Three-Dimensional Reduced Graphene Oxide Coupled with Mn₃O₄ for Highly Efficient Removal of Sb(III) and Sb(V) from Water

Abstract

Highly porous, three-dimensional (3D) nanostructured composite adsorbents of reduced graphene oxides/Mn3O4 (RGO/Mn3O4) were fabricated by a facile method of a combination of reflux condensation and solvothermal reactions and systemically characterized. The as-prepared RGO/Mn3O4 possesses a mesoporous 3D structure, in which Mn3O4 nanoparticles are uniformly deposited on the surface of the reduced graphene oxide. The adsorption properties of RGO/Mn3O4 to antimonite (Sb(III)) and antimonate (Sb(V)) were investigated using batch experiments of adsorption isotherms and kinetics. Experimental results show that the RGO/Mn3O4 composite has fast liquid transport and superior adsorption capacity toward antimony (Sb) species in comparison to six recent adsorbents reported in the literature and summarized in a table in this paper. Theoretical maximum adsorption capacities of RGO/Mn3O4 toward Sb(III) and Sb(V) are 151.84 and 105.50 mg/g, respectively, modeled by Langmuir isotherms. The application of RGO/Mn3O4 was demonstrated by using drinking water spiked with Sb (320 μg/L). Fixed-bed column adsorption experiments indicate that the effective breakthrough volumes were 859 and 633 mL bed volumes (BVs) for the Sb(III) and Sb(V), respectively, until the maximum contaminant level of 5 ppb was reached, which is below the maximum limits allowed in drinking water according to the most stringent regulations. The advantages of being nontoxic, highly stable, and resistant to acid and alkali and having high adsorption capacity toward Sb(III) and Sb(V) confirm the great potential application of RGO/Mn3O4 in Sb-spiked water treatment.

Aqueous removal of inorganic and organic contaminants by graphene-based nanoadsorbents: A review

“…Over a wide range pH conditions (2.5-11.5), the adsorption capacities of both Sb(III) and Sb(V) on Mn3O4-rGOs changed significantly (Zou et al, 2016). The adsorption capacity of the Mn3O4-rGOs for Sb(V) decreased slightly with increasing pH over the entire pH range.…”

Bioinspired synthesis of fiber-shaped silk fibroin-ferric oxide nanohybrid for superior elimination of antimonite

“…To our knowledge, this SNF-ferric oxide nanocomposite showed relatively better removal capacity than most of the recent reported nanocomposite materials, including porous MOFs, nanofiber-based materials and magnetic nanocomposites ( Fig. 4 ) [ 2 , 3 , 7 , [31] , [32] , [33] , [34] , [35] , [36] ]. In particular, except for the high removal capacity and selectivity, both silk fibroin and iron oxide are environmental-friendly.…”

Synthesis of nano-zirconium-iron oxide supported by activated carbon composite for the removal of Sb(v) in aqueous solution

“…For example, the adsorption capacity of ZIC is 11.80 mg g À1 (the initial concentration of Sb(V) is 1 mg L À1 ) is better than kaolinite (Q m ¼ 0.13 mg g À1 ), 36 bentonite (Q m ¼ 0.50 mg g À1 ), 37 ferrosoferric oxide (Q m ¼ 7.06 mg g À1 ) 38 and polyvinyl alcohol-stabilized granular adsorbent containing nanoscale zero-valent iron (Q m ¼ 1.65 mg g À1 ). 34 This adsorption capacity is still lower than zirconium oxide -carbon nano-bers (Q m ¼ 51.17 mg g À1 ), 35 reduced graphene oxide coupled with Mn 3 O 4 (Q m ¼ 105.50 mg g À1 ) 39 and a-MnO 2 Nanobers (Q m ¼ 89.99 mg g À1 ), 40 but the cost of ZIC is lower than these materials and has the advantage of magnetic separation.…”