Rational synthesis of one-dimensional carbon nitride-based nanofibers atomically doped with Au/Pd for efficient carbon monoxide oxidation Kamel Eid a , Mostafa H. Sliem a , Amal S. Eldesoky b , Halema Al-Kandari c , Aboubakr M. Abdullah a,* a Center for Advanced Materials, Qatar University, Doha 2713, Qatar b Department of Biomedical Engineering, Higher Technological Institute, 10th of Ramadan, 228, Egypt c Department of Health Environment, College of Health Sciences, Public Authority for Applied Education and Training, P.O. Box 1428, Faiha 72853, Kuwait article info Article history: Received 28 February 2019 Received in revised form 6 May 2019 Accepted 13 May 2019 Available online xxx Keywords: CO conversion CO 2 production Carbon nitride gC 3 N 4 nanofibers abstract Controlled synthesis of carbon nitride nanostructures doped with noble metal-based cat- alysts is important in various catalytic applications. Herein, we developed a scalable, facile, and template-free approach for one-pot synthesis of one-dimensional gC 3 N 4 nanofibers co- doped with Au and Pd donated as (Au/Pd/gC 3 N 4 NFs). The developed method tailored the high mass production of uniform gC 3 N 4 nanofibers with a great surface area of (85 m 2 g 1 ) and coherently co-doped with Au and Pd. Intriguingly, the complete CO oxidation tem- perature of Au/Pd/gC 3 N 4 NFs (144  C) is significantly lower than that of Pd/gC 3 N 4 NFs (191  C) and Au/gC 3 N 4 NFs (205  C). The superior activity of Au/Pd/gC 3 N 4 NFs is attributed to the combination between outstanding inherent catalytic merits of Au/Pd and the unique physicochemical properties of gC 3 N 4 nanofibers. Our newly designed simple approach may open the way for utilization of gC 3 N 4 nanofibers in CO oxidation reaction. © 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Introduction Noble metals such as Pt, Pd, Ru, and Au are prominent with their great catalytic activities towards numerous oxidation and reduction reactions [1e8]. To this end, the CO gas-phase oxida- tion reaction in a hydrogen-rich stream medium by oxygen under thermal collision is among the most crucial catalytic re- actions in multiple applications such as energy conversion, fuel cells, industrial, and environmental remediation [9e11]. Inten- sive efforts were devoted to developing active catalysts for CO oxidation [12e16]. In this regard, Au-based and Pd-based catalysts are among the most active and durable catalysts for the CO oxidation at low temperatures, owing to their ability to pro- vide various accessible active sites for adsorption and activation of oxygen simultaneously with CO [17e24]. Also, Pd possesses a strong ability for CO-adsorption along with the capacity for retarding the adsorption of CO 2 products, which accelerate the CO-oxidation kinetics. For instance, Au nanoparticles loaded with mesoporous Fe 2 O 3 catalyst revealed up to 20 % higher CO conversion rate than that of the commercial Au/Fe 2 O 3 catalyst at lower temperatures [25]. The high dispersion of Au nanoparticles and their interaction with Fe 2 O 3 can significantly enhance the CO oxidation activity [26,27]. The CO oxidation activity of Pd/TiO 2 * Corresponding author. E-mail address: bakr@qu.edu.qa (A.M. Abdullah). Available online at www.sciencedirect.com ScienceDirect journal homepage: www.elsevier.com/locate/he international journal of hydrogen energy xxx (xxxx) xxx https://doi.org/10.1016/j.ijhydene.2019.05.105 0360-3199/© 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved. Please cite this article as: Eid K et al., Rational synthesis of one-dimensional carbon nitride-based nanofibers atomically doped with Au/ Pd for efficient carbon monoxide oxidation, International Journal of Hydrogen Energy, https://doi.org/10.1016/j.ijhydene.2019.05.105