APPLIED CATALYSIS A-GENERAL
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2024
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IF 4.7
Lijiao Zhong,Xing Li,Yiquan Zhan,Yongsheng Liu,Kai Yang,Jinbiao Liu,Shiyong Liu,Junzhe Jiang,Liqing Li,Yoshihisa Sakata
Solar-driven hydrogen production through water splitting is currently one of the research hotspots nowadays. Lanthanum titanate (La 2 Ti 2 O 7 ) is one kind of layered-structure perovskite photocatalyst and possesses a superior electronic structure for photocatalytic overall water splitting. However, it suffers from several drawbacks, such as poor photo absorption and easy recombination of photogenerated charge carriers. In this study, sodium (Na) ion-doped La 2 Ti 2 O 7 with plate-like crystal morphology was synthesized by using molten salt synthesis (MSS). The XRD and TEM results indicated that the MSS method enhanced the crystallinity of La 2 Ti 2 O 7 . UV-vis, Raman and EPR spectra disclosed that Na doping through MSS introduced oxygen vacancies. The Na (0.3 mol%)-doped La 2 Ti 2 O 7 (MSS) provided the optimal hydrogen evolution rate, and the value was 6.43 times greater than that of pure La 2 Ti 2 O 7 synthesized by traditional solid-state reaction method. The synergistic effect of crystal facet engineering and defect engineering remarkably enhanced the photocatalytic activity of La 2 Ti 2 O 7 .
研究领域:
材料科学
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能源科学
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DOI
高影响因子
JOURNAL OF THE ELECTROCHEMICAL SOCIETY
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2021
·Vol. 168
·期 4
·043501
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IF 4.316
Kailiang Ren,Zeang Duan,Yuan Li,Lu Zhang,Shumin Han
LaFeO3 as a new negative electrode material for nickel-hydrogen batteries used as energy storage has the advantages of high capacity, advanced temperature resistance, and low cost. However, its conductivity and dynamic performance are poor, seriously hindering its applications. In light of increasing concentration of oxygen vacancies and improving conductivity after replacing A-site elements of the material, here we synthesize low-priced Na doping LaFeO3 oxides, La1−xNaxFeO3 (x = 0–0.8), as the negative electrode by a solid-state reaction method. Studies show that doping Na can reduce particle aggregation, thus helping to increase the surface area of LaFeO3. Therefore, its discharge capacity remarkably increases to 356.7 mAh g–1 (x = 0.6) from 178.8 mAh g–1 (x = 0) at 60 °C, which also maintains 73.4% after 100 cycles for La0.4Na0.6FeO3, elevated by 55.1% compared to LaFeO3. In addition, the high rate discharge ability of an La0.4Na0.6FeO3 electrode at a discharge current density of 1500 mA g–1 reaches 30.7% in contrast to 11.2% for undoped LaFeO3. As such, the La0.4Na0.6FeO3 material with superior cycling capacity is proven to be a more promising electrochemical hydrogen storage electrode compared to LaFeO3, which greatly increases the practical application value of the material.
研究领域:
材料科学
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电化学
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能源存储
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DOI
高影响因子
Journal of Physical Chemistry C
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2022
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IF 4.177
Zhenya Wang,Yang Yu,Weijin Kong,Lunhua He,Limei Sun,Xiangfeng Liu
Improving the electronic conductivity and lithium-ion diffusion ability is quite essential for Li4Ti5O12 (LTO) anode materials. Herein, we propose a synergistic strategy to facilitate Li+ insertion/extraction and conductivity by integrating Na2TiO3 coating, Na+ doping, and oxygen vacancy engineering. The rate capability (115 mAh/g vs 70 mAh/g at 5 C) and cyclic performance (91% retention vs 58% at 10 C after 500 cycles) have all been enhanced greatly, and the underlying modulation mechanism has been revealed. First, the Na2TiO3 coating layer mitigates the corrosion of the electrolyte and inhibits the side reactions between the electrode and electrolyte. Second, Na+ doping optimizes the crystal structure, expanding the lattice parameter as well as the unit cell volume and decreasing the bond length of Li1–O, which effectively facilitates Li+ diffusion. In addition, the introduction of oxygen vacancies promotes more Ti4+ to be reduced to Ti3+ and narrows the band gap of LTO material, thus improving the electronic conductivity. This “three-in-one” synergistic strategy sheds some new light on tuning crystal structure and electronic structure for designing high-performance electrode materials.
研究领域:
材料科学
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电化学
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DOI
高影响因子
Batteries-Basel
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2022
·Vol. 8
·期 8
·78
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IF 5.938
Dan Shao,Dewei Rao,Aihua Wu,Xiangyi Luo
Large cations such as potassium ion (K+) and sodium ion (Na+) could be introduced into the lithium-ion (Li-ion) battery system during material synthesis or battery assembly. However, the effect of these cations on charge storage or electrochemical performance has not been fully understood. In this study, sodium ion was taken as an example and introduced into the lithium titanium oxide (LTO) anode through the carboxymethyl cellulose (CMC) binder. After the charge/discharge cycles, these ions doped into the LTO lattice and improved both the lithium-ion diffusivity and the electronic conductivity of the anode. The sodium ion’s high concentration (>12.9%), however, resulted in internal doping of Na+into the LTO lattice, which retarded the transfer of lithium ions due to repulsion and physical blocking. The systematic study presented here shows that large cations with an appropriate concentration in the electrode would be beneficial to the electrochemical performance of the Li-ion battery.Keywords:lithium-ion battery;LTO anode;sodium doping;lithium-ion diffusivity
研究领域:
材料科学
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电化学
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DOI
高影响因子
ACS Applied Nano Materials
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2024
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IF 5.3
Hao Hu,Xia Zhao,Xiang Mao,Yongrun Dong,Wen Li,Zequan Li,Wei Gao
Room temperature phosphorescence (RTP) provides a longer and tunable afterglow time compared to conventional fluorescence, enabling complex information encryption effects. However, traditional RTP materials have a short afterglow, and acquiring the requisite raw materials is challenging. In this study, RTP carbon dots (CDs) were synthesized using a multifaceted method, achieving an extended lifetime of 743.55 ms. The afterglow duration of 23.5 s under 254 nm excitation. Additionally, the afterglow intensity was enhanced through Na doping. Notably, the B2O3 matrix confine the vibration and rotation of the CDs chromophores. Mechanisms such as hydrogen bonding and covalent bonding collectively mitigate nonradiative decay of the triplet exciton. Furthermore, the potential application of these materials in information encryption is demonstrated. This investigation serves as a valuable reference for enhancing the afterglow properties and applications of RTP-CDs.
研究领域:
材料科学
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光学
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DOI
高影响因子
Materials Express
·
2019
·Vol. 9
·期 8
·895-905
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IF 1.465
Yu Juan,Huang Wenlong,Meng Bicheng,Wang Lejie,Zhao Junkai,Li Linbo,Du Xiaoqing,Fang Zhao
Sodium ions have been successfully doped into LiNi0.8Co0.1Mn0.1O2 (NCM811) by solid phase method. The influences of Na doping on the electrochemical properties of the electrode at high current intensities were studied. The experimental results
show that 3% Na modified LiNi0.8Co0.1Mn0.1O2 has superior rate performance and cycling behavior due to the cation mixing is suppressed and the structural stability is enhanced by Na doping. The capacity retention of Li0.97Na0.03Ni0.8Co0.1Mn0.1O2
is 64.33% after 100th cycles at 10 C (1 C = 200 mA · g–1) in the potential range from 2.8 V to 4.3 V, which is greatly higher than the pristine NCM (only 35.01%). Li0.97Na0.03Ni0.8Co0.1Mn0.1O2 also shows
excellent rate performance of 140.5 mAh · g–1 at 10 C, and the discharge capacity of 3% Na-NCM is higher than that of the pristine NCM when the current intensity is returned from 10 C to 0.5 C. The analysis of the cyclic voltammetry (CV) and electrochemical impedance
spectroscopy (EIS) measurements confirm that the Na doping plays an important role in inhibiting the electrochemical polarization of LiNi0.8Co0.1Mn0.1O2 and improving the diffusion of lithium ions.
研究领域:
材料科学
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电化学
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DOI
高影响因子
Frontiers in Chemistry
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2020
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IF 3.693
Li Yujiao,Li Chen,Yu Huanqin,Yuan Beilei,Xu Fan,Wei Haoming,Cao Bingqiang
To regulate the optical and electrical properties of the crystals and films of the intrinsic methylammonium lead iodide (CH3NH3PbI3), we dope them with sodium (Na) by selecting sodium iodide (NaI) as a dopant source. The highly conductive p-type sodium-doped CH3NH3PbI3 (MAPbI3: Na) perovskite single crystals and thin films are successfully grown using the inverse temperature crystallization (ITC) method and antisolvent spin-coating (ASC) method, respectively. With the increase of Na+ doping concentration, the grain size of the film increases, the surface becomes smoother, and the crystallinity improves. Hall effect results demonstrate that both the MAPbI3: Na thin films and single crystals change their quasi-insulating intrinsic conductivity to a highly conductive p-type conductivity. The room-temperature photoluminescence (PL) peaks of doped MAPbI3 films slightly blue shift, while the photocarriers' lifetime becomes longer. The optical fingerprints of the doped levels in MAPbI3: Na perovskites can be identified by temperature-dependent PL. Obvious fingerprints of Na-related acceptor (A0X) levels in the doped MAPbI3: Na were observed at 10 K. These results suggest that sodium doping is an effective way to grow highly conductive p-type MAPbI3 perovskites.
研究领域:
材料科学
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物理化学
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产品关联
DOI
PubMed
高影响因子
RSC Advances
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2023
·Vol. 13
·期 7
·4729-4745
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IF 3.9
Kunyu Chen,Yiwei Huang,Meina Huang,Yanqiu Zhu,Ming Tang,Renjie Bi,Meiping Zhu
Photocatalytic oxidation (PCO) based on semiconductors offers a sustainable and promising way for environmental remediation. However, the photocatalytic performance currently suffers from weak light-harvesting ability, rapid charge combination and a lack of accessible reactive sites. Ultrathin two-dimensional (2D) materials are ideal candidates to overcome these problems and become hotpots in the research fields. Herein, we demonstrate an ultrathin (<4 nm thick) Na-doped BiOCl nanosheets with {001} facets (Na-BOC-001) fabricated via a facile bottom-up approach. Because of the synergistic effect of highly exposed active facets and optimal Na doping on the electronic and crystal structure, the Na-BOC-001 showed an upshifted conduction band (CB) with stronger reduction potential for O2 activation, more defective surface for enhanced O2 adsorption, as well as the highest visible-light driven charge separation and transfer ability. Compared with the bulk counterparts (BOC-010 and BOC-001), the largest amount of active species and the best photocatalytic performance for the tetracycline hydrochloride (TC) degradation were achieved for the Na-BOC-001 under visible-light irradiation, even though it had slightly weaker visible-light absorption ability. Moreover, the effect of the Na doping and crystal facet on the possible pathways for TC degradation was investigated. This work offers a feasible and economic strategy for the construction of highly efficient ultrathin 2D materials.
研究领域:
材料科学
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环境科学
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DOI
PubMed
高影响因子
Advanced Photonics Research
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2023
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IF 3.7
Yaoyu Liu,Tianyu Wang,Zongshuai Ji,Guanfeng Liu,Yunhe Chen,Xin Ding,Bing Teng,Shaohua Ji
Cs 3 Cu 2 Cl 5 is unstable owing to ionic migration and lattice decomposition in the atmosphere. In addition, obtaining large bulk single crystals of Cs 3 Cu 2 Cl 5 is challenging. Herein, a novel strategy is proposed for synthesizing a Cs 3 Cu 2 Cl 5 single crystal that exhibits excellent crystallinity and photoluminescence (PL) properties using an antisolvent-assisted method. Na + is doped into the Cs 3 Cu 2 Cl 5 lattice to replenish the lattice defects caused by chlorine vacancies, thus leading to stronger chemical interactions between Cu + and Cl − ions. Moreover, Na + doping circumvents ionic migration and lattice decomposition, thereby enhancing the PL intensity and maintaining the long-term stability of Cs 3 Cu 2 Cl 5 in the atmosphere. Incorporating 10% Na + into the Cs 3 Cu 2 Cl 5 lattice enhances the PL intensity by 18%, and the high-stability PL can maintain more than 48.5% of the PL intensity after 90 d in an atmospheric environment. In addition, a white light-emitting device (LED) is fabricated using the 10% Na + -doped Cs 3 Cu 2 Cl 5 crystal powder and it exhibits a high color-rendering index (93.7) and correlated color temperature (7120 K). Additionally, it exhibits superior stability, even at a high temperature of 120 °C. Thus, the excellent high-temperature stability of Cs 3 Cu 2 Cl 5 can promote its practical application in LED.
研究领域:
材料科学
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光学
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DOI
高影响因子
JOM
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2024
·Vol. 76
·期 8
·4169-4178
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IF 2.1
He Jie,Liu Jiaming,Yu Xiuyuan,Yang Chao,Liu Qingsheng
LiFePO 4 has become a mainstream cathode material, owing to its good safety and low price. However, its intrinsic limitations in terms of electronic and ionic conductivities hinder its further advancements. To overcome this challenge, element doping has been explored to enhance its conductivity. Here, Na and F co-doped LiFePO 4 /C was successfully synthesized via a carbothermic method. Structural characterization techniques were employed to confirm the formation of Li 0.97 Na 0.03 FePO 3.97 F 0.03 with controllable particle sizes. The incorporation of Na and F ions into the LiFePO 4 lattice results in a reduction of the Li-O bond energy. This decrease in bond energy facilitates the extraction and insertion of lithium ions during the charge and discharge processes, subsequently improving the overall kinetics of lithium-ion diffusion. Simultaneously, lattice distortion induced by doping led to charge compensation and accelerated Li + migration. Benefiting from the enhancement of intrinsic conductivity and Li + diffusivity, the specific capacitance of the co-doped LiFePO 4 /C cathode material was found to be 160 and 110 mAh g −1 at 0.1 and 5 C, respectively. Further, density functional theory calculations showed that Na/F co-doping enhanced the structural evolution in the material and increased free carrier concentration in LiFePO 4 . This work demonstrates that synergistic Na and F co-doping can optimize the rate performance of LiFePO 4 by enhancing intrinsic conductivity and Li + diffusivity, suggesting promising applications of the co-doped LiFePO 4 /C in high-power lithium-ion batteries for electric vehicles and grid-level energy storage systems.
研究领域:
材料科学
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电化学
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DOI
高影响因子
SENSORS AND ACTUATORS B-CHEMICAL
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2024
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IF 8
Xuan-Yu Yang,Hao-Nan Chen,Li-Juan Yue,Fei-Long Gong,Ke-Feng Xie,Shi-Zhong Wei,Yong-Hui Zhang
The design of novel functional nanostructures for advanced chemical engineering field is of great importance. In this work, Pd-modified Na-doped WO 3 nanorods are rationally designed for rapid and detection of hydrogen, which is a green and clean energy in modern industry. Notably, and H + as well as citrate ions play an important role in the formation of 1D nanorods, and the morphology formation mechanism is explored. Here, inspired by the novel Pd-modified Na-doped WO 3 nanorods structure, the Pd-400-Na/WO 3 NRs exhibit high sensing ability with ultra-high response to hydrogen (R a /R g = 218@25 ppm) and fast response time (3 s). The combination of experimental and theoretical results shows that Na doping effectively modulates the d-band center of Pd and enhances activation and desorption of H 2 on the Pd surface. The 1D porous structure also facilitates the diffusion of H 2 within the framework, and accelerate the charge transformation. Meanwhile, the surface Pd 0 sites are assigned as the surface active sites for H 2 adsorption and activation, and Pd 2+ sites facilitate the desorption process. Our work paves the new insights for the design of high performance H 2 sensing materials.
研究领域:
材料科学
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化学工程
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纳米技术
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DOI
高影响因子
Coatings
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2024
·Vol. 14
·期 2
·164
·
IF 2.9
Wanlei Dai,Zhaoyi Jiang,Yali Sun,Juhua Wang,Zeran Gao,Haoyu Xu,Xinzhan Wang,Chao Gao,Qiang Ma,Yinglong Wang,Wei Yu
In this study, a feasible strategy is proposed for directly depositing high-quality Cu(In,Ga)Se2(CIGS) films using Na-doped targets in a selenium-free atmosphere to boost the power conversion efficiency (PCE) of CIGS solar cells. Introducing a small amount of sodium dopant effectively promoted the textured growth of CIGS crystals in the prepared films, resulting in larger grain sizes and a smoother interface. The higher MoSe2content at the CIGS/Mo interface increased the carrier lifetime in the films. In addition, sodium doping increased the proportion of Se atoms on the film surface and reduced the concentration of defects caused by the direct sputtering of the films in the selenium-free atmosphere. Therefore, the separation and transportation of photo-generated carriers in the devices were effectively enhanced. Using the optimized parameters, a record-high PCE of 17.26% was achieved for the 7.5% Na-doped devices, which represents an improvement of nearly 63%.Keywords:Cu(In,Ga)Se2;sodium-doped targets;magnetron sputtering;solar cells
研究领域:
材料科学
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能源技术
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产品关联
DOI
高影响因子
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