Iron\nNanoparticles-Confined\nGraphene Oxide Membranes\nCoupled with Sulfite-Based Advanced Reduction Processes for Highly\nEfficient and Stable Removal of Bromate

Advanced\nreduction processes (ARPs) are promising for\npollutant\nremoval in drinking water treatment. In this study, we demonstrated\nhighly efficient reduction of bromate, a harmful disinfection byproduct,\nby coupling ARPs with an iron nanoparticles-intercalated graphene\noxide (GO@FeNPs) catalytic membrane. In the presence of 1.0 mM sulfite\n(S(IV)), the GO@FeNPs membrane/S(IV) system achieved nearly complete\nremoval of 80 μg/L bromate in 3 min. The first-order reaction\nrate constant for bromate removal in this system was 420 ± 42\nmin<sup>–1</sup>, up to 5 orders of magnitude faster than previously\nreported ARPs. The GO@FeNPs catalytic membrane may offer potential\nadvantages of nanoconfinement and facilitated electron shuttling in\naddition to the high surface area of the fine FeNPs, leading to the\nremarkable ARP performance. The GO@FeNPs membrane showed excellent\nstability, maintaining >97.0% bromate removal over 20 cycles of\nrepeated\nruns. The membrane can also be applied for fast catalytic reduction\nof other oxyanions, showing >98.0% removal of nitrate and chlorate.\nThis work may present a viable option for utilizing high-performance\nreductive catalytic membranes for water decontamination.