Week of 12/5-12/11

Dec 11, 2017

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.”

Month of 10/22-11/27

Nov 28, 2017

It’s been a few weeks since the first blog post of the year. Now it’s time for a recap of the past month as more and more teams have added updates to their google drive docs. Excuse the extra long post. We’ll be back to weekly updates soon!

Beckman has split into 4 groups, each testing a different 0.03M solution- Cd(NO3)2, Cr(NO3)2, Al(NO3)2, & Fe(NO3)2. Crescenta Valley has 3 teams. Team 1 made a 0.04 M BiVO4 plate and is considering mixing other solutions with BiVO4 in future. Team 2 made 1:2 ratio CoCl2 and FeNO3 and plans to study coffee-ring effect and using tesla coil in future. Team 3 continued with 0.5M MnCl2 but added .1M CoCl2 to the plate this time. Plates will be tested in future weeks. PCC completed a round of 11 plates testing bismuth and various other metals. They made 0.05M solutions and tested mixtures of Bismuth + Tin (II), Bismuth + Tin (IV), Bismuth + Manganese, Bismuth + Aluminum, Bismuth + Zinc, Bismuth + Iron. Interestingly bismuth by itself had the best results shown below. They plan to increase the metal concentrations and try mixing more than two metals. They also mention trouble aligning every spot with the LED and will be working on a new template.

Poly decided to test potassium manganese and sodium manganese oxide because the band gap for both solutions was within 1.5 V, which is what we are looking for. Made 0.1 M MnO4 & 0.1 M KNO3 stock solutions and 11 dilutions of each which will be mixed in varying ratios from 100% Mn to 100% K. Did the same for Mn and Na. The plates were baked on a 300 degree hotplate for 1 min after spotting to prevent coffee rings. Testing showed low currents, but dark current readings may have been unreliable for a few of the tests.

Mayfield has 3 teams: FAM, JES & KEY. The first four plates FAM tested had combinations of Fe:Co, Fe:Cu, Fe:Ni, and Fe:Zn. The two plates that had the best results (not dark blue) were Fe:Ni and Fe:Zn, which has also been shown by a past Mayfield team. They also tried using a Tesla coil to decrease coffee-rings but had some trouble with spots spreading too wide. JES is studying light absorption by colored materials. They are basing their research off of summer 2015 research by Caitlyn Delgadillo and an iron and nickel layering technique. Based on their research of artificial photosynthesis, KEY wants to investigate magnesium cofactors, especially iron and nickel since they are earth abundant and tend to do well in photocatalytic materials. The ratios tested had low current and flaked into solution. They plan to look into stabilizing agents or other metal combinations found more commonly in chloroplasts.

Finally San Marino has lots of updates from their two teams over the past month.

Blank team: Spotted one plate using 5 varying concentrations of CuSO4 and ZnSO4 salts totaling 20 microliters per spot.  After firing the Cu spots appeared white, but turned blue in solution and green upon removal. The current readings were all low, but the color changes were interesting so they remade the plate with CuCl2 instead of CuSO4 and only 10 microliter spots. They included spots of pure FeNO3, CuSO4, and ZnSO4 as controls. The wire was exposed and interfered with results so they will need to retest. They also remade this plate with CuSO4 instead of CuCl2 to directly compare to the other subteam’s results.

Green somethings: Tested a plate half (Fe²⁺, Fe³⁺, Cu²⁺) and half (Fe³⁺, Zn²⁺, Co²⁺). Only spots of 100% Cu²⁺ showed activity, everything else was dark blue. The spots were black and flaked during testing. Not sure if it was cuprous (I) or cupric (II) oxide, but Cu₂O has a band gap of 1.2 eV, while CuO has 1.2eV. For the next plate, they chose to test Fe³⁺ (best performing iron cation), Ce³⁺ (from the Pourbaix diagram of electrical activity at pH 13), and Co²⁺ (also from the Pourbaix). Six ratios were made, alternating between 100:0 and 50:50 combos. All spots were 5 μL, and all solutions were 0.1M except for the Co²⁺, which was 0.05M. They also added  a few spots of CuSO4 and CuCl2. The white cerium spots flaked during testing. Results were all dark blue. This could mean that solutions with Cu and Fe from 2 weeks ago could have been a fluke. A possible explanation is that amongst the group, there was a good catalyst and a bad light absorber, or everything was a medium catalyst. The difference in temperature at which the plates were fired could have also affected the performance of copper and iron on the plate. Two weeks ago, the plate was fired at 700°F but this plate was fired at 425°F.

Weeks of 3/6-3/19

Mar 20, 2017

With lots of schools on spring break, another 2 weeks have gone by. Same few teams have been posting, so thank you, but the rest of you please remember to update your google drive weekly. There have also been sadly very few comments and conversations on the blog so be sure to check the posts to see if you can answer or ask a question for a fellow team.

Poly worked up their HARPOON data after downloading the Image J software onto their laptops. Though they found no detectable oxygen evolution spots, they are determined not to give up and have reached out to the HARPOON experts at UW Oshkosh for some guidance. Good luck guys!

Mayfield’s Team SEA is zeroing in on a hit they got back with one of their colored vs non-colored tests. The combination was FeW so they have made two plates with varying ratios of the elements to test next time. Team RAM found results from BiVNiW 8:1:1:8, 8:1:1:13, 8:1:1:16 combinations to be ok, so they are making a new plate with the same metals, but less Bi and W (6:1:0.5:1, 6:1:0.5:5, 6:1:0.5:8). They also looked back at last year’s good results with BiVZn and decided to make a plate with BiVZnW to compare if adding W can help. Finally Team PEAK finished making plates 24 (CoZn 6:1 with layers) and 25 (FeZn 6:1 with layers). Results were not very good. Unfortunately all attempts at recreating a CoFeZn hit have gotten steadily worse overtime. They also made plate 26 (half CoZn 6:1, half FeZn 6:1) but the first layer was the Fe/Co and the second layer after drying on the hot plate was the Zn. This is to test whether different materials when applied in different layers make an impact on the plate’s success.

San Marino’s Red team were able to test only one plate that contains 10μL of combinations of Cu, Mn, and Ni because they spotted on the wrong side for one of the plates. They baked the plates at a higher temperature (around 650 C) which looks like it affected the FTO properties of the plate since the results showed no significant current. This week they made one plate using 3 different solutions: 1) 0.05M V; 2) 0.05M Fe + Cu; and 3) 0.05M V + Fe + Cu.  They decided to keep the concentration at 0.05M because that is the “sweet spot” at which there is reduced or no flaking (as supported by previous plate tests/experiments).  Each drop had a total of 10 microliters of solution. They added three drops of each solution at the three corners of the plate.  Next week, they plan on 1) testing this week’s plate, and 2) creating an identical copy of this week’s plate, but with some surfactant (soap) to see if the lowered surface tension of the solutions will reduce the coffee ring effect of each drop.

Lastly Beckman HS decided to take some time to reflect and do a bit of research. Group 1 is looking for a new element that is a strong photoanode and looking for elements that fall within a certain bandgap. These elements need to be cost-effective and abundant. Last week they tested a Nickel (III) Nitrate plate that did not have good results with most of the graphs concentrated in the blue region. For this reason, they are looking for a better element rather than jumping in immediately. Some of the things they are now considering from their research are zinc-related and chromium-related compounds. They are going to make 0.04 M Manganese  Nitrate(Mn(No3)2) and 0.04 M of CuZn solutions. They will spot two plates of each solution. Based on their research, they found that platinum iridium, titanium oxide, and ruthenium shared the characteristics of being white and having bandgaps between 1.2eV and 2.8eV. Group 1, then studied the band gaps of materials that were stored in the stockroom. Since Manganese Nitrate is both white and has a bandgap of 2.8 eV, they decided to try 0.04 M solution of it. They also found that CuZn has similar traits as platinum iridium.

Beckman’s Group 2 epoxied their 0.03M aluminum nitrate/copper (II) nitrate/iron (III) nitrate plate and will run it next week. They then researched other candidates for testing, looking into iron and its capabilities and other red oxides. They decided to experiment with old plates in order to clarify the unclear results that they got in the past. The areas that did not have spots still gave them results, which led them to suspect an error either from the plate or the box. Therefore, they planned to retest the plates (0.03M of Copper Nitrate (Cu(NO3)2), 0.03M Aluminum Nitrate (Al(NO3)3)and, 0.03M Iron Nitrate (Fe(No3)3) in ratio of 1:1:3 respectively). Also, they wanted to see how different the results will come out by using Zn(NO3)3 instead of Al(NO3)3 so they made another plate of 0.03 M Cu(NO3)2,0.03M of Zinc Nitrate (Zn(NO3)2), and 0.03M Fe(NO3)3, in ratio of 1:1:3 respectively. They plan to do UV treatment to both plates.

Group 3 is mixing different ratios of Cu (II) Nitrate and Iron (III) Nitrate that are both at 0.04M. They UV treated the plates before spotting and exposed them for five minutes. They tested the plate with coating method, which is spotting the plate with one compound and after they air dried it, then putting the second compound on. This did not work so they are making another plate by mixing two metal solutions in a fixed ratio. The resulting spots were very dark and they believed that this happened due to the high concentrations. Therefore they made a new plate with 0.02 M Co(NO3)-diluted from 0.04M CoNO3-  and 0.02 M Fe(NO3)2-diluted from 0.04M Fe(NO3)2 with different ratios. They made their plate with a different Molarity because they found out that  mixing method produced better results than that of coating method. However, they weren’t sure whether higher or lower concentration would give better results, which inspired them to test different molarities.

Group 4 ran their 0.03M Copper (II) Nitrate plate last week and the results were not that good. Most of the graph was in the blue zone indicating not strong results. This week, they researched other potential photoanodes and came across carbon nitride, which had not been heard of before. The American Chemistry Society website said it is a good photoanode that allotted high results, but it is not in the school inventory

Last week this group spotted 0.03MCo Nitrate 2 without the  iron standard. The results were not satisfying because of intense coffee ring effect seen despite their usage of UV treatment. They believe that this may have been a procedural error during the drying stage, so they produced another plate with 0.03 M Co(NO3)2 so that they can make sure that the plate can be spotted with no procedural error, especially during the drying stage. The spots will be tested during the next meeting.

Week of 2/27-3/5

Mar 6, 2017

A couple more schools included updates this week, but many others haven’t posted since the Annual Meeting. We want to hear what you’ve been up to! Write up a quick recap and then begin weekly posting again. SEAL Con is just over 2 months away so now is the time to ask questions and get help so you can finish off your research project as best you can before May 13.

First up, Beckman HS Group 1 tested a Ni(NO3)3 0.04M plate, but it didn’t have very good results. They also prepared a plate with 0.04 M Fe(NO3)3 which had shown promising results last time on an identical plate. They are currently testing the third iteration of this plate. The first iteration had high results but the second seemed to have a leak in the epoxy, which may have affected the results, so they are following up with their results with a duplicate of the original plate. Group 2 is testing a plate with multiple elements (Cu(NO3)2, Fe(NO3)3, and Al(NO3)3 all with 0.03 M). They decided to do this after doing research last week and concluded that this combination might have promising results. In the long run, they plan to consider remaking and improving this plate, and perhaps altering the molarities and the ratios to see how that might affect their results. Group 3 is trying two techniques in plating. They used cobalt nitrate and iron nitrate and tried layering them on the plate (iron on top of cobalt), as well as mixing them and spotting them. They saw both ideas at the CCI conference and saw good results. For the future, they will check their results to see which method works better and use this as a basis for future trials and use this technique for other combinations if it does show positive results. Group 4 is testing a Cu(NO3)2 with 0.03M duplicate plate after getting some red results on the original. The new results were not outstanding, so they decided to try different metal nitrates but want to stay with the same ratio for future tests.

Next, Poly was finally able to run a HARPOON experiment! Their mentor, Josef, was able to fix the power supply box. They took pictures every 30 seconds for 15 min of a plate spotted with the HARPOON standard, Ni:Fe:CO 1:2:2. Next week they will do a data analysis of these photos in ImageJ as well as start on Raman Spectroscopy experiments.

San Marino’s Team Photosynthesis created two duplicate plates identical to the plates made previously following this configuration to ensure consistency:

They were unable to test previous plates since they lost one and the other was left in the kiln for too long, resulting in the warping of the FTO coat on the plate making it nonconductive. They used the metals (Cu, Mn, Ni) because they are found in a photosynthesizing protein. Manganese is suspected to be the material flaking, and expect to see brown flakes floating in the NaOH solution if so, as well as inconsistent measurements of current in specific areas. If there is flaking, they plan to ozone treat the plate and make an identical plate to test. If even after there is still flaking, they will ozone treat individual plates, with each metal having its own plate, isolating each metal from each other. Also, they are looking into the coffee-ring effect that can result from drop-casting, and will test the two identical plates next week and talk about what they found about the coffee-ring effect.

San Marino’s Team Wand, also could not test the plate they made last week because it had the same problem of the FTO melting.  The temperature of the kiln was too high and the plate was left inside for too long, causing the FTO coating to melt and become warped, similar to cellophane.  During this week’s meeting, they remade the plate that was ruined, which contained vanadate and varying ratios of nickel.

Concordia analyzed results from the CON8 plate that was zapped with the Tesla coil and concluded that it discolored the spots of bismuth nitrate and ammonium vanadate. The discolored spots that they used the Tesla coil on had very low results. Then, they brainstormed to figure out what to work on next. They recorded previously used metal oxide solutions and wrote down others which they would like to test. They didn’t officially decide what materials to test yet, but we prepared a blank plate for next time.

Finally Mayfield’s Team SEA tested the aluminum copper plate, but it did not produce quantifiable results. They researched a few other good conductive metals but for now will stick with the elements they already decided on, testing the iron chromium plate next week. Team RAM tested plate 14 that contains bismuth, vanadium, and nickel with the ratio of 8:1:8, 8:1:13, 8:1:16. The results we’re not bad and performed better than plates 11 and 12. They also spotted plate 15 containing bismuth, vanadium, nickel, and tungsten with the ratio of 8:1:1:8, 8:1:1:13, 8:1:1:16. Team PEAK tested plate 23 (split CoZn 6:1 and FeZn 6:1 with multiple layers), but only got dark blue results. They plan to test the same materials with layering again, but without annealing them in between adding the layers. The previous plate was annealed after adding the first layer, which caused large spreading of metal solution when the second layer was applied and may have impacted results in unexpected ways. They started making plates 24 (FeZn 6:1 with layers) and 25 (CoZn 6:1 with layers, which they will finish next meeting with the additional layers.