Week 8

Hey everyone!

Like last week, this week was also focused on trying to fix the problem of collecting the hydrogen gas produced.

I checked the current caulk that I had on my device and found that there were some leaks because the material seemed to be dissolving away or was not fully leakproof.

I then researched about which caulk would be most suitable for my particular situation. I needed something that would both adhere well to plastic and not dissolve or crack under pressure or near water.

After searching online and going to the store, I talked to an associate about what I would need this caulk to do and showed them that the previous one had not worked. The associate then recommended me to try GE’s white silicone it caulk. I had researched online that 100% silicone was good for sealing and the product claimed to be permanently waterproof so I decided to try it out.

 

Before applying the new caulk I would have to remove all the old caulk and any dirt in the area in order for the new one to work effectively. I used a knife to scrape away at the old sealant and did so until it was sufficiently clean. I then carefully applied the new caulk (which was white rather than clear) to the device. This time I angled the electrodes to be closer together so that there was less resistance from the water between them when the experiment was run.

The label said that the caulk would be waterproof in 30 minutes but I decided to wait the full 24 hours before running the experiment so that the caulk could fully cure.

After the caulk was ready, I ran the experiment again, using my 9 Volt batteries in the same set up as before. Because I wasn’t sure if my makeshift balloon was tight enough (and thereby causing a leak), I found a real balloon and used a rubber band to tightly tie it to the collection tube instead of using string as before.

I left the experiment to run for a while, but again I did not see a change in the balloons shape. I’m still not sure what is wrong with the device but I decided I would talk to my professor about it the following week. 

Week 7

Hey Guys!

This week was spent focusing on trying to collect the Hydrogen gas that was produced by my device.

I went to the lab and talked to my professor about the issue and he suggested I try to increase the current output by putting more batteries in series. He also suggested I try to increase the water level so that there is less air in the container and so that it is more easily pressurized. He gave me some 1.5 Volt batteries, an old charger he didn’t need anymore and left me to work.

First thing I did was found some scissors and cut up the old charger into wires. I cut back the insulation so that the metal would be exposed to the batteries and made a set of mini wires I could use to connect the batteries. I didn’t have anything to hold the wires in place (I wouldn’t be able to hold all of them manually while I ran the experiment) so I found some parafilm and used it to tie the wires down onto the batteries, and then tie all of the batteries together. Together they made a much larger battery.

                      

Before I tested the new battery I increased the water level to 1000 mL and added a 1/4tsp of salt to keep the concentration of salt the same as before.

After preparing the solution, I tried the larger battery that I had created on my device. It contained four 1.5 volt batteries connected together in parallel. After wiring the battery to my device, I observed that there were no bubbles forming.

I then changed the set up of the battery and connected 2 batteries in parallel and connected it in series to another 2 batteries in parallel. The setup gave me 3 Volts instead of 1.5 as before. When testing it, I found that this time bubbles did form and gas was produced. The reaction however was still less severe than that of my 9 Volt battery.

I then sought some help from my graduate lab partners and they used a device called a potential state to check for the minimum voltage needed to start the reaction. To use the device, a range of different voltages are tested and the resulting current is measured.

 After experimenting we concluded from the graph above that the minimum voltage needed to start the reaction was 3 Volts because there was a drop in the rate of current increase at this location. At this point is where water begins to split. The reduction reaction uses the electrons to create the hydrogen gas causing a drop in the rate of current increase even with increasing voltage.  The graph also explained why the 1.5 volt batteries all in series did not work (we had not reached the minimum voltage required). 

I then tried using four 9 Volt batteries instead of 1.5 Volts to see if I could collect anything with the same setup (2 in parallel connected in series to another 2 in parallel) and left the device for an hour. After time was up there was still no change in the shape of the balloon and so I decided that I would have to change the brand of caulk I was using and check for any other leakages elsewhere.

Week 6

Hi everyone!

This week I finally got to put my device into action! Before I started I had to gather more materials. I went to visit my professor so that he could collect the salt needed to start testing. He gave me a small amount in a bag and told me that I wouldn’t need too much to get the reaction started. I also bought alligator clips with wire attached so that I would be able to connect my electrode to the battery/ solar cell.

Before experimenting, I had to choose a starting point for all of my variables. My container has a capacity that is slightly greater than 1 liter and my professor had suggested trying to fill the container about 3/4ths of the way with solution. I measured approximately 750ml of purified water with a beaker and put it inside my container. I started with my smallest measure, a 1/4^th tsp, to see if I could get a decent reaction and decided I could add more later on if needed. After stirring, I tested a 1.5 volt battery on the solution and checked for the formation of any bubbles at the cathode to indicate a presence of Hydrogen.

At 1.5 Volts, I didn’t see any reaction so I increased the voltage to 3 volts by adding another 1.5 Volt battery in a series circuit. This produced bubbles, but they formed very slowly, so I tried increasing the salt concentration in the water, adding another 1/4^th teaspoon, and the formation of bubbles increased. I added one more quarter teaspoon (with slightly increased bubble formation again) and then decided I needed a much bigger battery if I was going to produce enough Hydrogen to collect. I then went with one of the graduate students in my lab, Wen Si Huang, to go find one, and we purchased a 9 Volt battery from a nearby store to test.

The 9 Volt battery was visibly extremely effective at increasing bubble formation as shown in the video below:

Because it was rather difficult trying to ascertain whether or not there was any hydrogen flow coming from the collection tube, I cut a glove up and tied it with string to see if the makeshift balloon would inflate.

After waiting a while, unfortunately, even though there was hydrogen production, the balloon still did not inflate.

There are a couple of reasons I could think of for this result. Either there is not enough gas being produced to inflate the balloon, in which case I would have to try powering the device differently or there remains a leak in the devices sealing. I will have to try to resolve the issue next week.

Week 5

Hey guys!

This week was pretty exciting for me because I finally got to start building my device! First, I went to my mentor to collect the containers and graphite rods so I could have all my materials with me. After getting those I talked to my professor about which method of sealing he thought would work more effectively. I showed him both the rubber seal that he had suggested and the caulk that I had bought and he agreed that caulk might be the better choice. If used, we would not have to drill large holes to accommodate the rubber stoppers and would be able to fill the gaps more effectively with a liquid than with a solid. After choosing our sealing, my professor showed me how to use his electric drill, gave me access to the lab, and showed me to a table I could work at.

First thing I did at the lab was clear my work space and put all of my materials where I thought convenient. After that I obtained a device that my professor had shown me can be used to measure the diameters of the graphite rod and collection tube as shown below. With that information I would be able to find the matching drill bits.

 

The device opens and closes with a dial (that I’m holding) and has to be tightened around the object being measured until it will not close any further. The display will then read the diameter of the object.

After obtaining the diameters of the rods and tube, I looked through the different drill bit sizes I possessed to find the suitable one. The size was usually written on the side of the bit but if not, I could measure its diameter. The sizes of the drill bits would not always match perfectly with that of the rods and tube but  I decided that if there was not too much of a disparity in size, I would use the ones that were closest.  I tightened the drill around the bits I had chosen and drilled three holes into my container as shown below:

3/8 Drill Bit

 

Before using the caulk, I decided to test it out first so I could become more familiar with its consistency, ease of application, and drying time. I used an extra container I had and drilled two holes the size of the graphite rods into its lid. I then found two pen bodies that I was not using anymore from my backpack, inserted them into the holes, and used the caulk to seal the gaps. I was surprised to see that caulk was thicker and harder to apply than I had originally expected! Nonetheless, it seemed to work pretty well so I got started on the real thing.

I used a crayon I had to mark the spots on the rods right above the container to ensure that when I sealed the rods to the lid, they would be high enough so that the lid would still snap shut and low enough that they would be under water level once I filled the container. I then removed the orange stoppers that were on the rods from before and the duct tape that was on the collection tube.  After that I applied the caulk, trying to get as much of it as I could into the gaps and waited for it to dry.

My professor showed me that the best way to check if the container was airtight was by blowing into it from the collection tube. I tried doing so and found it increasingly difficult to blow air into the container as the caulk dried indicating the seals were working. However, there were still places where I could feel the air was escaping. Next week, I will have to finish caulking the tube, apply more to the gaps that still weren’t sealed, and find the batteries and wires needed to perform the electrolysis of water. 

Week 4

Hey everyone!

This week, I researched where to find the rest of the materials needed to create the device, which included the containers and the sealings.

For the container I searched online to see if I could find one that is airtight and would therefore prevent the Hydrogen gas from escaping. I immediately thought of food containers that were advertised to be airtight.

 

The container pictured above is called a Snapware container, and is commonly used to store food. The lids have sides that snap shut over the rest of the container and have a rubber band in between to ensure an airtight seal. I’m not completely sure how effective this container will be, but so far it has been the best that I could find that is both affordable and suits the needs of the device. I sent the order information for the containers to my mentor and was notified when they had arrived.

For the sealings, initially I had thought to use a rubber stopper to seal the hole between the container and collection tube. I bought a couple from the Home Depot of two different sizes and drilled a small hole through one, making sure that the hole was neither too tight so that the tube would not fit, nor too loose that it would not seal properly, and then inserted the tube through the stopper as shown below.

 

However, after discussing my plans with Mr.Ray, my school advisor, he brought up the possibility of using caulk as a sealant as well. Caulk, is a flexible material used to seal air leaks through gaps between building materials and would dry to fill the space between the collection tube and the container to prevent the escape of gas.  I went to Walmart and talked to an associate about which brand would work best for my project and was shown a couple of the products they had that might work. I ended up purchasing the Liquid Nails Clear Seal All-Purpose Sealant.

Next week, I will have the opportunity to talk to my mentor about both options and determine what to do. Looking forward to beginning to build my device!

Week 3

Hey Guys!

This week was mostly spent finding some of the materials I needed to build my device. I wanted to build a device with mostly commonplace materials so that it would both be affordable and easily assembled by anyone (including for classroom demonstrations of the applications of renewable energy).

My mentor and I looked through the materials that he had in his office and lab to see what we could find. We found that we already had some graphite rods that we could use for the electrodes and also found a container full of Na₂SO­₄ that would work for our salt.

Additionally we found an old copper tube that could be used as the collection tube.

Next week, I will have to research more about where I can find a suitable container and seals. When my mentor built a similar device before, one of the problems he ran into was the sealing. The cap on the container was not tight enough to prevent the escape of gases and the sealing on the collection tube, duct tape, as pictured above (I got the copper collection tube from his earlier device) was not adequate either. I hope to find a better method to seal the gaps. 

Week 2

Hey guys sorry for the late post but here’s what I did in Week 2!

During Week 1, Dr. Tao and I worked out the design of the device so this week we were able to work on figuring out what materials the parts were to be made of. These included the container, the electrodes, the collection tube, the salt, the seals, and the solar cell/ batteries.

The container: For the container, we would need an affordable material that wouldn’t interfere with the experiment. We narrowed down our focus to glass and plastic containers. In the end we decided plastic may be best so that it is easier to puncture the lid to make openings for the electrodes and the collection tube.  

The electrodes: I plan on using graphite rods for both the anode and cathode. Graphite is a good conductor and shouldn’t interfere with the electrolysis of water chemically.

The collection tube: While it would be alright to use any material for the tube as long as it doesn’t react with the gas, plastic tubing, for example, would not be the best choice because to test for the existence of hydrogen gas, we would try to ignite it using a flame and this may cause the tube to melt. With that in mind, we chose to use a copper tube so that it would not melt with the heat.

The salt: The salt should be chosen carefully so that noxious gases don’t form as a result of using them. For example, if NaCl were to be used it could result in the unwanted formation of Cl₂ gas. It would also be wise to use a gas with a high solubility product constant, Ksp, so that it can increase the conductivity of the solution more effectively. Taking both into consideration, we plan to use Na₂SO₄.

The seals: The purpose of the seals is to trap the hydrogen gas within the container so that there is enough to create a flow through the collection tube to ignite. As of now, I’m not completely sure if the seals we’ve chosen to use will be adequate enough, but I plan to use a rubber band to seal the space between the cap and the container. To seal the gaps between the electrodes and the container cap I will use rubber plugs that my professor already has, and for the gap between the collection tube and the cap, I have to find a plug that contains a hole with the correct diameter (that of the collection tube).

The solar panel/ batteries: Once the optimum voltage and current is found using the batteries, we can determine which solar panel to use for the device.

This week was also exciting because I got to meet some new people! Every Friday, all of the undergraduate and graduate students that work in Dr. Tao’s lab meet up for a team meeting to report their progress to him. It was interesting to listen as each of them shared their week’s findings and I had the opportunity to talk with a couple of them after the meeting was over. Looking forward to working with them!   

Week 1

Hey guys! Week 1 of Senior Research Projects is already over and I’ve been doing some pretty interesting things. This week I got to meet up with my on-site advisor, Dr. Meng Tao, for the first time since SRPs started and talk about my project.

First thing we did was tour the Engineering Research Center here at ASU Tempe, and I got to see the inside of my professor’s lab for the first time. He showed me some of the undergraduate and graduate students’ workspaces and where everything is. Afterwards we sat down in his office and got to discussing the device I’m going to create.

As mentioned in an earlier post, my device is designed to generate usable energy using solar power. I plan on using everyday items to build the device so that it can be used at home and for educational purposes to teach about renewable energy. The solar cells in the panel would capture energy from the sun and transfer it through the wiring to the electrodes. The splitting of water happens through an oxidation-reduction reaction so at the positively charged anode the following half reaction would take place generating oxygen gas:

                                      2 H₂O(l) → O₂(g) + 4 H⁺(aq) + 4e⁻

And at the negatively charged cathode, hydrogen gas is generated:

                                      2 H⁺(aq) + 2e⁻ → H₂(g)

The reaction can also be balanced using the basic method in which

            Cathode (reduction): 2 H₂O(l) + 2e⁻ → H₂(g) + 2 OH⁻(aq)

Anode (oxidation): 4 OH⁻(aq) → O₂(g) + 2 H₂O(l) + 4 e⁻

In either case combining the half reaction pair yields the same overall reaction:

                                      Overall reaction: 2 H₂O(l) → 2 H₂(g) + O₂(g)

Under ideal conditions the hydrogen gas would be produced at twice the volume of the oxygen gas. Electrolysis of pure water occurs very slowly or not at all, so to speed up the process, we would add a salt electrolyte to increase the electrical conductivity. A tube would then collect the gas from the container then it would be ascertained whether or not the gas would combust. If it ignites, there exists hydrogen, a usable fuel source. We would also make sure to seal the device properly so that there is minimal leakage of gas or there may not be enough hydrogen gas exiting the tube to combust.

Above is the anticipated design of the device.

About the Project

Global warming due to the use of non-renewable energy is one of the most pressing problems in the modern world because the supply of these sources cannot be relied on in the long term and continuous use of these substances are detrimental to the environment. Problems commonly associated with the use of non-renewable energy is the depletion of the ozone layer of the earth and the subsequent rise in global temperatures. Finding an alternative source of fuel would be taking a positive step towards protecting the planet against the consequences of climate change, protecting many of the Earth's natural habitats and minimizing the damage from natural disasters caused by climate change. 

To combat climate change, we must ascertain if there are renewable and environment friendly alternatives to the non-renewable fuel sources currently used. Both nuclear and solar power show promise as potential replacements, and have shown to be most effective. Nuclear power, however, is still not widely used so researching into utilizing and maximizing the efficiency of solar technology is  a promising investment. 

For my Senior Research Project, I aim to build and maximize the efficiency of a solar powered water splitting device. The device would break water into its constituents, hydrogen and oxygen gases, via electrodes using energy collected by a solar panel. The hydrogen gas could then be combusted and used as a source for fuel. Although a small device, I aim to develop technology that could be used as a model for more complex devices as well as serve as a point of discussion for other renewable innovations. 

Research Proposal
(Subject to Change)

Title of Project

Enhancing the Efficiency of the Solar Water Splitting Technology

Statement of Purpose

This research proposal aims to demonstrate the use of renewable methods to generate usable energy. In researching, I will try to determine whether or not solar power can be used to provide the energy to split water into its constituents, hydrogen and oxygen, so that there is enough hydrogen to be useful for combustion. I will then further research how to make the device more efficient.

Background

As a future electrical engineering student, I find this topic interesting because it gives me my first experience in the field. Solar water splitting involves using the energy gathered from solar panels to reverse the process of water formation. This energy is transferred via metal tubes to break down the water molecules into their constituents, H₂ and O₂, in their gaseous state. The gases are then collected and combusted to provide usable energy. The reverse reaction requires a minimum input of 1.23 eV according to current research and I will attempt to devise the most efficient method to exceed this threshold and maximize combustion. I have taken Advanced Placement Chemistry and Physics so I am prepared to study this topic. After reading about engineering, I have found it enjoyable to apply concepts from many of the different subjects I have taken to create devices and I am therefore excited to start my research.

Significance

The use of nonrenewable sources for power generation is a global issue because the supply of these sources can’t be guaranteed forever.  Solar and nuclear energy provide the most output energy for the amount of input energy. However, nuclear power is still not as widespread as solar, therefore researching in building and maximizing the efficiency of solar powered energy sources is a promising investment because it could be a potential renewable replacement for nonrenewable energy. Because the combustion of nonrenewable energy and the subsequent release of greenhouse gases has been linked to global warming, investigating whether or not solar power would serve as an effective alternative is critical to protecting the environment from the consequences of increasing global temperatures. My research is therefore important because it takes a step towards innovating technology to aid in this initiative.

Research Methodology

In order to complete my research project, I will be working alongside my professor in his lab. We will first use batteries to determine which voltage is most efficient for the process before obtaining a solar panel and using solar energy for the same process. Using copper metal tubes, a container, water, salts, sealing, panels/batteries and other materials, I will build and improve upon a device to split water into oxygen and hydrogen. If the emitted gas (hydrogen) burns, then it will be an indicator of a successful working device. I may use library books, research papers, and scientific manuscripts to aid in my understanding and to discover methods others may be using to make similar devices to improve upon the efficiency of my own device.

Anticipated Problems

The problems I may encounter while researching are mainly issues with the functioning of the device. I would have to figure out first and foremost how to seal the container edges and the gaps where holes are made to ensure there is no gas (hydrogen) leakage when the experiment is performed. I would have to figure out which salt would be best to ionize in the water and whether or not the concentration of the salt will affect the efficiency of the process. I would have to determine which metal would be best to conduct electricity from the panels to the water and the diameter these tubes and the gas collection tube should be. I would also have to figure out which voltage would make the reaction run most smoothly. If the reaction doesn’t work as planned, I would have to check all of these variables, and possibly others I have not considered, to find the source of the problem.

Bibliography
Coveney, Donna. "Solar-Power Breakthrough." MIT Technology Review. N.p., 31 July 2008. Web. 10 Dec. 2015.
Payne Research Group. "Solar Water Splitting." SYNTHESIS AND CHARACTERISATION OF FUNCTIONAL OXIDE MATERIALS. N.p., 25 Sept. 2011. Web. 10 Dec. 2015