We report on a facile method to synthesize carbon dots (CDs) using glycerol solvent as a single precursor via a pyrolysis process free from catalysts. This method is extremely simple and economical, and provides a feasible route for mass production of highly emissive CDs. For rationalization, a mechanism incorporating dehydration of glycerol, followed by acrylaldehyde formation is tentatively proposed for CD production. Further systematic improvement of particle homogeneity is made by harnessing the growth of CDs inside the mesoporous silica nanoparticles that act as a nano-reactor to regulate the size distribution. Simultaneously capping a polyethylene glycol (PEG)-derived reactant onto the CDs@SiO 2 enhances their luminescence, stability and bio-compatibility. The as-prepared CDs@mSiO 2 -PEG nanocomposites are then loaded with the anti-cancer drug doxorubicin (DOX), so that the controlled release of DOX could be monitored by both time-dependent and spatially resolved ratiometric fluorescence intensity for CDs versus DOX in HeLa cells, successfully demonstrating that the CDs@mSiO 2 -PEG nanocomposites are suitable for cell imaging and drug release.

Go for gold: As‐prepared insulin–Au nanoclusters (NCs) show intense red fluorescence, excellent biocompatibility, and preservation of natural insulin bioactivity in lowering the blood‐glucose level. Their versatility in applications is demonstrated by fluorescence imaging, X‐ray computed tomography, and insulin–inhibitor interactions (see picture; IDE=insulin‐degrading enzyme).

Photocatalytic water splitting is attracting enormous interest for the storage of solar energy but no practical method has yet been identified. In the past decades, various systems have been developed but most of them suffer from low activities, a narrow range of absorption and poor quantum efficiencies (Q.E.) due to fast recombination of charge carriers. Here we report a dramatic suppression of electron-hole pair recombination on the surface of N-doped TiO2 based nanocatalysts under enhanced concentrations of H+ and OH−, and local electric field polarization of a MgO (111) support during photolysis of water at elevated temperatures. Thus, a broad optical absorption is seen, producing O2 and H2 in a 1:2 molar ratio with a H2 evolution rate of over 11,000 μmol g−1 h−1 without any sacrificial reagents at 270 °C. An exceptional range of Q.E. from 81.8% at 437 nm to 3.2% at 1000 nm is also reported.

Hydrated niobium oxides are used as strong solid acids with a wide variety of catalytic applications, yet the correlations between structure and acidity remain unclear. New insights into the structural features giving rise to Lewis and Brønsted acid sites are presently achieved. It appears that Lewis acid sites can arise from lower coordinate NbO and in some cases NbO sites, which are due to the formation of oxygen vacancies in thin and flexible NbO systems. Such structural flexibility of Nb-O systems is particularly pronounced in high surface area nanostructured materials, including few-layer to monolayer or mesoporous NbO·nHO synthesized in the presence of stabilizers. Bulk materials on the other hand only possess a few acid sites due to lower surface areas and structural rigidity: small numbers of Brønsted acid sites on HNbO arise from a protonic structure due to the water content, whereas no acid sites are detected for anhydrous crystalline H-NbO.

Ein Cluster für alle Fälle: Insulin‐Au‐Nanocluster (NCs) zeigen eine intensive rote Fluoreszenz und exzellente Biokompatibilität, und sie behalten die natürliche Bioaktivität des Insulins zur Senkung des Blutglucosespiegels bei. Mehrere Anwendungen werden demonstriert: in der Fluoreszenzbildgebung, der Röntgen‐Computertomographie und zur Untersuchung von Insulin‐Inhibitor‐Wechselwirkungen (siehe Bild; IDE=Insulin abbauendes Enzym).