Optimized pore configuration in solar-driven regenerable adsorbent for organic micro-pollutants removal

Organic micro-pollutants (OMPs) in the aqueous environment are difficult to be removed by conventional wastewater treatment processes due to their slow kinetics and poor biodegradability. The strategy of sequential concentration and catalytic oxidation in situ provides a great potential scenario to enhance the removal efficiency of OMPs. In this study, adsorption-photocatalytic dual-functional aerogels (3D GCPA) with tunable pore structure are developed by coupling graphene nanosheets and covalent triazine frameworks via polyvinyl alcohol. Through the control of pore morphology, the size effect of mass transfer and photocatalytic removal of pollutants in low concentration is revealed for the first time. The results show that inerratic and modest pore structure are conducive to the exposure of active sites and interfacial charge transfer. The optimized pore configuration of 3D GCPA-m exhibits outstanding adsorption capacity (1862 μmol/g for BP-2) and self-regeneration performance (89.3% in the fourth cycle). The degradation process is dominated by hydroxyl radical oxidation. Furthermore, the natural water application of 3D GCPA-m shows stability and universality, which still maintains the percentage regenerated of 86.0% after a 7-day consecutive cycle. This study develops the comprehension of size effects in the removal of trace pollutants and presents an efficient and portable strategy to control OMPs.