Sulfate saturated biosorbent-derived Co-S@NC nanoarchitecture as an efficient catalyst for peroxymonosulfate activation

Using sulfate saturated bio-sorbent and cobalt(II) acetate as precursors, the homogeneous assembly of S-Co3O4 in nitrogen doped carbon martix (Co-S@NC) was obtained for the first time in an one-step pyrolysis. The reactions between peroxymonosulfate (PMS) and Co-S@NC for dinotefuran (DIN) decomposition were investigated. Co3O4 in Co@NC were primarily coordinated with the pyridinic N as catalytic sites. The adsorbed sulfate as S dopant was incorporated into the Co3O4 in carbon matrix due to the role of N as anchors, and the DIN decomposition of S-doped samples increased by 1.71 times as compared to the S-free sample (Co@NC). S incorporation can promote the formation of non-radical O-1(2) and various radicals. In addition, DFT calculations indicated the enhanced electronic conductivity after S incorporation, which would facilitate the DIN decomposition in Co-S@NC/PMS system. This work enables the first insight into the role of adsorbed sulfate as effective S dopant for PMS activation.