Dong-jun Wang

Hierarchical porous Co3O4@CoxFe3−xO4 film as an advanced electrocatalyst for oxygen evolution reaction

Fabricating a delicate structure for water oxidation is critical for developing highly efficient electrocatalysts, which hold significant promise for energy conversion devices. Herein, we show an effective approach for constructing a Co3O4@CoxFe3−xO4 hierarchical nanostructure with obviously improved electrocatalytic activity relative to CoxFe3−xO4 nanoplate and Co3O4 nanowire films. The enhancement is attributed to the formation of secondary CoxFe3−xO4 nanoplates outside of the Co3O4 nanowires, leading to a fantastic porous architecture that results in a more active electrocatalyst.

Photoluminescence of a novel red emitting phosphor LiLaMgWO6 : Eu3+

A novel red-emitting phosphor LiLaMgWO6 : Eu3+ has been synthesized by a high-temperature solid-state reaction. X-ray powder diffraction (XRD) analysis and FT-IR spectra confirmed the formation of LiLaMgWO6 : Eu3+ phase. The photoluminescence excitation and emission spectra, the concentration dependence of the emission intensity, decay curves, and UV–Vis absorption spectra of the phosphor were obtained. The phosphor could be efficiently excited by the near ultraviolet (NUV) and blue light, exhibiting red light emission. The decay time was also determined for various Eu3+ concentrations in LiLaMgWO6. The calculated color coordinates of the emitted light lie in the red region. Therefore, the obtained results suggest that the prepared phosphors exhibit great potential for use as red emitting phosphor for white light emitting diodes.

Investigation of luminescence properties and the energy transfer mechanism of LiSrBO3: Ce3+, Tb3+ phosphors

A series of LiSrBO3:Ce3+, Tb3+ phosphors have been prepared via a high-temperature solid-state reaction process. X-ray diffraction (XRD), scanning electric microscopy (SEM), photoluminescence (PL) spectra, and the diffuse reflection spectra were utilized to characterize the samples. The luminescence properties of LiSrBO3:Ce3+, Tb3+ phosphors have been discussed. The energy transfer process from Ce3+ to Tb3+ has been demonstrated to be a resonant type via the dipole–dipole interaction mechanism. The emissive colors of LiSrBO3:Ce3+, Tb3+ samples can be adjusted from blue to yellowish-green by the energy transfer of Ce3+ and Tb3+, respectively. The results suggest the present phosphors can be potentially applied as a candidate of green-light phosphor for UV-pumped W-LED.