Highly dispersed and low-cost N-doped carbon dots enhancing the hydration kinetics of tricalcium silicate: A multiscale investigation

作者：Haijie He, Xiangzhi Wang, Yangrui Wang, Jie Hong, E Shuang, Lei Xu, Chuang He · 发表于：Carbon · 年份：2025 · DOI：10.1016/j.carbon.2025.121083 · 被引用次数：2 · 研究领域：Concrete and Cement Materials Research、Smart Materials for Construction、Layered Double Hydroxides Synthesis and Applications

Carbon dots (CDs), as an innovative nanomaterial exhibiting superior dispersion properties and exceptional economic efficiency, display unique potential for application in regulating cement hydration. Nevertheless, the precise mechanism by which CDs affect cement hydration kinetics has yet to be fully elucidated. This research for the first time uncovers the impacts and regulatory mechanisms of CDs on tricalcium silicate (C 3 S) hydration utilizing a multiscale methodology that combines micro characterization with molecular dynamics (MD) simulations. Specifically, N-doped CDs (NCDs) are deliberately synthesized via a hydrothermal synthesis approach and showcase good dispersion stability within saturated Ca(OH) 2 solution. Experimental findings show that adding 0.1 wt.% NCDs reduces the hydration induction period of C 3 S by 0.9 h relative to pure C 3 S pastes, elevates the peak heat flow by 12%, and substantially increases the Ca 2+ concentration throughout hydration. Micro characterization analyses indicate that NCDs enhance both the formation and densification of calcium silicate hydrate (C–S–H), yielding a thicker layer of hydration products. Moreover, NCDs diminish the average silicate chain length within C–S–H while augmenting its structural disorganization. Mechanistic exploration elucidates that NCDs achieve dual modulation of the C 3 S dissolution-nucleation process, both by accelerating C 3 S dissolution and functioning as nucleation sites exhibiting strong adsorptio...