Efficient and Long-Lasting Removal of High-Level Formaldehyde at Room Temperature over a Cobalt Single-Atom Catalyst Anchored on Graphene-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.