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Jaehyeong Lee

A Novel Design of Electrode Surface Morphology to

Improve Water Electrolysis Eficiency

techniques include building nanowire arrays, nanopar-ticles, nanocrystals, nanotubes, nanoholes, structures with micropores, and three-dimensional dendrite formation structures using high current electroplating methods [10-15]. However, more recent advances in surface morphol-ogy modiication focus on nanowire and nanotube growth because the efective surface area of an electrode greatly increases with increasing aspect ratio between the height of the structure and its cross sectional area. However, those earlier publications focus mostly on fabrication methods for unique nanostructures rather than on a rigorous analy-sis on the eiciency of the electrolysis or on a quantitative analysis of the impact of the aspect ratio to the surface area [10-15].

his paper will quantitatively analyze the efective sur-face area as a function of aspect ratio. Based on this calcu-lation, it was found that the aspect ratio had greater impact to the eiciency than individual particle sizes. he primary focus of this research is to ind a simple way to increase the surface area even further with a given aspect ratio. A new electrode surface morphology involving curved sidewalls to make a structure with a protruding top, or mushroom top, was designed and tested, which further increased the efective surface area of an electrode compared to the straight side wall structure when the aspect ratio is same. In particular, the method used to produce the structure was economically viable, using existing technologies such as photoresist photolithography and electroplating. his apparently simple and easy method to produce electrodes for more efective water electrolysis has not

IntroductionToday, the majority of the world runs on a hydrocarbon-

based fuel supply. he source of this energy, however, is in fossil fuels, energy rich hydrocarbons that lie dormant un-der select regions of the Earth. hough energy eiciency is high for fossil fuels, the carbon emissions can cause many environmental concerns. In addition, sustainable forms of energy are currently not cost competitive against fossil fu-els: data from the Henry Hub natural gas distribution sys-tem versus data from the Norwegian University of Science and Technology (NTNU) in 2006 conirms the relatively high cost eiciency of natural gas, as the cost per million BTU of natural gas in December was around $6.734/Mil. BTU, and NTNU reported the cost per kilowatt hour to produce electrolytic hydrogen at $0.10/kWh (or $29.31/Mil. BTU) [1]. herefore, research in improving the ef-iciency of sustainable energy production, such as water electrolysis, is of critical importance.

here are two methods to improve the eiciency of wa-ter electrolysis: employ a metal with greater catalytic prop-erties or increase the efective surface area of the electrode.

Research on the catalytic properties of non-noble met-als in water electrolysis has been undertaken for over two centuries in search of cheaper metals with greater cata-lytic efects. Non-noble metals observed include cobalt, manganese, nickel, iron, copper, chromium, vanadium, and their alloys and oxides [2-9].

More recently, diferent electrode surface modifying techniques have been designed and tested to improve the hydrogen generation eiciency of water electrolysis. hese

ABSTRACT

A new surface morphology was proposed in this study to optimize the eiciency of water electrolysis. Past studies have shown that reducing particle size is less eicacious in improving electrolysis eiciency than modify-ing surface morphology. Using Ni metal and a speciied pattern thickness, along with a novel ilm pattern size, the design proposed in this study has ~13.4% more efective surface area than a simple pattern with straight side walls. To realize the proposed surface morphology, photoresist patterned Ni electroplating was used. he surface mor-phology of the photoresist and resulting plated Ni ilm were conirmed by a scanning electron microscope (SEM). To improve the accuracy of the measurement, the Kelvin probe method was used with a specially designed sample holder to reduce the efect of contact resistivity and external resistance of the system. For Ni electrode test, Ag/AgCl in 4 M KCl solution was used as a reference electrode and Pt was used as counter electrode. For quantitative analysis of the surface area efect, sputtered Ni ilm was tested with Telon tape as a masking material to deine the active area of the ilm. he test system was observed to accurately detect the efect of bubble accumulation on the ilm surface with a narrow trench like opening. he Voltammogram was analyzed using a modiied Butler-Volmer equation with series resistance. A data analysis program was written to ind resistance, rs (Ω), exchange current density, J0 (Amps/cm2), and the charge transfer coeicient, α. his new analysis method was compared to a con-ventional method from literature in order to ensure validity. he results showed that, using the proposed surface morphology modiication, the series resistance decreased 20.4% from its “expected” value – which then translates into a 25.6% increase in eiciency at a given bias voltage.

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Table 2. he deinitions of the symbols used in equa-tion 4a and 4b

he inconsistency in the aforementioned modiied Butler Volmer it is that it regards the resistive and Butler Volmer term dominant portions as independent identi-ties, whereas in reality, the two factors are related. To ad-dress this inconsistency, a new modiied Butler Volmer it was proposed. If the resistance is assumed to be rc, then the voltage drop caused by rc is Ic x rc, where Ic is the total current in the system.

his must be subtracted from E to ind the true po-tential. herefore, the equation 4(a) can be expressed as below without separating it in 2 voltage regions.

hen, to isolate the E – Ec0 term on one side, the ex-ponent must be removed.

*hese equations can substitute Ja for Jc, 1–αa for αc, and Ea0 for Ec0 to produce the formula related to the anode.

With this inal equation, it was possible to it the voltammogram curve using one it curve. To ind the de-sired rc, αc, and Jc0 values, Visual Basic (VB) program-ming was used, employing a search algorithm to mini-mize the discrepancy between the measured data and the calculated data from equation 5 within the range of parameters.

been tried before, based on an extensive literature search undertaken through an online library covering over 500 published materials for the last 60 years.

Background heoryCyclic voltammetry was used to collect the current

densities of an electrolysis system consisting of cathode and anode electrodes over a range of voltages with a de-ined rate of voltage change per unit time. he current voltage characteristics obtained from cyclic voltammetry are called voltammograms.

To analyze the curve of the voltammograms, a Butler Volmer equation with an Ohmic limiting resistance com-ponent was used [44].

According to the Nernst equation, the standard elec-trode potential of the cathode (Ec0) and anode (Ea0) can be expressed as a function of pH of a solution and the partial pressure of oxygen (p02) and hydrogen (pH2) as shown in equations (1) and (2) [44].

he atmospheric partial pressure of 0.2095 atm for oxy-gen and 5×10−5 atm for hydrogen were used to calculate standard electrode potential [44].

At room temperature, pH can be calculated using the Sorensen equation [44],

in which [OH-] is the concentration of hydroxide, OH-, in mole/liter.

Table 1 shows the calculated values of pH, Ec0, and Ea0 for KOH concentration used in this experiment.

Table 1. Calculated values of pH, Ec0 and Ea0 at room temperature as a function of KOH concentration

he voltammograms from water electrolysis were ana-lyzed using the Butler Volmer equation and Ohm’s law [44].

At high E–Ec0, equation (4) becomes Ohmic term dominant and at low E–Ec0, it becomes Butler Volmer term dominant. herefore, the data can be analyzed sepa-rately at 2 diferent regions.

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If the aspect ratio is given, the shape of the sidewall can further increase the efective surface area. he underlying goal of this research, then, was to synthesize mushroom-top shaped structures atop electrodes. Figure 3 shows the impact of the sidewall shape to the efective surface area. It is apparent that the mushroom top shape has the great-est impact. his structure can be realized with a relatively simple and economically viable method using photoresist patterning and electroplating.

Figure 3. Schematic diagram of photo resist proile and plated ilm. (a) Pyramid shape structure. Additional area is A-B per side (b) Mushroom top shape structure. Ad-ditional area is A+B per side (c) Standard square struc-ture. Additional area is A per side.

Figure 4 shows how much additional area can be made by having mushroom top surface morphology. he calcula-tion was made based on assumptions of a ilm thickness of 6 um, a side wall angle of 45 degrees, and a spacing between square patterns of 75 um. With these speciica-tions, the mushroom top surface morphology is shown to produce 13.4% more surface area compared to a straight sidewall with an aspect ratio of 0.06.

Figure 4. he calculated additional surface area from square patterns with mushroom top with 45 degree angle and straight sidewall. he thickness of the ilm wasassumed to be 6 um. he spacing between the pat-terns was ixed at 75 um.

Novel Design in Surface Morphology

Many international energy researchers have attempt-ed to make electrode surfaces using nanomaterials. To know the impact of those nanoparticles to surface area, it is necessary to calculate the surface area as a function of particle size. he equation to ind the surface area of the electrode for a square pattern given the distance between two squares (a) and the length of one side of the square (d) with a height (h) is stated thus:

In igure 1, the area in equation (8) is plotted with the height (h) is set to be the smaller of the dimensions d and a, which describes the resolution of the patterning tech-nique, and, therefore, the maximum height that can be at-tained for the structure. By this deinition, aspect ratio is kept constant, i.e. as pattern size decreases, thickness de-creases, which is characteristic of electrode surfaces made using nanoparticles with various particle sizes. Surpris-ingly, there is no additional advantage in reducing pattern resolution, which is relevant to the particle size. However, if the height of the pattern was constant and lengths of the sides of the structures were reduced (essentially increasing aspect ratio) the surface area increase becomes signiicant-ly greater, as shown in igure 2. As shown, it is apparent that within a given thickness, smaller and closer-spaced patterns yield greater efective surface areas.

Figure 1. Surface area with ixed aspect ratio as function of length and spacing of square patterns. Aspect ratio assumed to be 2.

Figure 2. Surface area with constant thickness as a func-tion of length and spacing between square patterns. hickness was set at 100 um.

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Figure 5. (a) Electroplating set up w/Keithley 220 pow-er supply, multimeter (voltage measurement), hot plate and thermometer. Wafer holder/anode is visible inside plating solution. (b) Ni sheet metal for anode and Ni ilm on a glass wafer for plating.

Several trials were required to ind an optimal electro-plating condition. he inal procedure involved 1 cm by 3 cm Ni metal slices which were plated for 30 minutes at 43.3° C with 14 mA of current bias (from the Caswell plating manual) for a plate thickness of 2 um. Figure 6 shows the SEM image of the plated Ni ilms plated at this condition.

Figure 6. SEM image of ~2 um plate thickness with 14 mA applied current for 30 minute plate time.

Photoresist Patterning Procedure

Photoresists are nonconductive, photosensitive poly-mer ilms that can be developed to create patterns on a surface. Typical photoresists are spin-coated onto surfaces and come in two variations: negative ilms and positive ilms. Negative photoresist patterns develop the opposite of the mask that covers it during light exposure; essentially, if there is a dark location on the pattern, the photoresist underneath it will be washed away by the developer solu-tion during developing [45].

Depending on the photoresist material, the contact method during UV exposure, the developing time and the heat treatment condition, the sidewalls of patterned pho-toresists could generate any of the three types shown ear-lier in igure 3. While electroplating, then, Ni metal would deposit onto the ilm on conductive surfaces in contact with the solution. he Ni ilm naturally forms to the mor-phology of the patterned photoresist.

Experimental DesignAn alkaline solution of potassium hydroxide (KOH)

was used as the electrolyte in the experiment. Platinum was used as a counter electrode and Pt or Ag/AgCl in 4 M KCl were used as reference electrodes, Pt for its high resis-tance to corrosion, and Ag/AgCl in 4 M KCl for its stable standard electrode potential under various electrolyte con-centrations and temperature of the system. Keithley cur-rent and voltage measurement devices and HP current/voltage power supply were connected to the computer via GPIB connection, and the instruments were controlled remotely using VEE (Virtual Engineering Environment) graphic user interface programming language. he elec-trochemical measurement was cyclic voltammetry, where the independent variables were current or voltage bias and scan speed, and the dependent variables were system volt-age for current bias and system current for voltage bias of each half cell.

Electroplating System

Two types of plating tested were electroless plating and electroplating. he plating solutions were bought from Caswell Plating Inc. and were operated under NCSSM’s lab hood to maintain air circulation. he metal ilm used as a seed layer was sputter coated Ni ilm, on 100 mm diam-eter glass wafers, with a thickness of 80 nm.

Electroplating has two advantages over electroless plat-ing. With electroplating, it becomes simpler to control the ilm thickness because it can be accurately controlled by current density and plating time. Also the electroplating is done at a much lower temperature and is much safer for the photoresist. herefore, electroplating was selected as the ilm deposition method for the experiment, after both methods were tested. Table 3 shows characteristics of electro- and electroless plating.

Table 3. Comparison between Electroplating and Elec-troless Plating in certain categories.

A Ni metal sheet was used as the anode, and a mount was made to hold the anode and Ni wafer in place in the solution, as shown in igure 5. Heat-shrink tube covered springs were used to keep the Ni wafers to be plated stable, and the anode was mounted onto the acrylic base plate using screws.

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he photo mask with 100 – 700 um square patterns were designed using CAD software and laser printed on a acrylic sheet by CAD/Art Services, Inc., a photoresist mask printing service provider.

AZ2070 is a negative photoresist that comes in a liq-uid form. It was spin coated and heat-treated to solidify for exposure and developing. After the photoresist was poured, the wafer was spun at 2000 rpm for 30 seconds on a vacuum chuck, then baked at 100° C for 1 minute to achieve a photoresist thickness of 9 um. For AZ2070, there were three parts to the developing process: exposure to 350-400 nm peak UV light with a patterned mask, heat treatment, then developing with MIF300 to remove the unexposed photoresist and reveal the design. After multi-ple trials, an optimal developing condition for a positively sloped sidewall was found: 2.5 minute UV exposure, 1.5 minute heat treatment at 120° C, then 1.5 minute devel-oping in MIF300. A cross sectional image of the photore-sist on the Ni ilm and the resulting electroplated Ni ilm is shown in igure 7.

he additional area from the sidewall shape of the plat-ed Ni ilms shown in SEM cross section was calculated as ~20.1 um per unit side length with 5.1 um thickness as shown in igure 8. After Ni electroplating with the desired conditions, the photoresist was stripped in acetone. Figure 9 shows optical microscope images of plated Ni ilms be-fore and after the photoresist was stripped after plating.

Figure 7. Cross sectional image of (a) photoresist on Ni coated glass substrate with a curved sidewall and (b) electroplated Ni ilm showing the curved sidewall of the mushroom top.

Figure 8. Calculated additional surface area from over-hang structure based on photo resist morphology.

Figure 9. Optical microscope picture of electroplated Ni ilms. (a) 300 um x 300 um pattern with 300 um spac-ing with photo resist. (b) 500 um x 500 um pattern with 300 um spacing with photoresist. (c) 500 um x 500 um pattern with 300 um spacing after photoresist stripped in acetone bath.

Figure 10. (a) Voltammogram test set up. HP6632B power supply, Keithley 617, Keithley 192 multimeter and Electrodes are mounted on an acrylic board. (b) Electrode holder.

Finding the Optimum KOH Concentration

Figure 11. Voltammogram of water electrolysis with Pt anode, cathode and reference electrode in 0.5, 1.0, 1.5, 2.0 M KOH solutions.

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Table 4. Extracted parameters with 0.5, 1.0, 1.5 and 2 M KOH solutions.

Figure 12. Example voltammograms of water electrol-ysis with Pt electrodes at 20° C for (a) a cathode with 0.5M KOH and (b) an anode with 0.5M KOH. Blue diamonds-measured data, red lines-Ohmic it, green lines-Butler Volmer it.

To ind the optimum KOH concentration, 0.5, 1.0, 1.5 and 2 M KOH solutions were tested with Pt as both the anode and cathode. 1 M KOH solution was found to be the optimal solution with a high conductivity using the minimal amount of KOH. he data is shown in igure 11.

Figure 12 shows example graphs with measured voltammograms with itted curves by Butler Volmer and Ohmic equations. his is the traditional way of itting the voltammogram in 2 separate voltage regions as described in theory section. It is clear the two it curves show larger discrepancy as they approach the middle region.

Table 4 shows the parameters calculated from the anal-ysis using equation (4). From the data in Table 4, it is clear that the limiting resistance decreases as the KOH concen-tration increases.

Figure 13 shows resistance of cathode and anode as a function of KOH concentration. hough the resistance continues to decrease as concentration increases, the change slows down at 1 M KOH and appears to remain similar. Because of this behavior, 1 M KOH solutions were selected for the rest of the experiment.

Figure 13. Resistance of Pt anode and cathode as a func-tion of KOH concentration

Catalytic Efect of Pt versus Ni Electrodes

he dependence of electrolysis systems on diferent metals and their inherent catalytic efects, by comparing diferent standard electrode potentials, could be seen by analyzing the voltammograms from a Pt/Pt system versus a Ni/Ni system, as shown in igure 14. he Pt ilm had 2 layers, 25 nm thick Ti adhesion layer at the bottom and 50 nm of Pt on the top, evaporated by an e-beam on a 100 mm diameter glass substrate. he Ni ilm was 80 nm thick, deposited with a sputtering system. For the cathode, the curves in igure 14 look similar; however, the turn-on volt-age at the anode has a dramatic diference. With Ni metal, the turn-on voltage became much lower than Pt, which indicated better catalytic efect. For wafer electrolysis, Ni is clearly better than Pt not only because it is cheaper, but also because it has a more pronounced catalytic efect.

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Figure 14. Voltammogram of water electrolysis with Pt ilm (Ti/Pt=25/50 nm thick) and Ni ilm (80 nm thick).

Electrode Mounting Method

To make it sure to have only the electrode material of interest is in contact with the solution, the electrical con-nection has to be made outside of the solution. Because of this coniguration, there was always an extra voltage drop from the ilm between the surface of the electrode inside the solution and the place where the contact was made, even though the Kelvin probe method was used to remove the voltage drop from the cables [46,47].

After a few iterations, the inal design for sample mounting for electrolysis was developed, as shown in ig-ure 15. he metal wafers were cut into 1 cm by 3~4 cm slices. Telon tape was used to deine the active area and to separate the active area from contact wire. A small piece of aluminum foil was placed underneath the Telon to reduce the voltage drop between the active area of electrolysis and the electrical contact. For each sample, 2-electrode con-tacts were made to make a Kelvin probe coniguration, one for power supply and one for voltage sense to minimize the efect of resistance from the wiring.

Figure 15. Schematic diagram of sample loading and electrical connection set up for water electrolysis for Ni ilms.

he contact was made using gold-plated pins soldered to a wire on a circuit board connected to the acrylic back plate with screws with springs around them to apply force against the screws to preserve the lifetime of the pins and

keep the pins from breaking the sample underneath. For Pt/Ni electrode system, to make more accurate measure-ment, Ag/AgCl in a 4 M KCl solution was used as ref-erence electrode. [48] he advantage of using Ag/AgCl as a reference electrode was its stabile standard electrode potential. At room temperature its standard electrode po-tential is known to be at 0.2 V compared to the Pt/H+

standard electrode, and has been found to be stable for various temperatures as well [49].

With the inal design of the electrode mounting scheme, the resolution of the voltammetry setup was conirmed to be high enough to even detect bubble formation during electrolysis. With very narrow electrode opening in work-ing electrode, dense gas formation is expected. At high current, the gas will form big size bubbles and it can block the part of electrode surface. As the electrode is partially covered by a bubble, the resistance of the system increases and it will be detected as current decrease if the system is sensitive enough. Figure 16 shows the voltammogram with Ni ilm with 0.087 cm2 opening. At high current region, the current oscillation is visible and it correlates to the period of bubble formation. Figure 17 shows a typical picture of the bubble when it is the biggest and right after it is removed from the surface because of its buoyancy.

Figure 16. he voltammogram of Ni electrode with 0.087 cm2 opening.

Figure 17. he pictures of Ni electrode with 0.087 cm2 opening when (a) the bubble is biggest so a part of the surface is covered and (b) the bubble is loated up be-cause of its buoyancy.

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Impact of Patterned Plated Ni Electrode with Mushroom Top Morphology

To ind the impact on electrolysis eiciency of the new surface morphology, the data from the sputtered Ni ilms with 2 diferent opening areas have been tested, as well as 3 diferent designs of patterned, plated Ni ilms with mushroom top surface morphologies. To keep the plated Ni ilm thickness constant for all 3 samples, the plating was done on a half of 100 mm diameter wafer with 3 dif-ferent photo resist patterns. he wafer was cut after the plating is done using diamond saw.

Also to improve the accuracy of the data analysis, a modiied Butler Volmer equation (equation 5) was used. Figure 18 shows an example of the analysis on sputtered Ni ilm with 0.87 cm2 opening with both the convention-al method (equation 4) and the new method developed in this research (equation 5). To use equation (5), a Visual Basic program was made to ind the parameters with the minimum square error between the measured data and the model. From the graph, it was clear that the new analysis method was more accurate, not only in the medium volt-age region but also in the low voltage region.

Figure 19 shows the current voltage characteristics of 5 samples tested, sputtered Ni ilms with 0.087 cm2 and 0.87 cm2 opening area and 3 electrodes with patterned plated Ni with mushroom top surface morphology. he pattern structures are 300x300 um2 with 100 um spac-ing, 300x300 um2 with 300 um spacing and 500x500 um2 with 100 um spacing. Since the data from a 0.087 cm2 opening was oscillating in the high current region, only the maximum point of each oscillation period was tak-en for analysis because those data points represent when there is no bubble covering the electrode surface.

Figure 18. Comparison between experimental data (dia-monds), original mod-BV it (red –low voltage region), Ohmic it (green – high voltage region), and new mod-BV it (blue circles) using the search algorithm devel-oped in Visual Basic.

From igure 19, it is clear that there is lot more cur-rent lowing at a given voltage if the opening area is larger. he plated ilms with mushroom top surface morphology shows largest current but more rigorous Butler Volmer analysis is necessary to see exactly how much impact was made by this surface modiication.

Figure 19. Current Voltage characteristics of 5 diferent Ni ilm electrodes. ▬ sputtered Ni ilm with 0.087 cm2 opening. It shows oscillating current as a result of bub-ble accumulation. ▬ maximum data points from each oscillation period from sputtered Ni ilm with 0.087 cm2 opening. ▬ sputtered Ni ilm with 0.87 cm2 open-ing. And patterned plated Ni ilm with mushroom top morphology with the patterns of 500x500 um2 with 100 um spacing(▬), 300x300 um2 with 100 um spacing(▬) and 300x300 um2 with 300 um spacing(▬).

he highest current was expected from 300x300 um2 with 100 um spacing. However, appeared that 500x500 um2 with 100 um spacing showed the highest current. It is still under investigation but it seems that the patterns generated were more rounded rather than square, and this distortion becomes more pronounced as the pattern size and spacing decreased due to low resolution of the photo-lithography setup used in this experiment.

Figure 20 shows the it parameters from the new model (equation 5) found with the aforementioned VB program. With the new it method, three graphs were generated, one for each critical parameter as a function of surface area for the anode and cathode. In igure 20a and 20d, there is a clear trend of resistance reduction as area increases. With a linear it of sputtered Ni ilms with 2 diferent opening ar-eas, it is noticeable that the resistances of patterned plated samples show lower resistance than expected from the lin-ear extrapolation. he resistance plot as a function of area with efective surface area of mushroom top morphology (green triangles in igure 20a and 20d) its very well with this linear trend.

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Figure 20. (a, b, c for anode; d, e, f for cathode) Resis-tance, Exchange Current Density ( Jc0, Ja0), and Charge Transfer Coeicients (1-αa, αc) compared to changes in Surface Area. Blue diamond represents data from the sputtered Ni ilms, while the red squares are from the patterned plated samples without consideration of additional surface area of the plated Ni patterns. For resistance plots (a and d), the same resistance data was plotted as a function of surface area with consideration of the sidewall shape of the plated Ni ilm as green tri-angles.

Conclusionhis research demonstrated the impact of novel elec-

trode surface design with mushroom top morphology to increase the efective surface area by using simple photo-lithography and electroplating. his design can be applied to other patterning methods with various aspect ratios. With cyclic voltammetry, these metal ilms were tested to gather voltammograms. Using a conventional and newly proposed modiied Butler Volmer equation with limiting resistance, critical parameters were extracted and analyzed in relation to the change in surface area. he resistance

of the system decreased below the ex-pected resistance from the linear ex-trapolation of the sputtered Ni ilms with known opening areas. From SEM pictures of the mushroom top patterns, the estimated advantage of the structure was about 4 times more than straight sidewall. With linear approximation, the average reduction in resistance was 20.4% more than what is expected from linear approxi-mation, which translates into a 25.6% increase in eiciency.

Future WorksIn the future, the experiment

should be done to ind the trend of electrolysis eiciency as a function of pattern size and spacing. To do so, photolithography techniques with higher controllability is required. Also it is desirable to use smaller pat-tern size to increase additional surface area from the plated metal sidewall so the efective surface area of this new structure can be further increased. As investigated in this study, higher aspect ratios show a greater efective surface area increase. If we apply this mushroom top surface morphology structures in high aspect ratio materi-als such as nanowires and nanotubes,

it will further increase the eiciency. Another focus of future works can be on other nonnoble metals that may provide greater catalytic efect than Ni, including cobalt or manganese, which have been previously tested and charac-terized in electrolytic systems to be suitable replacements for noble metals. With consideration to the future, high eiciency electrolysis will very likely become one of the greatest sources of fuel for the future.

Acknowledgements

I’d like to acknowledge my mentor, Dr. Lee, for read-ing materials and lab assistance he provided me through-out the project, as well as the motivation he had to try a new idea out of his ield. Also, my mother and sisters who cheered me on before going to bed, whose spirits kept me going till 4. Special thanks to the NCSSM Research in Chemistry program and Dr. Halpin for providing the bulk of the funding for my research and the resources to have my materials accepted and presented at many conventions throughout the year.

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[14] S.-C. Lin, Y.-F. Chiu, P.-W. Wu, Y.-F. Hsieh, and C.-Y. Wu, “Templated fabrication of nanostructured Ni brush for hydrogen evolution reaction,” Journal of Materials Research, vol. 25, no. 10, pp. 2001–2007, Jan. 2011.

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[20] Ranganathan, David; Zamponi, Silvia;Berrettoni, Ma-rio; Layla Mehdi, B; Cox, James A; “Oxidation and low-in-jection amperometric determination of 5-hydroxytryptophan at an electrode modiied by electrochemically assisted deposi-tion of a sol-gel ilm with templated nanoscale pores” Talanta (0039-9140), 09/2010, Volume82, Issue 4, pp. 1149 - 1155.

[21] Shibli, S M. A and Dilimon, V S. “Development of nano IrO 2 composite-reinforced nickel–phosphorous electrodes for hydrogen evolution reaction” Journal of Solid State Elec-trochemistry(1432-8488), 08/2007, Volume 11, Issue8, pp. 1119 - 1126.

[22] Gao, Feng; Yang, Yifu; Liu, Jun; Shao, Huixia. “Method for preparing a novel type of Pt–carbon iber disk ultrami-croelectrode” Ionics (0947-7047), 02/2010, Volume 16,Issue 1, pp. 45 - 50.

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