Recycling waste materials as catalysts in the oxygen evolution reaction (OER) offers an innovative approach to reducing catalyst costs. Scrap tungsten carbide–cobalt (WC–Co) die, used in wire drawing processes in industrial applications, may be recovered as tungsten trioxide (WO3) by the electrolysis method. In this study, all composite catalysts were prepared as their weight percentage IW-x (0 ≤ x ≤ 100). Here, I, W, and x represent IrO2, WO3, and the weight percent of Ir in the mixed composite oxide, respectively. Then, the prepared IW-75, IW-50, and IrO2 catalysts are referred to as 75% IrO2–25% WO3, 50% IrO2–50% WO3, and Ir’s pure oxide form, respectively. These materials are compared with WO3 and IrO2 to investigate their OER performance. According to the linear sweep voltammetry results, the IW-75 catalyst has a 15.03% higher current density than the pure IrO2 catalyst. In the Tafel polarization curve of the catalysts, it is determined that the corrosion potential of IW-75 is enhanced, and the overpotential value is decreased 1.2 times compared to the synthesized IrO2 catalyst sample. As a result, using composite oxide from scrap wire drawing die and IrO2, the cost of the proton-exchange membrane water electrolyzer’s anode catalyst is reduced by more than 25%.

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Additive manufacturing (AM) technologies have many advantages, such as design flexibility, minimal waste, manufacturing of very complex structures, cheaper production, and rapid prototyping. This technology is widely used in many fields, including health, energy, art, design, aircraft, and automotive sectors. In the manufacturing process of 3D printed products, it is possible to produce different objects with distinctive filament and powder materials using various production technologies. AM covers several 3D printing techniques such as fused deposition modeling (FDM), inkjet printing, selective laser melting (SLM), and stereolithography (SLA). The present review provides an extensive overview of the recent progress in 3D printing methods for electrochemical fields. A detailed review of polymeric and metallic 3D printing materials and their corresponding printing methods for electrodes is also presented. Finally, this paper comprehensively discusses the main benefits and the drawbacks of electrode production from AM methods for energy conversion systems.

In recent years, fossil fuels prices, greenhouse gas emissions, and need for sustainable energy sources have been increasing day by day. Thus, electric vehicles are seen as a promising candidate in the market due to their low-costs and cleaner fuel options such as electricity, hydrogen etc. Moreover, aerodynamics is one of the most important criteria to consider while designing an automobile for the most efficient driving conditions. For this reason, vehicle developers are studying to reduce drag resistance of the body to improve driving efficiency. On the other hand, Computational Fluid Dynamics (CFD) is one of the main tools for the automotive industry to obtain low-cost results before prototyping of any product. In this study, the aerodynamic characteristics of VoltaCAR electric vehicle is numerically investigated to obtain the best driving velocity. This car participates the TUBITAK-Electromobile car competition every year to achieve low fuel consumption for one hour driving. Thus, it is aimed that to minimize the resistance of the air hitting from the front, side, and roof of the vehicle. In the numerical model, polyhedral mesh structure is preferred to obtain faster convergence with fewer iterations, and shorter computation time is obtained compared to the tetrahedral mesh method. The aerodynamic drag coefficient (Cd) of the car model was calculated as approximately 0.17 at 22.22 and 27.78 m/s. The optimum velocity values were selected as 22.22 and 27.78 m/s by means of their lower Cd.