Sustainable Triplet-State Engineering in Cotton-Derived Carbon Dots: Mg-Based Matrices Enable Multicolor...

Area of Science:

• Materials Science
• Nanotechnology
• Biomass Conversion

Background:

• Sustainable production of color-tunable, room-temperature phosphorescent (RTP) carbon dots (CDs) from biomass is challenging.
• Carbon dots (CDs) are promising nanomaterials for optical applications.

Purpose of the Study:

• To develop a facile strategy for fabricating multicolor RTP CDs from natural cotton.
• To investigate the effect of calcination temperature on the optical properties and structure of CDs.
• To explore the potential applications of these RTP CDs in security and display technologies.

Main Methods:

• Controlled thermal treatment of natural cotton in Mg(NO3)2·6H2O at temperatures ranging from 300-500 °C.
• Characterization of the resulting materials using spectroscopic and microscopic techniques.
• Evaluation of RTP performance, including lifetime, quantum yield, and stability.

Main Results:

• Three distinct RTP materials were obtained with yellow, cyan, and blue emission, corresponding to different calcination temperatures.
• Emission color is tunable by controlling the calcination temperature, influencing carbon core states and surface functional groups.
• The Mg-based matrices enhance RTP properties by providing spatial confinement and forming bonds with CDs, leading to long lifetimes and high quantum yields.

Conclusions:

• A sustainable platform for producing color-tunable RTP CDs from cotton was established.
• The Mg-based matrices play a crucial role in achieving efficient phosphorescence.
• The developed RTP CDs show potential for advanced applications in data encryption, anti-counterfeiting, and dynamic password systems.