Rapid degradation of azo dye methyl orange using hollow cobalt nanoparticles.
A rapid and efficient method for methyl orange degradation using hollow cobalt (Co) nanoparticles is reported. Hollow Co nanoparticles were fabricated by a galvanic replacement reaction using aluminum (Al) nanoparticles as the template material. The methyl orange degradation characteristics were investigated by measuring the time dependent UV-Vis absorption of the dye solution, which showed a very fast degradation rate under acidic conditions. At an initial methyl orange concentration of 100 mg/L (pH = 2.5) and Co nanoparticle dosage of 0.5 g/L, the azo dye degradation efficiency reached up to 99% within 4 min, and the degradation constant rate was up to 2.444 min(-1), which is the highest value among other studies. A comparison of the decolorization rates at similar conditions with several other azo dyes, including Congo red, Amaranth, and Orange G, showed that the dye with a simpler structure and lower molecular mass decolorized considerably faster than the ones having a more complicated structure (higher molecular mass). The methyl orange degradation was also conducted using hollow nickel (Ni) nanoparticles and commercially available solid spherical Co and Ni nanoparticles. The results showed that Co-based nanoparticles outperformed Ni-based nanoparticles, with the hollow Co nanoparticles exhibiting the fastest degradation rate. Using the hollow Co nanoparticles is a very promising approach for the remediation of methyl orange dye containing wastewater due to the fast degradation rate and high degradation efficiency. In addition, these hollow Co nanoparticles are easily recycled because of their magnetic property.
Department of Chemical Engineering, University of Massachusetts Lowell, One University Ave, Lowell, MA 01854, USA.
Yingying
Y
Sha
Department of Chemical Engineering, University of Massachusetts Lowell, One University Ave, Lowell, MA 01854, USA.
Iswarya
I
Mathew
Department of Chemical Engineering, University of Massachusetts Lowell, One University Ave, Lowell, MA 01854, USA.
Qingzhou
Q
Cui
Department of Chemical Engineering, University of Massachusetts Lowell, One University Ave, Lowell, MA 01854, USA.
Molly
M
Clay
Department of Chemical Engineering, University of Massachusetts Lowell, One University Ave, Lowell, MA 01854, USA.
Fan
F
Gao
Department of Civil and Environmental Engineering, University of Massachusetts Lowell, One University Ave, Lowell, MA 01854, USA.
Xiaoqi Jackie
XJ
Zhang
Department of Chemical Engineering, University of Massachusetts Lowell, One University Ave, Lowell, MA 01854, USA. Electronic address: Zhiyong_Gu@uml.edu.
Zhiyong
Z
Gu
D001391:Azo Compounds / Q000737:chemistry*; D003035:Cobalt / Q000737:chemistry*; D004396:Coloring Agents / Q000737:chemistry*; D053768:Metal Nanoparticles / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry; D014865:Waste Disposal, Fluid / Q000379:methods; D018508:Water Purification / Q000379:methods
D001391:Azo Compounds; D004396:Coloring Agents; D003035:Cobalt; C100258:methyl orange; D009532:Nickel
Azo dye; Cobalt; Hollow particles; Magnetic separation; Methyl orange; Reductive degradation