High loads of rare earth single-atom lanthanum anchored carbon nitride with special double-layer coordination structure for efficient photocatalysis

A special two-layer coordination configuration anchored single-atom La (SALa) catalyst is synthesized to realize the effective separation of electrons in space and efficient active sites for the activation of O2 to produce more active species. The special SALa microenvironment is obtained by a novel and facile reduction method that avoids the formation of rare earth oxides and the concentration of loaded SALa (10.34 wt%) exceeds that in most previous studies. The photodegradation test results show that antibiotics are almost completely removed within 30 min by SALa/CN. The first-order kinetic constant of SALa/CN (0.10661 min−1) is approximately 9.81 times higher than that of 3DA-CN (0.01087 min−1). SALa can be considered as a bridge to transfer electrons and •O2−, 1O2 and h+ are the main active species to degrade tetracycline into some pollution-free small molecules. This work provides an efficient rare earth single-atom catalyst activity strategy possessing certain potential in practical applications.