Highly efficient and sustainable photocatalytic Fenton reactions utilizing catalyst-embedded inverse-opal structured membranes

Abstract

The inverse opal (IO) structure, known for its photonic crystal properties and uniform pores, promotes multiple internal light scatterings and reflections. This leads to a decrease in photon group velocity, generating a slow photon effect. When integrated with photocatalysts, this effect enhances light absorption by extending photon interaction with the catalyst, thereby significantly enhancing the efficacy of IO structures in photocatalytic applications. However, the integration of inorganic photocatalysts into IO structures presents challenges, such as mechanical brittleness and a tendency to form powders. To overcome these obstacles, we have engineered IO-structured polymeric membranes coated with graphitic carbon nitride tailored for photocatalytic Fenton reactions. These membranes, which encapsulate photocatalysts within the polymeric porous IO framework, facilitate the straightforward reaction and separation of catalysts from byproducts. They demonstrated superior photocatalytic performance, as evidenced by Rhodamine B degradation (∼7.1 %) and benzene hydroxylation (∼7.3 %). Extensive durability (>30 days) and recyclability tests (>5 times) confirmed their robustness, establishing their utility for various organic conversion reactions. By combining the advantages of the IO structure with tailored photocatalytic properties, these membranes offer promising potential for sustainable and efficient water treatment and the production of fine chemicals in industrial settings.