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A simple, sustainable route to flexible microporous carbon cloth for energy storage applications (2023)
Journal Article
Alkhaldi, T., Blankenship, L. S., & Mokaya, R. (2023). A simple, sustainable route to flexible microporous carbon cloth for energy storage applications. Materials Advances, 4(16), 3559-3571. https://doi.org/10.1039/d3ma00157a

Activated carbon cloth (ACC) has the potential to be extremely useful in gas capture and storage applications as it combines high porosity, robustness, and flexibility with ease of handling. While it has been produced by a few researchers, the synthe... Read More about A simple, sustainable route to flexible microporous carbon cloth for energy storage applications.

Solvothermal synthesis of organoclay/Cu-MOF composite and its application in film modified GCE for simultaneous electrochemical detection of deoxyepinephrine, acetaminophen and tyrosine (2023)
Journal Article
Mouafo-Tchinda, E., Kemmegne-Mbouguen, J. C., Nanseu-Njiki, C. P., Langmi, H. W., Kowenje, C., Musyoka, N. M., & Mokaya, R. (2023). Solvothermal synthesis of organoclay/Cu-MOF composite and its application in film modified GCE for simultaneous electrochemical detection of deoxyepinephrine, acetaminophen and tyrosine. RSC Advances, 13(30), 20816-20829. https://doi.org/10.1039/d3ra03850e

An organoclay/copper-based metal-organic framework (MOF) composite was synthesized using a solvothermal method by growing a Cu-BTC (copper(ii) benzene-1,3,5-tricarboxylate) MOF from a mixture of the MOF precursor solution in which various amounts of... Read More about Solvothermal synthesis of organoclay/Cu-MOF composite and its application in film modified GCE for simultaneous electrochemical detection of deoxyepinephrine, acetaminophen and tyrosine.

Electrochemical Sensor for Ascorbic Acid, Acetaminophen and Nitrite Based on Organoclay/Zr-MOF Film Modified Glassy Carbon Electrode (2022)
Journal Article
Ngwem, M. C. N., Kemmegne‐Mbouguen, J. C., Langmi, H. W., Musyoka, N. M., & Mokaya, R. (2022). Electrochemical Sensor for Ascorbic Acid, Acetaminophen and Nitrite Based on Organoclay/Zr-MOF Film Modified Glassy Carbon Electrode. ChemistrySelect, 7(40), Article e202202308. https://doi.org/10.1002/slct.202202308

A composite (Sa-HTDMA/UiO-66) consisting of organoclay (Sa-HTDMA) and a metal-organic framework (UiO-66) was prepared using organically modified natural Cameroonian clay and Zr-MOF. The organoclay was obtained by intercalating in its interlayer hexad... Read More about Electrochemical Sensor for Ascorbic Acid, Acetaminophen and Nitrite Based on Organoclay/Zr-MOF Film Modified Glassy Carbon Electrode.

Brute force determination of the optimum pore sizes for CO2 uptake in turbostratic carbons (2022)
Journal Article
Blankenship, L. S., Albeladi, N., Alkhaldi, T., Madkhali, A., & Mokaya, R. (2022). Brute force determination of the optimum pore sizes for CO2 uptake in turbostratic carbons. Energy Advances, 1(12), 1009-1020. https://doi.org/10.1039/d2ya00149g

Porosity, and in particular pore size is one of the most important considerations in the development of porous carbons for CO2 capture. Current methods for determining the optimum pore size for adsorption of gases either make very broad assumptions (... Read More about Brute force determination of the optimum pore sizes for CO2 uptake in turbostratic carbons.

Generalised predictability in the synthesis of biocarbons as clean energy materials: targeted high performance CO2 and CH4 storage (2022)
Journal Article
Alali, I., & Mokaya, R. (2022). Generalised predictability in the synthesis of biocarbons as clean energy materials: targeted high performance CO2 and CH4 storage. Energy and Environmental Science, 15(11), 4710-4724. https://doi.org/10.1039/d2ee02322a

This work shows how knowledge of any biomass and choice of carbonisation process can offer a generalised route to predictability in the preparation of activated biocarbons. We demonstrate that based on O/C ratio of carbonaceous matter, it is possible... Read More about Generalised predictability in the synthesis of biocarbons as clean energy materials: targeted high performance CO2 and CH4 storage.

Optimization of biodiesel synthesis from Jatropha curcas oil using kaolin derived zeolite Na-X as a catalyst (2022)
Journal Article
Otieno, S., Kengara, F., Kowenje, C., & Mokaya, R. (2022). Optimization of biodiesel synthesis from Jatropha curcas oil using kaolin derived zeolite Na-X as a catalyst. RSC Advances, 12(35), 22792-22805. https://doi.org/10.1039/d2ra03278c

Biodiesel is an alternative renewable green fuel obtainable from the reaction of plant or animal oil with a low molecular weight alcohol in the presence of a catalyst. However, the cost of its production remains high due to costly feedstock, the majo... Read More about Optimization of biodiesel synthesis from Jatropha curcas oil using kaolin derived zeolite Na-X as a catalyst.

Modulating the porosity of activated carbons via pre-mixed precursors for simultaneously enhanced gravimetric and volumetric methane uptake (2022)
Journal Article
Altwala, A., & Mokaya, R. (2022). Modulating the porosity of activated carbons via pre-mixed precursors for simultaneously enhanced gravimetric and volumetric methane uptake. Journal of Materials Chemistry A, 10(26), 13744-13757. https://doi.org/10.1039/d2ta00421f

Pre-mixed precursors containing biomass-derived carbonaceous matter of varying O/C ratio and polypyrrole have been used as starting materials to modulate the porosity of activated carbons. The use of pre-mixtures of polypyrrole and CNL carbon (from a... Read More about Modulating the porosity of activated carbons via pre-mixed precursors for simultaneously enhanced gravimetric and volumetric methane uptake.

Calcium coordination compounds of anionic forms of hydrogen dipicolinate and quinolinate: synthesis, characterization, crystal structures and DFT studies (2022)
Journal Article
Tella, A. C., Oladipo, A. C., Olayemi, V. T., Gordon, A., Ogunlaja, A. S., Alimi, L. O., …Walton, R. I. (2022). Calcium coordination compounds of anionic forms of hydrogen dipicolinate and quinolinate: synthesis, characterization, crystal structures and DFT studies. Structural Chemistry, https://doi.org/10.1007/s11224-022-01935-x

Two calcium coordination compounds [Ca(2,6-Hpdc)2(H2O)2] 1 and [Ca2(2,3-pdc)2(H2O)6]n2 (where 2,6-H2pdc = 2,6-pyridinedicarboxylic acid and 2,3-H2pdc = 2,3-pyridinedicarboxylic acid) were grown at room temperature. The compounds were characterized us... Read More about Calcium coordination compounds of anionic forms of hydrogen dipicolinate and quinolinate: synthesis, characterization, crystal structures and DFT studies.

Confirmation of pore formation mechanisms in biochars and activated carbons by dual isotherm analysis (2022)
Journal Article
Blankenship, L. S., Jagiello, J., & Mokaya, R. (2022). Confirmation of pore formation mechanisms in biochars and activated carbons by dual isotherm analysis. Materials Advances, https://doi.org/10.1039/d2ma00141a

In this study biochars and activated carbons were synthesized either directly via the pyrolysis of sodium carboxymethyl cellulose (NC) or via hydrothermal carbonization of sawdust (SD) in an aqueous solution of KOH. The amount of porogen was varied b... Read More about Confirmation of pore formation mechanisms in biochars and activated carbons by dual isotherm analysis.

Direct and mild non-hydroxide activation of biomass to carbons with enhanced CO2 storage capacity (2022)
Journal Article
Altwala, A., & Mokaya, R. (2022). Direct and mild non-hydroxide activation of biomass to carbons with enhanced CO2 storage capacity. Energy Advances, 1(4), 216-224. https://doi.org/10.1039/d1ya00085c

Potassium oxalate (PO) was trialled as a non-corrosive and less toxic activating agent for the direct activation of biomass (sawdust, SD). The PO + SD mixtures were activated either in powder form or after compaction into pellets. The resulting activ... Read More about Direct and mild non-hydroxide activation of biomass to carbons with enhanced CO2 storage capacity.

Modulating the porosity of carbons for improved adsorption of hydrogen, carbon dioxide, and methane: a review (2022)
Journal Article
Blankenship, L. S., & Mokaya, R. (2022). Modulating the porosity of carbons for improved adsorption of hydrogen, carbon dioxide, and methane: a review. Materials Advances, 3(4), 1905-1930. https://doi.org/10.1039/d1ma00911g

Porous carbons provide a low-cost route to a highly stable material for the adsorption of various gases. In particular, activated carbons (ACs) and zeolite templated carbons (ZTCs) show promise in their ability to capture and store environmentally re... Read More about Modulating the porosity of carbons for improved adsorption of hydrogen, carbon dioxide, and methane: a review.

Porous carbons from sustainable sources and mild activation for targeted high-performance CO2 capture and storage (2020)
Journal Article
Aljumialy, A. M., & Mokaya, R. (2020). Porous carbons from sustainable sources and mild activation for targeted high-performance CO2 capture and storage. Materials Advances, 1(9), 3267-3280. https://doi.org/10.1039/d0ma00449a

Carbon activation typically involves corrosive activating reagents such as KOH and NaOH. In this report, a less corrosive activating agent, i.e., potassium oxalate (PO), was explored for the preparation of activated carbons from biomass (hydrochar fr... Read More about Porous carbons from sustainable sources and mild activation for targeted high-performance CO2 capture and storage.

Synthesis, characterization and density functional theory of copper (ii) complex and cobalt (ii) coordination polymer for detection of nitroaromatic explosives (2020)
Journal Article
Tellaa, A. C., Olayemiab, V. T., Adekolaa, F. A., Oladipoac, A. C., Adimulaa, V. O., Ogare, J. O., …Mokaya, R. (2021). Synthesis, characterization and density functional theory of copper (ii) complex and cobalt (ii) coordination polymer for detection of nitroaromatic explosives. Inorganica Chimica Acta, 515, Article 120048. https://doi.org/10.1016/j.ica.2020.120048

In recent years there has been a significant interest to design luminescent materials to detect explosives with a great degree of selectivity, sensitivity, and fast response time. Two new luminescent compounds, [Cu(Biphen)(Meim)(H2O)] 1 and [Co(BDC)(... Read More about Synthesis, characterization and density functional theory of copper (ii) complex and cobalt (ii) coordination polymer for detection of nitroaromatic explosives.

Predictable and targeted activation of biomass to carbons with high surface area density and enhanced methane storage capacity (2020)
Journal Article
Altwala, A., & Mokaya, R. (2020). Predictable and targeted activation of biomass to carbons with high surface area density and enhanced methane storage capacity. Energy and Environmental Science, 13(9), 2967-2978. https://doi.org/10.1039/d0ee01340d

© The Royal Society of Chemistry. A challenge in the synthesis of activated carbons is that currently there is no way to prepare materials with predictable and targeted properties. In particular, there are no material parameters or characteristics of... Read More about Predictable and targeted activation of biomass to carbons with high surface area density and enhanced methane storage capacity.

Simultaneous quantification of acetaminophen and tryptophan using a composite graphene foam/Zr-MOF film modified electrode (2020)
Journal Article
Kemmegne-Mbouguen, J. C., Tchoumi, F. P., Mouafo-Tchinda, E., Langmi, H. W., Bambalaza, S. E., Musyoka, N. M., …Mokaya, R. (2020). Simultaneous quantification of acetaminophen and tryptophan using a composite graphene foam/Zr-MOF film modified electrode. New Journal of Chemistry, 44(30), 13108-13117. https://doi.org/10.1039/d0nj02374d

© The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. A graphene foam/zirconium-based metal-organic framework composite (GF/UiO-66) was synthesised and then employed to modify glassy carbon electrodes (GCE). These mod... Read More about Simultaneous quantification of acetaminophen and tryptophan using a composite graphene foam/Zr-MOF film modified electrode.

Experimental Demonstration of Dynamic Temperature-Dependent Behavior of UiO-66 Metal–Organic Framework: Compaction of Hydroxylated and Dehydroxylated Forms of UiO-66 for High-Pressure Hydrogen Storage (2020)
Journal Article
Bambalaza, S. E., Langmi, H. W., Mokaya, R., Musyoka, N. M., & Khotseng, L. E. (2020). Experimental Demonstration of Dynamic Temperature-Dependent Behavior of UiO-66 Metal–Organic Framework: Compaction of Hydroxylated and Dehydroxylated Forms of UiO-66 for High-Pressure Hydrogen Storage. ACS Applied Materials and Interfaces, 12(22), 24883-24894. https://doi.org/10.1021/acsami.0c06080

High-pressure (700 MPa or ∼100 000 psi) compaction of dehydroxylated and hydroxylated UiO-66 for H2 storage applications is reported. The dehydroxylation reaction was found to occur between 150 and 300 °C. The H2 uptake capacity of powdered hydroxyla... Read More about Experimental Demonstration of Dynamic Temperature-Dependent Behavior of UiO-66 Metal–Organic Framework: Compaction of Hydroxylated and Dehydroxylated Forms of UiO-66 for High-Pressure Hydrogen Storage.

The effects of metakaolinization and fused-metakaolinization on zeolites from quartz rich natural clays (2019)
Journal Article
Otieno, S. O., Kengara, F. O., Kemmegne-Mbouguen, J. C., Langmi, H. W., Kowenje, C. B., & Mokaya, R. (2019). The effects of metakaolinization and fused-metakaolinization on zeolites from quartz rich natural clays. Microporous and Mesoporous Materials, 290, Article 109668. https://doi.org/10.1016/j.micromeso.2019.109668

A variety of zeolites have been synthesized by performing either metakaolinization or fused-metakaolinization of natural clays prior to the hydrothermal synthesis step. To understand the differences arising from performing fused metakaolinization rat... Read More about The effects of metakaolinization and fused-metakaolinization on zeolites from quartz rich natural clays.

Pre-mixed precursors for modulating the porosity of carbons for enhanced hydrogen storage: towards predicting the activation behaviour of carbonaceous matter (2019)
Journal Article
Balahmar, N., & Mokaya, R. (2019). Pre-mixed precursors for modulating the porosity of carbons for enhanced hydrogen storage: towards predicting the activation behaviour of carbonaceous matter. Journal of Materials Chemistry A, 2019(29), 17466-17479. https://doi.org/10.1039/c9ta06308k

Highly porous carbons prepared from pre-mixtures of polypyrrole and raw sawdust or sawdust hydrochar achieve much higher surface area than is possible from single use of any one of the precursors. The pre-mixed precursors offer carbons with ultrahigh... Read More about Pre-mixed precursors for modulating the porosity of carbons for enhanced hydrogen storage: towards predicting the activation behaviour of carbonaceous matter.

New perspectives on supercritical methane adsorption in shales and associated thermodynamics (2019)
Journal Article
Tang, X., Ripepi, N., Rigby, S., Mokaya, R., & Gilliland, E. (2019). New perspectives on supercritical methane adsorption in shales and associated thermodynamics. Journal of Industrial and Engineering Chemistry, 78, 186-197. https://doi.org/10.1016/j.jiec.2019.06.015

Understanding methane adsorption behavior in shales is fundamental for optimizing shale gas development as the adsorbed methane is a large portion of the subsurface shale gas resource. However, the adsorption mechanism of supercritical methane in sha... Read More about New perspectives on supercritical methane adsorption in shales and associated thermodynamics.

Compaction of a zirconium metal–organic framework (UiO-66) for high density hydrogen storage applications (2018)
Journal Article
Bambalaza, S. E., Langmi, H. W., Mokaya, R., Musyoka, N. M., Ren, J., & Khotseng, L. E. (2018). Compaction of a zirconium metal–organic framework (UiO-66) for high density hydrogen storage applications. Journal of Materials Chemistry A, 6(46), 23569-23577. https://doi.org/10.1039/c8ta09227c

© The Royal Society of Chemistry. We report a rare case whereby a metal-organic framework (MOF), namely UiO-66, is compacted at high pressure (∼700 MPa or 100 000 psi) resulting in densification and improved total volumetric hydrogen storage capacity... Read More about Compaction of a zirconium metal–organic framework (UiO-66) for high density hydrogen storage applications.