Efficient andLong-Lasting Removal of High-Level Formaldehydeat Room Temperature over a Cobalt Single-Atom Catalyst Anchored onGraphene-like Carbon Nanosheets

The single-atom strategy has proven to be an effective approach for improving the catalytic performance of supported metal catalysts. In this study, we synthesized a Co single atom supported on an ultrathin carbon nanosheet (Co-SAs/NCS) to remove high-concentration formaldehyde (HCHO) pollutants at room temperature. The as-prepared catalyst exhibited a 2D graphene-like morphology with a high specific surface area and enhanced nitrogen doping level, which provided many active sites to firmly anchor the isolated Co atoms. The determined planar structure of Co–N₄ was found to have a superior ability to activate molecular oxygen from air, which was crucial for achieving a removal efficiency of 86% for 500 ppm formaldehyde at room temperature. The catalytic performance of the developed Co-SAs/NCS also exhibited good stability after a 108 h time-on-stream test. This study provides a promising approach for effective HCHO removal through the rational design of a single-atom catalyst.