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Explora: Environment
and Resource Experimental application of GQDs for nuclear materials removal

160 to 280 nm, with the most frequent heights around with zinc showing the best performance. For 99mTc, there
5 nm. The roughness of the GQDs was very low, indicating is more variation in efficacy, with PVC/plastic showing the
good homogeneity. The PXRD (Figure 2B) confirmed highest mean efficacy but also the greatest variability. In
the formation of GQDs, with a broad peak near 2θ = 25°. summary, GQDs demonstrated a good ability to remove
However, the presence of citrate used in the preparation radioisotopes from PVC or plastic surfaces. However, this
process resulted in additional peaks in the PXRD pattern. effectiveness varied significantly among different samples
Finally, GQDs exhibited maximum absorbance at 265 nm of this material.
(Figure 2D), with fluorescence emission observed between The effectiveness of GQDs in removing radioisotopes
500 and 550 nm, confirming their photoluminescence was high. This suggests that GQDs have a natural or
properties.
chemical affinity with the radioisotopes in question (131-I
GQDs exhibit attractive optical, electrical, and and 99mTc, in this case) when applied to PVC/plastic
electrochemical characteristics, resulting from their unique surfaces. The high variability indicates that although
quantum confinement effect, along with a high surface-to- GQDs worked well on most PVC or plastic samples,
volume ratio, low cytotoxicity, and easy functionalization. there were some samples where the effectiveness was
These properties make this nanomaterial widely used in significantly lower. This may be due to differences in the
both biomedical fields and environmental applications, surface properties of the PVC/plastic samples, such as the
where its photoluminescence characteristics and degree of polymerization.
effects allow it to serve as a well-organized and effective
nanomaterial for decontaminating surfaces contaminated The high P-value in the statistical analysis suggests that
with radioactive materials. 31 the material type (metal vs. plastic) does not significantly
impact the efficacy of GQDs in radioisotope removal. This
3.2. Surface contamination with 99mTc and 131-I could indicate that the interaction between GQDs and the
radioisotopes is more crucial than the material from which
Surface contamination with 99mTc and 131-I was assessed the radioisotopes are being removed.
for five material types: metals (monel, aluminum, and
zinc) and plastic (rigid PVC), as shown in Table 1: 4. Conclusion
The data demonstrated that GQDs were able to In conclusion, this study has demonstrated the significant
efficiently remove 131-I from all metals (aluminum, potential of GQDs as an effective nanomaterial for
zinc, and monel). They were also effective in removing decontaminating surfaces contaminated with radioactive
131-I from rigid PVC. Conversely, the efficacy for 99mTc materials. The unique properties of GQDs, including their
showed a very low value for the materials tested. GQDs chemical stability, high surface area, quantum confinement
appear to be generally effective in removing both 131-I effects, and electronic characteristics, make them exceptionally
and 99mTc from various materials, although, the efficacy suited for adsorbing radioactive isotopes. Through the
varies depending on the material and the radioisotope. For functionalization of GQDs, their affinity for specific radioactive
131-I, the efficacy is consistently high across all materials,
isotopes can be enhanced, thereby increasing the efficiency
and specificity of decontamination processes.
Table 1. Efficacy of graphene quantum dots in removing
radioisotopes Our findings suggest that GQDs offer a promising
solution to a critical problem: the rapid and effective
Radioisotope Material Mean efficacy (%) Standard decontamination of environments affected by the
deviation deployment of “dirty bombs” or other RDDs. Given the
131-I Aluminum 91.27 1.04 heightened global risk of such events, the ability of GQDs
131-I Monel 96.40 0.56 to facilitate swift decontamination and enable the rapid
131-I Zinc 98.67 0.06 reutilization of affected areas is particularly valuable. This
131-I Rigid PVC (plastic) 97.84 2.01 research contributes not only to the field of nanomaterials
99mTc Aluminum 55.11 5.34 but also has significant implications for public health,
99mTc Monel 64.93 1.04 environmental safety, and national security.
99mTc Zinc 41.80 1.71 Future research should focus on scaling up this
99mTc Rigid PVC (plastic) 65.30 15.02 technology for practical applications, exploring the long-
Notes: t-statistic: −0.0528; P-value: 0.9640. term environmental impacts of GQDs, and developing
Abbreviations: 131-I: Iodine-131; 99mTc: Technetium-99m; protocols for their safe and effective use in various real-
PVC: Polyvinyl chloride. world scenarios. The integration of GQDs into existing

Volume 1 Issue 1 (2024) 6 doi: 10.36922/eer.3403