Going sustainable is a better solution, but what about the waste generated by renewable energy industry, especially solar panels. To reduce the strain from this waste on environment researchers are using different methods. Recently, they have tried using green graphene for converting PV waste to silver.
James Cook University researchers developed a process to synthesize graphene from tangerine peel oil. This was then used to recover silver from the photovoltaic waste material. A dopamine sensor was made to demonstrate the quality of the silver recovered and the synthesized graphene.
According to the report published, the graphene synthesized was of high quality and it also demonstrated a good ability to recover silver selectively. Once tested in a silver-enhanced SPE dopamine sensor device, they outperformed the sensors made without the silver graphene composite.
Details of the Experiment Using Green Graphene Converts PV Waste to Silver
Step #1
The first step was to begin synthesizing graphene by using downstream microwave plasma in atmospheric conditions. With a Raman spectrum analysis, researchers found a distinctive 2D peak at microwave power that ranges from 200 W to 1000 W.
Step #2
The team then recovered silver from organic PV devices by leaching it in a nitric acid solution. After leaching, the cooled down solution was used as a stock for creating a graphene-coated SPE. After 10 minutes of electrodeposition, there was a slight drop in the Ag concentration to around 1.69 ppm.
This indicates that some silver ions were reduced and deposited on the electrode surface. Then, after 20 minutes, the Ag ion concentration decreased to 1.62 ppm, demonstrating a continuous reduction.
Quick Fact: PV coating contains zinc oxide (ZnO), silver (Ag), molybdenum oxide MoO3), and tin oxide (ITO).
Step #3
Next, a graphene-silver electrode (SPE/Ag) detector was made to illustrate the quantity of the material in real-world applications. Then it was compared to the bare SPE/graphene detectors. Results showed that the newly developed detectors displayed significant improvements in peak current in comparison to other two specimens.
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Application of Graphene-Silver Concentrate
Researchers suggested that other applications of the derived material are:
- Corrosion-resistant coatings
- Conductive inks for flexible devices in electronic industry
- Antimicrobial coatings for biomedical industry
- Sensors to detect biomolecules, pollutants, and gases.
The research demonstrating how green graphene converts PV waste to silver has received a positive response to date. Now, the team’s next step is to optimize the green synthesis process to improve scalability and economic viability. This way they will be aiming for a process to integrate into the existing PV recycling and e-waste infrastructure.
Source: Green synthesis of graphene for targeted recovery of silver from photovoltaic waste