Gram-scale synthesis of atomically dispersed p-block Al atoms on polymeric carbon nitride for efficient antibiotic photodegradation

Abstract

Single-atom decorating polymeric carbon nitride (PCN) is often regarded as a class of promising catalyst for energy conversion and environmental remediation due to its ultrahigh atom utilization and unparalleled performance. Herein, gram-scale atomically dispersed p-block aluminum (Al) atoms on PCN photocatalyst (denoted as ACN) was successfully synthesized via a facile thermal polymerization strategy. Atomic-level, optical characterizations and band structure analysis unveil that Al atoms are uniformly dispersed on PCN framework, which can effectively optimize the band structure, accelerate the separation and transport ability of carriers, and then facilitate antibiotics photodegradation efficiency. Remarkably, the optimal ACN-2 exhibits superb removal rates (∼80%) and outstanding pseudo-first-order kinetic constants (0.084 min−1, 0.051 min−1 and 0.067 min−1, respectively) over visible-light-induced degradation of tetracycline, oxytetracycline and chlortetracycline in just 20 min, and ca. 95% of the original removal rate can be maintained even in 10 consecutive TC degradation cycles, illustrating the superior stability and reusability of ACN-2. Notably, >30 g of photocatalyst (i.e., ACN-500) obtained via precursor amplification procedure still displayed excellent TC photodegradation performance. This work paves the way for practical application of an advanced single-atom Al-decorated PCN photocatalyst for pollutant remediation.