Center for Advanced Materials Research
http://hdl.handle.net/10576/3414
2024-03-28T12:18:21ZHighly porous PtPd nanoclusters synthesized via selective chemical etching as efficient catalyst for ethanol electro-oxidation
http://hdl.handle.net/10576/53397
Highly porous PtPd nanoclusters synthesized via selective chemical etching as efficient catalyst for ethanol electro-oxidation
Ahmad, Yahia H.; Mohamed, Assem T.; Alashraf, Abdullah; Matalqeh, Maha; El-Shafei, Ahmed; Al-Qaradawi, Siham Y.; Aljaber, Amina S.
Direct ethanol fuel cells (DEFCs) have received great interest owing to their high power density and environmental friendness. Nevertheless, the designing of active, durable, and efficient anode for DEFCs is a profound challenge. In this context, we reported the synthesis of PtPd porous nanoclusters (PtPd PNCs) as electrocatalyst for ethanol oxidation reaction (EOR). This was implemented through two-step synthesis. Firstly, ternary AgPtPd nanodendrites (NDs) were synthesized via ultrasound-assisted co-reduction of the metal precursors using ascorbic acid (AA) as a mild reductant and Pluronic F127 as structure-directing agent. Thereafter, PtPd PNCs were created by selective chemical etching of AgPtPd nanocrystals in 1 M HNO3. The textural properties, morphology, and elemental composition of the studied electrocatalysts were investigated, and their catalytic activities towards ethanol electrooxidation were examined. PtPd PNCs revealed a high surface area of 83.0 m2 g−1 and high porosity compared to its counterparts. Additionally, it depicted enhanced catalytic performance towards ethanol electrooxidation in 1 M KOH with mass activity of 1.8 A mg−1 compared to PtPd NDs (0.97 A mg−1), Pt NDs (0.51 A mg−1), and Pt/C (0.33 A mg−1). The enhanced catalytic performance of PtPd PNCs was ascribed to high surface area, high porosity, and increased active sites.
2020-01-01T00:00:00ZPolyolefin-Based Smart Self-Healing Composite Coatings Modified with Calcium Carbonate and Sodium Alginate.
http://hdl.handle.net/10576/53090
Polyolefin-Based Smart Self-Healing Composite Coatings Modified with Calcium Carbonate and Sodium Alginate.
Nawaz, Muddasir; Shakoor, Rana Abdul; Al-Qahtani, Noora; Bhadra, Jolly; Al-Thani, Noora Jabor; Kahraman, Ramazan
Corrosion-related damage incurs significant capital costs in many industries. In this study, an anti-corrosive pigment was synthesized by modifying calcium carbonate with sodium alginate (SA), and smart self-healing coatings were synthesized by reinforcing the anti-corrosive pigments into a polyolefin matrix. Structural changes during the synthesis of the anti-corrosive pigment were examined using scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Moreover, thermal gravimetric analysis confirmed the loading of the corrosion inhibitor, and electrochemical impedance spectroscopic analysis revealed a stable impedance value, confirming the improved corrosion resistance of the modified polyolefin coatings. The incorporation of the anticorrosive pigment into a polyolefin matrix resulted in improved pore resistance properties and capacitive behavior, indicating a good barrier property of the modified coatings. The formation of a protective film on the steel substrate reflected the adsorption of the corrosion inhibitor (SA) on the steel substrate, which further contributed to enhancing the corrosion resistance of the modified coatings. Moreover, the formation of the protective film was also analyzed by profilometry and elemental mapping analysis.
2024-02-27T00:00:00ZIon-imprinted membranes for lithium recovery: A review
http://hdl.handle.net/10576/52999
Ion-imprinted membranes for lithium recovery: A review
Sifani, Zavahir; Riyaz, Najamus Sahar; Elmakki, Tasneem; Tariq, Haseeb; Ahmad, Zubair; Chen, Yuan; Park, Hyunwoong; Ho, Yeek-Chia; Shon, Ho Kyong; Han, Dong Suk
This review critically examines the effectiveness of ion-imprinted membranes (IIMs) in selectively recovering lithium (Li) from challenging sources such as seawater and brine. These membranes feature customized binding sites that specifically target Li ions, enabling selective separation from other ions, thanks to cavities shaped with crown ether or calixarene for improved selectivity. The review thoroughly investigates the application of IIMs in Li extraction, covering extensive sections on 12-crown-4 ether (a fundamental crown ether for Li), its modifications, calixarenes, and other materials for creating imprinting sites. It evaluates these systems against several criteria, including the source solution's complexity, Li+ concentration, operational pH, selectivity, and membrane's ability for regeneration and repeated use. This evaluation places IIMs as a leading-edge technology for Li extraction, surpassing traditional methods like ion-sieves, particularly in high Mg2+/Li+ ratio brines. It also highlights the developmental challenges of IIMs, focusing on optimizing adsorption, maintaining selectivity across varied ionic solutions, and enhancing permselectivity. The review reveals that while the bulk of research is still exploratory, only a limited portion has progressed to detailed lab verification, indicating that the application of IIMs in Li+ recovery is still at an embryonic stage, with no instances of pilot-scale trials reported. This thorough review elucidates the potential of IIMs in Li recovery, cataloging advancements, pinpointing challenges, and suggesting directions for forthcoming research endeavors. This informative synthesis serves as a valuable resource for both the scientific community and industry professionals navigating this evolving field.
2024-04-30T00:00:00ZRecent Trends in Applications of X-ray Photoelectron Spectroscopy (XPS) Technique in Coatings for Corrosion Protection
http://hdl.handle.net/10576/52825
Recent Trends in Applications of X-ray Photoelectron Spectroscopy (XPS) Technique in Coatings for Corrosion Protection
Khan, Adnan; Fayyaz, Osama; Shakoor, R. A.; Mansoor, Bilal
Corrosion-primarily a surface phenomenon, strongly influences an asset's performance, durability, and reliability, as costs of corrosion-related repairs and refurbishment can run into millions of dollars. Notably, in the Middle East region, direct corrosion costs are estimated to be approximately 5% of the gross domestic product (GDP), a value that represents an enormous economic burden. In this context, the corrosion of metals is one of the most fundamental causes of components and equipment failure across different industrial sectors. In the oil and gas sector, extreme operating conditions and corrosive environments exacerbate the extent and seriousness of corrosion and result in a vast majority of component failures. Therefore, a comprehensive understanding of corrosion mechanisms and processes taking place on a component's surface is vital for efficient and cost-effective asset integrity management. Various advanced analytical techniques such as X-ray Photoelectron Spectroscopy (XPS), X-ray fluorescence (XRF) spectroscopy, Localized Electrochemical Impedance Spectroscopy (LEIS), Scanning vibrating electrode technique (SVET) and Scanning Ion-Selective Electrode Technique (SIET) provide useful quantitative information about corrosion. Amongst those, XPS is one of the most sophisticated technique that can be smartly utilized to study corroded surfaces, protective coatings and understanding of various corrosion mechanisms. XPS can also be effectively used to assess corrosion byproducts to understand the various surface reactions, localized surface chemistry and alteration in electrical responses under different corrosive environments. This chapter focuses on the utilization of XPS technique in coatings for materials protection. Special attention is paid to cover its role in compositional analysis of various types of coatings (metallic and polymeric) that are actively investigated for corrosion protection. At the same time, use of XPS can also be extended to explore smart polymeric coatings confirming the self-release of various inhibitors and self-healing agents loaded in nanocarriers. Furthermore, the role of XPS in post corrosion analysis is described, which provides ample information to understand the corrosion protection mechanism. A short note on future scope and challenges faced by XPS technology in corrosion research is also provided for the interest and motivation of the readers to excel in this important area of research.
2022-01-01T00:00:00Z