MODERN PHYSICS LETTERS B
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2024
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IF 1.8
Jiaqi Li,Jianyu Li,Bin Xu,Zhiyi Ren,Shixiao Yan,Di Zhang,Meng Wang,Xiaoliang Sun,Chi Liu,Jing Feng
This work aims to investigate the influence of Ca 2 + doping on the infrared emission properties of DyTa 3 O 9 ceramics. DyTa 3 O 9 is considered a promising high-temperature thermal protection material due to its low thermal conductivity and good high-temperature stability. However, there is currently no research on the infrared radiation performance of such materials. We synthesized DyTa 3 O 9 ceramics with different Ca 2 + doping concentrations using the solid-phase reaction method and systematically investigated the effect of doping concentration on the infrared emissivity of DyTa 3 O 9 ceramics. When Ca 2 + is doped into the DyTa 3 O 9 lattice, the original Dy elements are replaced by Ca, resulting in an increase in lattice constants and enhanced lattice distortion. The doping of Ca 2 + introduces impurity energy levels, making it possible for some low-energy electron transitions, achieving an enhancement in infrared absorption and emission capabilities. When the Ca 2 + doping concentration reaches 7.5% mol, the average infrared emissivity in the 3–5 μ m and 8–12 μ m ranges are 0.85 and 0.92, respectively, representing a 19.7% and 21% increase compared to DyTa 3 O 9 . This novel high-infrared-emissivity ceramic holds great potential for applications in high-temperature energy conservation and aerospace thermal protection.
研究领域:
材料科学
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陶瓷材料
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光学材料
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2024
·
IF 5.1
Wei Meng,Xiaoyan Fu,Chunqing Fu,Wenzhi Sun,Changsheng Wang,Hongwu Zhang
Here, we have developed a novel ultra long ultraviolet-A afterglow material CaMgGeO 4 : Bi 3+ , which shows more than 24 h UVA afterglow emission peaked at 346 nm. The crystal structure shows that the prepared sample is a pure phase with an orthogonal system of Pmnb space group. The composition of valence band and conduction band was analyzed by the density of states , which reveals that the bandgap of the CaMgGeO 4 matrix is 3.69 eV. The photoluminescence spectrum of the sample consists of a broadband in the 320–400 nm UVA region, which belongs to the 3 P 1 → 1 S 0 electron transition of Bi 3+ . More importantly, under the excitation of ultraviolet lamp for 3 min, CaMgGeO 4 : Bi 3+ exhibited an UVA ultra long persistent luminescence (LPL) with a duration of more than 24 h, which afterglow emission intensity still reaches 1500 cps and is about 6 times of the background intensity. In addition, the UVA emission of CaMgGeO 4 : Bi 3+ after 13 h day can be repeatedly by short periods of low-energy light sources stimulation. The thermoluminescence analysis indicates that the presence of shallow and deep traps is responsible for excellent UVA-LPL and photo-stimulate luminescence (PSL). The excellent LPL and PSL properties can prompt CaMgGeO4: Bi 3+ phosphor to be widely used in the field of photodynamic therapy.
研究领域:
材料科学
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光学
✓ 已验证
DOI
高影响因子
SEPARATION AND PURIFICATION TECHNOLOGY
·
2025
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IF 9
Yang Zhang,Caihao Wang,Ning Cao,Yang Liu,Chaocheng Zhao,Yongqiang Wang,Shaobin Wang,Jinqiang Zhang
Symmetrical planar unit cells and periodic layered structures of polymeric photocatalysts are the roots of poor light absorption and severe carrier recombination in photochemical process, which in turn diminish redox capabilities during photocatalytic overall water splitting. In this study, we synthesized porous and curled carbon nitride nanosheets (U-A400) featuring imperfect molecular structures through polycondensation of an asymmetric precursor molecule and a soft template. The twisted framework in U-A400 promoted strong n → π* electron transitions, generating a considerable built-in electrical field and prolonging the average fluorescence lifetime. Additionally, the structural distortion increased the number of surface acid-base active sites. Consequently, these adjustments in the micro- and topological structures rendered U-A400 highly effective for photocatalytic overall water splitting, achieving H 2 and O 2 average evolution rates of 65.93 and 38.53μmol g −1 h −1 , respectively, over 4 h of visible light (λ > 420 nm) irradiation, 38 times higher than those of graphitized carbon nitride. This work presents valuable insights into the development of advanced polymeric photocatalysts, efficiently harnessing sunlight for overall water splitting, thereby contributing to sustainable energy conversion and clean fuel production.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
Alexandria Engineering Journal
·
2025
·
IF 6.8
Wenliang Fan,Qinliang Gao,Yingying Yang,Ligang Wang,Yanlai Wang,Haiyan Yao
In order to discuss the intermediate band (IB) formation mechanism, influence on photoelectric conversion, electron transition process and other photovoltaic properties of Ti-doped p-CuGaS 2 light absorption material, p-CuGaS 2 and Ti-doped p-CuGaS 2 were synthesized through low-cost heat injection and annealing. Structural characterization results indicate that Ti 3 + partially replaced Ga 3+ in the Ti-doped p-CuGaS 2 . Two additional sub-band absorption peaks of Ti-doped p-CuGaS 2 confirm the formation of an IB. The band structures are confirmed by optical analysis and ultraviolet photoelectron spectroscopy, and the electron transition processes—from the valence band (VB) to the conduction band (CB), the valence band (VB) to the IB, and the IB to the conduction band (CB)—are analyzed. The IB formation mechanism is discussed using the band structure and theoretical calculations derived from density functional theory. A thin-film solar-cell model with Ti-doped p-CuGaS 2 as the absorbing layer is created. Numerical simulations based on experimental data show that the photoelectric conversion efficiency increase from 15.06 % for CuGaS 2 to 25.46 % for Ti-doped p-CuGaS 2 because of the IB effect, which enhances the optical absorption and extends the spectral response range. In conclusion, the research findings will establish a fundamental basis for the exploration of intermediate-band solar cells based on copper gallium sulfide.
研究领域:
材料科学
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光伏技术
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理论计算
✓ 已验证
产品关联
DOI
高影响因子
PHYSICA STATUS SOLIDI B-BASIC SOLID STATE PHYSICS
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2025
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IF 1.8
Jiahuan Zhu,Ruonan Miao,Huaxin Wu,Xueli Sun,Jiyang Fan
A semiconductor–molecule interface acts as a quasi-two dimensional system with fruitful physics. Up to date, how the surface or interface affects the photophysical properties of the ZnO nanocrystals (NCs) is still under debate. Here, we fabricate the ideally surface-passivated colloidal ZnO NCs, which exhibit nearly pure exciton-stemmed UV emission. The nitrogen atoms of amino-moiety of the long-chain oleylamine groups passivate the ZnO NC surfaces and cause complete vanishing of the green emission exhibited in the un-passivated ZnO NCs and usually observed in various kinds of ZnO nanostructures. It is found that the arising and disappearance of the green emission are reversible by breaking and recovering the optimal surface passivation. The green emission of these ZnO NCs originates from the electronic transition from the conduction-band delocalized state to surface-localized state.
研究领域:
材料科学
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光学
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纳米技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
·
2023
·Vol. 34
·期 10
·1-9
·
IF 2.8
Xue Ying,Wang Zhuo,Li Yanxin,Yi Zhihui,Li Xin,Wu Dan
The abundant requirements of smart terminals promote the rapid development of dielectric materials to further realize the integration and miniaturization of electronic devices. In this work, based on a solid-state reaction method, (In 0.5 Ta 0.5 ) 0.1 Ti 0.9 O 2 (ITTO) ceramics with dense microstructure, colossal permittivity of 1.18 × 10 5 , and ultralow dielectric loss of 0.0072 were obtained at 1 kHz and room temperature. In addition, the temperature coefficient stability and range of the ITTO ceramics were between ± 3.3% and − 100 to 235 °C, satisfying X9D (− 55 to 200 °C, Δ ε r / ε 25°C < ± 3.3%) requirement at 1 kHz. The dielectric mechanisms could be connected to the electron hopping and internal barrier layer capacitor (IBLC) effects. Thus, the acquired ITTO ceramics have advanced advantages with excellent dielectric properties and temperature stability in the practical applications of microelectronic fields.
研究领域:
材料科学
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电子工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry C
·
2021
·Vol. 10
·期 2
·665-671
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IF 7.393
Dandan Gao,Jiyang Xie,Jian Wang,Wanbiao Hu
It is widely accepted that localized electron hopping induces colossal permittivity in the bulk of transition-metal-based materials. However, the mechanism and the control of the electron hopping process remain to be explored. In this work, the effect of the B-site environment and multiple Cu valence-states on electron hopping were experimentally revealed in the LiCuNb2.95M0.05O9 (M = Mg, Ti) systems. The results demonstrated that Mg/Ti substitution for Nb5+ at the B-site effectively causes multivalent states of A-site Cu cations, i.e. Cu+/Cu2+/Cu3+, and distorted NbO6 octahedra. Upon Mg/Ti substitution, the dielectric permittivity was enhanced by approximately two orders of magnitude (at 1 kHz and 300 K) and an additional dielectric relaxation was induced. More importantly, it was revealed that the B-site substitution effectively adjusted the activation energy and average distances for the electron hopping.
研究领域:
材料科学
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凝聚态物理
✓ 已验证
DOI
高影响因子
CHINESE JOURNAL OF CATALYSIS
·
2020
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IF 6.146
Feiyue Ge,Shuquan Huang,Jia Yan,Liquan Jing,Feng Chen,Meng Xie,Yuanguo Xu,Hui Xu,Huaming Li
Expanding the optical absorption range of photocatalysts is still a key endeavor in graphitic carbon nitride (g-C 3 N 4 ) studies. Here, we report on a novel thiophene group extending the optical property, which is assigned to n-π* electronic transitions involving the two lone pairs on sulfur (TLPS). The as-prepared samples, denoted as CN-ThA x (where x indicates the amount of ThA added, mg), showed an additional absorption above 500 nm as compared to pristine g-C 3 N 4 . Further, the thiophene group enhanced charge carrier separation to suppress e − /h + pair recombination. The experimental results suggest that the thiophene group can obstruct the polymerization of melem to generate a large plane, thus exposing the lone electron pairs on the sulfur. The photocatalytic activity was evaluated in the decomposition of bisphenol A and H 2 evolution. Compared with g-C 3 N 4 , the optimized CN-ThA 30 sample led to a 6.6- and 2-fold enhancement of the degradation and H 2 generation rates, respectively. The CN-ThA 30 sample allowed for synchronous H 2 production and BPA decomposition.
研究领域:
材料科学
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环境科学
✓ 已验证
产品关联
DOI
高影响因子
ENVIRONMENTAL SCIENCE & TECHNOLOGY
·
2024
·
IF 10.8
Jianqiao Xu,Junyan Wei,Jiayu Zhang,Zhicheng Xing,Zunyao Wang,Ruijuan Qu
Dissolved organic matter (DOM) can affect the transformation of pollutants through photosensitization, but most current research focuses on hydrophilic pollutants, making it such that less attention is paid to hydrophobic pollutants. In this paper, the effect and action mechanism of coexisting DOM on the photodegradation of decachlorobiphenyl (PCB-209) on suspended particles collected from the Yellow River were systematically investigated in a heterogeneous system using DOM standards and model compounds. Through molecular probe experiments, mass spectrometry analysis and theoretical calculations, we found that the excited triplet state of DOM (3DOM*) could excite PCB-209 to undergo dechlorination reaction. Due to the different modes of electron transition, the presence of carbonyl groups decreased the energy of 3DOM*, whereas the electron-donating groups made the energy of 3DOM* higher. DOM containing phenolic hydroxyl groups led to a higher steady-state concentration of •OH, and DOM containing phenyl ketone structures had a stronger ability to produce •O2–. Compared with aqueous •OH, •O2– produced from hydrophobic microregions could react more readily with PCB-209. This study deepens the understanding of the role of different functional groups of DOM in the photosensitized transformation of hydrophobic compounds.
研究领域:
环境科学
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理论化学
·
污染生态学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2024
·Vol. 34
·期 34
·2401860
·
IF 18.5
Guojun Zhou,Yanting Wang,Yilin Mao,Caihong Guo,Jian Zhang,Maxim S. Molokeev,Zhiguo Xia,Xian-Ming Zhang
Hybrid metal halides (HMHs) have emerged as a promising platform for optically functional crystalline materials, but it is extremely challenging to thoroughly elucidate the electron transition coupled to additional ligand emission. Herein, to discover sequences of lead-free HMHs with distinct optically active metal cations are aimed, that is, Sb 3+ (5s 2 ) with the lone-pair electron configuration and In 3+ (4d 10 ) with the fully-filled electron configuration. (Me 2 NH 2 ) 4 M Cl 6 ·Cl (Me = −CH 3 , M = Sb, In) exhibits the superior temperature/component-dependent luminescence behaviors resulting from the competition transition between triplet-states (T n -S 0 ) self-trapped excitons (STEs) of inorganic units and singlet-state (S 1 -S 0 ) of organic cations, which is manipulated by the optical activity levels of [SbCl 6 ] 3− and [InCl 6 ] 3− . The bonding differences between Sb 3+ /In 3+ and Cl − in terms of electronic excitation and hybridization are emphasized, and the different electron-transition mechanisms are established according to the PL spectra at the extreme temperature of 5 to 305 K and theoretical calculations. By fine-tuning the B-site Sb 3+ /In 3+ alloying, the photoluminescence quantum yield (PLQY = 81.5%) and stability are optimized at 20% alloying of Sb 3+ . This research sheds light on the rules governing PL behaviors of HMHs, as well as exploring the optical-functional application of aviation temperature sensors and access-control systems.
研究领域:
材料科学
·
光学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2021
·
IF 9.676
Xiangang Lin,Haiwei Du,Daochuan Jiang,Peng Zhang,Zhiwu Yu,Hong Bi,Yupeng Yuan
The n-π* electronic transition in polymeric carbon nitride (PCN) can remarkably harvest visible light, which thus potentially promotes the photocatalytic hydrogen H 2 generation. However, awaking the n-π* electronic transition has proven to be a grand challenge. Herein, we reported on the awakening of n-π* electronic transition by microwave thermolysis of urea pellet, which yielded the PCN with absorption edge of 600 nm, near 140 nm red-shift from 460 nm of pristine PCN. The n-π* electronic transition endows PCN with an increased photocatalytic H 2 generation, with a highest H 2 rate of 61.7 μmol h −1 under visible light exposure, which is near 6 times higher than that by using the PCN from the thermolysis of urea pellets in an electric furnace (10.6 μmol h −1 ). Furthermore, the n-π* transition in PCN leads to the longest wavelength of 535 nm that can initiate H 2 generation, remarkably longer than the absorption edge of pristine PCN (460 nm). This work manifests the advantages of microwave sintering route to awaken the n-π* electronic transition in PCN for an increased photocatalytic performance.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Yan Chen,Yingpeng Cheng,Yue Liu,Yaqian Wang,Yi Qu,Daochuan Jiang,Zhaozhao Qin,Yupeng Yuan
The presence of short-lived shallow trapping states in semiconductor-based photocatalysts hinders efficient utilization of charge carrier, which compromises the solar-to-hydrogen efficiency. Here, we presented an engineered graphitic carbon nitride (g-CN) nanosheets with long-lived shallow trapping states achieved through an n-π * electronic transition. This transition induces a significant red-shifted absorption edge at 600 nm, effectively extending the range of light absorption compared to pristine g-CN. Moreover, the engineered g-CN nanosheets exhibit lower exciton binding energies (36 meV) compared to pristine counterparts (50.1 meV), as revealed by temperature-dependent photoluminescence (PL) spectra. Femtosecond transient absorption spectroscopy (fs-TAS) confirms the presence of long-lived shallow trapping states (lifetime: 565.8 ps) in the engineered g-CN nanosheets. These states enable a greater participation of photoinduced electrons in photocatalytic reactions, resulting in significantly enhanced photoactivity. Notably, the g-CN sample with the n-π * transition achieves a remarkable photocatalytic H 2 production rate of 61.8 µmol h −1 , which is a fivefold enhancement over pristine g-CN nanosheets. These findings highlight the crucial role of the n-π * transition in g-CN for prolonging shallow electron trapping and ultimately leading to superior photocatalytic performance.
研究领域:
材料科学
·
能源化学
✓ 已验证
产品关联
DOI
高影响因子
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