JOURNAL OF MATERIALS SCIENCE-MATERIALS IN ELECTRONICS
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2022
·Vol. 33
·期 26
·20981-20991
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IF 2.779
Yan Gui-wei,Liu Qing-qing,Fang Bi-jun,Chen Zhi-hui
Mg doped (Ba 0.98 Li 0.02 )TiO 3 energy storage ceramics with antiferroelectric-like double hysteresis loops were prepared using solid-state reaction method. XRD patterns indicated that tetragonal phase structure of the pure (Ba 0.98 Li 0.02 )TiO 3 ceramic was destroyed and the orthorhombic phase structure appeared with Mg doping. The ratio of orthorhombic/tetragonal phase increased with Mg content increasing, and the value of polarization was in direct proportion to the ratio of orthorhombic/tetragonal phase. The breakdown strength of (Ba 0.98 Li 0.02 )(Mg x Ti 1− x )O 3 ceramics was improved from 60.97 kV/cm at x = 0 to 103.66 kV/cm at x = 0.04. The optimum energy storage properties of (Ba 0.98 Li 0.02 )(Mg x Ti 1− x )O 3 ceramics were obtained with energy storage density of 0.76 J/cm 3 at 102.5 kV/cm when x = 0.04, which is nearly 2.3 times larger than the pure (Ba 0.98 Li 0.02 )TiO 3 ceramic, and the energy storage efficiency was improved from 64 to 87%.
研究领域:
材料科学
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物理学
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DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2022
·
IF 24.319
Guoan Lin,Xiaoqin Sun,Xiaoxiang Xu
LaTiO 2 N is modified by Mg doping to construct solid solution series, i.e ., LaTi 1−x Mg x O 2+y N 1−y (0 ≤ x ≤ 0.5). This modification effectively decreases the defect concentration (particularly bulk Ti 3+ species and anion vacancies), increases the surface hydrophilicity, positively shifts the valence band top albeit it also enlarges the bandgap and induces Ti/Mg ordering when x ≥ 0.2. These competitive tensions render an optimal composition at LaTi 0.9 Mg 0.1 O 2+y N 1−y (x = 0.1) where both a low defect concentration and a disordered state of Ti/Mg can be reached, demonstrating much-improved photocarrier separation and exceptional photocatalytic activity with apparent quantum efficiency as high as 13.02 % at 420 ± 20 nm for O 2 -evolution. Overall water splitting (H 2 /O 2 molar ratio = 2/1) with good recycling stability has been realized by integrating LaTi 0.9 Mg 0.1 O 2+y N 1−y into a Z-scheme system. These findings justify the efficacy of Mg as a useful modulator to improve the photocatalytic performance of metal oxynitrides.
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
APPLIED CATALYSIS B-ENVIRONMENTAL
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2023
·
IF 22.1
Lin Yang,Zhuo Li,Xiaoxiang Xu
With a light absorption up to 740 nm, BaNbO 2 N is promising for solar water splitting but normally owns a low activity due to a high defect concentration. Here, Mg is adopted as a dopant to modify the BaNbO 2 N. The presence of Mg not only reduces the defect concentration and enhances surface hydrophilicity but also tunes the bandgap as well as the band edge positions. These modifications greatly promote the charge separation and transfer of BaNbO 2 N, boosting the photocatalytic activities for O 2 -evolution reactions. An apparent quantum efficiency of 1.65 % at 420 ± 20 nm has been attained for Mg modified BaNbO 2 N. Overall water splitting at a stable gas-evolution rate (∼ 2.0 μmol·h −1 for H 2 and ∼ 1.0 μmol·h −1 for O 2 ) has been realized by integrating Mg-modified BaNbO 2 N into a Z-scheme system. These findings justify Mg as an effective dopant to modulate the photocatalytic behavior of Nb-based perovskite oxynitrides.
研究领域:
材料科学
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能源化学
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DOI
高影响因子
ACS Sustainable Chemistry & Engineering
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2024
·
IF 7.1
Rui Huang,Shaohua Luo,Pengyu Li,Qi Sun,Guodong Hao,Jie Feng,Lixiong Qian,Shengxue Yan,Jing Guo
Mn-rich ternary cathodes are highly regarded as a potential option for sodium-ion batteries (SIBs) due to their low cost and high theoretical capacity. Nonetheless, cycling stability was hindered by the occurrence of high-voltage phase transitions. In this work, Na0.67(Ni0.1Mn0.8Fe0.1)1–xMgxO2 (NaNMF-Mgx) cathode materials with high-voltage zero-phase transitions property were successfully synthesized. Amazingly, it was found that there was a valuable strengthening in the occupancy of stabler Nae sites by employing the Mg-doping strategy; and the calculation highlighted excellent structural stability and conductivity of NaNMF-Mg0.04, which has the lowest thermodynamic formation energy and a narrow band gap. The combination of theory and experiment demonstrated the underlying mechanisms of Mg substitution. Especially, Mg doping had the potential to regulate Nae/Naf ratio, and the ratio of NaNMF-Mg0.04 reached the maximum, indicating its most remarkable “rich-Nae” effect. Moreover, ex-situ XRD and ADF-STEM certified that NaNMF-Mg0.04 cathode maintained an intact P2 phase structure during high-voltage charging process. The “rich-Nae” and “zero-phase transitions” effects enabled NaNMF-Mg0.04 cathode to express remarkable initial capacitance (119.5 mAh g–1, 0.1 C), stability (80.0% over 200 cycles), and energy density (356.5 Wh kg–1). This unique mechanism provided fresh insights into revisiting the relationship between structure and performance and might open up a new idea for designing novel Mn-rich ternary cathodes with zero-phase transitions property in the future.
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
CHEMOSPHERE
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2021
·
IF 7.086
Fang Zhu,Siyi Zhou,Mengying Sun,Jianfeng Ma,Wei Zhang,Kunjie Li,Hao Cheng,Sridhar Komarneni
Mg doped Ni(OH) 2 was synthesized and investigated as an efficient material to activate persulfate (PS) for phenol degradation. The property of the Ni(OH) 2 material was enhanced by Mg doping as the removal efficiency of phenol was increased from 74.82 % in Ni(OH) 2 /PS system to 89.53 % in Mg-doped Ni(OH) 2 /PS system within 20 min. Such a high removal efficiency revealed that doping Mg into Ni(OH) 2 brings about more defects (oxygen vacancies), which facilitated the formation of more active species in the degradation process. The removal efficiencies of phenol increased with the increase of the initial pH from 3 to 11. The influences of Cl − , NO 3 − and HCO 3 − on the stability of the system were also studied and the results showed that removal rates of all systems in the presence of these different inorganic anions could reached about 90 % within 20 min. Based on the electron spin resonance (ESR) experiments, 1 O 2 , O 2 ·- , ·OH and SO 4 •− were identified as the active species in Mg-doped Ni(OH) 2 /PS system for phenol degradation and a degradation mechanism was proposed for this system. In addition, the as-prepared material retained its activation performance even after 3 repeated cycles.
研究领域:
环境科学
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化学工程
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产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2022
·Vol. 12
·期 6
·899
·
IF 5.719
Xiaoyan Wu,Wei Li,Qingrong Chen,Caixia Xu,Jiamian Wang,Lingyuan Wu,Guodong Liu,Weiping Wang,Ting Li,Ping Chen,Long Xu
Light-induced degradation (LID) phenomenon is commonly found in optoelectronics devices. Self-healing effect in halide lead perovskite solar cells was investigated since the electrons and holes in the shallow traps could escape easily at room temperature. However, the degradation in the semiconductors could not easily recover at room temperature, and many of them needed annealing at temperatures in the several hundreds, which was not friendly to the integrated optoelectronic semiconductor devices. To solve this problem, in this work, LID effect of photocurrent in p-type Mg-doped gallium nitride thin films was investigated, and deep defect and vacancy traps played a vital role in the LID and healing process. This work provides a contactless way to heal the photocurrent behavior to its initial level, which is desirable in integrated devices.Keywords:Mg-doped gallium nitride;light-induced degradation;photocurrent device;contactless healing
研究领域:
材料科学
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光电子学
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半导体物理
✓ 已验证
DOI
PubMed
高影响因子
Journal of Environmental Chemical Engineering
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2023
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IF 7.7
Hairus Abdullah,Sethupathi Shanmugasundaram,Mohamed Tarek Ahmed,Hardy Shuwanto,S.K. Krishna,Dong-Hau Kuo
Carbon-free based fuels are a promising solution to overcome the world energy crisis and environmental pollution . Therefore, hydrogen fuel is a critical and sustainable energy source to replace the limited carbon-based fossil fuels, which can be generated using a simple photocatalysis method. Herein, we demonstrated that Ni- and Mg-doped ZnIn 2 (O,S) 4 (NMZI) photocatalysts prepared with a hydrothermal process performed an unprecedented HER rate without a noble-metal cocatalyst under visible-light illumination. The amounts of Ni and Mg dopants in NMZI were varied and the as-prepared NMZI were characterized with SEM, TEM, XRD, Raman, FTIR, XPS, EPR, DRS, PL , EIS, TPC , CV, and tested for photocatalytic HER . It was found that the Ni and Mg co-dopants induced substitutional surface defects of Zn In − , Ni In − , and Mg In − . As a result, the formation of oxygen vacancy ( V O 2 + ) compensated the induced defect charges, which are crucial in the HER mechanism. EDS, ICP, and XPS analyses suggest a non-stoichiometric Zn(Zn,Ni,Mg,In) 2 (O,S) 3.5 with Zn, Ni, and Mg occupying In sites in the structure. The NMZI catalyst could achieve a maximum HER rate of 9.4 mmol/g․h under visible-light illumination. It is believed that the HER performance improvement is due to the defect formation on NMZI catalyst that subsequently enhances the optical, electrochemical, and photocatalytic properties. The photocatalytic HER mechanism has been elucidated and discussed thoroughly in this work.
研究领域:
材料科学
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能源与环境科学
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产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2024
·
IF 3.8
Xiaoxuan Song,Jian Yang,Shuai Wang,Jia Song,Biying Bao,Hancheng Zhu,Duanting Yan,Changshan Xu,Yuxue Liu
Herein, ZMGGO:Cr 3+ nanoparticles were prepared by incorporating Mg 2+ ions into Cr 3+ -doped zinc gallogermenate nanoparticles through a hydrothermal path in combination with a vacuum heating. The average size of ZMGGO:Cr 3+ nanoparticles minishes from 59 to 12 nm with growing Mg 2+ concentration. Meanwhile their luminescence intensity at 696 nm of ZMGGO:Cr 3+ nanoparticles was only decreased by less than half of that of the undoped nanoparticles due to the decreased particle size after Mg doping. Meanwhile, the integral luminescence intensity of their entire emission band shows an increasing trend with increasing temperature due to the enhanced phonon sideband luminescence at high temperature. More important, it is found that the formation energies associated with Mg′ Ga -Ga o Zn and Zn′ Ga -Ga o Zn defects are −1.2 and 1.69 eV, respectively, suggesting the enhanced afterglow intensity of ZMGGO:Cr 3+ can be ascribed to Mg doping leading to the increased number of these anti-site traps. Finally, the dual-level time-gate optical encryption was demonstrated using phosphorescent inks containing ZMGGO:Cr 3+ nanoparticles with different afterglow intensities.
研究领域:
材料科学
·
光学工程
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产品关联
DOI
高影响因子
ACS Applied Energy Materials
·
2024
·
IF 5.4
Chang Su,Guoqiang Liu,Qiang Sun,Lei Wen,Zeyu Chen,Meiju Zhao
The series P2-type Mn–Fe-based layered oxide materials (Na2/3MnxFe1–xO2) for sodium-ion batteries are regarded as potential commercial cathode materials due to their high specific capacity and low cost. However, the P2-type layered oxide cannot avoid some phase transformation during the charge–discharge process, which results in poor structural reversibility and low-capacity retention. Moreover, a high capacity usually means more insertion/extraction of Na+, which results in large changes in the lattice volume and poor cycling stability. Herein, a new strategy containing oxygen vacancies and Mg substitution is designed to obtain high-performance sodium storage of Mn–Fe-based layered oxide. The P′2-type Na0.67Mn0.85Fe0.1Mg0.05O2−δ (Ovs & Mg-sub) cathode material is synthesized by the above-mentioned dual-modification strategy. The effect of oxygen vacancies and Mg substitution on the structural evolution during the charge–discharge process is further investigated by in situ X-ray diffraction techniques. It demonstrates that Ovs & Mg-sub has reversible structural transformation and smaller lattice volume changes, thus further exhibiting prominent electrochemical properties. The initial discharge specific capacity reaches 190.2 mAh g–1 at a current density of 20 mA g–1 and remains at 152.9 mAh g–1 at a current density of 100 mA g–1 after 100 cycles. In addition, it has a superior rate capability of 88.9 mAh g–1 at a current density of 2000 mA g–1.
研究领域:
材料科学
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电化学
✓ 已验证
产品关联
DOI
高影响因子
Advances in Materials Science and Engineering
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2014
·
IF 0.897
M. S. H. Al-Furjan,Kui Cheng,Wenjian Weng
Electrochemical biosensors are essential for health monitors to help in diagnosis and detection of diseases. Enzyme adsorptions on biosensor electrodes and direct electron transfer between them have been recognized as key factors to affect biosensor performance. TiO2 has a good protein adsorption ability and facilitates having more enzyme adsorption and better electron transfer. In this work, Mg ions are introduced into TiO2 nanodots in order to further improve electrode performance because Mg ions are considered to have good affinity with proteins or enzymes. Mg doped TiO2 nanodots on Ti substrates were prepared by spin-coating and calcining. The effects of Mg doping on the nanodots morphology and performance of the electrodes were investigated. The density and size of TiO2 nanodots were obviously changed with Mg doping. The sensitivity of 2% Mg doped TiO2 nanodots based biosensor electrode increased to 1377.64 from 897.8 µA mM−1 cm−2 and its decreases to 0.83 from 1.27 mM, implying that the enzyme achieves higher catalytic efficiency due to better affinity of the enzyme with the Mg doped TiO2. The present work could provide an alternative to improve biosensor performances.
研究领域:
生物医学工程
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材料科学
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分析化学
✓ 已验证
产品关联
DOI
高影响因子
CERAMICS INTERNATIONAL
·
2016
·
IF 2.758
Weixuan Zeng,Xianfeng Yang,Minghui Shang,Xiewen Xu,Weiyou Yang,Huilin Hou
The tailored doping levels towards the band gap tunability are one of the challenges to push forward the potential application of one-dimensional (1D) ZnO nanostructures in the opto/electric nanodevices . In present work, we reported the exploration of Mg-doped ZnO nanofibers via electrospinning of polyvinylpyrrolidone (PVP), Zn(CH 3 COO) 2 (ZnAc) and Mg(CH 3 COO) 2 (MgAc), followed by calcination in air. The resultant products were systematically characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscope (HRTEM), and X-ray photoelectron spectroscopy (XPS). The optical measurements (UV–vis) of the Mg-doped ZnO nanofibers suggested that the optical band gaps of the ZnO nanofibers could be tuned from 3.33 to 3.40 eV as a function of the Mg doing levels. This tunability of the band gap of ZnO nanofibers with an intentional impurity could eventually be useful for optoelectronic applications .
研究领域:
材料科学
·
光学工程
✓ 已验证
产品关联
DOI
高影响因子
OPTICAL MATERIALS
·
2023
·
IF 3.9
Shuaibing Guo,Zhaokai He,Siyuan Ma,Zhe Jiang,Jia Dong,Jinbiao Jia
NiO x is one of the most promising inorganic hole transport materials for perovskite solar cells . However, lots of fabrication methods refer to NiO x are limited in n-i-p type perovskite solar cells. Because the deposition procedure of NiO x film such as polar solvents and high temperature process is seriously incompatible with perovskite light-absorption underlayers. In this work, highly crystalline NiO x nanocrystals are prepared using solvothermal method under the presence of long-chain oleylamine molecules. The resulted NiO x nanocrystals can be easily dispersed in weak-polar toluene and form films on perovskite layer without annealing procedure. The n-i-p type device with NiO x hole transport layer achieves an efficiency of 10.34%. Later, Mg 2+ with different molar ratios are incorporated into the NiO x nanocrystals. It is found that introducing a certain amount of Mg 2+ benefits to improve the ratio of Ni 3+ /Ni 2+ , thereby changing the work function and increasing the hole conductivity. As a result, the n-i-p type device with Mg-NiO x hole transport layer yields an improved efficiency of 12.41%.
研究领域:
材料科学
·
能源科学
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产品关联
DOI
高影响因子
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