly heptazine imide (PHI-K) exhibits rewarding piezo-photocatalytic performance, removing 98.4 % of U(VI) within 30 min. Experimental results demonstrate that high crystallinity, piezoelectric electric fields, and K + ion intercalation effectively facilitate carrier separation, thereby enhancing photocatalytic activity. Characterization and density functional theory calculation further reveal enhanced piezoelectric properties induced by K + ion polarization. In addition, the material exhibits excellent stability and resistance to ionic interference. Finally, a potential U(VI) removal technique is proposed. This work is anticipated to present a promising alternative for piezo-photocatalytic U(VI) removal.