BaTiF₆:Mn⁴⁺bifunctional microstructures with photoluminescence and photocatalysis: hydrothermal synthesis and controlled morphology

Abstract

A series of BaTiF6:Mn 4+ samples have been synthesized via a facile hydrothermal route. The crystal structure and morphology of the obtained products were studied. Detailed investigations indicate that the morphology of bundle-like, microrods, and flower-like structures can be observed by varying hydrothermal reaction time. Simultaneously, we investigated the influences of the reaction temperature and the barium source on the crystal phases and morphology of the prepared BaTiF6:Mn 4+ products. The luminescence properties of the as-synthesized samples were systematically evaluated. The results clearly demonstrate that two intense excitation bands are observed in the near-UV and the blue region, suggesting that BaTiF6:Mn 4+ samples provide a great opportunity for preferable application in light-emitting diodes (LED) with blue-chip excitation. The prepared BaTiF6:Mn 4+ samples exhibit an intense red emission under 470 nm light excitation. Additionally, the changes of the Mn 4+ emissions based on different reaction temperature and barium source were studied in detail. Temperature dependent luminescence experiments have been performed in order to evaluate the thermal stability of BaTiF6:Mn 4+ samples. Furthermore, the thorough study on the photocatalytic activities of the asprepared samples demonstrated that the BaTiF6:Mn 4+ powers promote satisfactory photocatalytic activities.

Cs2MnF6 Red Phosphor with Ultrahigh Absorption Efficiency

“…Fluoride phosphors doped with Mn 4+ have narrow-band red emission ranging from 600 to 650 nm, favorable thermal stability, and high luminescent efficiency of radiation, showing great potential to improve the optical performance of WLEDs . Until now, Mn 4+ ion activated fluoride phosphors have been extensively studied, such as A 2 MF 6 :Mn 4+ (A = Na, K, Rb, and Cs; M = Si, Ge, Sn, Zr, and Ti), − BMF 6 :Mn 4+ (B = Ba and Zn; M = Si, Ge, and Ti) and A 3 MF 6 :Mn 4+ (A = Na and K; M = Al, Ga, and Sc). − More recently, Zhang’s group synthesized a Mn 4+ -ion-doped Cs 2 SiF 6 :Mn 4+ red-emitting fluoride phosphor . The optimal doping amount of Mn 4+ in the Cs 2 SiF 6 host is 10.75 mol %.…”

Narrow-band red emitting phosphor BaTiF6:Mn4+: preparation, characterization and application for warm white LED devices

“…Therefore, the hydrothermal method is a commendable approach for the synthesis of this red phosphor. [33][34][35] In addition, surfactants are applied commonly to realize the control of particle size and shape at the nanometer and micrometer levels. Citric acid, as a small chelating ligand, has already been used as a structure directing agent to control and adjust the size and morphology of products due to its high thermal stability and ability to form complexes with other metal ions.…”

Controlled Morphology, Improved Photoluminescent Properties, and Application of an Efficient Non-rare Earth Deep Red-Emitting Phosphor

“…The BaGeF 6 :Mn 4+ sample obtained from Ba­(NO 3 ) 2 exhibits the strongest emission peak compared with the samples prepared by other barium sources. The reason for the dramatic difference in luminescence intensity may be derived from the difference in particle size and the number of surface defects …”

“…The reason for the dramatic difference in luminescence intensity may be derived from the difference in particle size and the number of surface defects. 38 To investigate the influence of the amount of EDTA on the morphology evolution in our synthesis process, a series of Mn 4+ -doped BaGeF 6 red phosphors BaGeF 6 were obtained through adding different molar ratios of BaF 2 to EDTA at 180 °C for 8 h. Figure 7A reveals the XRD patterns of BaGeF 6 :Mn 4+ red phosphor through different amounts of EDTA. All the diffraction peaks correspond to the standard cards of BaGeF 6 (PDF No.…”