OPTICAL MATERIALS
·
2017
·
IF 2.238
Jianjian Sun,Bijun Fang,Shuai Zhang,Zhihui Chen,Jianning Ding,Xiangyong Zhao,Haosu Luo
Er 3+ -doped Na 0.5 Bi 0.5 TiO 3 (Er-doped NBT) ceramics were prepared via a hydrothermal method . High sintering active Er-doped NBT nano cubic particles with perovskite structure were synthesized at hydrothermal condition of 200 °C for 24 h in 12 M NaOH solution, which were self-assembled via in situ crystallization mechanism by the initially as-grown nanowires. The Er-doped NBT ceramics sintered at 1100 °C for 2 h exhibit pure rhombohedral perovskite structure, high densification and rather homogenous microstructure morphology. Under 488 nm light excitation , the strong green emission peaks centering at 530 nm and 550 nm and the weak red emission peaks locating at 665 nm and 735 nm are excited, which can be attributed to the 2 H 11/2 , 4 S 3/2 , 4 F 9/2 and 4 I 9/2 → 4 I 15/2 transitions, respectively. The maximum emission intensity is obtained when the Er doping content reaches 1.0 mol%. A strong upconversion emission peak centering around 550 nm in green light range is excited under 800 nm light excitation, which is correlated with the 4 S 3/2 → 4 I 15/2 transition.
研究领域:
材料科学
·
无机非金属材料
·
功能陶瓷
·
光电子学
·
固体化学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2015
·
IF 2.288
J.L. Wang,E.H. Song,M. Wu,W.B. Dai,S. Ye,Q.Y. Zhang
Selectively enhanced green upconversion (UC) and near-infrared (NIR) downconversion (DC) emissions of Er 3+ by Yb 3+ -Mn 2+ dimer sensitizing have been demonstrated in Er 3+ /Yb 3+ /Mn 2+ tri-doped spinel MgGa 2 O 4 upon excitation of 980 nm laser diode (LD). By optimizing the doping rate of Mn 2+ , the intensity ratio of green to red UC emission intensities of Er 3+ (G/R) could be enhanced about 10 times. Meanwhile, the 1.5 μm NIR DC emission could also be increased about 3.6 times in this system. The DC and UC emission properties, UC mechanism, as well as the enhancing mechanism have been investigated and discussed in detail. A selectively enhancing mechanism based on Yb 3+ -Mn 2+ dimer sensitizing is proposed to explain the selectively enhancing phenomena. This work could inspire the design of novel UC materials for various applications, such as temperature sensors and optical transmission, etc.
研究领域:
光学材料
·
生物医学光子学
·
无机功能材料
·
分子影像
·
转化医学
✓ 已验证
DOI
高影响因子
MATERIALS RESEARCH BULLETIN
·
2019
·
IF 3.355
Yanqiu Zhang,Sai Xu,Xiangping Li,Jinsu Zhang,Jiashi Sun,Haiping Xia,Ruinian Hua,Baojiu Chen
Novel nanoplatform with excellent photothermal conversion and temperature feedback are preferable in clinical photothermal therapy (PTT). In this work, a hybrid of NaYF 4 :Er 3+ ,Yb 3+ @NaYF 4 upconversion nanoparticles (UCNPs) conjugated with gold nanorods (GNRs) was fabricated in order to achieve effective photothermal conversion and excellent temperature detection. In this nanoplatform, the GNRs as photo-activated nano-heaters could effectively convert the 808 nm photoenergy into heat, meanwhile UCNPs as 980 nm triggered temperature probe could read the temperature in an exact microdomain where the nanocomposite was located at. The effects of excitation source, GNRs concentration and power density on photothermal conversion were investigated. In addition, the difference between eigen temperature of nanoparticles and solution temperature, and the potential for temperature feedback were analyzed under double lasers excitation. Moreover, the photothermal conversion efficiency was experimentally confirmed from thermodynamic analysis. It was found that the nanocomposite can be an excellent nanoplatform for potential application in advanced PTT.
研究领域:
生物医学工程
·
纳米医学
·
肿瘤治疗
·
光热疗法
·
分子影像
·
热疗监测
·
转化医学
✓ 已验证
DOI
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2018
·
IF 6.735
Huining Huang,Huiliang Li,Zeyan Wang,Peng Wang,Zhaoke Zheng,Yuanyuan Liu,Ying Dai,Yingjie Li,Baibiao Huang
In this work, we fabricated NaYF 4 :Yb 3+ ,Tm 3+ @NaYF 4 :Yb 3+ ,Nd 3+ @TiO 2 (Tm@Nd@TiO 2 ) core@shell nanoparticles and investigated their near-infrared (NIR) photocatalytic activities. Comparing to traditional TiO 2 based upconversion (UC) photocatalysts (i.e., NaYF 4 :Yb 3+ ,Tm 3+ @TiO 2 , named Tm@TiO 2 ), Tm@Nd@TiO 2 exhibits enhanced photocatalytic activity under NIR light irradiation. The photocatalytic activity of Tm@Nd@TiO 2 under 980, 808, and 980 + 808 nm laser irradiation is 4.40, 5.84, and 9.83 times as high as that of Tm@TiO 2 under only 980 nm irradiation, respectively. The ethylene degradation rate of Tm@Nd@TiO 2 under 980 + 808 nm laser irradiation is 6.4 times as that of Tm@TiO 2 . The photocatalytic activity of Tm@Nd@TiO 2 under visible + NIR irradiation is even comparable with (∼2/3) that under UV light irradiation during Rhodamine B (RhB) degradation. The enhanced photocatalytic activity of Tm@Nd@TiO 2 can be attributed to the stronger light absorption in NIR region ascribed to Nd 3+ , lower water absorption and the enhanced UC emission of Tm@Nd with unique core@shell nanostructures. This work can provide a possible route to improve the NIR photocatalytic activity and stimulate the applications in many other fields.
研究领域:
材料科学
·
光催化技术
✓ 已验证
产品关联
DOI
高影响因子
INTERNATIONAL JOURNAL OF ENERGY RESEARCH
·
2020
·Vol. 44
·期 11
·8555-8566
·
IF 3.741
Li Yang,Yanping Yuan,Nan Zhang,Yanfang Dong,Yafen Sun,Wenhui Ji
Summary To make better use of solar energy, lauric acid/expanded graphite (LA/EG) composite phase change materials (PCMs) were synthesized to collect and store solar energy as latent heat thermal energy. The results of thermal characteristics show that when the mass fraction of EG is 5%, 10%, and 15%, the latent heat of LA/EG is 164.5, 156.9, and 148.0 J/g, and the thermal conductivity is 2.73, 7.98, and 10.54 W/(m·K). Leakage test shows that LA/EG PCMs with EG mass fraction of 10% and 15% are form stable after phase change. One thousand thermal cycles prove good thermal reliability of LA/EG. TG analysis indicates LA/EG PCMs have good thermal stability within operating temperature range. The Ultraviolet-visible spectra reveal that the absorbance of LA/EG composite PCMs would increase as the mass fraction of EG increases. Photothermal conversion experiment results indicate that the photothermal conversion efficiency of LA/EG composite PCMs increases as the mass fraction of EG increases, and the efficiency can reach 95% when the mass fraction of EG is 15%. Moreover, it was also found that the process of photothermal conversion can be accelerated with stronger illumination intensity or smaller heat transfer size. All the results show that the prepared LA/EG PCMs can convert solar energy into thermal energy and store it in the form of latent heat at the same time, which indicates it has promising prospect in the application of solar energy conversion and storage.
研究领域:
材料科学
·
能源化学
·
热能工程
·
功能材料
·
可再生能源
✓ 已验证
DOI
高影响因子
RSC Advances
·
2017
·Vol. 7
·期 76
·48238-48244
·
IF 3.108
Jiangyun Dai,Chao Yang,Hong Zhang,Hua Zhang,Guoying Feng,Shouhuan Zhou
The successful synthesis of rare earth doped nano/microcrystals with the desired morphology, uniform monodispersity, and intense infrared emission is of fundamental significance, and would facilitate their application in infrared emission-related miniaturization and integration in optoelectronics. However, simultaneously controlling the morphology and enhancing the infrared emission through simple and effective methods has not been well explored. In this study, via Ca2+ doping with an optimized concentration of 25 mol% in the hydrothermal solution, irregular NaGdF4:Yb/Er submicrocrystals converted into highly uniform submicrorods. Meanwhile, an obvious enhancement of visible upconversion (UC) and near-infrared (NIR) downconversion (DC) emission were obtained, probably due to the improved morphology and lowering the local crystal field symmetry around the rare earth ions induced by Ca2+ doping. Furthermore, Ce3+ ions with an optimized concentration of 2 mol% were codoped to intentionally tailor the branching ratio through efficient energy transfer from Er3+ to Ce3+. As a result, the ∼1530 nm emission intensity of the NaGdF4: 25Ca/2Ce/20Yb/2Er submicrorods increased by about 6.4 times in comparison with the NaGdF4:20Yb/2Er counterpart.
研究领域:
材料科学
·
光学工程
·
纳米技术
·
稀土化学
·
光电子学
✓ 已验证
DOI
高影响因子
APPLIED PHYSICS A-MATERIALS SCIENCE & PROCESSING
·
2024
·Vol. 130
·期 11
·835
·
IF 2.5
Kou Chen,Duan Bin,Shi Lichun,Yang Hongcai,Ni Heng,Wang Haiyuan,Ye Qing,Hu Junshan,Hu Shigang
The Sc 3+ ions doped NaYF 4 : Yb 3+ , Er 3+ upconversion (UC) nanoparticles are synthesized by thermal decomposition method. We successfully obtained the upconversion luminescence (UCL) nanoparticles from green emission to red emission through doping Sc 3+ ions with different concentrations. Based on the XRD, the phase change process of Sc 3+ ions doped NaYF 4 nanocrystalline phase were demonstrated. More importantly, through the analysis of UC spectrum data, the change in the phase of the NaY/ScF 4 : Yb 3+ , Er 3+ nanocrystalline corresponds to the change in its luminous properties. It determines that the change of crystal field will lead to the change of luminescence, and then modulate the luminescence. NaScF 4 : Yb 3+ , Er 3+ UC nanoparticles exhibit strong red light emission. In addition, the temperature-sensitive properties of the optimal doping concentration of Sc 3+ ion were tested. The sensitivity of NaYF 4 : Yb 3+ , Er 3+ nanoparticles doped with Sc 3+ ion reached the maximum value of 0.024 K − 1 at 498 K. The nanocrystalline has great application value in the fields of optical temperature measurement, biomedicine, bioprobes and colorful display.
研究领域:
材料科学
·
光学工程
·
生物医学工程
·
纳米技术
·
分子影像学
✓ 已验证
DOI
高影响因子
MATERIALS & DESIGN
·
2017
·
IF 4.364
Puhong Wen,Lili Ai,Taotao Liu,Dengwei Hu,Fangyi Yao
The regular orthorhombic Nb 2 O 5 (O-Nb 2 O 5 ) rectangle nanosheets dominantly exposed (010) facet are synthesized by a hydrothermal topological reaction with a precursor of K 4 Nb 6 O 17 ·4.5H 2 O (KNbO). The structure and morphology of the samples obtained at different temperatures and pH values of reacting solution are investigated. The results suggest that there are two topological reactions in this process. One is the acid-exchanging reaction transforming into H 4 Nb 6 O 17 ·3H 2 O (HNbO) nanosheets from KNbO rectangle nanosheets , and the other is dehydration reaction transforming into O-Nb 2 O 5 rectangle nanosheets from HNbO nanosheets. And the {010} facets of O-Nb 2 O 5 crystal are transformed from the {010} facets of HNbO crystal in the ingenious topological reaction. The photoelectric performance of the obtained O-Nb 2 O 5 nanosheets is evaluated by decomposing water to H 2 under 370 nm UV light illumination and measuring the accompanying photocurrent . The photocurrent density is 680 nA·cm − 2 generated by splitting water with O-Nb 2 O 5 nanosheets as photocatalyst , and it is 4.3 times of the contrast sample. The result indicates that the (010) facet of O-Nb 2 O 5 is one of the highest photocatalytic active surfaces and shows high photoelectric conversion efficiency. Thus, the O-Nb 2 O 5 nanosheets dominantly exposed (010) facet have potential applications in photocatalyst and photoelectric nanodevices .
研究领域:
材料科学
·
光催化
·
纳米材料
·
无机化学
·
能源材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2020
·
IF 4.65
Dan Yang,Qingfeng Guo,Libing Liao,Yidi Zhang,Lefu Mei,Haikun Liu
In this paper, K 3 ScF 6 :Er 3+ ,Yb 3+ up-conversion luminescent materials with cryolite structure were synthesized via solid-state method. The X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray photoelectron spectroscopy (XPS) and photoluminescence spectroscopy (PL) under the excitation of a 980 nm laser with different power density were used to investigate the phase structure, elemental composition , and up-conversion luminescence properties of K 3 ScF 6 :Er 3+ ,Yb 3+ . The quenching concentrations of Yb 3+ and Er 3+ were confirmed to 0.15 and 0.05 (mol concentration) in this system, respectively. Upon 980 nm excitation, the K 3 ScF 6 :Er 3+ ,Yb 3+ showed a typical transition of Er 3+ which contains two main bands in the visible region that green and red. According to the fitting result of the pump power dependence of up-conversion intensity, all the green and red up-conversion emission of K 3 ScF 6 :0.05Er 3+ ,0.15 Yb 3+ belong to the two-photon process. To better understand the origin of radiation and energy transfer mechanism of the red and green up-conversion, the possible mechanism and electron transition process were also discussed.
研究领域:
材料科学
·
无机化学
·
光功能材料
·
固体化学
·
发光物理
✓ 已验证
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2024
·
IF 9.4
Qijing Guo,Hao Yi,Feifei Jia,Shaoxian Song
Phase change materials (PCMs) offer significant advantages in energy conversion and storage by facilitating the storage and release of thermal energy during phase transition processes. However, challenges such as leakage during PCM phase transitions and poor light absorption properties have constrained their application in the field of photothermal energy storage. In this study, Montmorillonite (Mt) and molybdenum disulfide (MoS 2 ) has been used to design and synthesize hybrid aerogels (MoS 2 /Mt) boasting high mechanical strength and excellent photothermal conversion performance. These aerogels are then used to encapsulate polyethylene glycol (PEG) to prepare composite PCMs with outstanding solar-thermal conversion and storage performances. The results show that the synthesized MoS 2 /Mt-PEG composite PCMs exhibit high enthalpies of melting and solidification of 169.16 J/g and 170.78 J/g, respectively, while the aerogel supporting material has a high compressive modulus of 1.96 MPa. Moreover, the composite material displayed excellent thermal stability and leakage resistance after undergoing 30 melting-cooling cycles. Furthermore, the incorporation of MoS 2 imparted outstanding light absorption properties to the MoS 2 /Mt-PEG composite, resulting in a high light absorption and photothermal conversion-storage efficiency of 93.4 % and 96.47 %, respectively. Synthesized composite PCMs also demonstrate outstanding performance in solar-thermal-electricity conversion, achieving a voltage output of 458 mV under illumination conditions and maintaining a sustainable voltage output even after removing the light source. Thus, the composite PCMs prepared in this work can meet the requirements of high enthalpy, effective leakage prevention, efficient solar-thermal conversion and solar-thermal-electricity conversion performance, thereby presenting potential applications in practical solar energy collection, conversion, and storage.
研究领域:
材料科学
·
能源化学
·
纳米复合材料
·
热能存储
·
光热转换
✓ 已验证
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2017
·
IF 3.387
Hui Chen,Jinfeng Wang,Chenchen Jia,Junpeng Mou,Lei Zhu
For the purpose of increasing the power conversion efficiency (PCE) meanwhile decreasing the cost of dye-sensitized solar cell (DSSC), Cu 2 ZnSnS 4 - multiwall carbon nanotubes (CZTS-MWCNTs) nanohybrid Pt-free counter electrode (CE) was prepared via a facile fabricating route. In brief, CZTS nanoparticles were synthesized by a solvothermal method and the composite film was fabricated by spin coating the aqueous solution of the composite. The short-circuit current density and PCE of the DSSC with CZTS-MWCNTs CE were found to be 16.62 mA cm −2 and 9.04%, respectively. But the corresponding values were 15.42 mA cm −2 and 8.74% for a DSSC with a pure Pt-CE. This is owing to the synergistic effect of the intrinsic superior electrocatalytic activity of the CZTS nanoparticles and highly specific surface area and high electrical conductivity of the MWCNTs . The presence and distribution of CZTS-MWCNTs on the CE were characterized by X-Ray Diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and scanning electron microscope (SEM), respectively. Cyclic voltammetry (CV) and electrochemical impedance spectra (EIS) were examined for confirming the high electrocatalytic efficiency of this nanohybrid system.
研究领域:
材料科学
·
能源化学
·
纳米技术
·
电化学
·
光伏器件
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2023
·Vol. 50
·期 1
·1452-1460
·
IF 5.2
Shangwei Wang,Ran Pang,Xuexia Chen,Tao Tan,Qi Wang,Chengyu Li,Su Zhang,Taixing Tan,Hongpeng You,Hongjie Zhang
Near-infrared phosphor conversion light-emitting diode (NIR pc-LED) is a widely used ideal NIR light source due to its unique advantages of low cost, energy saving, compactness and long operational lifetime. However, there is currently a scarcity of appropriate phosphor for NIR light sources utilized in spectral detection, with emission peak larger than 850 nm and steady spectrum output of ultra broadband spectra. Here, a broadband Cr 3+ activated LiScSnO 4 (LSS) phosphor ( λ ex-max = 460 nm) matching the pump band of commercial blue LED chips has been developed, which shows a long wavelength NIR emission peaking at 900 nm. Cr 3+ simultaneously replace the Wyckoff site co-occupied by Sc and Sn in LSS. Due to the difference of local environment of the specific crystal field , two different wide emission bands are caused. These two broad emission bands both contribute to the broadband luminescence with a full width at half maximum (FWHM) of 227 nm. Benefiting from the crystallography consistent Wyckoff position occupation of Cr 3+ ions, the spectral distribution of LSS:Cr 3+ exhibit excellent stability over a wide temperature span (80–423 K). The broadband NIR pc-LED prototype based on LSS:Cr 3+ shows great potential in NIR spectrum detection, night vision imaging applications.
研究领域:
材料科学
·
光学工程
·
固态物理
·
光电子学
·
分析化学
✓ 已验证
DOI
高影响因子
危险品化学品经营许可证（带存储）