Coordination polymer-derived porous Co3O4 nanosheet as an effective catalyst for activating peroxymonosulfate to degrade sulfosalicylic acid

Abstract

As sulfosalicylic acid (SSA) is a widely-employed medical intermediate, the release of SSA into water causes serious damage to the aquatic environment. Because of its low bio-degradability, chemical oxidation processes are necessitated to eliminate SSA. Since sulfate-radical (SR)-based chemical oxidation processes are increasingly developed for degradation of emerging contaminants, it is important to establish effective SR-based processes for SSA degradation. As Peroxymonosulfate (PMS) is an extensively adopted source for SR and cobalt (Co) is validated as a useful metal to activate PMS, a facile technique is proposed here to develop a heterogeneous catalyst comprised of Co3O4 with a 2D sheet-like and porous configuration for enhancing catalytic activity for PMS activation to degrade SSA. Specifically, a Co-based coordination polymer consisting of Co and trismercaptotriazine (TMT) with a hexagonal nanosheet structure is adopted as a precursor. After calcination, CoTMT is transformed to porous Co3O4 nanosheet (PCNS), and this PCNS exhibits distinct surficial reactivity and textural properties from the commercial Co3O4 NP. These advantageous features enable PCNS to show much higher catalytic activities than the Co3O4 NP for activation of PMS to degrade SSA. PCNS is also reusable for multiple cycles for activating PMS to degrade SSA without loss of catalytic activity.