Publications
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CuFe2O4/GNPs nanocomposites for symmetric supercapacitors and photocatalytic applications
Israr M., Iqbal J., Arshad A., Sadaf A., Rani M., Rani M., Jabeen S. Journal of Physics D: Applied Physics; 54 (39, 395501) 2021. 10.1088/1361-6463/ac036c. IF: 3.207
The design of novel and highly efficient multifunctional nanocomposite materials has attracted great attention due to the materials' applications in supercapacitors and wastewater treatment. In this work, CuFe2O4 (CuF) nanoparticle and graphene nanoplatelet nanocomposites ((CuF)1-x (GNPs) x ) have been fabricated by an in situ coprecipitation technique. The prepared (CuF)1-x (GNPs) x nanocomposites exhibit high energy storage (264.0 F g-1) with appreciable cyclic durability (74% over 1000 cycles), in a symmetric two-electrode supercapacitor cell, which can be attributed to the GNPs' induced conductivity enhancement, reduced agglomeration of CuF nanoparticles, interfacial transfer of charge and Fe-O-C and Cu-O-C covalent bonds in the nanocomposites. These factors also play a central role in increasing the photocatalytic efficiency. The nanocomposites show excellent visible light-mediated photodegradation efficiency (99.1% in 160 min) for methylene blue in water solution. The results suggest that the synthesized nanocomposites could be potential materials for the storage of electrochemical energy and photocatalytic decontamination of wastewater. © 2021 IOP Publishing Ltd.
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MOF-derived conformal cobalt oxide/C composite material as high-performance electrode in hybrid supercapacitors
Hosseinzadeh B., Nagar B., Benages-Vilau R., Gomez-Romero P., Kazemi S.H. Electrochimica Acta; 389 (138657) 2021. 10.1016/j.electacta.2021.138657. IF: 6.901
By pyrolysis of a simple Cobalt Metal Organic Framework (MOF) we have been able to synthesize a high-performance hybrid composite electrode with fibrous morphology conformal to the MOF, in a single step and at relatively low temperature (700°C). Indeed, the composite material containing cobalt oxide micro-nano-particles in highly graphitized carbon matrix (cobalt oxide/C-700) presents superb capacity of 1372 F/g (381 mAh/g) at a current density of 2.5 A/g. Besides, an asymmetric supercapacitor (ASC) was fabricated by using the CoxOy/C-700 composite as positive electrode and activated carbon (AC) as negative electrode. This ASC system delivered maximum energy density of 51.5 Wh/kg and maximum power density of 1687 W/kg © 2021
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Optimisation of NiO electrodeposition on 3D graphene electrode for electrochemical energy storage using response surface methodology
Agudosi E.S., Abdullah E.C., Numan A., Khalid M., Mubarak N.M., Benages-Vilau R., Gómez-Romero P., Aid S.R., Omar N. Journal of Electroanalytical Chemistry; 882 (114992) 2021. 10.1016/j.jelechem.2021.114992. IF: 4.464
In this study, NiO was electrodeposited on a 3D graphene electrode to produce a nanocomposite with enhanced electrochemical properties. The electrodeposition process parameters such as electrolyte concentration, deposition time, and deposition potential were statistically optimised using response surface methodology. The statistical analysis showed that the optimal electrodeposition conditions to be 0.3 M, 10 min, and -1.2 V for electrolyte concentration, deposition time, and deposition potential, respectively. Furthermore, the predicted model and experimental results for the specific capacity of G-NiO were determined to be 240.91 C/g and 240.58 C/g at 3 mV/s. The results show that the electrochemical deposition technique can be employed as a fast and reliable synthesis route to develop graphene-based metal oxide nanocomposites. The structural and morphological properties were determined by XRD and FESEM studies. The electrochemical measurements revealed the excellent electrochemical performance of 3D graphene NiO composite (G-NiO) for energy storage applications. © 2021 Elsevier B.V.
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Polyoxometalates (POMs): From electroactive clusters to energy materials
Horn M.R., Singh A., Alomari S., Goberna-Ferrón S., Benages-Vilau R., Chodankar N., Motta N., Ostrikov K., Macleod J., Sonar P., Gomez-Romero P., Dubal D. Energy and Environmental Science; 14 (4): 1652 - 1700. 2021. 10.1039/d0ee03407j. IF: 38.532
Polyoxometalates (POMs) represent a class of nanomaterials, which hold enormous promise for a range of energy-related applications. Their promise is owing to their "special"structure that gives POMs a truly unique ability to control redox reactions in energy conversion and storage. One such amazing capability is their large number of redox active sites that arises from the complex three-dimensional cluster of metal-oxide ions linked together by oxygen atoms. Here, a critical review on how POMs emerged from being molecular clusters for fundamental studies, to next-generation materials for energy applications is provided. We highlight how exploiting the versatility and activity of these molecules can lead to improved performance in energy devices such as supercapacitors and batteries, and in energy catalyst applications. The potential of POMs across numerous fields is systematically outlined by investigating structure-property-performance relationships and the determinant factors for energy systems. Finally, the challenges and opportunities for this class of materials with respect to addressing our pressing energy-related concerns are identified. This journal is © The Royal Society of Chemistry.
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Sheet-on-sheet like calcium ferrite and graphene nanoplatelets nanocomposite: A multifunctional nanocomposite for high-performance supercapacitor and visible light driven photocatalysis
Israr M., Iqbal J., Arshad A., Gómez-Romero P. Journal of Solid State Chemistry; 293 (121646) 2021. 10.1016/j.jssc.2020.121646. IF: 3.498
Calcium ferrite-graphene nanoplatelets nanocomposites with sheet-on-sheet like morphology are fabricated and investigated for their physicochemical characteristics, electrochemical energy storage capacity and photocatalysis. Interestingly, the (CF)1-x (GNPs)x nanocomposite-based electrode has shown maximum specific capacitance up to 422 Fg-1 at 0.25 Ag-1 with excellent cycling stability, 2.6 times higher than that of neat CF nanosheets. Furthermore, the synergistic contribution from photocatalytic and photo-Fenton reactions enables (CF)1-x (GNPs)x nanocomposites to offer superior photocatalytic activity (99.4% dye removal in 90 min). The inclusion of GNPs significantly enhances the charge carriers separation and transportation. The excellent electrochemical efficiency of (CF)1-x (GNPs)x could be attributed to the 2D interfacial interactions that provide a better charge transport at electrode/electrolyte interface. These interactions are also responsible for creating effective charge transport pathways and efficient e−/h+ separation leading to rapid dye-degradation, which make the material potential for remediation of water pollution and energy storage systems. © 2020 Elsevier Inc.
