Interfacial engineering of vacancy-rich nitrogen-doped FexOy@MoS2 Co-catalytic carbonaceous beads mediated non-radicals for fast catalytic oxidation

How to accelerate the Fe3+/Fe2+ conversion and fabricate recyclable iron-based catalysts with high reactivity and stability is highly desired yet challenging. Herein, vacancy-rich N@FexOy@MoS2 carbonaceous beads were firstly developed via employing sodium alginate, molybdenum disulfide (MoS2), and Fe-ZIFs through sol-gel self-assembly, followed by in-situ growth and pyrolysis strategies. As expected, A series of characterizations reflected that N@FexOy@MoS2 had high dispersibility and conductivity for fast mass and electron transport, and MoS2 as co-catalyst accelerated the circulation of Fe3+ to Fe2+ that attained 99.4% (0.345 min-1) norfloxacin degradation via PMS activation in a synergistic ''adsorption-driven-oxidation'' process, which much outperformed those of pure MoS2 (32.4%) and N@FexOy powder catalyst (45.3%). Moreover, confined Fe species, graphitic N, pyrrolic N, pyridinic N, and sulfur/oxygen vacancies were found as highly exposed active sites that contributed to the activation of PMS to dominate non-radicals (1O2 and O2·-) and other radicals following a contribution order 1O2 > O2·- > SO4·- > ·OH. More importantly, a fluidized-bed catalytic unit was evaluated and maintained the continuous zero discharge of NX. Overall, this study offered a generally applicable approach to fabricate removable Fe-based catalysts for contaminants remediation.