Education Standards
Photocatalysis for Clean Water
Overview
Students will be undertaking several nanotechnology experiments to discover nanotech applications in their own lives and see its potential for the future.
Standards
1. Next Generation Science Standards (NGSS)
Design a solution to a complex real-world problem by breaking it down into smaller, more manageable problems that can be solved through engineering. (Grades 9 - 12 )
2. Common Core State Standards- Math
Reason abstractly and quantitatively. (Grades K - 12 )
Summarize, represent, and interpret data on a single count or measurement variable (Grades 9 – 12)
3. International Technology and Engineering Educators Association- Technology
Students will develop an understanding of the attributes of design. (Grades K - 12 )
Students will develop an understanding of the role of troubleshooting, research and development, invention and innovation, and experimentation in problem solving. (Grades K - 12 )
4. Indiana State Standards
9-10.LST.7.1: Conduct short as well as more sustained research assignments and tasks to answer a question (including a self-generated question), test a hypothesis, or solve a problem; narrow or broaden the inquiry when appropriate; synthesize multiple sources on the subject, demonstrating an understanding of the subject under investigation.
Learning Objectives
• Explain how nanoparticles can have photocatalytic properties.
• Demonstrate the process of photocatalysis.
• Determine which nanoparticle more efficiently breaks down the dye, (which is an indication of purification of water) by calculating the time taken for complete photocatalysis.
Materials
8 clear plastic 2-oz. cups with lids
Methyl orange solution; 3 ml for each sample and 3 ml for the control (equivalent to 1 full pipette, approx. 12 ml); 30 ml for $4.50 from Home Science Tools
Methylene blue solution; 3 ml for each sample and 3 ml for the control (equivalent to 1 full pipette, approx. 12 ml); 30 ml for $4.50 from Home Science Tools
Titanium dioxide (TiO2) sample solution (prepared by teacher using 5 g TiO2); enough for both dye samples (3 drops = 1 sample); 100 g of TiO2 nanopowder for $64 from SkySpring Nanomaterials
Zinc oxide (ZnO) sample solution (prepared by teacher using 5 g ZnO)
220 ml distilled water
Stopwatch
6 plastic pipettes
50-ml graduated cylinder, to measure distilled water
Black permanent marker pen, to label samples
Safety equipment: lab apron, safety goggles, gloves
Procedure
Students should label 2 sets of 4 cups as ZnO, MgO, TiO2, and “Control.”
Pour 20 ml of distilled water into each of the eight plastic cups.
Ask students to pour 3 ml of methyl orange into four of the cups; pour 3 ml of methylene blue into the other four cups.
Using a pipette, tell students to place 3 drops of each sample into the cups as labelled (for example, put three zinc oxide drops into the ZnO cup; do the same with the magnesium oxide in the MgO cup and titanium dioxide in the TiO2 cup). They should stir/mix the solutions well with the used pipette.
Have students take a picture of the solutions and controls (pre-UV light).
Tell students to carefully take the cups outside for exposure to UV light. Using a stopwatch, measure the length of time (in minutes and seconds) it takes for each sample to bleach (do not run longer than 10 minutes).
Have students record the time in the given data table; take another picture of the solutions and control. Have them complete their illustrations based off of their pictures.
Model what the procedure will look like before students begin the activity. Do this by having your own set of dye solutions and make one as they observe the process.
Clarify any questions regarding the activity. Remind students where and how their data will be recorded on their lab reports; suggest that they write down any observations they recorded during their experiment.
Credits
This learning module was created by Rafeela Nalim, a participant in Indiana University-Purdue University’s NSF-Funded “Nanotechnology Experiences for Students and Teachers (NEST)” Program (Award # 1513112).