Ultrahigh antipsychotics selective accumulation and efficient photocatalytic degradation using a novel 2D BiOIO3-based molecularly imprinted photocatalyst

Abstract

Adsorption-assisted photocatalytic degradation of pollutants is an effective method to improve degradation efficiency. However, most adsorptive photocatalysts are not selective and cannot efficiently remove low-concentration targets in complex systems, which limit their practical application. Therefore, a novel molecularly imprinted photocatalyst (MI-BiOIO₃) with high selectivity and adsorption capacity was prepared using two-dimensional BiOIO₃ nanosheet as the matrix. Based on the abundant imprinting sites in the surface imprinted polymer of BiOIO₃, the prepared MI-BiOIO₃ exhibited ultrahigh risperidone (RIS) selective accumulation performance, with a theoretical maximum adsorption capacity calculated by the Langmuir equation reaching 272.24 mg g⁻¹ within 5 min and an imprinting factor as high as 15.3. The adsorption property was not affected by common pH changes and the coexistence of humic acid and inorganic ions. Due to the synergistic effect of adsorption and photocatalysis, RIS after being concentrated by MI-BiOIO₃ could be completely degraded within 30 min, and more than two-thirds of the degradation intermediates were nontoxic. After five cycles, the selective adsorption and degradation performance of MI-BiOIO₃ toward RIS did not reduce considerably. As an adsorptive photocatalyst, the prepared MI-BiOIO₃ could selectively remove 50.3%–61.5% of 1 mg L⁻¹ of RIS in river, lake, and municipal wastewater samples. DFT simulation analysis verified that the ultrahigh selective accumulation performance was due to the van der Waals force, hydrogen bonds, electrostatic interaction, and π–π stacking interactions between MI-BiOIO₃ and RIS. This study provides a new concentrate-and-destroy strategy by photocatalysts for low-concentration drug contaminants in complex media.