Search

Through the utilization of a singular annealing procedure to merge CoFe, CoFe 2 C, and BDD, a novel BDD-based OER catalyst exhibiting remarkable long-lasting stability has been developed. This catalyst surpasses the performance of conventional RuO 2 catalysts and previously documented carbon-based FeCo catalysts. The exceptional performance of this catalyst is primarily attributed to the coherent interface and enduring BDD substrate. [Display omitted] The urgent need to develop efficient, durable, and cost-effective oxygen evolution reaction (OER) catalysts for energy conversion and storage has prompted extensive research. Currently available commercial noble metal-based OER catalysts are expensive and exhibit limited long-term stability. In this study, boron-doped diamond composites (BDDCs) consisting of CoFe and CoFe 2 C nanoparticles supported by boron-doped diamond (BDD) particles have been prepared. The BDDC catalyst, prepared through a straightforward annealing process, exhibits exceptional durability (up to 72 h at 10 mA cm−2), a low overpotential (306 mV at 10 mA cm−2), and modest Tafel slope (58 mV dec-1). The coherent interfaces between CoFe/CoFe 2 C nanoparticles and the BDD substrate are essential for enhancing the OER performance. The fabrication method and composite structures presented in this study may facilitate the design and production of promising catalysts. [ABSTRACT FROM AUTHOR]

Reaching emissive nanomaterials at short wavelengths with a high quantum efficiency (QE) is an attractive task for researchers. This is more demanding in carbon dots (CDs) with diverse applications that usually emit photons at wavelengths around 450â€"620 nm. In this study, deep blue-emissive doped-CDs (d-CDs) with high photoluminescence (PL) QE up to 62% and excitation-independent properties were prepared via a short-time microwave irradiation method. The prepared CDs showed simultaneous amorphous and crystalline features, with average sizes of 4.75 nm and bright emission color located at 422 nm. It was found that the presence of sulfur-related dopant levels plays a key role in emission properties in such a way that the PL signal drops significantly in the absence of N-acetyl-l-cysteine (NAC) as a dopant source. On the other hand, the trisodium citrate dihydrate (TSC) was selected as a carbon source to form the main carbon skeleton without it no emission was recorded. Monoexponential-fitted recombination trend with an average lifetime of about 10 ns also confirmed excellent PL emission properties with uniform energy levels and minimized defect-contributing recombinations. The practical use of the as-prepared N, S-doped CDs was assessed in fingerprint detection indicating a bright and clear scheme for both core and termination regions of the fingerprint. Simplicity, cost-effectiveness, high-product yield, low toxicity, along with high/stable PL quantum efficiency in deep-blue wavelengths, and demonstrated ability for fingerprint purposes, support the prospective application of these dual doped-CDs for sensing and bioimaging applications. [ABSTRACT FROM AUTHOR]

Persistent mechanoluminescence (PML) is highly desirable for its ability to overcome transient‐emitting behavior, but its applications are hindered by the limited emission wavelengths. Herein, a universal chemical interlinkage‐assisted efficient energy transfer (ET) strategy is introduced to achieve color conversion from green to red in traditional PML materials. A straightforward chemical route to create the RhB@SiO2/SAOED system is established via covalent chemical interlinkage by depositing mesoporous silica‐encapsulated Rhodamine B (RhB) nanoparticles (RhB@SiO2) onto SrAl2O4:Eu, Dy (SAOED) particles. The resulting system exhibits a high ET efficiency of 53.5%. The multicolor PML of the RhB@SiO2/SAOED system remains visible to the naked eye for exceeding 28 s after mechanical stimulation. With this unique PML behavior, the RhB@SiO2/SAOED system demonstrates the potential applications ranging from visualized reading activities to multi‐mode anticounterfeiting. This universal PML color‐conversion strategy provides a new approach to high‐performance mechanical light energy‐conversion systems and may further inspire more diverse functional applications of classical PML materials. [ABSTRACT FROM AUTHOR]

Carbon nanodots (CDs) have emerged as an alternative option for traditional nanocrystals due to their excellent optical properties and low toxicity. Nevertheless, high emission efficiency is a long‐lasting pursuit for CDs. Herein, CDs with near‐unity emission efficiency are prepared via atomic condensation of doped pyrrolic nitrogen, which can highly localize the excited states thus lead to the formation of bound excitons and the symmetry break of the π–electron conjugation. The short radiative lifetimes (<8 ns) and diffusion lengths (<50 nm) of the CDs imply that excitons can be efficiently localized by radiative recombination centers for a defect‐insensitive emission of CDs. By incorporating the CDs into polystyrene, flexible light‐converting films with a high solid‐state quantum efficiency of 84% and good resistance to water, heating, and UV light are obtained. With the CD–polymer films as light conversion layers, CD‐based white light‐emitting diodes (WLEDs) with a luminous efficiency of 140 lm W−1 and a flat‐panel illumination system with lighting sizes of more than 100 cm2 are achieved, matching state‐of‐the‐art nanocrystal‐based LEDs. These results pave the way toward carbon‐based luminescent materials for solid‐state lighting technology. [ABSTRACT FROM AUTHOR]