Rational Synthesis of Porous Graphitic-like Carbon Nitride Nanotubes Codoped with Au and Pd as an Efficient Catalyst for Carbon Monoxide Oxidation

Abstract

The precise fabrication of efficient catalysts for CO oxidation is of particular interest in a wide range of industrial and environmental applications. Herein, a scalable method is presented for the controlled synthesis of graphitic-like porous carbon nitride nanotubes (gC3N4NTs) codoped with Au and Pd (Au/Pd/gC3N4NTs) as efficient catalysts for carbon monoxide (CO) conversion. This includes the activation of melamine with nitric acid in the presence of ethylene glycol and metal precursors followed by consecutive polymerization and carbonization. This drives the formation of porous one-dimensional gC3N4NT with an outstanding surface area of (320.6 m2 g–1) and an atomic-level distribution of Au and Pd. Intriguingly, the CO conversion efficiency of Au/Pd/gC3N4NTs was substantially greater than that for gC3N4NTs. The approach thus presented may provide new avenues for the utilization of gC3N4 doped with multiple metal-based catalysts for CO conversion reactions which had been rarely reported before.

Data on the catalytic CO oxidation and CO2 reduction durability on gC3N4 nanotubes Co-doped atomically with Pd and Cu

“…We tested the CO oxidation reaction in a fixed bed quartz tubular reactor connected to an online gas analyzer (IR200, Yokogawa, Japan) in the presence of 50 mg of each catalyst. Initial pretreatment was carried out at 250 °C under an O 2 flow of 50 mL min −1 for 1 h, and then H 2 (30 mL min −1 ) for 1 h. Following that, the catalysts were exposed to the gas mixture involving of 4% CO, 20% O 2 , and 76% Ar with a total flow of 50 mL min −1 under continuous heating from 25 °C to 400 °C (5°min −1 ) [1], [2], [3], [4], [5]. The percentage of CO conversion (% CO) was calculated using the following equation:…”

“…Scheme 1 shows the fabrication process of Pd/Cu/gC 3 N 4 NTs, including the initial slow mixing of melamine in an aqueous solution of ethylene glycol solution, contains Pd- and Cu precursors [3]. Then, nitric acid was added dropwise to slowly deprotonate melamine and facilities the polymerization step to polymeric gC 3 N 4 , followed by annealing at elevated temperature to allow the carbonization process and formation of gC 3 N 4 NTs doped with Pd and Cu.

Scheme 1Schematic shows the synthesis process of Pd/Cu/gC 3 N 4 NTs.

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“…In particular, the addition of melamine and nitric acid should be sluggish to provide enough time for a consistent polymerization into uniform nanotubes. Nitric acid facilitates the deprotonation of active –NH 2 groups of melamine and allowing the conversion of melamine into melem and then to polymeric gC 3 N 4 composed of triazine-based units after carbonization at an elevated temperature [1], [2], [3], [4], [5]. Meanwhile, the concertation of Pd/Cu precursors should be lower to be anchored on the N-atoms of melamine and then facilitating the atomic doping of Pd/Cu instead of formation of nanoparticles [1], [2], [3], [4], [5].…”

The Recent Advances in the Mechanical Properties of Self-Standing Two-Dimensional MXene-Based Nanostructures: Deep Insights into the Supercapacitor

“…Carbon-based nanostructures (C-Ns) such as graphene, carbon nanotubes, and carbon nitride are of great interest due to their unique physiochemical merits such as high surface area, thermal stability, and outstanding mechanical properties [ 1 , 2 , 3 , 4 ]. These properties promoted the utilization of C-Ns in structural composites, protective coatings, fibers, energy storage, catalysis, and durable wearable sensors; however, their complicated fabrication process remains a major challenge [ 5 , 6 , 7 ].…”

Graphitic carbon nitride nanotubes: a new material for emerging applications

“…125 Simultaneous scrolling of GCN nanosheets and reduction of Au and Pd salts was applied to form Au-Pd NC-decorated GCNTs showing a promising high catalytic activity in the CO oxidation to CO 2 by molecular oxygen. 143 The tubes provide a carrier with a high surface area (around 320 m 2 g À1 ) for the catalytically active metal NCs as well as ensure the electronic contact among the distant Au-Pd NCs allowing for an efficient transfer of electrons between adsorbed CO and O 2 molecules.…”