Facile Liquid-Phase Synthesis of a High-Performance Cd-Doped ZnO-Quantum-Dot-Based Photocatalyst

Doping is an effective functional modification method for improving the optical, electrical, and magnetic properties of semiconductors. Here, Cd-doped wurtzite ZnO-quantum-dot (ZQ) zero-dimensional nanomaterials were successfully prepared via liquid-phase synthesis. The experimental results showed that Cd doping can effectively shorten the bandgap, where the optical bandgap range of Cd-doping photocatalysts were 3.31-3.36 eV; in particular, the Cd5-ZQ (Cd contents of 0.5 wt%) sample reduced the bandgap from 3.39 to 3.31 eV compared to that of pure ZQ . This is consistent with the experimental results, where the simulation calculation results indicated the bandgap reduced from 3.107 to 2.912 eV after introducing Cd. Photoluminescence spectroscopy results confirmed the Cd-ion dopants efficiently capture excited electrons and further prolongs the charge lifetime. The degradation of a methylene blue solution under simulated solar light irradiation revealed that the photocatalytic properties of Cd-ZQ nanomaterial with suitable dopant concentration (Cd content 0.5 wt%) was significantly better than those of pure ZQ. The underlying mechanism involves a synergistic effect, and a reasonable and convenient strategy for uprated performance is presented.

Graphene's Correlation of Electrical and Magnetic Properties Manages the Modification and Increasing the Energy of Li Batteries

Importance of lithium power sources is confirmed by the fact that on October 10, 2019, the Nobel Prize in Chemistry in 2019 was awarded for the development of lithium-ion batteries. 10 years earlier, in 2010,physicists Andre Geim and Kostya Novoselov were awarded the Nobel Prize in Physics "For groundbreaking experiments regarding the two dimensional material graphene". A synergistic effect of theory and practicality in the area of lithium batteries, and the theory and practicality in the field of graphene materials creates the unique possibility generate the innovative high-energy Li batteries based on the graphene materials.

Structural, electrical, and magnetic study of La-, Eu-, and Er- doped bismuth ferrite nanomaterials obtained by solution combustion synthesis

In this work, the multiferroic bismuth ferrite materials Bi0.9RE0.1FeO3 doped by rare-earth (RE = La, Eu, and Er) elements were obtained by the solution combustion synthesis. Structure, electrical, and magnetic properties of prepared samples were investigated by X-ray photoelectron spectroscopy, Mössbauer spectroscopy, electrical hysteresis measurement, broadband dielectric spectroscopy, and SQUID magnetometry. All obtained nanomaterials are characterized by spontaneous electrical polarization, which confirmed their ferroelectric properties. Investigation of magnetic properties at 300.0 K and 2.0 K showed that all investigated Bi0.9RE0.1FeO3 ferrites possess significantly higher magnetization in comparison to bismuth ferrites obtained by different methods. The highest saturation magnetisation of 5.161 emu/g at 300.0 K was observed for the BLaFO sample, while at 2.0 K it was 12.07 emu/g for the BErFO sample. Several possible reasons for these phenomena were proposed and discussed.