Facile synthesis of porous nitrogen doped carbon dots (NCDs)@g-C3N4 for highly efficient photocatalytic and anti-counterfeiting applications

Novel g-C3N4/C/Fe2O3 Composite for Efficient Photocatalytic Reduction of Aqueous Cr(VI) under Light Irradiation

“…Several carbon materials, such as graphene oxide, carbon nanotubes, and biochar, are regarded as ideal materials for doping photocatalysts to improve their conductivity and optical characteristics and thus promote favorable band gap structures with excellent separation of photogenerated e – /h + . − For example, biochar, which is the byproduct of biomass pyrolysis, is used to dope g-C 3 N 4 to prepare carbon-coupled g-C 3 N 4 catalysts. Li et al fabricated biochar-coupled g-C 3 N 4 nanosheet composites using waste Camellia oleifera shells as the biochar source.…”

Metal-Ion-Cross-Linked Nitrogen-Doped Carbon Dot Hydrogels for Dual-Spectral Detection and Extractable Removal of Divalent Heavy Metal Ions

“…After further magnification, the NCDs, as the smallest structural unit of the gel, are tightly cross-linked Figure d,e. The inset in Figure e shows that NCDs have the well-resolved lattice fringes with a lattice spacing of 0.21 nm corresponding to the (100) crystal plane of graphene. , The XRD pattern shows a broad peak at about 22.40°, corresponding to the (002) crystal plane of graphene. , The EDS spectrum and mapping pictures confirm the uniform distribution of multiple elements (C, N, and Cu) within the gel (Figures S6 and f–i). As shown in Figure S12, The specific surface area of the Hyd Cu/NCDs is as high as 159.285 m 2 /g, and it contains abundant mesopores of 5–10 nm.…”

“…Therefore, 430 nm was selected as the excitation wavelength for fluorescence detection of heavy metal ion content subsequently. The photoluminescence decay curve of NCDs was fitted, and the average lifetime was estimated to be 3.8 ns (Figure e) . The extremely fast decay time facilitates rapid fluorescence detection of heavy metal ions without causing interference to the next sample test.…”

“…Morphologies, molecule sizes, and energy-dispersive spectroscopy (EDS) natural mapping of NCD hydrogels were inspected employing a field emission scanning electron microscope (Zeiss Gemini SEM 300) and a transmission electron microscope (FEI, TF20, United States). Fourier-transform infrared (FT-IR) and X-ray photoelectron spectroscopy (XPS) were used to test the surface functional groups of NCDs . The fluorescence performance of NCDs was tested on the FLS1000 spectrophotometer (Edinburgh Instruments).…”

“…Among the many methods for detecting heavy metal ions, − fluorescence detection is a relatively new approach attracting more and more attention due to its high sensitivity and simple process. ,− Generally, a fluorescent probe can “perceive” target molecules either by adjusting its fluorescence intensity or by converting its emitting color. , New rich nanomaterials such as perovskite quantum dots, metal-organic framework (MOF) materials, and two-dimensional layered nanomaterials are attracting widespread attention due to their ultra-small size, selectivity, and promising fluorescence properties. ,, However, their wide range of applications was restricted due to the limitation of inconvenient synthesis, high cost, and poor stability. Carbon dots (CDs) are a type of emerging nanomaterial with striking and interesting fluorescence properties. ,− The CDs can sensitively “perceive” the target due to the rich dangling bonds on the surface. What is more, CDs are becoming a potential candidate for various sensing applications because of their stable fluorescence emission, convenient synthesis methods, low cost, and excellent biocompatibility. ,, …”