# Experimental and artificial intelligence molecular models to predict quenching behavior of carbon materials from petroleum waste for sustainable corrosion monitoring

## TL;DR

Researchers developed carbon-based quantum dots from petroleum waste that can detect early corrosion and serve as a secure ink, offering sustainable industrial applications.

## Contribution

The novel synthesis of petroleum coke quantum dots (PCQDs) with high selectivity for iron ions and dual functionality in corrosion monitoring and security inks.

## Key findings

- PCQDs effectively differentiate Fe2+ and Fe3+ with low detection limits of 0.39 µM and 0.36 µM.
- PCQDs show high selectivity for iron ions amid various interferents and stability under harsh conditions.
- PCQDs have a 70 wt% yield, 50% quantum yield, and can be used as fluorescent security ink due to their blue emission.

## Abstract

Quantum dots have attracted a lot of interest because of their special optical characteristics and potential for a variety of uses, such as in inks and sensors. Additionally, petroleum coke recycling is crucial for resource efficiency, economic growth, and environmental sustainability. It solves problems linked to carbon emissions and landfill waste. Industries can reduce their environmental impact while generating new opportunities for innovation and expansion. Petroleum coke quantum dots (PCQDs) were synthesized using the reflux method at 120 °C for 12 h, then characterized using scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and electron pair resonance spectroscopy (EPR), and were utilized to differentiate Fe2+ and Fe3+ for early-stage corrosion detection in real samples. LOD values of 0.39 µM and 0.36 µM for Fe2+ and Fe3+ were obtained using a Stern–Volmer plot. PCQDs demonstrate outstanding selectivity for iron in the presence of diverse cationic and anionic interferents, as well as remarkable stability under harsh continuous optical and thermal conditions. In addition, due to the intense blue emission of PCQDs, they have been utilized as a fluorescent security invisible ink for documenting sensitive information. The PCQDs exhibit around 70 wt% yield, 50% quantum yield, and a half-life of 9.5 ns. Due to their excellent efficiency and simplicity in synthesis, PCQDs can be utilized for industrial-scale production.

Quantum dots have attracted a lot of interest because of their special optical characteristics and potential for a variety of uses, such as in inks and sensors.