Science China Chemistry最新文献

Carbon dots (CDs), as emerging zero-dimensional carbon-based nanomaterials, demonstrate immense potential across optical displays, bioimaging, chemical sensing, information anti-counterfeiting, and optoelectronic devices. This promise stems from their exceptional tunable photoluminescence, low toxicity, biocompatibility, and abundant raw material sources. Since their discovery, research has centered on resolving controversies regarding classification, formation mechanism, microstructure, and luminescence principles while achieving controllable optoelectronic properties. Applications have evolved from basic fluorescent labeling to advanced domains including multimodal theranostics, high-sensitivity (bio/chemical) sensing, stable optoelectronic devices, intelligent anti-counterfeiting systems, and environmental/energy catalysis. Future challenges demand breakthroughs in structural homogeneity/scalable eco-fabrication, universal structure-opto/electronic-property models, stability/efficiency in complex environments, and multifunctional synergy (e.g., photo-electro-catalysis). This comprehensive review systematically examines milestone advances in CDs research over the past decade—spanning synthesis methodologies, photo/electronic property modulation mechanisms, and innovative applications—while dissecting key challenges and envisioning future pathways as versatile intelligent nano-platforms.

Accurate and sensitive determination of uric acid (UA) is critical, as abnormal UA concentrations are associated with various pathologies. Electrochemical sensing is an effective method for the detection of UA concentrations. The electrochemical behavior of UA sensors is fundamentally governed by the electronic configurations of catalytically active sites, where enhanced site activity significantly improves overall performance. In this work, biocompatible g-C₃N₄ is selectively doped with cobalt to generate UA-specific surface centers. These are synergistically integrated with highly conductive Ti₃CN to optimize charge transport efficiency. The oxygen-terminated surface of Ti₃CN forms strong chemical bonds with the Co-doped sites, enabling precise modulation of their electronic structure. DFT calculations reveal substantial electron transfer from cobalt atoms to surface oxygen groups, which shifts the Co d-band center, reduces the desorption barrier for UA oxidation intermediates, and accelerates the catalytic process. The resulting Co-CN/Ti₃CN-modified GCE demonstrates a broad linear detection range and ultralow detection limit. This study establishes an atomic-scale design strategy for electrochemical sensors capable of trace-level UA detection, offering a promising platform for clinical diagnostics and biomedical monitoring.

The development of efficient photocatalysts for crucial organic transformation, such as aerobic oxidation, remains challenging. Although powdered porous materials offer abundant accessible active sites, their application in liquid-phase catalysis is often limited by insufficient light absorption and inevitable charge recombination, which are inherent drawbacks of conventional heterogeneous catalysts. Here, through rational design and nanoscale-engineering of porous aromatic frameworks (PAFs) comprising porphyrin and porous organic cage, a quasi-homogeneous porous photocatalyst with high catalytic activity and controllable dimension was developed. The interface-directed growth in oil-in-water emulsion shaped the morphology of photoactive PAFs from powders to nanoflakes, which facilitated the light absorbance and catalyst-substrate interaction. Compared with PAF powders, PAF nanoflakes exhibited superior photocatalytic activity for aerobic oxidation. For mustard gas simulant (2-chloroethyl ethyl sulfide, CEES), PAF nanoflakes exhibited ultrafast detoxification rates in room air with a half-life (t_1/2) as fast as 26 s, which even exceeded other catalysts in pure oxygen. It also completely catalyzed the aerobic oxidation of thioether within 15 min, which is almost the fastest rate among any reported organic photocatalysts. Furthermore, the efficient catalytic performance under mild conditions caused by improved light enrichment, surface charge transfer and carrier lifetime was elucidated.