Low-temperature growth of nitrogen-doped carbon nanofibers by acetonitrile catalytic CVD using Ni-based catalysts

Tomohiro Iwasaki,Satoru Watano,Yuri Makino,Makoto Fukukawa,Hideya Nakamura

doi:10.1007/s13204-016-0535-x

Tomohiro Iwasaki, Satoru Watano + Show 3 more

Open Access

https://doi.org/10.1007/s13204-016-0535-x

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Journal: Applied nanoscience	Publication Date: Jun 15, 2016
Citations: 22	License type: CC BY 4.0

Affiliation: Osaka Prefecture University

Abstract

To synthesize nitrogen-doped carbon nanofibers (N-CNFs) at high growth rates and low temperatures less than 673 K, nickel species (metallic nickel and nickel oxide) supported on alumina particles were used as the catalysts for an acetonitrile catalytic chemical vapor deposition (CVD) process. The nickel:alumina mass ratio in the catalysts was fixed at 0.05:1. The catalyst precursors were prepared from various nickel salts (nitrate, chloride, sulfate, acetate, and lactate) and then calcined at 1073 K for 1 h in oxidative (air), reductive (hydrogen-containing argon), or inert (pure argon) atmospheres to activate the nickel-based catalysts. The effects of precursors and calcination atmosphere on the catalyst activity at low temperatures were studied. We found that the catalysts derived from nickel nitrate had relatively small crystallite sizes of nickel species and provided N-CNFs at high growth rates of 57 ± 4 g-CNF/g-Ni/h at 673 K in the CVD process using 10 vol% hydrogen-containing argon as the carrier gas of acetonitrile vapor, which were approximately 4 times larger than that of a conventional CVD process. The obtained results reveal that nitrate ions in the catalyst precursor and hydrogen in the carrier gas can contribute effectively to the activation of catalysts in low-temperature CVD. The fiber diameter and nitrogen content of N-CNFs synthesized at high growth rates were several tens of nanometers and 3.5 ± 0.3 at.%, respectively. Our catalysts and CVD process may lead to cost reductions in the production of N-CNFs.

Highlights

We found that the catalysts derived from nickel nitrate had relatively small crystallite sizes of nickel species and provided nitrogen-doped carbon nanofibers (N-carbon nanofibers (CNFs)) at high growth rates of 57 ± 4 g-CNF/g-Ni/h at 673 K in the chemical vapor deposition (CVD) process using 10 vol% hydrogen-containing argon as the carrier gas of acetonitrile vapor, which were approximately 4 times larger than that of a conventional CVD process
N-doped CNFs were synthesized at high growth rates and low temperatures in an acetonitrile catalytic CVD process using Al2O3-supported Ni-based (Ni/NiO) catalysts
We found that both the use of Ni(NO3)2 as the catalyst precursor and H2-containing Ar as the carrier gas of acetonitrile vapor in CVD could contribute effectively to enhancement of the catalytic activity, resulting in high growth rates of 57 ± 4 g-CNF/g-Ni/h at 400 °C—

Summary

Introduction

The use of carbon nanofibers (CNFs) is being expanded to improve the performance of industrial products, such as batteries, supercapacitors, solar cells, sensors, catalysts, and adsorbents, because CNFs have excellent electrical, thermal, mechanical, and physicochemical properties resulting from their unique carbon nanostructure and morphologies (Desmaris et al 2015; Feng et al 2014; Jiang 2014; Peng et al 2016; Song and Shen 2014; Zhang et al 2014, 2016). Abstract To synthesize nitrogen-doped carbon nanofibers (N-CNFs) at high growth rates and low temperatures less than 673 K, nickel species (metallic nickel and nickel oxide) supported on alumina particles were used as the catalysts for an acetonitrile catalytic chemical vapor deposition (CVD) process.

Results

Conclusion