Phosphorescence shows great potential for application in bioimaging and ion detection because of its long-lived luminescence and high signal-to-noise ratio, but establishing phosphorescence emission in aqueous environments remains a challenge. Herein, we present a general design strategy that effectively promotes phosphorescence by utilising water molecules to construct hydrogen-bonded networks between carbon dots (CDs) and cyanuric acid (CA). Interestingly, water molecules not only cause no phosphorescence quenching but also greatly enhance the phosphorescence emission. This enhancement behaviour can be explained by the fact that the highly ordered bound water on the CA particle surface can construct robust bridge-like hydrogen-bonded networks between the CDs and CA, which not only effectively rigidifies the C=O bonds of the CDs but also greatly enhances the rigidity of the entire system. In addition, the CD-CA suspension exhibits a high phosphorescence lifetime (687 ms) and is successfully applied in ion detection based on its visible phosphorescence.

The slippage effect at the interface between a confined fluid and the surface around it has a potential application in microfluidic and nanofluidic devices. To investigate the slippage effect of fluid on superhydrophobic surfaces, a series of rheological experiments are carried out for superhydrophobic surfaces coated with carbon nanotube forests (CNTs), which are prepared by the chemical vapor deposition method (CVD). The results show that such surfaces can create certain slippage effects for a fluid flowing over them and that the slip length is in accordance with the theoretical prediction as well as the value measured through other experimental methods. As the same trend is observed for both the theoretical and experimental slip lengths, the theoretical model can be used to optimize the superhydrophobic surfaces for the slippage effect or drag reduction. The superhydrophobic surfaces with considerable slippage effects have broad potential application in micro- and nanofluidic devices or biodevices to solve the fluid resistance problem.

The fabrication of a photodetector and gas sensor based on hierarchical Bi₂S₃ nanostructures is reported. Single crystalline Bi₂S₃ nanostructures with [001] growth direction were obtained via a facile hydrothermal method without any templates or surfactants. The photodetector showed steady photoresponses with a fast response time of ∼50 ms. Moreover, these Bi₂S₃ nanostructures exhibited a good sensing to methanol. These results show these hierarchical Bi₂S₃ nanostructures are promising candidates for constructing optoelectronic and gas sensing devices.