Coatings
·
2022
·Vol. 12
·期 12
·1837
·
IF 3.236
Haotian Cai,Kamale Tuokedaerhan,Zhenchuan Lu,Renjia Zhang,Hongguo Du
In this article, we report the preparation of Al-doped ZrO2(AZO) thin films by the sol–gel method. The electrical properties, microstructure, and optical properties of AZO high-k gate dielectric films at different annealing temperatures were systematically investigated. XRD results confirm that the AZO film was amorphous at a temperature of 600 °C, and Al doping raises the crystallization temperature of ZrO2. AFM and FESEM show a smooth surface of AZO film without cracks. As the annealing temperature increased from 600 to 900 °C, all of the films had similar RMS roughness under 1 nm, the film thickness decreased accordingly, the bandgap value increased from 5.77 to 5.82 eV, the valence band shift (ΔEv) increased, and the conduction band shift (ΔEc) decreased. XPS analysis showed that silicates were formed at the AZO/Si interfacial layer. Electrical performance tests showed that high-temperature annealing can effectively improve the electrical properties, as shown by the increase in dielectric constant (k) and the decrease in flat-band voltage (ΔVfb). However, an increase in leakage current density with increasing annealing temperature was observed due to the decrease inΔEcand the appearance of crystallization caused by the increase in annealing temperature.Keywords:high-k gate dielectrics;sol–gel;Al-doped ZrO2;thin films
研究领域:
材料科学
·
电子工程
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DOI
高影响因子
IONICS
·
2020
·Vol. 26
·期 5
·2147-2156
·
IF 2.394
Wang Hongqiang,Yang Guangchang,Lai Feiyan,Chu Youqi,Zhang Xiaohui,Ma Zhaoling,Li Qingyu
Ni-rich oxide materials suffer poor rate capability and rapid capacity fading, which seriously hinder its further commercialization. In this study, an ultrathin Al 2 O 3 coating layer on surface of the LiNi 0.6 Co 0.2 Mn 0.2 O 2 (NCM) material was prepared with Al(OC 4 H 9 ) 4 in organic medium; the process followed by heat treatment achieves Al doping. The synergistic effect of surface modification and Al doping significantly enhances the capacity retention and rate performance, while the resistance to moisture is also improved. The coated sample with 2wt% Al 2 O 3 shows superior electrochemical performances with an initial capacity of 175 mAh g −1 at 1 C and a retention of 80% after 500 cycles, which is 10% higher than the uncoated raw materials. In addition, it delivers 152 mAh g −1 at 10 C, suggesting an excellent rate capability. The substitution of Al 3+ and the Al 2 O 3 protective layer facilitates ion diffusion dynamic characteristic and improves electrochemical stability.
研究领域:
材料科学
·
能源存储技术
✓ 已验证
DOI
高影响因子
SOLID STATE IONICS
·
2020
·
IF 3.107
Erqing Zhao,Yudi Guo,Yuan Xin,Guangri Xu
Nasicon-type Li 1+x Al x Ge 2-x (PO 4 ) 3 (x = 0–0.5) electrolytes have been prepared via a facile and economic method. All synthetic electrolyte samples show Nasicon structure and good crystallinity . The Al doping content has a great influence on the electrical conductivity of electrolyte. The electrolyte with the composition of Li 1.4 Al 0.4 Ge 1.6 (PO 4 ) 3 exhibits a highest electrical conductivity of 2.72 × 10 −4 S/cm at room temperature , which is mainly attributable to fewer impurity and dense electrolyte structure. The LiFePO 4 /Li cell assembled with this electrolyte delivers an initial specific discharge capacity of 127.86 mAh g −1 at a charge/discharge current density of 0.5C at 60 °C, which shows an excellent cycling performance with high discharge capacity of 131.2 mAhg −1 after 150 cycles. These results suggest that the Li 1.4 Al 0.4 Ge 1.6 (PO 4 ) 3 electrolyte is a potential electrolyte for all solid state lithium-ion battery.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
PHYSICA SCRIPTA
·
2024
·Vol. 100
·期 1
·015948
·
IF 2.6
Fucheng Yu,Zengguang Huang,Jinghong Zhang,Sihua Zhong
Cu3BiS3 has been considered as an attractive photovoltaic material due to its suitable bandgap, excellent photoelectric properties, abundant component elements and low toxicity. However, most of the reported Cu3BiS3 solar cells contain toxic components in other functioning layers such as CdS in electron-transport layers (ETLs). In this study, the Cu3BiS3 thin films were prepared by spin-coating method. We find that the CuCl concentration in precursor solutions has influences on both the optical bandgap and grain size of the Cu3BiS3 thin films, thus affecting the performance of solar cells. The optimal CuCl concentration is 0.91 M. Besides, Al doped TiO2 (ATO) and MoOx films are employed as ETLs and hole-transport layers (HTLs) respectively, constructing a totally non-toxic thin film solar cell. Moreover, it is demonstrated that the ratio (RAl:Ti) of Al source (Aluminum nitrate nonahydrate) to Ti source [Titanium diisopropoxide bis(acetylacetonate)] in the precursor solution of ATO and the thickness of MoOx have significant influences on solar cells. Moderate Al doping in ATO, e.g. RAl:Ti=1:50, can produce oxygen vacancies and accelerate the interfacial charge transfer, thus resulting in the increased short-circuit current density and fill factor. With the optimized Cu3BiS3 absorber, ETL and HTL, improved cell performances are observed comparted to the spin-coated Cu3BiS3 counterparts with CdS as ETLs in literature.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
Sustainable Energy & Fuels
·
2023
·Vol. 7
·期 4
·1027-1040
·
IF 5.6
Ke Gao,Xianglei Liu,Qi Wang,Zhixing Jiang,Cheng Tian,Nan Sun,Yimin Xuan
Solar thermochemical CO2 splitting has emerged as a promising strategy for solar fuel production to alleviate climate change challenges and reduce the energy crisis. However, traditional redox materials still suffer from low CO production, poor cycle stability, high operating temperature, and large temperature swing, leading to low solar-to-fuel efficiency. Herein, Ce- and Al-doped SrMnO3 perovskites are proposed for high-performance solar thermochemical CO2 splitting within moderate temperature swing (1350/1100 °C). Sr0.6Ce0.4Mn0.8Al0.2O3 demonstrates a remarkable CO yield of 799.34 μmol g−1, which is ∼6.67 times as high as that of benchmark CeO2. Fast CO2 splitting kinetics of SCMA20 is demonstrated by the CO peak production rate enhanced by 142% compared with undoped SrMnO3. The proposed Sr0.6Ce0.4Mn0.8Al0.2O3 also exhibits excellent stability with no obvious deactivation or degradation over multiple cycles. The ultrahigh CO yield can be attributed to lower oxygen vacancy formation (3.65 eV) and migration energy (2.14 eV) as confirmed by DFT calculations, and the transformation of the first-order reaction (F1) to the second-order reaction (F2) compared to SrMnO3. This work provides a new path for high-performance solar thermochemical CO2 splitting with high CO production, fast reaction kinetics, good cycling stability, moderate temperature swing, and high solar absorptance.
研究领域:
材料科学
·
能源化学
·
环境科学
✓ 已验证
产品关联
DOI
高影响因子
Journal of Energy Chemistry
·
2024
·
IF 14
Yueming Xia,Jianrui Feng,Jinhui Li,Yan Li,Zhengfeng Zhang,Xiaoqi Wang,Jianli Shao,Manling Sui,Pengfei Yan
Constructing robust surface and bulk structure is the prerequisite for realizing high performance high voltage LiCoO 2 (LCO). Herein, we manage to synthesize a surface Mg-doping and bulk Al-doping core-shell structured LCO, which demonstrates excellent cycling performance. Half-cell shows 94.2% capacity retention after 100 cycles at 3.0–4.6 V (vs. Li/Li + ) cycling, and no capacity decay after 300 cycles for full-cell test (3.0–4.55 V). Based on comprehensive microanalysis and theoretical calculations, the degradation mechanisms and doping effects are systematically revealed. For the undoped LCO, high voltage cycling induces severe interfacial and bulk degradations, where cracks, stripe defects, fatigue H2 phase, and spinel phase are identified in grain bulk. For the doped LCO, Mg-doped surface shell can suppress the interfacial degradations, which not only stabilizes the surface structure by forming a thin rock-salt layer but also significantly improves the electronic conductivity, thus enabling superior rate performance. Bulk Al-doping can suppress the lattice “breathing” effect and the detrimental H3 to H1-3 phase transition, which minimizes the internal strain and defects growth, maintaining the layered structure after prolonged cycling. Combining theoretical calculations, this work deepens our understanding of the doping effects of Mg and Al, which is valuable in guiding the future material design of high voltage LCO.
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
高影响因子
JOURNAL OF THE SCIENCE OF FOOD AND AGRICULTURE
·
2022
·Vol. 102
·期 11
·4714-4723
·
IF 4.125
Ke Cheng,Jianghua Zhang,Shasha Yang,Fawen Yin,Zixuan Li,Ting Wang,Dayong Zhou
BACKGROUND Efficient and sustainable production of structured phospholipids (SPLs) enriched in medium-chain fatty acids (MCFAs) in a heterogeneous manner is crucial for their potential applications in functional foods and drugs. Herein, for the first time, Zn- and Al-incorporated SBA-15 silicas were prepared by the coprecipitation method and further researched for catalytic synthesis of MCFA-enriched SPLs through acidolysis reaction of natural phospholipids with capric or caprylic acid. RESULTS The as-prepared Zn- and Al-incorporated SBA-15 samples exhibited superior catalytic activities under mild experimental conditions (50 °C, 6 h) to commercial homogeneous Lewis acids and benchmark enzymes. Correspondingly, the capric acid and caprylic acid incorporations were respectively achieved up to ~40.25 ± 0.40% (or 35.08 ± 0.09%) and 37.26 ± 0.38% (or 33.02 ± 0.13%) for Zn- (or Al-) incorporated SBA-15 catalyst. Moreover, various methods such as scanning electron microscopy with energy-dispersive X-ray spectrometry, ultraviolet–visible diffuse reflectance spectroscopy and pyridine–Fourier transform infrared spectroscopy were utilized to characterize the two catalysts in order to elucidate the possible structure–performance relationship. Accordingly, the above-mentioned satisfactory results are most probably due to the well-ordered mesostructures and large amounts of active Lewis acid sites existing in the investigated materials. Noticeably, the two catalysts featured good separation and excellent recyclability as well. CONCLUSION The Zn- and Al-incorporated SBA-15 catalysts studied in this work might shed light on novel, sustainable and economic alternatives for effective SPL production to diminish the applications of conventional homogeneous catalysts and biocatalysts in food industries. © 2022 Society of Chemical Industry.
研究领域:
食品科学
·
生物化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHIMICA ACTA
·
2015
·
IF 4.504
Jianmeng Chen,Yijing Xia,Qizhou Dai
This study presents an electrochemical method for the degradation of chloramphenicol (CAP) in aqueous solution with a novel Al doped PbO 2 electrode. The Al-doped PbO 2 electrode showed high electrochemical activity, oxygen evolution potential, radical utilization rate, reusability and safety. The influence factors on CAP degradation with the Al-doped PbO 2 electrode were investigated in detail, and under the optimal conditions the removal rates of CAP and TOC reached 87.30% and 52.06% in acid conditions after 2.5 h electrolysis with a 0.2 mol dm −3 Na 2 SO 4 at a current density of 30 mA cm −2 , respectively. The electrochemical degradation of CAP at Al-doped PbO 2 electrode electrode followed pseudo-first-order kinetics. The degradation mechanism was proposed by cyclic voltammograms tests and it was deduced that hydroxyl radicals generated in the electrochemical process played a key role in oxidizing CAP. Finally, based on the reaction products identified, a possible degradation pathway including radical reaction, ring open and mineralization was proposed.
研究领域:
环境科学
·
电化学工程
✓ 已验证
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2022
·
IF 5.532
Zhiyu Ma,Weijia Guo,Zhenxing Yue
TiO 2 -added Ba 4 (Sm 0.65 Nd 0.35 ) 9.33 Ti 17.75 Al 0.33 O 54 (BSNTA) ceramics were fabricated with a solid-state reaction method. Slight TiO 2 addition increased the dielectric constant ( ε r ) of BSNTA ceramics and brought about a near-zero temperature coefficient of resonant frequency ( τ f ). Sintering in oxygen increased the density of TiO 2 -added BSNTA ceramics and surprisingly concurrently improved the ε r and Q × f value. Thermally stimulated depolarization current (TSDC) measurements indicated that TiO 2 addition introduced oxygen vacancies ( V O .. ) and Ti Ti ' − V O .. defect dipoles and that an oxygen-sufficient sintering atmosphere decreased the concentration of these defects and thus increased Q × f values. From the viewpoint of defect behaviors, this observation offered original insight into the mechanism by which the sintering atmosphere had impacts on the Q × f value of titanate ceramics. Satisfying dielectric properties ( ε r = 79.5, Q × f = 14,840 GHz, τ f = 0 ppm/°C) were attained in oxygen-sintered BSNTA-0.6%TiO 2 ceramics that might be suitable for the manufacture of miniature microwave devices such as filters and antennas.
研究领域:
材料科学
·
电子工程
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Qi Chen,Xinjian Li,Yao Wang,Jian Wang,Lijie Chang,Yuewen Zhang,Hongan Ma,Xiaopeng Jia
ZnO has excellent electrical properties such as high conductivity ( σ ) and Seebeck coefficient (S) that are important for its thermoelectric properties and have provided the basis for obtaining improved ZnO-based thermoelectric materials by doping. In particular, the most representative Al-doped ZnO (AZO) has excellent thermoelectric performance. Although the Al doping is beneficial for reducing the lattice thermal conductivity of ZnO, the solubility of Al 2 O 3 in ZnO is limited and excessive doping of Al gives rise to the generation of a large amount of the ZnAl 2 O 4 secondary phase that limits the further improvement of the electrical properties. Thus, it is crucial to develop approaches to reduce thermal conductivity while still maintaining high electrical properties. In this work, high pressure and high temperature (HPHT) synthesis was used to adjust the ZnO optical band gap by modifying the lattice parameters of ZnO, and thereby improving the electrical properties of the sample. It was found that the optimal doping content for the samples synthesized at high pressure is different from that of the samples synthesized at normal pressure, providing a new approach for the further improvement of the thermoelectric properties of ZnO. Additionally, high pressure can promote grain refinement that is conducive to the generation of the multi-scale hierarchical structure of the sample that introduces a variety of phonon scattering mechanisms to reduce the thermal conductivity while maintaining a high power factor. The Zn 0.96 Al 0.04 O material obtained by sintering at a pressure of 3 GPa and a temperature of 1053 K for 30 min reached the highest power factor (7.8 µW cm −1 K −2 ) and the highest zT (0.16) at 973 K.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY A-CHEMISTRY
·
2016
·
IF 2.477
Ran Li,Yin Zhao,Ruien Hou,Xin Ren,Shuai Yuan,Yanyan Lou,Zhuyi Wang,Dongdong Li,Liyi Shi
The optimization of charge transfer at the TiO 2 /dye/electrolyte interface is crucial to the design of dye-sensitized solar cells. In this paper, the Al doped TiO 2 layers were coated on the mesoporous TiO 2 films by a chemical bath deposition process, followed by sintering at 500 °C. Its performance as the TiO 2 /dye/electrolyte interface layer was investigated. The analysis results reveals that the Al doped TiO 2 coating can reduce the oxygen vacancy-Ti 3+ concentrations in the photoanodes significantly, which is beneficial to suppress the back electron transfer process from TiO 2 to electrolyte. Furthermore, the electron mobility of the modified photoanodes was increased. Consequently, the dye sensitized solar cells (DSSC) based on the photoanodes modified by Al-doped TiO 2 coating show an improvement on both enhancing the electron transport and suppressing the charge recombination process. The dye sensitized solar cell based on the photoanode modified by 1.0 mol% Al-doped TiO 2 layer, shows a power conversion efficiency as high as 7.66%, increasing 9.12% compared with the unmodified reference cell. Finally, our works show a facile and scalable technique to further optimize interfacial charge transfer process in dye sensitized solar cells.
研究领域:
材料科学
·
能源科学
✓ 已验证
产品关联
DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
·
2021
·
IF 7.46
Xu Tian,Lijia Yao,Xiuxiu Cui,Rongjun Zhao,Xuechun Xiao,Yude Wang
Fast and effective detection of harmful gases is crucial criterion for the current development of gas sensors. In this paper, a novel n-butanol gas sensor using Al-doped CdIn 2 O 4 nanofibers (ACO NFs) is synthesized by an electrospinning method . The different morphologies of the as-prepared ACO NFs are controlled by doping different Al contents . Systematic characterizations demonstrate that the doping of Al to CdIn 2 O 4 NFs would enhance the reaction activities between the gas and sensing materials, such as generating large amounts of adsorbed oxygen and improving the specific surface area of sensing materials. The results show that the detection limit of all prepared sensors for n-butanol is sub-ppm, and less than 250 ppb. The optimal Al-doped CdIn 2 O 4 (5.0% Al/Cd molar ratio) based gas sensor results in 3.32-fold enhancement in gas response to 200 ppm n-butanol at an operating temperature of 300 °C and exhibits excellent long-term stability compared with the pure CdIn 2 O 4 . Hence, ACO NFs can be regarded as a promising sensing material for low-concentration n-butanol gas detecting. Also, the mechanisms for improving the sensing performance of ACO NFs based gas sensor are proposed.
研究领域:
材料科学
·
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）