Dynamic Reconfiguration and Local Polarization of NiFe-Layered Double Hydroxide-Bi2MoO6- x Heterojunction for Enhancing Piezo-Photocatalytic Nitrogen Oxidation to Nitric Acid.

Constructing heterojunctions with vacancies has garnered substantial attention in the field of piezo-photocatalysis. However, the presence of interfacial vacancies can serve as charge-trapping sites, leading to the localization of electrons and hindering interfacial charge transfer. Herein, dual oxygen vacancies in the NiFe-layered double hydroxide and Bi2MoO6- x induced interfacial bonds have been designed for the piezo-photocatalytic N2 oxidation to NO3 -. Fortunately, it achieves sensational nitric acid production rates (7.23 mg g-1 h-1) in the absence of cocatalysts and sacrificial agents, which is 6.03 times of pure Bi2MoO6 that under ultrasound and light illumination. Theoretical and experimental results indicate that interfacial bonds act as "charge bridge" and "strain center" to break the carrier local effect and negative effects with piezocatalysis and photocatalysis for promoting exciton dissociation and charge transfer. Moreover, the strong electronic interaction of the interfacial bond induces internal reconstruction under ultrasound for promoting the local polarization and adsorption of N2, which accelerates the fracture of the N≡N bonds and reduces the activation energy of the reaction. The research not only establishes a novel approach for optimizing the combined effects of piezo-catalysis and photocatalysis, but also achieves equilibrium between the synergistic impacts of vacancies and heterojunctions.

Dual substitution of host lattice ions to enhance the luminescence properties of Zn2TiO4:Cr3+ phosphor.

Near-infrared light sources have potential applications in many fields. Cr3+ is a good luminescence centre to prepare near-infrared phosphors. Improving the performance of existing near-infrared luminescent materials has indeed attracted great interest from researchers. The luminescence properties of Zn2TiO4:Cr3+ were improved by crystal field engineering strategies. Zn2+-Ti4+ was partially replaced using a Li+-Nb5+ ion pair based on the Zn2TiO4:Cr3+ phosphors. Luminescence Cr3+-activated luminescent materials are sensitive to changes in the local crystal structure and crystal field environment. Doping of Li+-Nb5+ increased the luminescence intensity up to 2.7 times that of the undoped sample. Also, the thermal stability of the phosphor was greatly increased by the replacement of Li+-Nb5+.

Crystal structure and luminescence properties of a novel near-infrared phosphor LiAlO2:Fe3.

Cr3+-free near-infrared (NIR) phosphors are currently gaining significant attention in various application fields. A novel Fe3+-activated LiAlO2 NIR phosphor was successfully synthesized by high-temperature solid-state method. Under excitation of 391 nm and 467 nm, the phosphor emits near-infrared light with wavelengths ranging from 600 to 850 nm. The emission bands with peaks at 725 nm correspond to the transition from 4T1(4G) to the ground state energy level 6A1(6S). The optical band gap of LiAlO2 was calculated using Density Function Theory (DFT) and diffuse reflectance spectrum, respectively. The thermal stability of the sample was measured under 391 nm and 467 nm excitation, showing that the emission intensity at 413 K is 55.3 % and 52.4 % of the emission intensity at room temperature.