Synthesis, Characterization, and Electrochemical Performance of rGO-MWCNT/Mn-Co-Cu Nanohybrid as Novel Catalyst for Methanol Electrooxidation

Abstract

The design of new electrocatalysts based on transition metals for direct alcohol fuel cells can lead to the wide application of these renewable energy sources by reducing costs and improving stability. Here, we report a hydrothermal method to modify graphene oxide (GO) by the addition of multiwalled carbon nanotubes (MWCNTs) to prepare reduced GO (rGO)-MWCNT as a support material for direct methanol fuel cells. Oxid composites based on Mn, Co, and Cu are synthesized and placed on the surface of the support material through a hydrothermal method. Structural and textural characteristics of bimetallic and trimetallic nanohybrids are examined. Modified carbon paste electrodes are used to study the electrochemical performance of nanohybrids toward methanol electrooxidation in an alkaline medium. The modified support material shows higher surface area and porosity compared to GO, which increased the amount of loading without agglomeration of metallic particles. The current density obtained by rGO-MWCNT/Mn-Co-Cu is higher compared to bimetallic catalysts with the same support material, which confirms the synergistic effect of using these metals together. This nanohybrid preserves 91.40% and 83.01% of the initial current density after 500 and 1000 cycles of cyclic voltammetry, respectively. The high stability and durability of rGO-MWCNT/Mn-Co-Cu confirm that this transition metal-based nanohybrid can be effectively used as an electrocatalyst for methanol electrooxidation in an alkaline medium.

Critical Role of Interface Design in Acceleration of Overall Water Splitting and Hybrid Electrolysis Process: State of the Art and Perspectives

“…Similarly, a NiS 2 film produced a 10 mA cm –2 current density in the presence of 0.45 M 2-propanol, 2-butanol, 2-pentanol, and cyclohexanol during conversion to acetone, 2-butanone, 2-pentanone, and cyclohexanone, respectively, which is nearly 160 mV lower than that required for water splitting with corresponding Faradaic efficiencies of 99.8, 99.5, 98.5, and 92.2%. Ternary metal nanoparticles like Mn–Co–Cu nanohybrid or metal oxides like NiCoZn could efficiently oxidize methanol. , …”

Characteristics and Applicability Analysis of Nanomorphological Structures for Chemosensors: A Systematic Review

“…Research related to MWCNTs includes electrochemical performance, sensors, thin films, electrocatalysts, batteries, etc. [100][101][102][103][104][105].…”

Geometric Transformation of Modified Multiwalled Carbon Nanotubes-Based Heterometallic Nanostructured Material: A Model for the Electrochemical Discrimination of Insecticides

“…27−29 The modification mainly intensifies the conductivity of MWCNTs by providing more electron transfer and making it a more advantageous nanomaterial for electrochemical studies. 30,31 The modification of MWCNTs with heterocomplexes manipulates the properties of the combined material and provides an excellent electrochemical activity. 32 Novel strategies for the development of new materials as well as improving the electrocatalytic activity and stability of current materials are greatly desired.…”

“…Therefore, modification of MWCNTs by different materials such as metal nanoparticles, metal oxides, and organic ligands tends to open up these bundles and make them dispersible in different solvents. − Song et al synthesized a hybrid containing FeCo bimetallic organic frameworks, a melamine mixture, and bamboo-like N-doped CNTs, entangled with N-doped carbon nanosheet nanocomposites (FexCoy–N–C), which shows an outstanding oxygen reduction reaction performance in alkaline medium by the synergistic effect . Moreover, materials containing heterometal having application in homogenous catalysis, electrocatalysis, excellent electrical conductivity had also been reported. , In particular, noncovalent immobilization of polyaromatic hydrocarbons such as the pyrene moiety on the sidewall of MWCNTs via π–π interactions was reported as a straightforward strategy. − The CNTs functionalized with small organic molecules or polymer-based molecules have been utilized for increasing the dispersibility as well as surface area of MWCNTs via π–π interactions, van der Waals interaction, and electrostatic interaction. − The modification mainly intensifies the conductivity of MWCNTs by providing more electron transfer and making it a more advantageous nanomaterial for electrochemical studies. , The modification of MWCNTs with heterocomplexes manipulates the properties of the combined material and provides an excellent electrochemical activity . Novel strategies for the development of new materials as well as improving the electrocatalytic activity and stability of current materials are greatly desired .…”