Jingtao Zhang,Mengwan Zhai,Xueying Wang,Shurui Liu,Lijuan Zhang,Xing Liu,Yao Geng,Xiaodong Sun,Bingkun Liu
In the present work, Ti 3+ -self-doped TiO 2 heterostructure photocatalysts were prepared by coupling with different additions of palladium quantum dots by means of deposition-reduction methodology. The electron paramagnetic resonance (EPR) analysis indicated the existence of Ti 3+ in synthesized samples. The transmission electron microscopy (TEM) images presented the modification of TiO 2-x nanoparticles by coupling with nano palladium. Photoluminescence (PL) results demonstrated the lowest charge carrier recombination rate in 5% Pd/TiO 2-x composites. Photocatalytic performances of photocatalysts were evaluated by degrading Tetracycline (TC) and inactivating Escherichia coli ( E. coli ) and Fusarium oxysporum f. sp. Vasinfectum ( Fov ) with the presence of visible light , in which an enhanced photocatalytic degradation and inactivation activity was found in all Pd coupled composites with the highest efficiency in 5% Pd/TiO 2-x . The improved photocatalytic activity of Pd/TiO 2-x was associated to the generation of more hydroxyl radicals (•OH) and superoxide anions radicals (•O 2- ) during photocatalytic process which were demonstrated by the electron spin-resonance spectroscopy (ESR) technique. Moreover, 5% Pd/TiO 2-x composites were found to remain high photocatalytic properties in a circulating photo-disinfection system.
Bingsuo Zou,Lipeng Hou,Ye Tian,Junbo Han,Hui Peng,Xiongtao Yang,Lijie Shi
The magnetic excitons in diluted magnetic semiconductor (DMS) have varied formats due to the inhomogeneous phases out of doping concentration and/or structural relaxations or defects. Here the high quality cobalt-doped zinc blende ZnSe nanoribbons (NRs) were synthesized, showing bright and color-variable emissions from blue, yellow to a little mixed white colors. Their power and temperature dependent micro-photoluminescence (PL) spectra have been obtained in which two emission bands, one magnetic exciton band near the band-edge and a Co2+ high-level d–d transition emission band at 550 nm out of their ferromagnetic (FM) coupled aggregates in ZnSe lattice, both bands could also be reflected by a nonlinear optical absorption enhancement. The easy formed stacking fault defects in a chemical vapor deposition (CVD) grown ZnSe zincblende NR took part in the above optical processes out of magnetic polaronic excitons (PXs). The femtosecond (fs) laser pulse pumping on single ZnSe:Co NR produces obvious lasing behavior but with profile of a complicated magnetic exciton interactions with indication of a crossover from collective exciton magnetic polarons (EMP) to bound magnetic polaron (BMP) scattering in Co doped ZnSe NR. These findings indicate the complication of the magnetic coupling natures in varied DMS structures, whose optical properties have been found to be highly nonlinear, due to the involvement of the spin–spin, spin–exciton and spin–phonon interactions, verified by the theoretic calculation in Yang X-T et al (2019 Interstitial Zn-modulated ferromagnetism in Co-doped ZnSe Mater. Res. Express 6 106121).
To address the growing challenge of counterfeit prevention, this study developed a novel anti-counterfeiting ink system based on bacterial cellulose nanocrystals (BCNC) and lanthanide (Er, Yb)‑nitrogen (N) co-dropped graphene quantum dots (GQDs), which exhibited both photoluminescence (PL) and upconversion photoluminescence (UCPL) fluorescent properties as well as excellent rheological characteristics . The Er/Yb/N-GQDs with positive charges were synthesized by a one-step hydrothermal method and subsequently assembled with negatively charged BCNC through electrostatic self-assembly to fabricate a novel nanohybrid , Er/Yb/N-GQDs-BCNC. Raman spectroscopy results indicated an enhancement in the graphitization of GQDs due to lanthanide modification. The TEM results demonstrated a homogeneous distribution of Er/Yb/N-GQDs on BCNC, while XRD , FTIR, and XPS analyses confirmed their physical binding, thus validating the successful synthesis of novel nanohybrids. Then, Er/Yb/N-GQDs-BCNC was introduced into PVA waterborne ink and exhibited dual anti-counterfeiting properties by emitting blue fluorescence at Em 440 nm under Ex 370 nm and green fluorescence at Em 550 nm under Ex 980 nm. Furthermore, the incorporation of BCNC significantly enhanced the thixotropic behavior and yield stress of the PVA waterborne ink. This enhancement made the dual anti-counterfeiting fluorescent ink more suitable for diversified applications on different devices and various substrates, thus providing a novel approach for convenient and rapid information encryption and high security anti-counterfeiting.
危险品化学品经营许可证（带存储）