Numerical analysis and performance improvement of nanostructured Cu2O/TiO2 pn heterojunction solar cells using SCAPS

Abstract: This paper reported numerical analysis and performance improvement of nanostructured Cu2O/TiO2 pn heterojunction solar cells. Metal oxides thin films including Copper oxides are promising materials for photovoltaic applications. Although, the efficiency is still lower than other solar cells materials. This paper focused on improving the efficiency of Cu2O/TiO2 solar cells using SCAPS simulation tool. This was done by varying the effect of film surface thickness and effect of varying deposition temperature on the solar cells. The aim of the study is to serve as a theoretical guide for laboratory research on the improvement of efficiency of Cu2O metal oxide solar cells. The solar cells equations were modelled and thereafter theoretical validation of the nanostructured metal oxides was performed. The model working points input power of 100 mW/m2 using an illumination of AM1.5 lamp. The modelled solar cell exhibits a short-circuit current (Jsc) of 26.57 mA/cm2, 0.7188 V open-circuit voltage (Voc), fill factor (FF) of 70, and 13.37% efficiency (η). A value of 2.30 eV was recorded for the band gap. Also, electron affinity and Nyquist plot were obtained for the solar cells. Solar cells with thin absorber surface thickness will result in lower fabrication cost. This will open a new frontier for modelling of metal oxide based thin films solar cells especially Cu2O thin films solar cells

Facile fabrication of vanadium sensitized silver titanium oxides (V-Ag/TiO2) photocatalyst nanocomposite for pollutants removal in river water

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Development of 3-Point Flexural Test Fixtures

In developing economies, the cost of acquiring laboratory testing equipment and accessories is huge, thereby depriving most of the supposedly advanced laboratories of most of this necessary research equipment. In this study, a 3-point flexural test accessory has been designed and developed for a universal mechanical testing equipment. The 3-piont flexural accessory is an important accessory in mechanical examination for the flexural strength of engineering materials. The computer aided design and modelling as well as the materials selection was done using Pro/engineer and Granta software. The material selected for the development of the components is austenitic stainless steel which is readily available and accessible in Nigerian market The developed flexural test accessory was used on the test equipment to conduct flexural tests on composite samples and the results were found to conform to international standard. Keywords: Mechanical, Flexural Test, accessory, Equipment, Design and Developmen

Modelling and optimization of the impact strength of plantain (Musa paradisiacal) fibre/MWCNT hybrid nanocomposite using response surface methodology

This study, examine a natural fibre reinforced hybrid nanocomposite, fabricated using plantain (Musa paradisiacal) fibre and multiwall carbon nanotube (MWCNT) in epoxy resin. 0.05% potassium permanganate (KMnO4)-acetone solution was used to reinforce the adhesion interface between the fibre and matrix. Response surface methodology (RSM) based on the Box–Behnken design (BBD), was utilized in the experimental design to optimize the influence of three variable parameters, namely: MWCNT volume content (0.5, 1, 2%), KMnO4 Treatment time (1, 3, 5 min) and fibre content (10, 20, 30 wt.%) on the Impact strength of the hybrid nanocomposite. FTIR spectral indicates the fractional elimination of natural wax, hemicellulose and lignin substance present in the fibre surface after treatments. Analysis of variance (ANOVA) shows that fibre content, KMnO4 Treatment time and MWCNT volume content, significantly affects the Impact strength of the hybrid nanocomposite as demonstrated by scanning electron microscopy (SEM) micrographs. The expected findings were in near alignment with the experimental results with the value of R2 = 0.9869. The optimal operational condition for ultimate impact strength was observed as MWCNT concentration 1.23%, KMnO4 Treatment time 2.60 min, and a fibre content 13.50 wt.%. The optimum impact strength of the hybrid nanocomposite was increase by 58.16% over pristine epoxy-resin system. This current research has demonstrated that RSM via the BBD technique is an effective way of achieving optimal values for mechanical properties over the least amount of time, reducing production costs and saving resources

Physical, mechanical and thermal properties of high frequency microwave treated plantain (Musa Paradisiaca) fibre/MWCNT hybrid epoxy nanocomposites

Abstract: Natural fibre reinforced polymer composite has many industrial applications especially inautomobile. However low mechanical and thermal property has limited its application. Inthis study, natural fibre reinforced hybrid nanocomposite was manufactured by the incorpo-ration of high frequency microwave treated Plantain (Musa paradisiaca) fibre and multiwalledcarbon nanotubes (MWCNT) using a single epoxy resin matrix. The consequence of harmo-nized existence of MWCNT at different loading (0.5−2 wt.%) on the physical, mechanicaland thermal Properties of the hybrid nanocomposite was examined, using the ultrasonictechnique for dispersion of nanoparticles and hand lay-up and compression moulding pro-cess for composite production. The experimental results demonstrate that the mechanicalproperties strength improve up to 52%, while up to 30% improvement was recorded formicro-hardness and impact strength, caused by increment in MWCNT content. Scanningelectron microscope (SEM) analysis reveals good mechanical dovetailing of hybrid fibreswith polymer matrix. Thermal conductivity has shown significant improvement up to 43%as MWCNT contents increases. These enhancements are primarily ascribed to the highaspect ratio, high modulus, strength and good dispersal of carbon nanotubes (CNT) in thehybrid nanocomposites

Facile Preparation and Characterization of Silica Nanoparticles from South Africa Fly Ash Using a Sol–Gel Hydrothermal Method

Silica nanoparticles (SNPs) consist of several applications which include lightweight aggregates, energy storage, and drug delivery. Nevertheless, the silica reagents used in SNP synthesis are both costly and hazardous. As a result, it is critical to look for other sources of silica. For this research, a simple sol–gel hydrothermal approach is used to make SNPs from South African fly ash (SAFA). SAFA is classified as fly ash class F according to X-ray fluorescence (XRF) analysis. The wide-angle X-ray diffraction (XRD) pattern reveals the structural composition of SAFA and the amorphous phase of extracted SNPs, while Fourier transform infrared (FTIR) examination reveals the presence of silanol and siloxane groups. Basic SNPs were generally spherical with diameters of about 60 nm, according to scanning electron microscopy (SEM) and transition electron microscope (TEM) studies. The presence of SiO2 is confirmed by energy-dispersive X-ray spectroscopy (EDX) spectrum analysis. Particle size assessment indicates particle sizes ranging from 48 nm to 87 nm in diameter, with a mean diameter of 67 nm. The application of SNPs in wastewater treatment demonstrated that they can be used to remove Cd2+ from an aqueous solution. This research offers new ideas for using South African fly ash in SNP manufacturing

Preparation and characterization of NbxOy thin films : a review

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Synthesis and photocatalytic performance of Ag-TiVOX nanocomposite

Abstract: A silver, vanadium and silver/vanadium doped titanium dioxide (TiO2, Ag-TiO2, V-TiO2 and Ag-TiVOX) nanocomposite photocatalyst was achieved via a modify sol–gel and hydrothermal method. Structural analysis by X-Ray Diffraction (XRD) depicted the lattice fringes for both anatase and rutile in its crystalline phase in the synthesized nanocomposites. Surface areas (SBET) analysis shows that surface area of synthesized Ag-TiVOX is 46.01 m2/g, compare to TiO2 64.75 m2/g, Ag-TiO2 61.33 m2/g and V-TiO2 62.73 m2/g. Optical absorption results demonstrated by UV–Visible Spectroscopy (UV–Vis) shows that the effects of Ag and V doping was a shift in spectrum to the visible light region, enhancing the visible light absorption capacity of the synthesized photocatalyst. The optical absorption of Ag-TiVOX achieved a reduced bandgap energy of 2.2 eV, as compared to Ag-TiO2 (2.8 eV), V-TiO2 (2.3 eV) and TiO2 (2.9 eV). Morphological characterization by Transition Electron Microscope (TEM) and Scanning Electron Microscope (SEM), depicting a cluster composed of spherical aggregates particles of non-uniform diameter nanoparticles with particle size ranging between 10 and 50 nm. Synthesized Ag-TiVOx demonstrated remarkable photocatalytic capabilities under visible light irradiation, as 99.83 percent of methylene blue (MB) degradation was accomplished during the first 15 min. Impact of Ag and V doping of TiO2 showed enhancement in the photocatalytic activity, reporting excellent removal rates and achieving well desirable decline in the band gap energy

Mechanical and water absorption behaviour of potassium permanganate (KMnO4) treated plantain (Musa Paradisiaca) fibre/epoxy bio-composites

Abstract: The use of environmentally friendly agro-waste fibres as reinforcement has opened a newdirection to polymer composite science. Research has suggested that changing the surfaceof the fibre by both physical and chemical processes improves the efficiency of the naturalfibre/polymer matrix. This research explores the kinetic and function of water absorptionand its relevance for the mechanical properties of potassium permanganate (KMnO4) treatedplantain (Muse Paradisiaca) fibres reinforced epoxy bio-composite. Treated fibres were char-acterized by wide-angle X-ray diffraction (XRD), Fourier transform infrared (FT-IR), scanningelectron microscope (SEM) and thermogravimetric analysis (TGA). The XRD study shows asignificant shift in the crystallographic parameters of the material, the FTIR spectral indi-cates the fractional elimination of wax, hemicellulose and lignin substance. TGA indicatesthat the thermal stability of the fibres was improved following treatment. Ruptured sampleswere studied using a SEM. The analysis indicates that, owing to the water penetration of thefibre matrix interface and prolongation of the water-immersion cycle, there was a decreasein the tensile and flexural strength of the bio-composites. Nevertheless, the mechanicaland water-resistant properties have been strengthened by KMnO4. The mechanism andkinetic of water absorption reveals a Fickian kind of diffusion and propensity to followFickian behaviour thus creating prospects and reliability of the bio-composite to be usein engineering and structural applications