Browsing by Author "Eze, C. N."

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A Study of Chemically Deposited Barium Titanate (Batio3) Thin Films Doped with Natural Dyes and Their Photovoltaic Applications.
(International Journal of Scientific Research in Physics and Applied Sciences, 2023-12) Eze, C. N.; A.I. Onyia; M.N. Nnabuchi
Abstract - Ternary thin films of BaTiO3 nanostructures were synthesized at 90 0C via the Chemical Bath Deposition (CBD) route under room temperature. They were doped with three natural (local/organic) dyes extracted from Lawsonia inermis leaves, Beta vulgaries roots, and Jatropha curcas leaves and thereafter annealed at 400 0C. doped and as-deposited nanostructures were studied employing XRD, SEM, FTIR, UV VIS, and EDXRF. Our X-ray diffraction (XRD) studies revealed a polycrystalline structure. The SEM studies exhibited porous structures advantageous for dye loading. The EDXRF shows the compositional elements. The FTIR reveals the carboxylate and photo physical properties of the dyes. The UV-VIS investigation presented band gap energies Eg of the doped as ad (BR) = 2.60 eV; bd (OO) = 1.61 eV; ccd (LL) = 1.90 eV against the as-deposited AD (g1) = 3.10 eV showing that the dyes reduced the Eg of the thin films occurring from an increased absorption coefficient α. The Nano porous, as-deposited thin films adsorb the extracted dyes on the surface and the interaction between the Nano porous films and the natural dyes used to dope BaTiO3 was studied using UV-VIS spectrophotometer with the aim of investigating their photovoltaic applications
A STUDY OF CHEMICALLY DEPOSITED OXIDE- BASED TERNARY THIN FILM OF ZINC TITANATE (ZnTiO3) DOPED WITH NATURAL DYES AND THEIR POTENTIAL PHOTOVOLTAIC APPLICATIONS.
(journal of nano and material science research, 2025) Eze, C. N.
The ternary metal oxide thin film of ZnTiO3 doped with three different natural dyes were synthesized on glass substrate via solution growth (SG) at room temperature. Chemical baths were used which contained Zinc Sulphate (ZnSO4.7H2O), Sodium Hydroxide (NaOH), Titanium Chloride (TiCl3), distilled water and calibrated drops per bath of organic dyes: Lawsonia inermis, Beta vulgaries and Jatropha curcas respectively. Each deposit which was set at a temperature of 80 0C lasted for 1 h and each deposit was annealed at 400 0C for 1 h. These deposited nano thin films were characterized for their structural, morphological, optical properties, elemental composition and electronic (chemical) structure and presence of functional groups by means of X-ray diffraction (XRD), Scanning Electron Microscope (SEM), UV-VIS spectrophotometer, Energy Dispersive X-ray Fluoroscopy (EDXRF) and photoluminescence Fourier Transform Infrared Radiation Spectroscopy (FTIR). Polycrystalline thin films were evidenced which marked porosity offered them maximum surface area for dye loading which is critical for photosensitization in dye sensitized solar cells (DSSCs). Such doping presented band gaps of doped ZnTiO3 from 1.84 eV to 3.45 eV depending on dopants applied as against undoped film band gap that was 3.55 eV. The FTIR results showed good photophysical, carboxylate and modification properties of the dyes which helps in sunlight harvesting, anchoring and surface structure modification of the films. The dye influenced the optical properties of the samples and in particular, the reduction of the energy band gap, Eg from an increase in absorption coefficient α, giving high absorbance A, low extinction coefficient k, low reflectance R, which inferred its potential applications in solar energy devices when used in construction, poultry houses, solar cells and DSSCs.
ANALYSIS OF NUCLEAR POWER GENERATION AND MANAGEMENT IN NIGERIA
(The Nigerian Journal of Research and Production, 2011-04) Eze, C. N.
Abstract Energy is the biggest challenge of the twenty-first century. We must lift much of the world out of poverty, which will require large increases in energy production while simultaneously curbing greenhouse gas emissions. In order to accomplish this, we must adopt solutions that are based on efficiency, renewable, nuclear energy production and safety, and if it can be demonstrated, carbon sequestration and then adopt the idea which said that “an energy future without a significant contribution from nuclear energy simply isn't an option”. Since renewables are by their very nature intermittent, they cannot have a huge impact unless--and until--we develop adequate energy storage technologies and drastically improve our fragile electricity distribution network. In a developing country like Nigeria where energy demand is far more than the supply due to insufficient power generation, incessant outage of power as a result of failure of power generation plants, due to technical faults and ageing, the use of nuclear power plant provides answers to the problems of electricity generation. Since energy is important for socio-economic development considering safety, economy, reliability, sustainability and even waste management, nuclear energy as an alternative source of energy should be used. The nuclear power option once again is appealing to some opinion leaders in the world. As an alternative to fossil fuels and looming energy crisis, we can find a solution to the problem of climate change, environmental degradation, and fossil fuel dependency, while guaranteeing equitable, sustainable development. Many problems stand in the way of this so called renaissance, not least the mammoth costs involved and the fact that no safe system has yet been devised for the long-term storage of nuclear wastes. Furthermore despite many improvements in the safety of nuclear power plants, worries persist about the risk of nuclear accidents such as those that occurred at Three Mile Island in USA in 1979 and Chernobyl in Ukraine in 1986. However, this alternative source of energy will pose a political problem in that nuclear power plant could be used for both military and economic purposes. It is observed that all attempts, so far, to produce enough electricity power for its citizens have hit the rocks in this country, Nigeria, due to various reasons including inefficiency and corruption. The purpose of this paper is to urge Nigeria (and other countries like it) not to give up its efforts to generate sufficient electric power by the usual traditional methods (coal, solar, wind, etc) but to continue to try until success has been achieved in the short term and to vigorously endeavour to go nuclear in the long term since nuclear generation of electricity is the ultimate in power supply. The paper also shows how the nuclear program has been achieved in some other countries and how Nigeria can follow suit in the development of nuclear energy for peaceful purposes.
ATTAINMENT OF THE 7-POINT AGENDA IN NIGERIA THROUGH SCIENCE AND TECHNOLOGY
(The Nigerian Journal of Research and Production, 2010-04) Eze, C. N.
The 7-point agenda of the Nigerian President, Musa Umaru Yar’adua is a suitable road map to the quick modernization and industrialization of Nigeria. The agenda touches on the most important aspects of the needs of the people of this country. For instance, adequate supply of power and energy, the effective modernization of education at all levels from primary to tertiary, the beefing up of the system of transportation throughout the country, the departure from the dependence on crude oil to new areas of employment and wealth creation such as in agriculture and solid minerals and the assurance of security especially in Niger Delta zone of the country – all these will give this country a new lease of life never experienced before. This paper, therefore, contains analysis of the bone of contention of the -point agenda as enumerated by the president himself. Namely, power and energy, food security, wealth creation, transportation, land reform, education and security as epitomized in the Niger Delta situation. The purpose of this paper is to critically examine the issues involved in achieving the agenda, or otherwise, show the strengths and weaknesses of the various proposals, in relationship with the existing science and technology in this country at the moment, and finally draw conclusion and make recommendations. The science and technology available in this country has already produced very formidable manpower that can handle Nigeria’s current state of development. If, however, there are certain rare areas where suitable technology is not available, the country is rich enough to pay for technology transfer from outside. The re-branding of Nigeria now in progress, though not part of the 7-point agenda, has created excellent opportunities for smoothening the rough edges of the agenda and, hopefully, will act as icing sugar and finishing touches to it. Keywords: Science and technology, the 7-point agenda, development, Nigerian government and the masses.
Chemically Deposited Doped Titanate Ternary Metal Oxide Thin Films Via Spray Pyrolysis Route-Preparation, Characterization and Solar Cell Application Analysis
(4th Africa Nano Conference and Workshop, 2021-07) Eze, C. N.; Onyia, A. I; Nnabuchi, A. I
Spray pyrolysis method of deposition is a simple, cheap, low cost and conventional method that gives uniform deposition. With this motivation, a simple approach of spraying ZnTiO3 nanoparticles on a substrate is reported. The approach occurs with ternary metal oxide and is environmentally friendly. This follows the quest to further improve the physical and chemical properties of ternary metal oxide which has become noticeable in recent times. The crystallization temperature of ZnTiO3 was 2000C. Among other investigations the SEM result shows a perovskite structure-like morphology. Further characterization performed on the thin film for the structural aspect which gives XRD of the thin film shown on the diffractogram is in agreement with the standard diffraction of ZnTiO3 which is identified as tetragonal structure. UV-Vis absorption spectroscopy was also used to characterize the final product and the spectra indicated that the absorbance obviously increased in the visible light region with absorption peak at about 209 nm and with optical band gap which infers that it has potential application in solar energy devices.
Doped Metal Oxide Thin Films for Enhanced Solar Energy Applications
(Springer, 2021) Eze, C. N.; Obodoa, R. M; Ezugwu, S. C; Ezemaa, F .I.
Solar energy is energy from the sun and its provision is in abundance without payments. It is renewable and more promising than its counterpart energy source called fossil fuels. Fossil fuels have energy crises ranging from inadequacy to depletion, pollution etc. This solar energy could be technically collected, utilized but there could still be an improved method of collecting the solar energy for more advanced utilization called solar energy. Achieving this by the process of doping metal oxide thin films with impurities like carbon derivatives, organic synthetic dyes etc. will harnesses dopant characteristics for optimal performance. The doped materials help in controlling the composition and structure of dopants, which enhance their performance. The metal oxide semiconductor thin films are synthesized via varieties of processes on working active layer materials with stable interfaces for solar energy conversion and versatile applications in several areas valuable for humankind.
Electrode Materials for Energy Storage and Conversion
(Tailor and Francis, 2022) Eze, C. N.; Obodo, R. M; Ezema, F. I; Kebede, M. A
Alkaline earth stannates are rare earths and are crucial material systems evident of their attractive physical properties. They are ternary metal oxide semiconductors.They have both perovskite structures (BaSnO3, SrSnO3) and spinel structures(ZnSnO4).They are compounds of tin (Sn). Broadly, these compoundsexhibit elevated melting-points, elevated thermal stability, great thermal expansion coefficient, excellent chemical resistance, small thermal conductivity and great ionic conductivity which guarantee their possible applicacability in thermal barrier coating, hosts for luminescence centers, hosts for nuclear wastes, oxygen monitoring sensors, high-temperature catalysts, solar cells applicability and solid electrolytes in large temperature fuel cells. When these materials are produced as nanoparticles, the decreased particle size as well as enlarged specific surface area could result in diverse phase transition temperatures, improved catalytic activity, and enhanced processability. Commonly, these rare earth complex oxide nanomaterialscould be fabricated via conventional solid-state reactions, coprecipitation, sol-gel, hydrothermal, self-propagation techniques, etc.In the background of energy crisis, climate change, long-term supply and security, solar energy is a striking source. For these stannates to be better utilized in solar energy harvesting applications, they are better doped.The stannates considered here are SrSnO3, BaSnO3 and ZnSnO4.The doped stannates are used in various ways as stated above and equally as transparent conductors, light absorbers, photoanodes, etc. This is in relation to optical properties.The Optical properties, structural order and surface properties of these materials are considered. On doping, thesestannates maintain excellent transparency which makes them excellent materials as transparent conductor particularlyZnSnO4. They are found highly useful in photocatalysis and other areas.In solar energy harvesting, solar energy harvesting devices could have a better output when nanostructures like doped stannates are incorporated in them. Such advance is hopeful. It improves the power conversion efficiencies (PCE) of such devices by utilizing new nanostructures to update device structural designs. This is an applauded process.
Estimation of the Calorific Value and Electrical Energy Potential of Waste Generated Biomass Within Abakaliki Meteropolis Ebonyi State, Nigeria
(American Journal of Nano Research and Applications, 2020) Igbo, M. E; Chikeleze, P. C; Onyia, A.I; Igbo, N. E; Eze, C. N.; Chima, A.I
Abstract: This study was conducted to determine the electrical energy potential of municipal solid waste (MSW) generated biomass within Abakaliki metropolis, Ebonyi State, Nigeria. The MSW samples were collected at two different points from each of the waste management zones, with each zone covering at least twelve (12) streets. It was then sorted into three major categories according to their constituents viz; metals, plastics and biomass. In this study, the biomass component of the MSW sample was is our focus. Thus, the biomass sample was sun dried and then ground into powdered form. It was thoroughly mixed, shredded, sieved and subsequently analysed at the Lorcin Technologies Port Harcourt, Nigeria. Currently, an average of 360 tons of MSW is generated within Abakaliki metropolis on daily bases. This translates to an electrical energy potential of approximately 320MW. The MSW-generated biomass analysis estimates the Gross Calorific Value (GCV) or Higher Heating Values (HHV) to be 11.644MJ/kg. This value which practically determines the electrical energy of the waste sample is highly suitable for many thermal conversion processe. This translate to the fact 0.925kg of biomass will generate electrical power of 1KWh. Hence, one unit of electricity=10765KJ/Kg/GVC (KJ/Kg).
HARVESTING RENEWABLE ENERGY FOR A SUSTAINABLE FUTURE USING QUANTUM DOT TECHNOLOGY
(13th annual and international hybrid conference of the renewable and alternative energy of nigeria, 2025-03) Ikeri, H.I; Ndubueze, D. N; Eze, C. N.; Achuka, E. I; Nwagbara, O.; Onuabuchi, V. C
This paper explores the role of quantum dots in revolutionizing renewable energy technologies, addressing challenges such as stability and environmental impact. Renewable energy is essential for a sustainable future and advancements in nanotechnology have opened new possibilities for efficient energy harvesting. The result obtained indicates that quantum dots (QDs), display tunable electronic properties, discrete electronic state and high photon absorption efficiency. The novel properties allow for new design architectures such as immediate band, multiple exciton generation and multiple junction solar cell technologies. These mechanics have shown to derive quantitative gains in the solar to electricity conversion efficiency to surpass the Shockley and Quisser limit imposed on conventional cells. By integrating QD-based systems with solar photovoltaics and next generation batteries would paves the way for more efficient and sustainable energy solutions.
Modern Optics Waves for Universities and Polytechnics
(Sofiata publishers, 2022) Ikeri, H.I; Eze, C. N.; Nicholas, N. T
Optical Properties of PbSe, PbS, and PbTe Semiconductor Quantum Dots and their Applications
(2025-08) Ikeri, H.I; Harry, S.T; Achuka, E.I; Eze, C. N.; Asielue, O.K; Ndubueze, N.D
Abstract - Optical properties of PbSe, PbS, and PbTe semiconductors in confinement regimes have been studied using the Brus equation. The results indicate that QDs exhibit size-dependent optical behavior and, hence, tunable bandgaps and emission wavelengths as a consequence of quantum confinement. As the QD size decreases, the absorption edge and emission peak are blue-shifted for all three materials. It is found that PbSe QDs display significant quantum confinement even at larger sizes. Due to its relatively large exciton Bohr radius (~46 nm), as the size decreases from 10 nm to 2 nm, the bandgap increases from 0.27 eV to over 1 eV, shifting absorption and emission into the near-infrared (NIR), leading to applications into NIR photodetectors, solar cells, and biomedical imaging. Also, PbS QDs exhibit significant quantum confinement effects at smaller sizes due to their smaller exciton Bohr radius (~20 nm) compared to PbSe. The bandgap increases from 0.41 eV to around 1.5 eV as the size decreases from 10 nm to 2 nm, shifting absorption and emission from the NIR into the visible range. This is utilized in solar cells, visible to NIR photodetectors and LEDs. Furthermore, PbTe QDs also exhibit pronounced quantum confinement effects because of their relatively large exciton Bohr radius (~46 nm). The bandgap increases from 0.32 eV to around 1 eV as the size decreases from 10 nm to 2 nm, shifting absorption and emission into the NIR and Mid-Infrared (MIR) regions, making them excellent materials for infrared detectors, thermoelectric and MIR applications. Among the semiconductor materials studied, PbS QD typically exhibits the largest increase in bandgap with decreasing size, making them suitable for applications requiring larger bandgap tunability, followed by PbSe and PbTe. These different optical characteristics are due to their unique electronic properties and exciton Bohr radii.
Surface Modification and Functionalization of Ceramic Composites.
(Elsevier, 2023) Okeke, I. S; Obodo, R. M; Eze, C. N.; Orji, M. P; Agwu, K. K; Ubachukwu, A. A; Ezema, F. I
Materials with high dielectric constants are essential in the control and advancement of electronics and electrical power systems. The dielectric properties of materials majorly include dielectric constants (ꜫo) and loss tangent (tan ẟ), and for a material to be considered a very good dielectric material, it needs greater ꜫo, lower tan ẟ and reduced leakage current (J). Inorganic mixed transition oxides (MTMOS) ceramics composites have shown huge potential than the transition metal oxide because they constitute two or more metal elements with different expansion coefficients that give rise to synergistic effects. MTMOs ceramics composites are mostly found with spinel structure such as normal spinel structure (NSS) and inverse spinel structure (IVS). Several synthesis techniques have been used in formulation of MTMOs ceramic composites. Their dielectric properties have been modified considerately by altering its morphology, use of modifying agent, and high calcination temperatures. In this chapter, we summarized MTMOs major structure type synthesis technique that have been successfully used in preparation of MTMOs, the dielectric properties of MTMOs and basis of surface modification in MTMOs as well as its effect in the dielectric properties.
Synthesis and Characterization of Chemically Deposited Doped Stannate Ternary Metal Oxide Thin Films and Their Solar Energy Applications
(4th Africa Nano Conference and Workshop, 2021-07) Eze, C. N.; Onyia, A. I; Nnabuchi, M. N
Nano structured ternary metal oxide thin film like ZnSnO4 have receive much attention in the last decades owing to their unique properties rendering them suitable for wide range of applications. ZnSnO4 were grown by the chemical spray pyrolysis method. Home made spray pyrolysis technique is employed to prepared thin films. ZnSnO4 film was deposited on glas substrate using aqueous solution of zinc acetate dehydrate (Zn (CH3COO)2.2H2O and Tin (11) Chloride dehydrate or Stanic Chloride pentahydrate, SnCl2.5H2O as precursor at temperature of 2000C. the concentration of Zinc was varied from 0.001 to 0.005 while that of Tin was at 0.5. The product was annealed at 1hr at 2000C to improve its crystallinity. Various investigative techniques like XRD, SEM, EDX, UV-Visible, Raman spectroscopy analysis were carried out to find out the structural, morphological, spectroscopic and other properties of the ternary oxide thin film. The synthesized ZnSnO4 is of average crystalline size nano flowered having transmittance which increases with increase in wavelength. It has various band gaps which makes it find its application in photocatalysis and DSSCs (photoanode).Self
The Role of Local Dyes in Dye-Doped Stannates and Titanates for Enhancement f Solar Energy Capture
(FUDMA Journal of Sciences, 2025) Eze, C. N.
Local dyes play a crucial role in enhancing solar energy capture in dye-doped stannates and titanates by acting as light-harvesting agents, boosting the efficiency of dye-sensitized solar cells (DSSCs). These dyes, when adsorbed onto the surfaces of porous semiconductor materials like TiO2, absorb incoming sunlight and then inject electrons into the semiconductor, initiating an electron transfer process that generates electricity. This process is similar to how plants capture sunlight in photosynthesis. Stannates and titanates, such as TiO2, ZnTiO3, BaSnO3 etc provide a porous surface for dye adsorption and act as the conductive material for electron transport. Their nanostructured surfaces increase the surface area available for dye adsorption, enhancing light capture.