Fibrous porous carbon electrocatalysts for hydrazine oxidation by using cellulose filter paper as precursor and self-template

Abstract

Hydrazine is often regarded as one of the most appealing fuels for fuel cells due to its high energy content, and also because it gives off only environmentally benign byproducts when it is used in fuel cells (cf. many other fuels produce the greenhouse gas CO 2). However, current electrocatalysts for the hydrazine oxidation reaction (HOR) in direct hydrazine fuel cells involve the expensive, unsustainable noble metals such as Pt. Herein, using cellulose filter paper both as a precursor and a self-template, we show the synthesis of nanoporous carbon electrocatalysts that can efficiently electrocatalyze HOR. To make the electrocatalysts, first cellulose filter paper is modified with metalamine complexes and then with silica shells. After carbonization of the resulting composite material at different temperatures, followed by removal of the silica shells, nanoporous carbon-based electrocatalysts are obtained. Notably, the intertwined structure of the cellulose matrix in the paper is taken advantage of to serve as selftemplate, allowing the formation of the desired fibrous, nanoporous carbon electrocatalysts. The materials show good electrocatalytic activity toward HOR, giving low overpotential and high current density. Thus, such nanoporous carbons can be good candidate materials to replace conventional metal-based catalysts commonly used in HOR and other related reactions.

Sensitive determination of hydrazine using poly(phenolphthalein), Au nanoparticles and multiwalled carbon nanotubes modified glassy carbon electrode

“…( Figure 6B and Table S3), If the diffusion coefficient for hydrazine is considered equal to 2.37×10 -5 cm 2 s -1 [33], the number of electrons can be calculated from the Cottrell equation, which is in good agreement with values reported in literature [34]. The number of electrons was calculated as 4.2 for the oxidation of hydrazine at the AuNPs/CNT/poly(PP)/GCE.…”

Superaerophobic graphene nano-hills for direct hydrazine fuel cells

“…Furthermore, our electrode takes advantage of its facile direct growth avoiding the utilization of binding agents that lead to deteriorated performance toward hydrazine oxidation. Similarly, VGNH-45 outperforms the fibrous porous carbon electrocatalysts reported by Martins et al 28 both in current density (~4 mA cm − 2 vs SCE at 0.1 V with a scan rate of 50 mV s − 1 ) and onset potential (−0.3 V vs SCE). Furthermore, VGNH-45 exhibits the lowest onset potential among previously published metallic/non-metallic electrocatalysts for hydrazine oxidation (Supplementary Table S2), making it one of the best available electrocatalysts for hydrazine oxidation.…”

“…Moreover, further mixing of binding agents increases the inactive volume and results in poor catalytic activity, as evidenced in other studies. 4,8,28 The inherent superaerophobic characteristics of our vertical graphene further facilitate and enhance the electro-oxidation of hydrazine on the electrode surface by swiftly removing the nitrogen bubbles produced on its surface. Such swift removal is the result of the creation of a discontinuous TPCL layer on the electrode surface, which then effectively shifts the potential toward a more negative onset value during electro-oxidation.…”

Preparation of a Stable Nanoscale Manganese Residue-Derived FeS@Starch-Derived Carbon Composite for the Adsorption of Safranine T

“…The full-survey spectrum (Figure 7a) shows that the main elements were C, O, Fe, Si, and S. The high-resolution C 1s, O 1s, Fe 2p, and S 2p XPS spectra provided detailed information referring to the surface chemistry. The C 1s spectrum was deconvoluted into four peaks at approximately 283.4, 283.9, 284.6, and 288.0 eV (Figure 7b), which were assigned to C–C/C–H, C–O, C=O, and O=C–O, respectively [29,36]. The O 1s core-level peak could be fitted into three peaks at 529.8, 531.0, and 532.2 eV (Figure 7c), ascribed to C–O, –OH, and C=O, respectively [12].…”