Polymeric carbon nitride (CN)-based photocatalysts suffer from a low specific surface area and rapid electron–hole recombination, limiting their efficiency under visible light. To address these issues, a pillar-architected composite aerogel, consisting of boron (B) and phosphorus (P) co-doped CN rods (BPCN) integrated within a graphene aerogel (GA) matrix (BPCN/GA), is developed in this study. The BPCN rods are synthesized via supramolecular self-assembly, yielding a pillar-like structure. The simultaneous incorporation of B and P introduces spatially separated electron-rich and electron-deficient centers within the CN lattice. These dopant-induced charge polarizations narrow the bandgap and establish internal electric fields, markedly enhancing visible light absorption and promoting charge carrier separation. Embedding the BPCN rods into conductive, porous graphene-based sheets further suppress electron–hole recombination by rapidly shuttling photogenerated electrons through the π-conjugated interconnected graphene network. The robust three-dimensional (3D) aerogel structure also provides structural stability and imparts floatability, allowing easy catalyst recovery and maximal light exposure at the air–water interface. Under visible light irradiation, the BPCN/GA achieved ∼92% degradation of acetaminophen, a common pharmaceutical contaminant in water, significantly outperforming pristine CN. The composite also exhibits excellent reusability over multiple photocatalytic cycles, and the treated water shows significantly reduced phytotoxicity, highlighting the potential of BPCN/GA for sustainable water purification. Overall, this work demonstrates a synergistic strategy of concurrent heteroatom doping and 3D nanoarchitecturing to develop a next-generation metal-free photocatalyst with greatly improved visible light-driven remediation of emerging organic contaminants.
Shafi et al. (Fri,) studied this question.