Precisely constructed core-shell organic/inorganic heterojunction for heightened photoreduction of Cr(VI): Synergy of reinforced interface interaction and high-speed carrier transfer

Abstract

Photocatalysis technology has been widely studied for treating Cr(VI) pollution in water and constructing heterogeneous structures presents a compelling approach to enhance the efficiency of Cr(VI) treatment. Pitifully, solely utilizing heterostructure, especially random composites of heterogeneous photocatalysts, often falls short of effectively enhancing the separation efficiency of photogenerated carriers. Furthermore, most photocatalysts interact weakly with the Cr(VI) anions, greatly reducing the utilization efficiency of photogenerated carriers. Herein, pyridine-based conjugated imprinted polymer (CIP) photocatalyst was precisely coated on urchin-like TiO using an in-situ condensation approach, forming a compact core–shell structure of organic/inorganic heterojunction. On the one hand, the compact heterojunction structure of the core–shell effectively improved the separation efficiency of photogenerated carriers. On the other hand, CIP enhanced the adsorption between the photocatalyst and Cr(VI), effectively improving the utilization efficiency of photogenerated carriers. Due to the collaborative effects of selective adsorption and core–shell heterojunction photocatalysis, the photocatalyst demonstrated remarkable performance in eliminating Cr(VI). For high concentration Cr(VI) pollution of 100 ppm, complete elimination could be achieved within 90 min. This research presented an innovative and efficient approach for the precise synthesis of photocatalysts.