Autor: |
Fraga TJM; Chemical Engineering Department, Federal University of Pernambuco (UFPE), 1235 Prof. Moraes Rego Avenue, Cidade Universitária, Recife, Pernambuco, 50670-901, Brazil. tiago_mfraga@hotmail.com., de Lima LEM; Center of Biosciences, Federal University of Pernambuco (UFPE), W/N Prof. Moraes Rego Avenue, Cidade Universitária, Recife, Pernambuco, 50670-420, Brazil., de Souza ZSB; Chemical Engineering Department, Federal University of Pernambuco (UFPE), 1235 Prof. Moraes Rego Avenue, Cidade Universitária, Recife, Pernambuco, 50670-901, Brazil., Carvalho MN; Chemical Engineering Department, Federal University of Pernambuco (UFPE), 1235 Prof. Moraes Rego Avenue, Cidade Universitária, Recife, Pernambuco, 50670-901, Brazil., Freire EMPL; Chemical Engineering Department, Federal University of Pernambuco (UFPE), 1235 Prof. Moraes Rego Avenue, Cidade Universitária, Recife, Pernambuco, 50670-901, Brazil., Ghislandi MG; Engineering Campus - UACSA, Federal Rural University of Pernambuco (UFRPE), 300 Cento e sessenta e Três Av, Cabo de Santo Agostinho, Pernambuco, Brazil., da Motta MA; Chemical Engineering Department, Federal University of Pernambuco (UFPE), 1235 Prof. Moraes Rego Avenue, Cidade Universitária, Recife, Pernambuco, 50670-901, Brazil. |
Abstrakt: |
Graphene oxide (GO) was synthetized from graphite oxidation via the modified Hummers method. Afterwards, the GO was functionalized with diethylenetriamine (DETA) and FeCl 3 to obtain the novel amino-iron oxide functionalized graphene (GO-NH 2 -Fe 3 O 4 ). FTIR, XRD, SEM with EDX, and Raman spectroscopy were performed to characterize both GO and GO-NH 2 -Fe 3 O 4 . The GO-NH 2 -Fe 3 O 4 was then evaluated as adsorbent of the cationic dye Methylene Blue (MB); analysis of the point of zero net charge (pH PZC ) and pH effect showed that the GO-NH 2 -Fe 3 O 4 pH PZC was 8.2; hence, the MB adsorption was higher at pH 12.0. Adsorption kinetics studies indicated that the system reached the equilibrium state after 5 min, with adsorption capacity at equilibrium (q e ) and kinetic constant (k S ) of 966.39 mg g -1 and 3.17∙10 -2 g mg -1 min -1 , respectively; moreover, the pseudo-second-order model was better fitted to the experimental data. Equilibrium studies showed maximum adsorption capacity of 1047.81 mg g -1 ; furthermore, Langmuir isotherm better fitted the adsorption. Recycling experiments showed that the GO-NH 2 -Fe 3 O 4 maintained the MB removal rate above 95% after 10 cycles. All the results showed sorbent high adsorption capacity and outstanding regeneration capability and evidenced the employment of novel GO-NH 2 -Fe 3 O 4 as a profitable adsorbent of textile dyes. |