Ejikeme Raphael Ezeigwe

• PhD
• Norwegian University of Science and Technology

NiMoO4 nanorods have been directly synthesised on graphene sheet using a facile solvothermal method with subsequent calcination treatment. As an electrode for electrochemical capacitors, the graphene-NiMoO4 composite electrode prepared at a mass ratio of 1:8 exhibited a specific capacitance of 670 F/g at 0.3 A/g and good rate capability. When cycle...

Highly pyrolytic graphite (HOPG) was used as a precursor to produce graphene in an apt ratio of ethanol and water. The as-synthesised graphene was subsequently used to produce graphene-Cobalt oxide (Co3O4) composites via solvothermal method. Morphological and structural characterizations of the prepared composites demonstrated that Co3O4 was succes...

A facile, green and efficient approach consisted of a novel liquid phase exfoliation and solvothermal synthesis method has been adopted to prepare graphene/ZnO nanocomposites as electrode material for electrochemical capacitors. Highly pristine graphene was produced from mild sonication treatment of raw highly pyrolytic graphite in a solution at a...

Well-crystallized Manganese Dioxide (MnO2) nanorods anchored on graphene sheets have been successfully synthesis via a facile, effective and scalable solvothermal process as electrode material for electrochemical capacitors. Highly pristine graphene synthesized from mild treatment of raw highly pyrolytic graphite in a proper ratio of ethanol and wa...

Lithium-ion batteries are poised to play a pivotal role in achieving net-zero emissions amidst the ongoing global green transition. The quest for new and sustainable battery chemistries is imperative to meet the anticipated increase in demand. Consequently, the development of cost-effective electrochemical techniques holds significant importance in...

Extending the lifespan of lithium-ion batteries (LIBs) can be achieved either by repurposing batteries under similar conditions within the same application segment, as a first-life extension, or by extending them into different segments with different operations as a second-life application. In the latter case, it is crucial to comprehend not only...

The specific energy of lithium-ion batteries (LIBs) can be enhanced through various approaches, one of which is increasing the proportion of active materials by thickening the electrodes. However, this typically leads to the battery having lower performance at a high cycling rate, a phenomenon commonly known as rate capacity retention. One solution...

The environmental impact of lithium-ion batteries (LiBs) depends directly on their useful lifetime. Doubling the useful lifetime cuts the environmental impact per functional unit in half. However, if the cell is insufficient for one application it can still be sufficient for another. The beneficial operational value of LiBs between various applicat...

The sluggish kinetics of multiphase sulfur conversion with homogeneous and heterogeneous electrochemical processes, causing the “shuttle effect” of soluble polysulfide species (PSs), is the challenges in terms of lithium–sulfur batteries (LSBs). In this paper, a Mn3O4−x catalyst, which has much higher activity for heterogeneous reactions than for h...

Flexible and all‐solid‐state zinc‐air batteries (ZABs) are highly useful and also in demand due to their theoretical high energy densities and special applications. The limitation in their performance arises due to their catalyst‐coated cathode electrodes in terms of catalytic activity and stability as well as cost. In this paper, a novel and envir...

Vast improvements in nanotechnology have led to the wide usage of nanomaterials (NMs) in daily products. This study reviews the interactions between NMs and microalgae in terms of impacts on growth and photosynthetic efficiency, and their toxicity on microalgae. All types of NMs such as carbon-based NMs (CNMs), metal oxide-based NMs (MONMs) and nob...

Rechargeable lithium-O2/CO2 and lithium-CO2 batteries are the promising energy devices expected to be the next generation of lithium batteries with high energy densities. However, their unsatisfactory performance of crucial materials such as electrodes, catalysts and electrolytes are still the challenges hindering the technology’s practical applica...

The performance degradation of electrochemical energy storage devices such as batteries is one of the largest challenges hindering their many practical applications. Developing novel electrode and electrolyte materials with self-healing abilities to repair internal or external damages is an important and effective approach for mitigating the degrad...

In this study, an MOF-derived ternary zinc-nickel-cobalt hollow polyhedron (ZNC ZIF-67) is synthesized via a facile and scalable templated method and evaluated as the electrode material for supercapacitors. Several physical methods, including XRD, EDX, SEM, TEM, and HR-TEM, are used to characterize the morphology, structure, and composition of this...

This study reports a facile, environmentally-friendly and scalable liquid-phase exfoliation of HOPG process combined with a simple solvothermal method, consequently with calcination for the synthesis of highly porous graphene/Zinc–Nickel–Cobalt (ZNC) nanosheets arrays. The crystallographic and morphological information of the nanostructures were ev...

In order to improve the energy density of the supercapacitor, fabrication of next-generation materials with inimitable morphology and superior electrochemical performance is highly desired. Herein, a novel hybrid electrode material, namely graphene-Zn3V2O8 nanocomposites, were successfully prepared via facile solvothermal process followed by therma...

NiMoO4 were synthesised on multiwalled carbon nanotubes (MWCNTs) via a simple and environment-friendly solvothermal method. The nanostructures were interconnected forming a sponge-like network providing a large surface area easily accessible to electrons and ion during intercalation-deintercalation process. The MWCNT/NiMoO4 nanocomposite exhibited...

The key motivation of this study is to investigate the potential of graphene/metal oxides nanocomposites as electrodes for electrochemical capacitor applications. It is envisioned that the positive synergistic effect between graphene and metal oxides (where novel graphene material acts as a highly conductive platform for ease of ion transfer kineti...

In the present study, graphene/Ni3V2O8 nanocomposites were successfully synthesised by a facile solvothermal approach in which the graphene sheets were fabricated via the environmentally benign liquid phase exfoliation with optimised ethanol to water volume ratio (2:3). The nanocomposites integrated separately the advantages of graphene sheet and p...