Sulfur-doped carbon dots (S-doped C-dots)were synthesized using a simple and straightforward hydrothermal method. The as-prepared S-doped C-dots exhibit significant fluorescence quantum yield (67%) and unique emission behavior. The spherical S-doped C-dots have an average diameter of 4.6 nm and the fluorescence of S-doped C-dots can be effectively and selectively quenched by Fe³⁺ ions. Thus, S-doped C-dots were applied as probes toward Fe³⁺ detection, exhibiting a limit of detection of 0.1 μM.

Monolayer molybdenum disulfide (MoS₂) has attracted tremendous attention due to its promising applications in high-performance field-effect transistors, phototransistors, spintronic devices and nonlinear optics. The enhanced photoluminescence effect in monolayer MoS₂ was discovered and, as a strong tool, was employed for strain and defect analysis in MoS₂. Recently, large-size monolayer MoS₂ has been produced by chemical vapour deposition, but has not yet been fully explored. Here we systematically characterize chemical vapour deposition-grown MoS₂ by photoluminescence spectroscopy and mapping and demonstrate non-uniform strain in single-crystalline monolayer MoS₂ and strain-induced bandgap engineering. We also evaluate the effective strain transferred from polymer substrates to MoS₂ by three-dimensional finite element analysis. Furthermore, our work demonstrates that photoluminescence mapping can be used as a non-contact approach for quick identification of grain boundaries in MoS₂.

This review summarized the recent progress in the synthesis, characterization, properties, photoluminescence mechanism and biological applications of carbon dots.

Smart windows are a promising way to modulate solar light transmittance, which is crucial for energy saving buildings. We provide an overview of the recent progress in hydrogel-based smart windows.

The dual-emissive N, S co-doped carbon dots (N, S-CDs) with a long emission wavelength were synthesized via solvothermal method. The N, S-CDs possess relatively high photoluminescence (PL) quantum yield (QY) (35.7%) towards near-infrared fluorescent peak up to 648 nm. With the advanced characterization techniques including X-ray photoelectron spectroscopy (XPS), Fourier transform infrared spectroscopy (FTIR), etc. It is found that the doped N, S elements play an important role in the formation of high QY CDs. The N, S-CDs exist distinct pH-sensitive feature with reversible fluorescence in a good linear relationship with pH values in the range of 1.0–13.0. What is more, N, S-CDs can be used as an ultrasensitive Ag⁺ probe sensor with the resolution up to 0.4 μM. This finding will expand the application of as prepared N, S-CDs in sensing and environmental fields. Open image in new window