An N,S-Anchored Single-Atom Catalyst Derived from Domestic Waste for Environmental Remediation

As the smallest entities in catalysts, single-atom catalysts (SACs) exhibit superior atomic efficiency, advanced activity, and high selectivity. However, their practical applications are inhibited due to their high preparation costs. Here, we developed a novel cobalt–carbon-based SAC derived from the mild pyrolysis of spent coffee grounds soaked in Co (Co-CGBC), in which cobalt atoms atomically disperse and coordinate with the N and S atoms in the carbon substance, as identified by X-ray absorption fine structure (XAFS) spectroscopy combined with high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). Co-CGBC is inexpensive and exhibits high efficiency in the activation of peroxymonosulfate (PMS) to degrade a wide range of organic pollutants with a degradation efficiency of 90–100%. Density functional theory (DFT) calculations confirm that the sulfur in the Co–N3S1 active site plays a crucial role in reducing the adsorption energy of PMS and facilitating electron transfer. This work supplies new opportunities to synthesize cost-effective SACs for application in environmental remediation.