Biomass‐Derived 3D Carbon Aerogel with Carbon Shell‐Confined Binary Metallic Nanoparticles in CNTs as an Efficient Electrocatalyst for Microfluidic Direct Ethylene Glycol Fuel Cells

Abstract

as biological renewability, low toxicity, and easy storability. [5] Despite the recent improvements in DEGFCs, the technology is still hindered by the problems of conventional platinum (Pt) anode catalysts, such as surface poisoning, high cost, and scarcity. [6] Recently, palladium (Pd) nanostructures have emerged as a promising EG oxidation catalyst in alkaline media, eliminating the necessity of the Pt nanocatalyst for EG oxidation. [7] However, Pd nanocatalysts are prone to rapid deterioration under surface poisoning and instability. [8] The formation of bimetals with non-precious transition metals (PdM, M = Ni, Co, Fe, Cu, Mo, Sn, etc.) is an efficient strategy to improve the stability without sacrificing the catalytic activity. [9] The oxophilic nickel (Ni) is recognized as a naturally abundant metal with enhanced corrosion resistance. [10] The inclusion of Ni into the crystal lattice of Pd facilitates active sites for -OH adsorption (OH ads ) and weakens their interaction with reaction intermediates adsorbed onto the Pd surface. [10,11] In parallel, metal nanoparticles decorated on carbon supports have also been shown to improve EG oxidation via their high electrical conductivity and catalytic activity. [12] The 3D porous structure of carbon nanotubes (CNTs) could considerably control the aggregation or stacking of the adjacent subunits, facilitating a uniform distribution of metal nanoparticles and increasing the number of accessible reactive sites for catalytic surface reactions. [13] However, the conventional strategy used for the fabrication of metal nanoparticles anchored onto CNTs involves strenuous multistep procedures, and the acidification process involved distorts the interconnected conduction channels, which consequently limits the EG oxidation kinetics. [14] Hence, the development of catalytically active metal nanoparticles encased within the graphitic layers of CNTs is highly desirable. [15] The mass transfer capability and catalytic activity of carbon nanostructures could be further improved with the development of porosity and heteroatom doping into the carbon skeleton. [16] Recently, 3D carbon aerogels (CAs) have grasped prevailing research attention as free-standing electrodes for diverse energy applications owing to their large specific surface area, low density, interconnected fibrous structure, and rapid charge transport pathways. [17,18] In this context, Pd nanoparticles Flexible and 3D carbon aerogels (CAs) composed of carbon nanotubes (CNTs) with carbon shell-confined binary palladium-nickel (Pd x -Ni y ) nanocatalysts on carbon fibers (Pd x -Ni y /NSCNT/CA) have been developed through a facile chemical vapor deposition method. The 3D porous carbon network and the synergistic effect of carbon shell-confined bimetal nanoparticles of rationally constructed aerogels facilitate enhanced electrocatalytic and antipoisoning activities toward ethylene glycol (EG) oxidation reaction compared to the commercial Pt/C catalyst. With the 3D morphological features and direct growth of Pd-Ni bimet...

NiCo2S4 Nanowire‐Decorated Flexible Carbon Foam for Sensitive Glucose Sensors

“…In the last few decades, various nanomaterials (e. g., noble metals, alloy metals, transition metal compounds) were applied to construct enzyme‐free glucose sensors. Recently, transition metal oxides, transition metal hydroxides and transition metal sulfides have been prevalently used as non‐noble‐metal catalysts for glucose electro‐oxidation, originating from its good electrocatalytic activity, low cost and abundant source.…”

A Remarkable Class of Nanocomposites: Aerogel Supported Bimetallic Nanoparticles

“…For smaller Co:Ni ratios, presence of Co decreased NP size. N and S doped PdNi/CA was prepared by adding raw cotton into palladium(II) chloride and nickel(II) acetate solution (Raj kumar et al, 2019). After hydrothermal treatment with thiourea, PdNi anchored carbon fiber hydrogels doped with N and S were obtained.…”

“…Supported Pd electrocatalysts also suffered from rapid degradation and poisoning (Li et al, 2016). N and S doped PdNi/CA NPs confined in carbon nanotubes (CNT) were tested for ethylene glycol oxidation by cyclic voltammetry (CV) in alkaline electrolyte and in a microfluidic direct ethylene glycol fuel cell (Raj kumar et al, 2019). Authors reported that CNT growth increased the flexibility of CA and the carbon shell around the PdNi NPs prevented agglomeration, delamination, and dissolution, hence increasing the stability.…”

Few‐layer graphene coated on indium tin oxide electrodes prepared by chemical vapor deposition and their enhanced glucose electrooxidation activity

“…Fuel cells are clean, efficient, and promising technology for the future . Fuel cells are available of different types such as proton exchange membrane fuel cells, direct methanol fuel cells, direct ethanol fuel cells, alkaline fuel cells, direct formic acid fuel cells, direct urea fuel cells, direct ethylene glycol fuel cells, and direct glucose fuel cells . Glucose is the valuable carbohydrate in nature and could be readily extracted from biomass.…”