## 1 Introduction  
With the expansion of contemporary industry, the problem of polluted industrial wastewater is getting more severe, and untreated pollutants can enter the environment via a variety of routes and impair the health of living beings [1]. Among these, dye wastewater is difficult to biodegradable due to its enormous stock, weak biochemical characteristics, and complicated composition [2]. Rhodamine B (RhB) is extensively investigated as a model contaminant for the treatment of dye effluent. It is found in wastewater from the textile, cosmetic, and food industries, and is on the World Health Organization's list of carcinogens in Class III [3; 4; 5; 6].  
The advanced oxidation process based on peroxymonosulfate (PMS-AOP) is used to treat resistant wastewater [7]. Peroxymonosulfate (PMS) is stable under normal settings, and ROC are produced slowly. Previous research showed chloride ion (Cl\({}^{-}\)), organic ligand with reducing capability, and microwave (MW) heating, was introduced into AOP for enhanced removal of organic contaminants in wastewater [8; 9; 10; 11]. Due to their gentle reaction conditions, high ROC generation rate, and low energy consumption, PMS-AOP focuses on transition metal-based catalysts to catalyze PMS [12]. Improving transition metal oxide dispersion to minimize agglomeration and boosting activated PMS efficiency are key research areas [13; 14]. Zeolitic Imidazolate Frameworks (ZIFs), like normal MOFs, are widely employed in adsorption, separation, and catalysis [13; 15; 14]. MOF-derived carbon is employed in adsorption, catalytic gas reactions, and fuel cell construction. MOF-derived carbon materials can activate PMS to generate reactive oxygen species for treating refractory organic contaminants in wastewater due to the presence of transition metals such as Fe and Co in their structure and heteroatom (nitrogen and sulfur) doping [16; 17; 18; 19; 20]. Numerous studies have shown that sulfur doping can change the electron distribution of nitrogen-doped carbon materials, which facilitates the catalytic process and provides stability [21; 22; 23]. The process of synthesizing simple and large quantities of materials that change the electron distribution of carbon materials by introducing sulfur doping for efficient catalytic persulfate activation deserves further investigation.  
In this study, the sulfur-functionalized MOFs precursor ZIF-67-S was synthesized with alkylthiourea utilizing a one-pot technique. Co-doped sulfur-nitrogen porous carbon materials (CoSN@C) were produced by roasting in N\({}_{2}\) atmosphere. Their performance in catalyzing the degradation of Rhodamine B (RhB), a common dye, by PMS was studied, and their structure and morphology were characterized. The experimentally prepared CoSN@C inherited the MOFs precursor's well-dispersed and porous three-dimensional spatial structure. The complete contact with PMS and sulfur doping further enhanced its catalytic ability, and the material demonstrated outstanding performance in activating PMS degradation of pollutants. In addition, the experiments investigated the effects of material dosing amount, PMS dosing concentration, temperature, pH, and other parameters on the RhB degradation effect to determine the optimal conditions for degradation. The catalytic degradation mechanisms of CoSN@C + PMS system and CoN@C + PMS system were compared through quenching experiments and electron paramagnetic resonance (EPR) tests to identify the effect of S doping.