Chiral catalysis is one of the most direct and effective approach to obtain pure optical enantiomers. Chiral carbon dots (CDs) as carbon-based chiral catalysts show great potential in chiral catalysis. Herein, we report a facile one step base-catalyzed aldol condensation to fabricate the chiral CDs from glucose at ambient temperature and pressure. The formation of chiral CDs involves the processes of isomerization and aldol condensation. These chiral CDs have been demonstrated that they have selective capacity for electrocatalytic oxidization of tryptophan enantiomers. L type of CDs (LCDs) is more likely to catalyze L-tryptophan (Trp) than D-Trp with the selective factor (I_L/I_D) of 1.60, whereas the D type of CDs (DCDs) tends to catalyze D-Trp (I_L/I_D: 0.63). Theoretical calculations combined with various contrast experiments (temperature and pH) demonstrate that the selectively electrocatalytic capacity of chiral CDs toward Trp isomers is due to the different hydrogen-bond interactions between chiral CDs and Trp.

Lithium-sulfur (Li-S) batteries can provide far higher energy density than currently commercialized lithium ion batteries, but challenges remain before it they are used in practice. One of the challenges is the shuttle effect that originates from soluble intermediates, like lithium polysulfides. To address this issue, we report a novel laminar composite, N,O-carboxymethyl chitosan-reduced graphene oxide (CC-rGO), which is manufactured via the self-assembly of CC onto GO and subsequent reduction of GO under an extreme condition of 1 Pa and −50 ℃. The synthesized laminar CC-rGO composite is mixed with acetylene black (AB) and coated on a commercial polypropylene (PP) membrane, resulting in a separator (CC-rGO/AB/PP) that can not only completely suppress the polysulfides penetration, but also can accelerate the lithium ion transportation, providing a Li-S battery with excellent cyclic stability and rate capability. As confirmed by theoretic simulations, this unique feature of CC-rGO is attributed to its strong repulsive interaction to polysulfide anions and its benefit for fast lithium ion transportation through the paths paved by the heteroatoms in CC.

Mesoporous silica nanoparticles (MSNs) have attracted tremendous attention in recent years as drug delivery carriers due to their large surface areas, tunable sizes, facile modification and considerable biocompatibility. In this work, we fabricate an interesting type of MSNs which are intrinsically doped with photosensitizing molecules, chlorin e6 (Ce6). By increasing the amount of Ce6 doped inside the silica matrix, it is found that the morphology of MSNs changes from spheres to rod-like shapes. The obtained Ce6-doped mesoporous silica nanorods (CMSNRs) are not only able to produce singlet oxygen for photodynamic therapy, but can also serve as a drug delivery platform with high drug loading capacity by utilizing their mesoporous structure. Compared to spherical nanoparticles, it is found that CMSNRs with a larger aspect ratio show much faster uptake by cancer cells. With doxorubicin (DOX) employed as a model drug, the combined photodynamic and chemotherapy is carried out, achieving synergistic anti-tumor effects both in vitro and in vivo. Our study presents a new design of an MSN-based drug delivery platform, which intrinsically is fluorescent and able to serve as a photodynamic agent, promising for future imaging-guided combination therapy of cancer.