http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/110 Tue, 17 Feb 2026 15:35:04 GMT 2026-02-17T15:35:04Z http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/27920 Title: Innovating Perovskite Materials for High-performing Reversible Solid Oxide Cells Authors: Essien, Ubong; Neagu, Dragos Abstract: Reversible Solid Oxide Cells (RSOCs) are not just devices for hydrogen production (electrolytic cell mode) and power generation (fuel cell mode). They are a beacon of hope, a technological marvel that can meet the demanding electrochemical requirements of high-performing RSOCs. The development of innovative perovskites with enhanced exsolution (the in-situ growth of catalytically active nano-particles) capability is a testament to our commitment to a sustainable future. By leveraging the power of renewable energy sources and green hydrogen, RSOCs can catalyse a net zero society, with hydrogen taking centre stage as the primary energy carrier. Description: Conference Poster Tue, 12 Dec 2023 00:00:00 GMT http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/27920 2023-12-12T00:00:00Z http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/27919 Title: MATERIAL DEVELOPMENT TO ENHANCE REVERSIBLE SOLID OXIDE CELLS FOR HYDROGEN PRODUCTION AND POWER GENERATION Authors: Essien, Ubong; Neagu, Dragos Abstract: In electrolysis mode, reversible solid oxide cells (RSOCs) can use electricity from renewable sources to produce green hydrogen and, in reverse, in fuel cell mode, use hydrogen to generate electricity.1 RSOCs present a viable opportunity to solve renewable energy intermittency and achieve on-demand hydrogen and electricity production. However, multiple requirements, including high catalytic activity, high ionic and electronic conductivity, and cell component stability, must be simultaneously satisfied for electrolytic to fuel cell mode switching to be effective in RSOCs. While the state-of-the-art materials for fabricating solid oxide cells cannot currently fulfil these multiple electrochemical requirements, an exsolution process can simultaneously improve such functionalities in these materials. An exsolution process entails the segregation of metallic cations to form catalytically active nanoparticles on the surface of a perovskite lattice (the support structure) – this results in highly active, anchored and therefore stable catalytic sites.2,3 Also, the growth of such nanoparticles to reside within the bulk of the perovskite lattice (bulk exsolution) has been recently shown to improve ionic conductivity.3 Therefore, this research seeks to develop new perovskite materials using surface and bulk exsolution to fulfil the multiple electrochemical requirements of RSOCs. An A-site deficient perovskite with a stoichiometric composition such as (Sr,Ca)1-α(Ti,Fe,Ni)O3, known for its ability to drive B-site exsolution in their tendency to revert to a stable ABO3 perovskite stoichiometry,2 is targeted in this research. Parameters related to the synthesis of the new perovskite have been examined at the current stage of this research. Also, five potential precursor materials, (Fe(NO3)3.9H2O, Ni(NO3)26H2O, SrCO3, CaCO3, and TiO2) have been studied to ascertain their suitability and develop a synthesis route for the new perovskite materials. The methodology adopted for the study involved the characterisation of the potential precursor materials using thermogravimetry analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD)analysis. The TGA results revealed Fe2O3, NiO, SrO and CaO as the decomposition products of Fe(NO3)3.9H2O, Ni(NO3)26H2O, SrCO3 and CaCO3, while no substantial decomposition occurred in TiO2. These decomposition products have indicated the suitability of the different materials as precursors for the desired A-site deficient perovskite material. Furthermore, the XRD analysis of Fe(NO3)3.9H2O, Ni(NO3)2.6H2O and CaCO3 have confirmed their respective crystalline composition and shall help in understanding the complex crystal changes the precursor materials will undergo to form the desired perovskite material. Considering the decomposition temperature ranges: 50 – 400 oC, 56 – 573 oC, 600 – 850 oC, and 620 – 900 oC, respectively, for Fe(NO3)3.9H2O, Ni(NO3)26H2O, CaCO3, and SrCO3, it is expected that all the precursors, except TiO2, shall fully decompose into reactive oxides before 950 oC. This indicates that the desired perovskite synthesis reaction will likely occur between the 600 – 1000 oC temperature range, following the decomposition time of CaCO3 and SrCO3. Description: The paper is an extended abstract Wed, 12 Jul 2023 00:00:00 GMT http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/27919 2023-07-12T00:00:00Z http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/27916 Title: Solid Oxide Cell Electrode Material for On-demand Production of Hydrogen and Electricity Authors: Essien, Ubong; Neagu, Dragos Abstract: Reversible solid oxide cells (RSOCs) can revolutionize energy production, enabling on-demand hydrogen and electricity production and addressing the intermittent supply of renewable energy. However, their commercialization has been hindered by the lack of materials that can efficiently function as both a solid oxide electrolytic cell and a solid oxide fuel cell electrode. This research aims to address this challenge by developing a novel perovskite material that can meet the multiple electrochemical requirements of RSOCs, potentially accelerating the commercialization of this promising technology. Developing materials that are capable of enhancing the exsolution process offers some possibilities for solving this problem. Exsolution entails the segregation of metallic cations to form highly active and anchored nanoparticles on the surface of a perovskite lattice – enhancing catalytic and electrochemical stability in the material. Forming such nanoparticles within the bulk of the perovskite lattice (bulk exsolution) has recently improved ionic conductivity. This research there sought to develop a novel perovskite material that is capable of surface and bulk exsolution processes to fulfil the stability and electrochemical requirements of RSOCs. Five potential precursor materials were studied to ascertain their suitability and develop a synthesis route for the novel perovskite material. The study involved detailed characterisation of the potential precursor materials via thermogravimetry analysis (TGA), scanning electron microscopy (SEM), and X-ray diffraction (XRD) analysis. The TGA results revealed Fe2O3, NiO, SrO and CaO as the decomposition products of the respective precursor materials, which are useful oxides desired in the novel perovskite. Only TiO2¬ is stable within the other precursors' decomposition temperature range (50 – 900 oC). The TGA result, therefore, predicted that the chemical reaction to form the desired perovskite will likely be in the temperature range of 600 – 1000 oC. Hence, a modified solid-state synthesis method was adopted for the novel perovskite synthesis. In the two different compositions of the perovskite samples, it has been observed that homogeneous mixing of the precursors before their calcination encouraged homogeneous dispersion of species in the samples. Description: Book of abstract Thu, 15 Jun 2023 00:00:00 GMT http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/27916 2023-06-15T00:00:00Z http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/27914 Title: Exploitation of Bulk and Surface Exsolution in Perovskites Oxide for Hydrogen Production and Power Generation Authors: Essien, Ubong; Neagu, Dragos Abstract: Exsolution entails the in-situ growth of catalytically active nanoparticles directly from an oxide-metal solid solution (perovskite) lattice.1 The exsolution process has been advantageous in developing solid oxide cells for hydrogen production or power generation, but not necessarily for both simultaneously, which would be required for reversible solid oxide cells (RSOC).2 RSOC could address renewable intermittency by working as an electrolytic cell for hydrogen production and, in reverse mode, as a fuel cell for power generation.3 For example, exsolution enhances surface nanoparticles' stability and resilience to agglomeration and deactivation, while bulk exsolution can enhance conductivity.4 Additional functionalities such as high electronic and ionic conductivity and catalytic activity must be maintained for RSOC when switching between electrolysis and fuel cell mode.3 Here, we seek to develop new perovskite materials that fulfil these requirements, using both surface and bulk exsolution to achieve this. The target compositions would belong to a family of A-site deficient perovskite with a stoichiometric composition such as (Sr,Ca)1-α(Ti,Fe,Ni)O3. Such A-site deficiencies are known for their ability to drive B-site exsolution while attempting to revert the perovskite to a defect-free or stable ABO3 stoichiometry.1,5 To this end, we examine the parameters related to synthesising such new perovskite materials in this work. The thermogravimetry analysis (TGA) result revealed Fe2O3, NiO, and CaO as the decomposition products from three precursors. These decomposition products (oxides) could combine with SrCO3 and TiO2 to form the desired A-site deficient perovskite.1,5 The scanning electron microscopy (SEM) result has revealed the morphologies of the respective precursor materials. It could be used to study the effect of such parameters on the resulting perovskite microstructure and the synthesis reaction. Therefore, this study's result has given insight into the need to properly understand precursor materials before their selection for a given perovskite synthesis. Description: The uploaded paper is an extended abstract Fri, 31 Mar 2023 00:00:00 GMT http://irepo.futminna.edu.ng:8080/jspui/handle/123456789/27914 2023-03-31T00:00:00Z