Molten salt synthesis, growth mechanism, and photoluminescence of rod chlorapatite microcrystallites

Wen, Xiao; He, Can; Wu, Bogang; Huang, Ximing; Huang, Zhaohui; Yin, Zhaoyu; Liu, Yicen; Fang, Minghao; Wu, Xiaowen; Min, Xin

doi:10.1039/c8ce02040j

Cited by 18 publications

(8 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Low-temperature molten salt mixtures were prepared using low melting inorganic salts such as nitrates, sulfates or chlorides. [26] Since salt is at a molten state, ions have a higher diffusion coefficient (10 −5 to 10 −8 cm 2 s −1 ) [27] and diffuse faster than the conventional solid-state chemistry route (diffusion coefficient is in the order of 10 −18 cm 2 s −1 ), [27] resulting in an enhancement of the reaction kinetics and homogeneous mixing of reactants. [27][28][29] In our experiments, nitrate powder was firstly heated in air to reach a molten state (Figure 1a).…”

Section: Materials Characterizationsmentioning

confidence: 99%

“…[25] To date, various types of reaction mechanisms have been reported for Mn oxide-based positive electrode of Zn-MnO 2 battery in Zn-containing aqueous electrolyte. [15,[26][27][28] Pan et al [26] proposed a chemical-assisted conversion reaction mechanism Recently, rechargeable zinc-ion batteries in mild acidic electrolytes have attracted considerable research interest as a result of their high sustainability, safety, and low cost. However, the use of conventional Zn-ion storage materials is hindered by insufficient specific capacity, sluggish reaction kinetics, or poor cycle life.…”

mentioning

confidence: 99%

“…at the surface of the electrode. [26] Another mechanism based on Zn 2+ insertion/extraction from MnO 2 was proposed by Alfaruqi et al, who observed the formation of ZnMn 2 O 4 and Zn x MnO 2 , via ex situ X-ray diffraction (XRD) analysis. [15] Moreover, Sun et al reported the co-insertion of H + and Zn 2+ by galvanostatic intermittent titration technique and ex situ XRD analysis, [27] where Zn 2+ intercalation occurred only after H + insertion during the reduction process.…”

mentioning

confidence: 99%

See 2 more Smart Citations

Alkali Ions Pre‐Intercalated Layered MnO₂ Nanosheet for Zinc‐Ions Storage

Liu

Huang

et al. 2021

Advanced Energy Materials

167

116

View full text Add to dashboard Cite

Compared with organic electrolytes, aqueous electrolytes are safer (no risk of burning) and can achieve an ionic conductivity several orders of magnitude higher than organic electrolytes. [1][2][3][4] This makes aqueous rechargeable batteries cheap, nonpolluting and safe, with potentially high power density capability (although the cell voltage is limited). [1] However, the widely studied aqueous lithium-ion batteries and sodium-ion batteries have low specific capacities (<150 mAh g −1 ). [2] Among potential alternatives, the aqueous Zn-ion battery (AZIB) is currently attracting significant attention due to key features of Zn metal, including abundance (low cost) and high theoretical specific capacity (820 mAh g −1 ). [5][6][7][8][9] The main challenges for the development of aqueous Zn-ion batteries are to achieve dendrite-free Zn deposit at the anode [10,11] and find suitable cathode materials. MnO 2 (theoretical capacity is 308 mAh g −1 ) is one of the most attractive cathode materials for aqueous zinc ion batteries due to their high energy density and high power density. [5,6,8,[11][12][13][14][15] Among various crystallographic polymorphs (α-, β-, γ-, δ-, λ-, and εtype), birnessite-type δ-MnO 2 with layered structure owns a large interlayer spacing (≈0.7 nm), which is more suitable for rapid and reversible (de-)insertion of Zn ions. [16] However, δ-MnO 2 was reported to show poor rate capability and cycling stability. [15] According to the literature, δ-MnO 2 -based cathodes are limited by the serious structural degradation with phase transformation, which is mainly attributed to the cointercalation of water molecules and dissolution of Mn during cycling processes. [17,18] It has been reported that the preintercalation of large cations (such as, K + , Ce 3+ , and Ca 2+ ) in MnO 2 during synthetic process can stabilize the structure through coordination of guest-ions with adjacent host atoms. [16,[19][20][21][22][23][24][25] Moreover, the preintercalation of alkaline ion strategy in MnO 2 has also attracted much attention as an effective approach to enhance the electronic conductivity, activating more active sites, and promoting diffusion kinetics. [25] To date, various types of reaction mechanisms have been reported for Mn oxide-based positive electrode of Zn-MnO 2 battery in Zn-containing aqueous electrolyte. [15,[26][27][28] Pan et al. [26] proposed a chemical-assisted conversion reaction mechanism Recently, rechargeable zinc-ion batteries in mild acidic electrolytes have attracted considerable research interest as a result of their high sustainability, safety, and low cost. However, the use of conventional Zn-ion storage materials is hindered by insufficient specific capacity, sluggish reaction kinetics, or poor cycle life. Here, these limitations are addressed by preintercalating alkali ions and water crystals into layered δ-MnO 2 (birnessite) to prepare K 0.27 MnO 2 •0.54H 2 O (KMO) and Na 0.55 Mn 2 O 4 •1.5H 2 O with ultrathin nanosheet morphology via a rapid molten salt method. In these materials, alk...

show abstract

Section: Materials Characterizationsmentioning

confidence: 99%

mentioning

confidence: 99%

mentioning

confidence: 99%

See 1 more Smart Citation

Alkali Ions Pre‐Intercalated Layered MnO₂ Nanosheet for Zinc‐Ions Storage

Liu

Huang

et al. 2021

Advanced Energy Materials

167

116

View full text Add to dashboard Cite

show abstract

“…Molten salt synthesis is a facile method to synthesize inorganic materials with controllable particle size and morphology, as well as a pure crystal phase and high crystallinity, having the advantages of good scalability, environmental friendliness, and low cost. − Appropriate molten salts are of vital importance for this synthesis method, which provides a homogeneous fluid environment at high temperatures to promote phase formation and affect crystal growth. For borate-based phosphor materials, the starting material boric acid has a low melting point and thus can serve as the molten salt medium at the same time.…”

Section: Introductionmentioning

confidence: 99%

Molten Salt Synthesis of Broad-Band Near-Infrared InBO₃:Cr³⁺ Submicron Phosphor and Its Luminescent Enhancement by Lanthanide Ion Codoping

et al. 2022

View full text Add to dashboard Cite

Phosphor materials with small particle sizes and high luminescent efficiency are desired for the fabrication of phosphor-converted light-emitting diodes (pc-LEDs). Near-infrared (NIR) pc-LED light sources have great application potential in the food industry and medical fields, which stimulate the extensive exploration of NIR phosphors. In this work, broad-band NIR-emitting InBO 3 :Cr 3+ phosphors with submicron size and spherical morphology are successfully synthesized via the molten salt method. The InBO 3 :Cr 3+ phosphor exhibits a broad emission band covering 700−1000 nm and peaking at ∼820 nm. The maximum emission intensity is obtained for InBO 3 :0.02Cr 3+ with an internal quantum yield (IQY) of ∼62%, which is higher than that of microsized counterparts derived from solid-state reaction. Furthermore, the absorption and emission enhancements are achieved by codoping lanthanide ions into InBO 3 :Cr 3+ submicron phosphors. The codoping of inert La 3+ ions can increase the absorption efficiency of InBO 3 :Cr 3+ , due to the increased octahedral distortion of Cr 3+ sites. The codoping of active Yb 3+ ions can significantly enhance the NIR emissions of InBO 3 :Cr 3+ between 950 and 1100 nm. Meanwhile, the increased IQY of ∼73% is achieved for InBO 3 :0.02Cr 3+ ,0.005Yb 3+ simultaneously with suppressed thermal quenching, originating from the effective energy transfer from Cr 3+ to Yb 3+ ions.

show abstract

“…Apparently, phosphors are an important influence on the light output and optical properties of pc-LEDs . In order to improve performance of pc-LEDs in general lighting and other special applications, many scientists are devoted to exploring new phosphors and promoting the performance of existing luminescence materials. − …”

Section: Introductionmentioning

confidence: 99%

Ca₈Mg₇Si₉N₂₂:Ce³⁺—A Yellow-Emitting Nitride Phosphor for White Light Emitting Diodes

Wang

Yang

et al. 2020

ACS Appl. Electron. Mater.

View full text Add to dashboard Cite

Nitridomagnesosilicate phosphors are promising candidates for white light emitting diodes. Here, we report a yellow nitride phosphor Ca 8 Mg 7 Si 9 N 22 :Ce 3+ , which exhibits a broad band emission in the spectral range of 475−675 nm under the excitation of 445 nm. The photoluminescence intensity of Ca 8−x Mg 7 Si 9 N 22 :xCe 3+ (0.01 ≤ x ≤ 0.11) reaches a maximum when x = 0.05. CIE coordinates and the color purity of Ca 7.95 Mg 7 Si 9 N 22 :0.05Ce 3+ are (0.449, 0.531) and 84.0%, respectively. The Ca 7.95 Mg 7 Si 9 N 22 :0.05Ce 3+ phosphor exhibits a good color drifting resistance with a maximum chromaticity shift of 0.0085 at 475 K. By combining the as-synthesized yellow nitride phosphor Ca 7.95 Mg 7 Si 9 N 22 :0.05Ce 3+ and red nitride phosphor SrLiAl 3 N 4 :Eu 2+ with a commercial blue InGaN chip, an all-nitride white light emitting diode device is fabricated, and a warm white light is generated with chromatic coordinates (0.471, 0.364) and color temperature of 2194 K.

show abstract

Molten salt synthesis, growth mechanism, and photoluminescence of rod chlorapatite microcrystallites

Abstract: The molten salt method was used to synthesize chlorapatite microcrystallites with regular shapes and uniform sizes at a relatively low temperature under an air atmosphere.

Cited by 18 publications

References 30 publications

Alkali Ions Pre‐Intercalated Layered MnO₂ Nanosheet for Zinc‐Ions Storage

Alkali Ions Pre‐Intercalated Layered MnO₂ Nanosheet for Zinc‐Ions Storage

Molten Salt Synthesis of Broad-Band Near-Infrared InBO₃:Cr³⁺ Submicron Phosphor and Its Luminescent Enhancement by Lanthanide Ion Codoping

Ca₈Mg₇Si₉N₂₂:Ce³⁺—A Yellow-Emitting Nitride Phosphor for White Light Emitting Diodes

Contact Info

Product

Resources

About

Molten salt synthesis, growth mechanism, and photoluminescence of rod chlorapatite microcrystallites

Abstract: The molten salt method was used to synthesize chlorapatite microcrystallites with regular shapes and uniform sizes at a relatively low temperature under an air atmosphere.

Cited by 18 publications

References 30 publications

Alkali Ions Pre‐Intercalated Layered MnO2 Nanosheet for Zinc‐Ions Storage

Alkali Ions Pre‐Intercalated Layered MnO2 Nanosheet for Zinc‐Ions Storage

Molten Salt Synthesis of Broad-Band Near-Infrared InBO3:Cr3+ Submicron Phosphor and Its Luminescent Enhancement by Lanthanide Ion Codoping

Ca8Mg7Si9N22:Ce3+—A Yellow-Emitting Nitride Phosphor for White Light Emitting Diodes

Contact Info

Product

Resources

About

Alkali Ions Pre‐Intercalated Layered MnO₂ Nanosheet for Zinc‐Ions Storage

Alkali Ions Pre‐Intercalated Layered MnO₂ Nanosheet for Zinc‐Ions Storage

Molten Salt Synthesis of Broad-Band Near-Infrared InBO₃:Cr³⁺ Submicron Phosphor and Its Luminescent Enhancement by Lanthanide Ion Codoping

Ca₈Mg₇Si₉N₂₂:Ce³⁺—A Yellow-Emitting Nitride Phosphor for White Light Emitting Diodes