Begin preparing the precursor solution by mixing 105 milliliters of ethylene glycol and 15 milliliters of ultrapure water. Then add 4.1 grams of uria and add 5.0 grams of nickel nitrate hexahydrate, and cover the solution. Sonicate the precursor solution for 30 minutes in a bath sonicator filled with ice and water at 40 kilohertz frequency and full power without pulse.
Transfer 20 milliliters of the sonic precursor solution into a microwave reaction vial fitted with a PTFE stir bar. Seal the reaction vessel using a locking lid with a PTFE liner. Place the vial inside the microwave reactor and set the reactor program to as fast as possible, which applies maximum power until the desired temperature is achieved.
Thereafter, apply variable power to maintain the reaction temperature for 13 to 30 minutes. Upon completion of the reaction, vent the reaction chamber with compressed air until the solution temperature reaches 55 degrees Celsius. Transfer the post reaction solution to 50 milliliter centrifuge tubes.
Centrifuge the tubes at room temperature for four minutes, and decant the supernatant. Resuspend the resulting nickel hydroxide nano sheets in 25 milliliters of ultrapure water and centrifuge once more as demonstrated previously. After decanting the supernatant, cover the centrifuge tubes with a tissue or paper towel serving as a porous cover to minimize potential contamination.
Finally, dry the nano sheets under an ambient atmosphere in a sample oven at 70 degrees Celsius for 21 hours. At 120 degrees Celsius, the maximum reaction pressure generated was nine to 11.5 pounds per square inch or PSI. Whereas at 180 degrees Celsius, it increased to 138 PSI.
Increasing the reaction temperature from 120 to 180 degrees Celsius also changed the post-reaction supernatant color from green to blue. In C2 photographs of the reaction at 180 degrees Celsius showed a murky green color when the reaction terminated, but it changed to murky blue as the reaction cooled. After centrifugation, washing, and drying, all the reactions, irrespective of time and temperature, produced a green powder.
The pH of the supernatant of the 180 degree Celsius reaction was much higher relative to the 120 degree Celsius reaction supernatants. The 180 degree Celsius reaction also recorded a much higher yield than the reactions at 120 degrees Celsius.
