Synthesis of carbon quantum dots using unutilized low-grade lignite coal

/g and average pore diameter of 2.297 nm. With moderate surface area, multi-elemental doping, and tunable optical properties, the coal-derived CQDs demonstrated strong potential for industrial applications in environmental remediation, catalysis, optoelectronics, and biomedical imaging. This approach not only supports sustainable nanomaterial production but also promotes economic revitalization of the coal sector and environmental management through innovative reuse of local resources.