Cobalt Catalysts Supported on CTAB-Functionalized Reduced Graphene Oxide for Heterogeneous Fenton-like Processes

The development of efficient heterogeneous catalysts for Fenton-type processes is essential for advancing wastewater treatment technologies. In this study, cobalt-based catalysts supported on reduced graphene oxide (rGO) were synthesized using cetyltrimethylammonium bromide (CTAB) as a structure-directing agent. The materials were prepared via wet impregnation and characterized by multiple techniques. The results indicate that CTAB promotes improved dispersion of graphene sheets and cobalt species during synthesis, acting primarily as a structure-directing agent. Among the evaluated materials, the 15Co/rGOF catalyst exhibited the highest catalytic performance, achieving 97% tartrazine removal over a wide pH range, including near-neutral conditions. The degradation kinetics followed a pseudo-first-order model (k = 0.0204 min− 1), and radical scavenging experiments using isopropanol confirmed that hydroxyl radicals (•OH) are the dominant reactive species. The catalyst also demonstrated good stability over multiple reuse cycles, with negligible cobalt leaching. Furthermore, a total organic carbon (TOC) reduction of approximately 95% and toxicity decrease, evaluated using Lactuca sativa, confirmed the high oxidative efficiency of the process. These findings highlight the potential of rGO-supported cobalt catalysts as promising materials for heterogeneous Fenton-like applications.