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131 results on '"Ola, Oluwafunmilola"'

10. Effect of metal doping and supports on TiO₂-based catalysts for CO₂ photoreduction

Author

Ola, Oluwafunmilola and Maroto-Valer, Mercedes

Subjects
662.6
Abstract

CO₂ photoreduction into fuels has the potential to reduce future dependence on fossil fuels. This work has examined the effects of metal ion doping on the properties and performance of TiO₂ for CO₂ reduction in different photoreactor configurations. Metal (Pd/Rh, Ni, Cu, V, Cr and Co) doped TiO₂ photcatalysts synthesized by the sol-gel method were suspended or immobilized onto monoliths threaded with optical fibers or quartz plates. Doping with Cu, V and Cr facilitated anatase to rutile phase transformation, while Ni and Co doping inhibited transformation to rutile. All the metal atoms were found to be replacing some of the Ti atoms in the cystal lattice of TiO₂ during synthesis, thus causing a shift to longer wavelengths. Metal doping can considerably enhance the photocatalytic activity of TiO₂ for CO₂ reduction to fuels under UV or visible light irradiation when H₂O was used as a reductant. The activities of the best photocatalysts (lwt%Cu-TiO₂ and lwt%Co-TiO₂) were 67 times higher than pure TiO₂. More importantly, the conversion rate, 79.95μmol/gcath achieved using the quartz plate reactor was near one order of magnitude higher than other reactor configurations due to better accessibility of the catalytic surface to photons and the reactants during photocatalytic reaction.

Published
2014

19. Recent Progress in Multifunctional Graphene-Based Nanocomposites for Photocatalysis and Electrocatalysis Application.

Author

Yang, Zanhe, Zhou, Siqi, Feng, Xiangyu, Wang, Nannan, Ola, Oluwafunmilola, and Zhu, Yanqiu

Subjects
PHOTOCATALYSIS, CHEMICAL stability, CHEMICAL properties, NANOCOMPOSITE materials, PHOTOREDUCTION, ENERGY shortages
Abstract

The global energy shortage and environmental degradation are two major issues of concern in today's society. The production of renewable energy and the treatment of pollutants are currently the mainstream research directions in the field of photocatalysis. In addition, over the last decade or so, graphene (GR) has been widely used in photocatalysis due to its unique physical and chemical properties, such as its large light-absorption range, high adsorption capacity, large specific surface area, and excellent electronic conductivity. Here, we first introduce the unique properties of graphene, such as its high specific surface area, chemical stability, etc. Then, the basic principles of photocatalytic hydrolysis, pollutant degradation, and the photocatalytic reduction of CO2 are summarized. We then give an overview of the optimization strategies for graphene-based photocatalysis and the latest advances in its application. Finally, we present challenges and perspectives for graphene-based applications in this field in light of recent developments. [ABSTRACT FROM AUTHOR]

Published
2023
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20. Multifunctional ultralight, recoverable, piezoresistive, and super thermal insulating SiC nanowire sponges

Author

Chen, Yu, primary, Han, Lei, additional, Ola, Oluwafunmilola, additional, Liu, Guangsheng, additional, Wang, Nannan, additional, Saadi, Zakaria, additional, Neves, Ana I. S., additional, Tabari, Rana Sabouni, additional, Thummavichai, Kunyapat, additional, Khalil, Ahmed M. E., additional, Xia, Yongde, additional, Sun, Shibin, additional, and Zhu, Yanqiu, additional

Published
2022
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26. Reaction and Reactor Engineering

Author

Lauwaert, Jeroen, primary, Thybaut, Joris W., additional, Goguet, Alexandre, additional, Hardacre, Christopher, additional, Ola, Oluwafunmilola, additional, and Maroto-Valer, Mercedes, additional

Published
2017
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28. Multifunctional ultralight, recoverable, piezoresistive, and super thermal insulating SiC nanowire sponges.

Author

Chen, Yu, Han, Lei, Ola, Oluwafunmilola, Liu, Guangsheng, Wang, Nannan, Saadi, Zakaria, Neves, Ana I. S., Tabari, Rana Sabouni, Thummavichai, Kunyapat, Khalil, Ahmed M. E., Xia, Yongde, Sun, Shibin, and Zhu, Yanqiu

Subjects
FATIGUE limit, NANOWIRES, THERMAL insulation, PHOTOTHERMAL effect, THERMAL conductivity, SILICON carbide, CHEMICAL stability, THERMAL stability
Abstract

Ultralight three‐dimensional (3D) architectured silicon carbide (SiC) nanowire sponges with integrated properties of recoverable compressibility, outstanding high‐temperature thermal and chemical stability, and fire‐retardance have been actively pursued in recent years. However, efficient construction of SiC nanowire sponges with well‐controlled overall shapes and distribution of SiC nanowires remains challenging. Herein, by coupling the electrospinning technique and carbothermal reduction process, we have developed a new fabrication process for highly porous and free‐standing 3D SiC nanowire (SiCNW) sponges with closely attached nanowires through thermal treatment of stacked electrospun PAN/SiO2 nanofiber membranes. The resulting SiCNW sponges possess ultralow density (∼29 mg cm−3), excellent compressive recoverability from large compressive deformation (up to 40% strain), and fatigue resistance, which endow them with excellent piezoresistive sensing capability under a variety of complex conditions. Furthermore, the sponges display superb thermal insulation (thermal conductivity of 24 mW m−1K−1) and fire‐retardance. We believe that the present process provides technical clues for the development of other multifunctional ceramic sponges, and that further development of these ultralight multifunctional ceramic sponges offers potential for the design of advanced components for application in harsh engineering environments. [ABSTRACT FROM AUTHOR]

Published
2023
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29. Construction of CoP/Co2P Coexisting Bifunctional Self-Supporting Electrocatalysts for High-Efficiency Oxygen Evolution and Hydrogen Evolution

Author

Zhang, Linyi, Chen, Yu, Liu, Guangsheng, Li, Zhen, Liu, Song, Tiwari, Santosh K., Ola, Oluwafunmilola, Pang, Bingyan, Wang, Nannan, and Zhu, Yanqiu

Subjects
General Chemical Engineering, General Chemistry
Abstract

Development of a low cost, high activity, and stable nonprecious metal bifunctional catalyst for electrocatalytic water cracking is a hot topic and big challenge. In this paper, we prepared a nitrogen-doped carbon nanotube (NCNT)-enhanced three-dimensional self-supported electrocatalyst with CoP and Co2P coexistence by a two-step strategy of high-temperature carbonization and low-temperature phosphorylation. Furthermore, the induced three-dimensional carbon network skeleton facilitates rapid charge transfer. In addition, the active sites of the carbon foam (CF) are greatly increased by the construction of hollow structures. As a bifunctional electrocatalyst, CoP/Co2P/NCNT@CF exhibited excellent catalytic activity for both hydrogen evolution reaction and oxygen evolution reaction in alkaline media, requiring low overpotentials of 133 and 289 mV to obtain a current density of 10 mA cm-2, respectively. Additionally, the synthesized catalysts also exhibit good long-term stability, maintaining high catalytic activity after 20 h of continuous operation. We also confirmed the main driving force to improve the electron transfer between the heterostructures of Co and P by XPS spectra. The excellent electrocatalytic performance can be attributed to the close synergy between the highly active CoP/Co2P/NCNT and CF. This study provides a new strategy for the design of highly active bifunctional self-supporting electrocatalysts.

Published
2022

39. Implanting MnO 2 into Hexagonal Boron Nitride as Nanoadditives for Enhancing Tribological Performance.

Author

Chen, Xiaorong, Chen, Wenting, Zhang, Linyi, Zeng, Minli, Yang, Shiming, Yang, Zanhe, Ola, Oluwafunmilola, Thummavichai, Kunyapat, Wang, Nannan, and Zhu, Yanqiu

Subjects
BORON nitride, LUBRICANT additives, TRIBOLOGY, LUBRICATING oils, NANOCOMPOSITE materials, FRICTION
Abstract

Hexagonal boron nitride nanosheets (h-BNNs) show great potential in the field of tribology due to their typical two-dimensional layered structure and are essential for replacing conventional sulfur/phosphate-containing additives. However, the large particle size and poor dispersion of h-BNs seriously restrict their green lubrication application. In this paper, MnO2@h-BNNs nanocomposites were successfully prepared by ultrasonically exfoliating a hydrothermal method. The tribological properties of MnO2@h-BNNs nanocomposites as lubricant additives in poly-alpha-olefin oil (PAO) were investigated. The results show the oil dispersed with 0.25 wt% MnO2@h-BNNs had the best friction reduction and antiwear effect with 42% and 11.2% reduction, respectively, compared with the plain oil. Through further wear surface analyzing, we verified the antiwear mechanism of additives in filling the micropits and grooves on the wear surface and forming a friction protection film including Fe2O3, MnO2, and BN on the wear surface, avoiding direct contact between the friction subsets. This can provide ideas for other lubricating oil additives. [ABSTRACT FROM AUTHOR]

Published
2022
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43. Metal Sulfide Nanoparticles Anchored N, S Co-doped Porous Carbon Nanofibers as Highly Efficient Bifunctional Electrocatalysts for Oxygen Reduction/Evolution Reactions

Author

Niu, Qijian, Ola, Oluwafunmilola, Chen, Binling, Zhu, Yanqiu, Xia, Yongde, and Ma, Guiping

Subjects
Electrochemistry
Abstract

Developing multi-functional electrocatalysts is a key for new energy techniques, such as fuel cells, metal-air batteries, and water splitting. In this paper, a bifunctional (ORR/OER) electrocatalysts, metal sulfide nanoparticles anchored N, S co-doped porous carbon nanofibers were successfully synthesized by a simultaneous carbonization and sulfurization of ZIFs/PAN electrospun composite nanofibers. The as-prepared material Zn/Co-ZIFs/PAN-CS-800 catalyst exhibited an excellent electrocatalytic performance in both ORR and OER. Such excellent ORR and OER performance comes from the active metal sulfide species, N, S co-doping effect, porous structure, and good conductivity. Our method can be used to produce other metal sulfide nanoparticles combined with N, S co-doped porous carbon materials with potential applications in the field of energy storage and conversion.

Published
2020

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