Enhanced electrocatalytic activity of Pt‑SnO2 nanoparticles supported on natural bentonite‑functionalized reduced graphene oxide‑extracted chitosan from shrimp wastes for methanol electro‑oxidation

چکیده مقاله

In this work, tin (IV) oxide (SnO2) nanoparticles were synthesized based on Amaranthus spinosus plant.The produced graphene oxide by a modified Hummers’ method was functionalized with melamine (mRGO) and used accompanied by natural bentonite (Bnt) and extracted chitosan from shrimp wastes to prepare Bnt-mRGO-CH. This was utilized as novel support for anchoring Pt and SnO2 nanoparticles to prepare the novel Pt-SnO2/Bnt-mRGO-CH catalyst. The crystalline structure, morphology and uniform dispersion of nanoparticles in the prepared catalyst were determined by TEM images and XRD technique. The electrocatalytic performance of the Pt-SnO2/Bnt-mRGO-CH catalyst was evaluated for methanol electro-oxidation through electrochemical investigations including cyclic voltammetry, electrochemical impedance spectroscopy, and chronoamperometry techniques. Pt-SnO2/BntmRGO- CH showed enhanced catalytic activity compared to Pt/Bnt-mRGO-CH and Pt/Bnt-CH catalysts considering its higher electrochemically active surface area, higher mass activity, and better stability for methanol oxidation. SnO2/ Bnt-mRGO and Bnt-mRGO nanocomposites were also synthesized and did not show any significant activity for methanol oxidation. The results showed that Pt-SnO2/BntmRGO- CH could be a promising catalyst as anode material in direct methanol fuel cells