The hydrogen-based economy is gaining momentum with the advent of fuel cell electric cars and other systems. Hence hydrogen production becomes critically important to meet a supply-demand in the near future. One of the cheapest hydrogen generation sources can be based on solar energy and seawater or water in the lakes and rivers. One can utilize solar energy to provide electricity or energy for the photocatalytic process to split water into hydrogen and oxygen. Hydrogen can be stored in tanks and shipped like existing fossil fuel-based energy sources; gasoline and natural gas. Hydrogen gas production from water electrolysis is a popular approach. Under electrolysis, electricity is supplied to provide the energy required for water splitting converting hydrogen ions into hydrogen gas from the aqueous medium. There is a strong need to create innovative electrodes for hydrogen generation that are economical in production and highly efficient. To address this issue, we have focused on designing electrodes for photocatalytic electrolysis for hydrogen generation. This paper focuses on our efforts to 3D print different electrodes with various surface features to provide optimum surface area. On the surface of 3D printed metal components, we produce nickel coatings. It is noteworthy that nickel is a promising metal to produce hydrogen economically. We use the Taguchi Design of Experiment approach to optimize the nickel coating on the 3D printed metal electrodes.The success of the final nickel-coated electrode depends on multiple factors:1. 3D printed design that governs the shape of the metal electrode.2. Post-processing of the printed metal electrodes to prepare the surface for electroless nickel deposition.3. The duration of the nickel strike treatment of the 3D printed electrode immediately before nickel coating.&nbsp;4. The phosphorus content in the electroless nickel coating solutions.In this paper, we report our systematic experiments that study these factors' effect by applying the L9 Taguchi Design of Experiment (TDOE) scheme. The L9 TDOE effectively accommodates the four nickel-coated metal electrode factors with three levels each. We generated three designs for the shape of the electrodes: a flat square, a hollow cylinder, and a cylinder with a patterned surface. Once printed, the electrodes can be post-processed to prepare the surfaces for electroless nickel coating. Surface preparation can be done by subjecting the surface to (1) chemical polish, (2) plasma clean, or (3) organically cleaning the surface with acetone, isopropyl alcohol, and DI water. Following the post-process that prepares the surface for nickel coating, an additional step of nickel strike is taken. The nickel strike process adheres a thin layer of high-quality nickel plating on the 3D printed metal electrode surface before electroless nickel plating. We vary the nickel strike duration by 50%, 100%, and 150% of the suggested strike time to observe any improvements in the nickel coating quality. Finally, we use three electroless nickel solutions with varying phosphorus content: low, medium, and high. Once the final 3D printed nickel-coated electrodes are produced, we test the efficacy of hydrogen production in a photocatalytic cell. We will discuss the results of these experiments in this paper.

3d Printed and Nickel-Coated Electrodes for Photocatalytic Electrolysis for Hydrogen Generation

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

Supporting the need among researchers worldwide for additional online and multimedia content, ASME now offers the ASME Conference Video Collection. This platform will collect and provide long-term access to conference presentation videos, encompassing all technology areas within ASME's technical conference and events program. About 30,000-40,000 engineers across all mechanical engineering and related disciplines participate in ASME conferences each year. This includes authors of approximately 6,000 to 8,000 technical papers published by ASME, the majority of whom also submit video presentations for our virtual conferences. The video collection will be available as an add-on to existing product packages or as a separate subscription.