Welcome to the Southern California SEAL infantry! SoCal SEAL students check here for important information regarding the SEAL program at Caltech
Important dates for 2017-2018 school year:
SEAL Kickoff- Sept 30, 2017 10am-12pm
(Link to Kickoff Talks- email Michelle for password)
SEAL Con IX- May 12, 2018 10am-2pm
2017-18 SEAL Roster
Every member of a SoCal SEAL team needs to sign-up on the roster. This ensures you will receive communications about upcoming events and helps us keep track of our membership. You also won’t get a certificate or T-shirt at SEAL Con unless your name is on this list!
SEAL Permission Slip
All SoCal SEAL students need to fill out this permission slip and return it back to Michelle DeBoever either via email, mail or in person through their mentor. Students under 18 must have the form signed by a parent or guardian.
SoCal SEAL Blog
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Beckman Group 1 is spotting a plate with ratios of iron (III) nitrate to aluminum nitrate. Their plate, 1-52, will have four different ratios of iron (III) nitrate to aluminum nitrate—1:1, 1:2, 1:3, and 1:4, each ratio having their own section on their plate. Group 2 ran Plate 2-70 with 0.01 M bismuth nitrate, since 0.03 M was not soluble. Their ratios of bismuth nitrate to iron (III) nitrate are 1:3, 1:6, and 2:3, and the fourth section solely has the pure 0.01 M solution of bismuth nitrate. They also reran Plate 2-68 with both 0.03 M chromium (III) nitrate and 0.03 M zinc (II) nitrate, using three ratios—0:1, 1:1, and 1:0. Group spotted plate 3-62 with ratios of bismuth nitrate to iron standard, which are 1:0, 1:1, and 0:1. Group 4 ran plate 4-54, the plate treated by UV for 5 minutes, as part of their efforts to discover the effects of elongated UV treatment on the coffee ring effect.
Poly: After brushing up on some conceptual understanding of band gaps, electron excitation, and the solar spectrum, we’ve decided to try spotting two solutions on one plate in order to take advantage of the band gaps of multiple materials. We hope that the relatively low band gap of Cobalt will aid in capturing a wide spectrum of light while an additional layer of Iron will actually carry out water-splitting. We’re using 0.1 M solutions of Cobalt Acetate and Iron Nitrate (the same solution as last time). In addition, we’ve taken to drying our recently-washed plates with Nitrogen, and we’re cleaning two plates with plasma again this week to further explore effect of plasma etching.
The other group cleaned eight plates using the plasma cleaner at the Atwater lab. We then went to the Kavli Nanoscience Institute to observe what a real clean room fab looks like. We took back the plasma cleaned plates to the lab and dried them with nitrogen gas to remove any remaining/gathered dust. Finally, we spotted two plasma cleaned plates with 0.1 Iron Nitrate, two with 0.1 Manganese Sulfate, two with 0.1 Cobalt Acetate, and the last two with both the Manganese solution and the Cobalt solution.
Alverno: BASIC group made an MnSO4 and TiO2 plate to see how they react with each other. They also made an Iron plate along with a Strontium and Manganese plate. They tried running plates 180306ES-1 and 180223ES-1 but had issues with dark current. CO2 group explored different concentrations of Iron standard plates and in doing so noticed crystallization on the 0.4 M plates. They made another 0.4 M Iron plate and a 0.1 M Iron plate. DOLPHIN group used a Dremel to cut metal into pieces so that they can raise the printer to fit SEAL plates inside.
San Marino Green Team: Last week’s plate had nothing but noise. In the beginning of the year, they believed they had discovered a Cu spot that was a huge hit, so they continued to play with copper. The reasoning for this plate is simply to finish “The Copper Adventure”. From the plate made last week, there was actually a solid spike in Spot #1 (Cu:Zn in a 99:1 ratio). Rather than just noise as per the plate tested last week where everything was under 0.1, Spot #1 was reproducibly good, peaking up to 0.3 on the scale while many of the other spots hovered around 0.1. They expected to have bad results to finish off the Copper narrative, but instead found something interesting— though it was still blue, it is worth looking at if Zinc is a viable combination with Copper.
Blank Team noticed there is significant flaking for the iron control spot – Fe(NO3)3 after annealing. Other spots containing Fe did show some flaking, but not as much. As concentration of iron increases, the spots flake more and more. The reason for the significant flaking is probably because the Fe(NO3)3 solution used was old and cloudy. It could also be because the plate was baked at a 450 degrees C, which is higher than normal temperature.
When the plate was placed in the base solution, before applying voltage, significant flaking occurred, specifically on the “pure” MnCl2 spots and the iron control spots. Despite the flaking of the MnCl2 spots, much of the spot material remained attached to the plate in a deformed state (in pieces instead of a round circle). The iron control spots, which had already significantly flaked after baking before placing it in the base solution, completely flaked away after being placed in the base solution. For the first scan, the dark current is around 0.5V, and applied a current of -0.002V. MnCl2 had a the highest bar (0.2V) out of all the spots. Second scan was performed with -0.002 V applied; dark current remained steady and dropped after the second scan. The third scan applied -0.005 V with dropping dark current; results are overall the same. Scan four has the same result despite the positive applied potential 0.005. Overall, given the four scans, there are no conclusive results.
They are planning to use barium for the next plate because they don’t have any cadmium. They will mix the barium salt solution with a manganese salt solution and repeat some spots containing iron using a newer solution. Since the vanadate tended to react to form new materials, they will not test it for this new plate. 10 microliters per spot of:
0.2 M MnCl2, 0.1 M Ba(NO3)2, 0.1 M ZnSO4, 0.1 M Fe(NO3)3
Ba(NO3)2 + MnCl2 (7.5 : 2.5); (5 : 5); (2.5 : 7.5)
Ba(NO3)2 + Fe(NO3)3 (7.5 : 2.5); (5 : 5); (2.5 : 7.5)
Ba(NO3)2 + ZnSO4 (7.5 : 2.5); (5 : 5); (2.5 : 7.5)
MnCl2 + Fe(NO3)3 (7.5 : 2.5); (5 : 5); (2.5 : 7.5)
MnCl2 + ZnSO4 (7.5 : 2.5); (5 : 5); (2.5 : 7.5)
ZnSO4 + Fe(NO3)3 (7.5 : 2.5); (5 : 5); (2.5 : 7.5)
Beckman worked on testing their plates this week in a 50.0 mL of sulfite solution and 50.0 mL of NaOH solution. Group 1 started testing their plate (BHS-1-51). This plate had iron standard and the different ratios of 0.03 M of Cd(NO3)2 and Cu(NO3)3. The ratios of Cu:Cd is 5:1, 4:1, 3:1, and 2:1. Group 2 made an error with epoxy on one of their plates and will start testing next week. They also started epoxying another one of their plates (BHS-2-70). Group 3 started testing two of their plates (BHS-3-60) and (BHS-3-58). BHS-3-60 is a plate that is testing 0.03 M solution of iron standard and Al(NO3)3 with ratios of 2:1, 1:2, and 1:1. The BHS-3-58 plate is testing a 0.03 M of iron standard, Cd(NO3)2, Cu(NO3)3, and Al(NO3)3. The ratios of Al:Cd:Cr for this plate is 1:1:1, 1:3:1, 3:1:1, and 1:1:3. Group 4 will test their plate next week.
Canyon Crest did a short test of air-drying vs hotplate evaporation of spots (of Sr:Ba:Zn) and found that air-drying reduced the coffee ring effect. They also tested two more plates, CrCl3:K2Cr2O7:CoCl2 and K2Cr2O7:NH4VO3:KMnO4. They saw very good results in a spot with roughly equal proportions Co and Cr (which was promisingly surrounded by a gradient of high readings). One of the plates to be tested next week contains a spot similar to this so they will use that as an opportunity to confirm the result.
Poly finished epoxying plates of Fe(NO3)3. Tested both plates of Fe(NO3)3. One was plasma etch treated for thirty seconds before spotted. The other plate was treated normally → rinsed with acetone and isopropyl alcohol and deionized water. The Fe(NO3)3 plate treated with plasma had significantly better results than the non-treated plate, possibly due to the larger and less faded spots seen on the treated plate in comparison to the coffee-ring effect on the non-treated plate. See picture below
The data on the left was cleaned with an oxygen plasma and the data on the right was the control. Although these results show that there was success with the plasma cleaner, the results for the control were questionable given that they were unusually unsuccessful. Poly also looked for salts to layer with the iron and found manganese and cobalt had good band gaps. They made a 0.1 M MnSO4 solution, will make the 0.1 M cobalt solution next time.
San Marino Green Team observed last week that for spots with a higher concentration of Cu, the addition of Na2SO3 increased the relative size of the peak. They tested a new plate this week, baked at 400℉. (1) 100% Cu, Uniform dark gray; (2) 0:100 Cu:Ni, uniform pale gray; (3) 50:50 Cu:Ni, uniform dark brown; (4) 75:25 Cu:Ni, Dark yellow brown; (5) 25:75 Cu:Ni, lighter yellow brown; (6) 90:10 Cu:Ni, looks very similar to (1), uniform dark gray.
While at first, they observed that certain peaks were present in the graphs, the low overall voltage led them to the conclusion that this plate was mostly “noise”. The variation in the dark current was greater than or equal to the height of these peaks, meaning that we could not comment with any certainty on the performance of individual spots or the effect of adding Na2SO3. For next week’s plate, they have decided to continue the narrative with copper. They will once again revisit the 1:99 and 1:999 ratios, with Cu as the base material and Zn and Co as the trace materials. They will also test this plate in Na2SO3.
Blank team made a new plate (10 microliters per spot, most spots dried out before baking in kiln). Solutions used were 0.10 M NH4VO3, 0.10 M ZnSO4, 0.10 M Fe(NO3)3, 0.20 M MnCl2. Made spots with ZnSO4 + NH4VO3 (2.5:7.5), (5:5), (7.5:2.5); Fe(NO3)3 + NH4VO3 (2.5:7.5), (5:5), (7.5:2.5); MnCl2 + NH4VO3 (2.5:7.5), (5:5), (7.5:2.5); 0.1 M Fe(NO3)3; 0.2 MMnCl2; 0.1 M ZnSO4.
In order to be able to run more plates and become more efficient in the long run, Beckman decided to install the SEAL Kit Software onto another computer. Because it took time, it was too late to run any plates this week. After researching and looking through previous lab notebook reports, Group 1 concluded that there had been the most success using iron nitrate and aluminum nitrate so far. Therefore, they decided to prepare a plate with different ratios of aluminum nitrate to iron nitrate. Group 2: saw there was success using bismuth from PCC’s work. Therefore they decided to retry bismuth with a lower concentration (0.01 M) in order to achieve greater solubility. Then, they spotted a plate using different ratios of bismuth nitrate and iron nitrate. Groups 3 and 4 installed the SEAL Kit Software onto a Windows 10 laptop and set the SEAL Kit up to confirm that it worked. They also spotted a plate with 0.03 M Fe(NO3)3 and then UV treated the plate for thirty minutes as part of the research on the effects of different time intervals of UV treatment.
Canyon Crest Academy was able to spot two more plates and kiln and epoxy several others. However, more interesting is what they failed to do: make a plate of iron, tin, and lead. They attempted it three times and discovered issues with all three solutions. The first mistake was using tin (II) chloride (SnCl2)which was past its shelf life. This particular bottle of tin had been prepared in 2006 and had apparently transformed into stannic chloride (SnCl4) via exposure to air. Second, there were some precipitation issues with a beaker of iron sulfate mislabeled as iron nitrate (leading them to believe it was soluble in lead). Finally, they didn’t take into account the limited solubility of the lead chloride solution made (the solubility of lead which is 10.8 g/L; the attempted solution was 27.8 g/L). These issues were resolved quickly though and they made two new plates.
San Marino’s Blank Team: Last week’s plate had severe coffee ringing effect, but it is unlikely that it will actually affect test results. The greater the concentration of copper/nickel, the darker the oxides are. 100% Sodium Metavanadate is white in color; 100% Ammonium metavanadate is white-yellow in color.
Potential materials stable above/below water oxidation line:
- Manganese vanadate
- Manganese oxide
- Cadmium oxide
- Barium oxide
Testing: dark current = 0.1-0.3V and applied voltage = 0.07V. The current increases from left to right, with the 75% nickel/copper compounds resulting in the highest current. The highest peak was only ~0.2V, and the differences in height were not dramatic (within 0.1v). The purported sodium metavanadate and ammonium metavanadate spots washed away (as expected; they should be water soluble). This is similar to what occurred last year when sodium metavanadate washed away from one of our plates. Overall, no significant results.
Made new plate (total volume each spot is 10 microliters):
ZnSO4 + NH4VO3 (2.5:7.5), (5:5), (7.5:2.5)
Fe(NO3)3 + NH4VO3 (2.5:7.5), (5:5), (7.5:2.5)
Beckman Group 1 created a sodium sulfite solution for testing. Because the epoxy has proven to be weaker when being put into the testing solution after five to ten minutes of drying, they are waiting for 45 minutes for it to dry before testing. Group 2 is testing a plate with chromium nitrate with iron standard that they made previously. They also plan to test a plate with zinc nitrate, chromium nitrate, and iron standard afterwards. Groups 3 & 4 collaborated in continuing to test the effect of varying lengths of UV treatment of the FTO plates. They have prepared the plates of 5 min, 10 min, 30 min and 60 min and they are trying to test the plates. Today they are running the 5 minute plate. Last week, they realized that their iron nitrate solution was old and looked cloudy, which they predicted may skew their results. Today, they recreated the solution to make the same 5 minute UV-treated FTO plate to compare it with the old 5 minute UV-treated FTO plate to see if there is any difference.
Alverno has updates from their 4 teams. Acid: Made 4 plates of Nickel Nitrate and Nickel Nitrate Titanium Dioxide to test this week. Basic: Have 4 plates to test, all of which plates have been made with two different metals at the concentrations 0/100, 25/75, 50/50, 25/75, and 0/100. There are a total of 14 spots on each plate. The metals were chosen at random in hopes of stumbling upon a combination that works very effectively. CO2: Figured out a relatively good concentration of TiO2 and the acid group is going to proceed and use that concentration with their future studies. The CO2 group on the other hand had abandoned the idea of TiO2 in their plates, and started randomly picking metal combos from the periodic table (with certain selections). The SEAL kit has been malfunctioning so they are holding back on making more than their existing 10 plates until that is resolved. DOLPHIN: They have cut the printer in half so that they can raise it’s height for the seal plates and they will reattach it with a spacer.
Canyon Crest Academy has gotten organized and created a sheet listing out all of the plates and materials made so far (to avoid testing duplicates). They were also able to create an two additional interesting plates using Iron Ferrocyanide, Ammonium Cerium Nitrate and the potassium chemicals Potassium Dichromate and Potassium Permanganate. In preparing these plates, the metal cations in the solution were not homogenized in the solution: causing the hot-plated slides to have some spots with the coffee ring effect or small pieces of precipitated matter. They expect this to impede getting “good data” since the spots will not be tested as completely as they would otherwise. To avoid the rapid evaporation in future, they will set the hotplates on lower temperature settings and keep a keener eye on the homogeneousness of solutions. Because of their surplus of prepared and epoxied plates, the next meeting will be dedicated to testing existing plates.
It’s been a slow few weeks so I combined the updates into one post.
Poly tested two MnCaO and two MnVO plates but didn’t report on the results (not good?). They also wanted to try a different method of pre-cleaning plates to allow for better results, so they went to the Atwater lab and used their plasma cleaner for 30 seconds. This should get rid of any extra debris and material on the plates. They spotted Fe(NO3)3 to test as a control.
Beckman Group 1 re-epoxyed their plate from last week, whose epoxy binding had come apart in the sodium sulfite solution after they let it dry for well over five minutes. They will let the epoxy sit for about an hour before they test it again. They are also baking the plate that they previously spotted. Group 2 is testing a plate with chromium (III) nitrate. They are also making a new plate with chromium and zinc with a ratio of 1:1. Group 3 made a new 0.03 M iron nitrate solution since they were running low. They also set up last week’s plate for testing, and will test it after the teams that are in line for testing. Group 4 has discovered several inconsistencies that may have played a role in how their plates turned out. They had set up a plate last week for testing this week – which was UV-tested for five minutes – so they planned to test the plate today. However, the five-minute and one-hour treated plates had much better consistency in their spots than the ten-minute plate; they switched to a new micropipette for the ten minute-plate with a thinner tip, which may have resulted in discrepancies. Moreover, the iron (III) nitrate solution that they used for the four plates has become cloudy, so they will have to remake the solution and UV treat a new batch of plates starting next week, using both the new solution and the new micropipette. Despite this, they will still follow through with testing the plates they already have, including the thirty-minute plate, which has air dried but will needs to be fired.
San Marino Blank Team Tested the new nickel-copper plate. Spots were clean and had minimal coffee ring effect. Iron spots are slightly flaking. Overall, the least flaking of all the plates done so far! Plate did not flake much when placed in KOH solution. All tests: every area (spotted and unspotted) had blue peaks, with exception of the two Cu control spots. Results are inconclusive (perhaps except for the flat Cu spot)
Made new plate (total volume each spot is 10 microliters):
0.1 M Cu(NO3)2 + 0.1M NH4VO3 (2.5:7.5) – Turned bright yellow, (5:5), (7.5:2.5)
0.1 M Ni(NO3)2 + 0.1 M NH4VO3 (2.5:7.5), (5:5), (7.5:2.5)
0.1 M Fe(NO3)3 control
0.05 M NaVO3 (sodium metavanadate)
0.1 M NH4VO3 (ammonium metavanadate)
Green Team tested the plate made on 1/22, got no significant peaks, probably due to the low temperature (~375℃) at which it was fired. Remade the plate but got deep coffee rings this time with not much substance in the middle. Worrisome since it could mean that the light is not actually hitting the particles and only faded parts of the particles. This might mean that the testing on this plate was flawed. Results were as usual— all blue with negligible difference even when the concentration of a material multiplied by ten. However, the substances are in a 1:999 ratio and a 1:99 ratio, so it seems like these materials aren’t actually contributing at all. The plan for next week is to plate a control of copper and iron to see how hydrogen peroxide layered over the spots influences the results and also see if the materials are good light absorbers or not.
Earlier in the week, they plated 0.10M Fe(NO3)3 and 0.10M Cu(NO3)2 in a checkerboard pattern as a control. They aimed to observe the effect of adding Na2SO3 to our NaOH testing solution. The plate reached a temperature of 500℃ and the Cu spots were solid, dull, and black. The Fe spots had a faint red/brown coffee ring, with shattered metallic bits in the center. These bits flaked off once the plate was inserted into the NaOH solution. Initially tested the control plate in the regular NaOH solution. With no bias applied, Scan #1 displayed very low Cu spots, while the Fe peaks and background dark current were at roughly the same level. After applying a voltage of 0.05V, similar results were observed. Subsequently, applied a voltage of -0.05V. This time, the Cu spot peaked, with the dark current on the same level as the low Fe. With a voltage of -0.1V, the results were the same, except the dark current increased slightly.
They then replaced the NaOH solution and added 0.1 mol of Na2SO3 to the 100 mL of NaOH solution. With no bias applied, the Fe peaked again. The Cu and dark current remained at the same level. With 0.05V applied, the dark current increased slightly. Just before -0.05V could be applied, the voltmeter ran out of battery and had to be replaced. The dark current briefly read 0.1. At -0.1V, the dark current was -0.3. The Cu spots peaked this time, with the dark current significantly higher than the low Fe spots.
With the addition of Na2SO3, the peaks seemed to decrease in height, possible as a result of the plate spending a long time in the solution. With a higher applied voltage, the peaks seemed to return to normal. When applied voltage was reversed, it was that the peaks flipped, with Cu now higher than Fe. Whether or not they expected this outcome depends on how the SEAL program interprets negative values…
Beckman‘s Group 1 fired the Cr(NO3)3, Cd(NO3)2, plate from last week and treated a plate with UV to prepare for next week’s endeavors. Group 2 made a solution of 0.03M of bismuth nitrate, spotted their plates and plan to let it dry over the weekend and fire it before next Friday’s meeting for testing. Group 3 spotted a UV treated plate with 0.1M of Fe(NO3)3 and Al(NO3)2 using three different ratios of 2:1, 1:2, and 1:1. They are planning to fire the FTO plate and test it next week. Group 4 has been continuing to test the effects of varying length of exposure to UV treatment on the FTO plates. Today, they etched a new, clean FTO plate and UV treated it for exactly five minutes. This plate that was treated for five minutes was spotted with 0.03M Fe(NO3)3 solution to be fired in the oven. They also did the same for another plate etched with UV for sixty minutes.
Canyon Crest was able to create 5 more well plates of materials this week including Al:Co:Cr which is pictured below and has an interesting greyscale arising from the Chromium solution in different concentrations in the other, transparent, solutions. They also made a very interesting experimental plate consisting of 0.0005M NH4VO3; 0.1M Fe(NO3)3; 0.1M K2Cr2O7. They were able to create some nice looking color gradients (that are also easier to spot on the well plate when arranging the concentrations).
*Helpful tip from Canyon Crest: find the solubility of a solution before you prepare it- either from the bottle or a website like PubChem. They had a failed attempt at making BiNO3 solution trying to dissolve in Nitric Acid, Acetone, and Glycol while on a stirring hotplate – as the bottle instructed. However, the bismuth always precipitated down to the bottom of the beaker and individual particles were easily seen.
Crescenta Valley Team 2 attempted to spot Fe(NO3)3 on a plate last week that had been cleaned with the Tesla coil but the spots spread out. This week they turned to glycerin as a solution, finding a test solution of Fe(NO3)3 and glycerin more or less held together. During the meeting they worked on a new solution of iron nitrate and glycerin in a 1:1 ratio but had some difficulty measuring out the glycerin as it was viscous. They weighed it (instead of pouring it), knowing its density, and created a solution with which they can spot future plates that have been cleaned with the Tesla coil
San Marino Blank Team tested their last plate made in 2017. Flaking after baking is evident. Applied voltage of 0.05V and had dark current around 0.3V, but the results were all in the dark blue range. Reason why there are not so good results is because severe flaking during baking (temperature exceeded 500 degrees as evidenced by silvery powder within iron rings). This is true especially for Cu spots, which are very faint, probably not enough to make the “incident” from last week happen again. Next time they plan to spot a new plate using iron/copper controls. Iron is the “primary” control, copper control exists to see if they can reproduce the “incident” from last week. Main focus for this new plate is Ni and Cu: 100% Ni; 75% Ni, 25% Cu; 50% Ni, 50% Cu; 25% Ni, 75% Cu; 90% Ni, 10% Cu.
Happy 2018 everyone! Now that we’re getting back into the swing of things after winter break, it’s time to share some SEAL updates. We have lots more this month
Alverno has posted their first update! They are divided into four groups this year: CO2 Reduction, Classic SEAL, Acid SEAL and Deconstructed Oxide Laboratory Printer Happily Inking Nonfoods (DOLPHIN) SEAL.The goal of the CO2 Reduction group is to utilize the SEAL kit in a setup that allows them to perform CO2 reduction by bubbling CO2 from subliming dry ice into the electrolyte. They will be looking at titanium dioxide, zinc, nickel for their efficacy at photoactive reduction of CO2.
The Classic group created some protocols such as using the kiln or spotting plates that will be uploaded to protocols.io soon. Last year, Alverno struggled with consistency but this year have had much more success replicating results for Fe and Ni plates. Next up is testing Manganese and Calcium salts as found in Photosystem II. The plates made in Classic SEAL can then be used by other groups, such as comparing the results in sodium hydroxide solution with the results Acid SEAL might get in hydrochloric acid.
The DOLPHIN group is designing a printer this year that can print out spots rather than pipetting them— this could help with making sure the spots are aligned with the template and are consistent. There’s some programming involved and it’s unclear which metal solutions will be compatible with the printer, but they are excited to see what happens!
Beckman’s Group 1 made ratios of 1:1, 1:2, 1:3 and 1:4 of 0.03M Cr(NO3)3, 0.03M Cd(NO3)2. They UV treated plate BHS-1-50 for five minutes and then spotted the plate with different ratios, including 0.03M Fe(NO3)3 standard spot in the top right corner.
Group 2 tested a plate they made previously which included a chromium nitrate, aluminum nitrate, and cadmium nitrate solution. They also spotted a chromium nitrate FTO plate and plan to test it next week.
Group 3 spotted BHS-1-60 with ratios of 2:1, 1:2, and 1:1 of 0.03M Fe(NO3)3 and 0.03M Al(NO3)3, with the iron standard in the top right corner. Iron nitrate is a significant and well-known photoanode while aluminum nitrate may further enhance the effective OER (oxygen evolution reaction) properties. Therefore, the main goal for the next session is to research and test another effective OER catalyst according to the results obtained with this plate.
Group 4 is testing the effects of varying lengths of UV treatments on the FTO plate. They first exposed an FTO plate to the UV treatment in the germicidal cabinet for thirty minutes and spotted with Fe(NO3)3, let it dry, then baked in the kiln. They repeated this process with a new plate for 15 min, 10 min and 5 min. They will compare the results of these plates to see if longer UV exposure time makes a difference.
Canyon Crest‘s first update as well. They had some issues with solutions evaporating over break, but were able to remake them and spot 5(!) plates shown below:
This meeting we were also able to use some odder solutions including using potassium dichromate (K2Cr2O7) which they had to stabilize with Nitric Acid. Mixing this with a 0.1M solution of CrCl3 we created a 0.1M chromium dichromate solution, Cr2(CrO7)3 (aq). They were surprised at its solubility, and will keep it for next meeting. They also speculated about isolating titanium in solution – converting between the titanium dioxide available in the stockroom and usable titanium tetrachloride by using nitric acid. However, they need to find a way to add chloride ions to the equation…
Also here is a link they found to a recently published Columbia University study on a new technology for seawater electrolysis which yields Hydrogen fuel as a product!
San Marino‘s Blank Team focused on the copper nitrate “incident.” They explain “We know something is wrong because nearly every spot on the plate began the test with a “bar” (see pictures of test runs) of the same level (green or blue-green). We also know that the problem has something to do with the machine/kit. The spots that were “outliers” (not having the same level as all the others) were made from a solution of only a copper salt.” Thoughts for them?
Green Team re-spotted their 10-31 plate, with Fe3+, Fe2+, Cu2+, Co2+. First scan produced nothing of significance. It was mostly dark blue. The lone outstanding spot was 50:50 Fe3+ and Zn2+. Spots began to crack and flake in the plate. The dark current was around 0.3V. (Sound familiar MSS KEY team? You should compare notes!)
Mayfield‘s Team KEY made plates to test additional metals with the successful FeZn material. 9:1:1 FeZnMg; FeZnNi; FeZnCu; FeZnAl; FeZnCo. Team JES had to remake their plates 3, 4 & 5 which to refresh your memory are a series of plates with Fe(NO3)3 and Ni(NO3)2 layered with various applications of a tesla coil. Plate 3 is Fe & Ni layered with 3 min of Tesla coil between the layers, plate 4 is treated with Tesla coil before the Fe, and plate 5 is treated with the tesla coil after both layers. After testing this series they hope to move on to experimenting with absorption spectra and artificial photosynthesis.
Only update this week is from San Marino‘s Blank Team. They tested last week’s plate (see last week for template), though there was a considerable coffee ring effect and mild flaking, especially the center of the “pure” Zn spots.
Spots are all green (starting), about same level. The 4 spots for “pure” Cu is very low (dark blue). Another 75% Cu and 25% Zn spot is in the middle (lower than majority green bars, but higher than the “pure” Cu). “Pure” Cu spots around 0.1 and 0.2V, and the majority green bars are around 2V. Run again and starts out blue with varying peaks, but then goes to about the same level of blue (slight green). “Pure” Cu is still relatively low (blue). They expect something as photoactive Cu to have good results, so need to look at the delta difference and figure out what happened.
They spotted a new plate using mixtures of Ni(NO3)2 and ZnSO4 and had Cu(NO3)2 and FeNO3 controls. Each spot is 10 microliters, 0.1 M concentration of each solution. They will test this plate after winter break.
Updates have been thinning out from all of our teams… remember to post EVERY week! Even if it’s just to say you didn’t have a meeting.
Beckman has decided they will do a quick experiment to test the effects of using UV light (ie ozone cleaning) on their plates before spotting. They will be using iron nitrate as a control and varying the amount of time left in the germicidal cabinet with the UV light from 5 min up to 1 hour. This will allow them to leave plates in the cabinet as short amount of time as possible while still getting the benefits of reduced coffee rings. This info will also be useful to other schools who have such a cabinet and wish to do the same technique.
San Marino’s Blank team made a new plate this week once again using Cu(NO3)2 and ZnSO4. Control of Fe(NO3)3. Spot ratios (Cu:Zn) are 10 to 0; 7.5 to 2.5; 5 to 5; 2.5 to 7.5; and 0 to 10.
Green team has 2 updates. They remade the plate with Fe3+, Ce3+, and Co2+, from 11/14. Along with the ratios shown below, they also added 3 spots of Cu(NO3)2 and 2 spots of CuCl2. It was fired at < 450℃.
Upon testing, they found the two highest peaks corresponded to 100% Fe3. Usually, the Fe3+ control spot returns a light blue color, as it did at the beginning of the season. The fact that it was a darker color this time may indicate that a subpar material on one portion of the plate is impacting the performance of other spots. Changing the applied voltage from 0.05V to 0.1V depressed the peaks across the board.
They explain these results in the following manner: “As usual, the dark current was measured before each scan. It remained stable and below 0.5V, but we discussed that these checks don’t tell us everything. Corrosion and/or oxidation could be occurring on other parts of the plate. Essentially, there may be one or more “bad” materials on the plate that are acting as voltage leaks. Relative to the applied potential of our plate, they are “downhill”, meaning that any spike in current is hidden. Instead of jumping above the water splitting potential and releasing “downhill” to generate a current, it goes “through” the leak. Because the plate measures the difference in current when light is shined on a spot, a material that acts as a “leak” while in the dark can influence the spot being tested. One compelling fact is that even though our baking and testing proceeded without a hitch, we still got subpar results. In addition to our strange iron control spots, the Cu2+ spots on the side were not reaching the yellow/green range. The current leak concept is a possibility because it reveals why electrical activity may be masked. Next Monday, we will strive to eliminate the “bad” material combination, possibly by spotting multiple plates.”
Beckman: Made their first plates this week with different ratios of Cd(NO3)2, Fe(NO3)3, and Cr(NO3)3. They used a standard pattern to predetermine the locations of the iron standard spots to use consistently throughout the year. For the first plate, they used different ratios of the three solutions (1:1:1, 1:3:1, 3:1:1, and 1:1:3). For the second, they spotted the solutions separately, no mixing.
Poly: After analyzing results from last week they decided to use lower concentrations of the solutions, making it easier for the compounds to disperse. Planning to use a titanium oxide solution and an iron oxide solution first to make sure the setup is working. Last year they got good results from FeVO (only Fe worked best), so they may try to repeat this result and possibly TiVO to check the experimental set up.
San Marino: Blank team saw a lot of flaking on their Cu/Zn plate. No good results. The Fe control spot was also low & dark blue so something might be wrong with the plate. No new plates made this week, but plan to remake the Cu (II) nitrate plate from a few weeks ago that didn’t work due to copper wire exposed in the KOH solution.
Mayfield: Team JES got incredible results from their tests of plates 3 & 4 but this was likely in error as even areas with no spots had tall red bars. They will retest and compare to plate 5 next time. (Recap: Plate 3 is Fe & Ni layered with 3 min of Tesla coil between the layers, plate 4 was treated with Tesla coil before the Fe, and plate 5 was treated with the tesla coil after both layers).