Pressure-Induced Mixed Protonic–Electronic to Pure Electronic Conduction Transition in Goethite

Su, Ning; Sun, Meng; Wang, Qinglin; Jin, Jingjing; Sui, Jian; Liu, Cailong; Chen, Gao

doi:10.1021/acs.jpcc.0c10067

Cited by 4 publications

(3 citation statements)

References 30 publications

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“…Moreover, this range of values we observed is in good correlation with the data in the literature on various materials with dominant electron transport and (partially) disordered structure [ 49 , 50 ]. Interestingly, the presence of mixed protonic–electronic conduction in goethite was identified by Su et al [ 51 ] in the study on electrical properties under pressure by impedance spectroscopy. It shows how different conditions can influence the overall transport mechanism.…”

Section: Resultsmentioning

confidence: 93%

Debye Temperature Evaluation for Secondary Battery Cathode of α-SnxFe1−xOOH Nanoparticles Derived from the 57Fe- and 119Sn-Mössbauer Spectra

Ibrahim,

Tani,

Hashi

et al. 2024

IJMS

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Debye temperatures of α-SnxFe1−xOOH nanoparticles (x = 0, 0.05, 0.10, 0.15 and 0.20, abbreviated as Sn100x NPs) prepared by hydrothermal reaction were estimated with 57Fe- and 119Sn-Mössbauer spectra measured by varying the temperature from 20 to 300 K. Electrical properties were studied by solid-state impedance spectroscopy (SS-IS). Together, the charge–discharge capacity of Li- and Na-ion batteries containing Sn100x NPs as a cathode were evaluated. 57Fe-Mössbauer spectra of Sn10, Sn15, and Sn20 measured at 300 K showed only one doublet due to the superparamagnetic doublet, while the doublet decomposed into a sextet due to goethite at the temperature below 50 K for Sn 10, 200 K for Sn15, and 100 K for Sn20. These results suggest that Sn10, Sn15 and Sn20 had smaller particles than Sn0. On the other hand, 20 K 119Sn-Mössbauer spectra of Sn15 were composed of a paramagnetic doublet with an isomer shift (δ) of 0.24 mm s−1 and quadrupole splitting (∆) of 3.52 mm s−1. These values were larger than those of Sn10 (δ: 0.08 mm s−1, ∆: 0.00 mm s−1) and Sn20 (δ: 0.10 mm s−1, ∆: 0.00 mm s−1), suggesting that the SnIV-O chemical bond is shorter and the distortion of octahedral SnO6 is larger in Sn15 than in Sn10 and Sn20 due to the increase in the covalency and polarization of the SnIV-O chemical bond. Debye temperatures determined from 57Fe-Mössbauer spectra measured at the low temperature were 210 K, 228 K, and 250 K for Sn10, Sn15, and Sn20, while that of α-Fe2O3 was 324 K. Similarly, the Debye temperature of 199, 251, and 269 K for Sn10, Sn15, and Sn20 were estimated from the temperature-dependent 119Sn-Mössbauer spectra, which were significantly smaller than that of BaSnO3 (=658 K) and SnO2 (=382 K). These results suggest that Fe and Sn are a weakly bound lattice in goethite NPs with low crystallinity. Modification of NPs and addition of Sn has a positive effect, resulting in an increase in DC conductivity of almost 5 orders of magnitude, from a σDC value of 9.37 × 10−7 (Ω cm)−1 for pure goethite Sn (Sn0) up to DC plateau for samples containing 0.15 and 0.20 Sn (Sn15 and Sn20) with a DC value of ~4 × 10−7 (Ω cm)−1 @423 K. This non-linear conductivity pattern and levelling at a higher Sn content suggests that structural modifications have a notable impact on electron transport, which is primarily governed by the thermally activated via three-dimensional hopping of small polarons (SPH). Measurements of SIB performance, including the Sn100x cathode under a current density of 50 mA g−1, showed initial capacities of 81 and 85 mAh g−1 for Sn0 and Sn15, which were larger than the others. The large initial capacities were measured at a current density of 5 mA g−1 found at 170 and 182 mAh g−1 for Sn15 and Sn20, respectively. It is concluded that tin-goethite NPs are an excellent material for a secondary battery cathode and that Sn15 is the best cathode among the studied Sn100x NPs.

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Section: Resultsmentioning

confidence: 93%

Debye Temperature Evaluation for Secondary Battery Cathode of α-SnxFe1−xOOH Nanoparticles Derived from the 57Fe- and 119Sn-Mössbauer Spectra

Ibrahim,

Tani,

Hashi

et al. 2024

IJMS

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“…Conversely, the activation energy for DC conductivity, E DC , follows the opposite trend, with values increasing in the 73.0-82.5 kJmol −1 range. The pathway involving migration along the double chain ([001] direction) through shared octahedral edges, with electron transport mediated by O and OH species, is characterized by Fe atoms with parallel spins and with the shortest Fe 2+ -Fe 3+ distance of approximately 3 Å. Su et al [55] studied the electrical conduction mechanism of goethite under pressures up to 17.1 GPa using impedance spectroscopy. The results indicate a pressure-induced conduction mechanism transition around 5 GPa from mixed protonic-electronic conduction to pure electronic conduction, which is associated with the pressureinduced magnetic state transition.…”

Section: Electrical Properties-solid-state Impedance Spectra and DC C...mentioning

confidence: 99%

Photocatalytic and Cathode Active Abilities of Ni-Substituted α-FeOOH Nanoparticles

Ibrahim,

Shiraishi,

Homonnay

et al. 2023

IJMS

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The present study investigates the relationship between the local structure, photocatalytic ability, and cathode performances in sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs) using Ni-substituted goethite nanoparticles (NixFe1−xOOH NPs) with a range of ‘x’ values from 0 to 0.5. The structural characterization was performed applying various techniques, including X-ray diffractometry (XRD); thermogravimetry differential thermal analysis (TG-DTA); Fourier transform infrared spectroscopy (FT-IR); X-ray absorption spectroscopy (XANES/EXAFS), both measured at room temperature (RT); 57Fe Mössbauer spectroscopy recorded at RT and low temperatures (LT) from 20 K to 300 K; Brunauer–Emmett–Teller surface area measurement (BET), and diffuse reflectance spectroscopy (DRS). In addition, the electrical properties of NixFe1−xOOH NPs were evaluated by solid-state impedance spectroscopy (SS-IS). XRD showed the presence of goethite as the only crystalline phase in prepared samples with x ≤ 0.20, and goethite and α-Ni(OH)2 in the samples with x > 0.20. The sample with x = 0.10 (Ni10) showed the highest photo-Fenton ability with a first-order rate constant value (k) of 15.8 × 10−3 min−1. The 57Fe Mössbauer spectrum of Ni0, measured at RT, displayed a sextet corresponding to goethite, with an isomer shift (δ) of 0.36 mm s−1 and a hyperfine magnetic distribution (Bhf) of 32.95 T. Moreover, the DC conductivity decreased from 5.52 × 10−10 to 5.30 × 10−12 (Ω cm)–1 with ‘x’ increasing from 0.10 to 0.50. Ni20 showed the highest initial discharge capacity of 223 mAh g−1, attributed to its largest specific surface area of 174.0 m2 g−1. In conclusion, NixFe1−xOOH NPs can be effectively utilized as visible-light-activated catalysts and active cathode materials in secondary batteries.

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“…间的对应关系以及不同结构之间的相变机制，对于拓宽 TiO 2 的应用领域有着重要的意义．不同于传统的合成途径，压力被认为是一种"清洁"的调控手段，可以更好地揭示材料的结构与性能之间的关系 [7] ．基于此，在过去几十年里，人们对 TiO 2 体材料和纳米材料展开了大量的研究工作．研究表明 TiO 2 体材料和纳米材料的高压相变存在着很大的差异，受到样品尺寸、形貌及生长晶向等因素的影响 [8][9][10][11][12][13][14] ．TiO 2 体材料的高压相变次序比较清晰，锐钛矿相 TiO 2 在高压下经历由锐钛矿到 a-PbO 2 到斜锆石的结构相变 [15][16][17][18][19][20][21][22] ．而对于 TiO 2 纳米材料而言，其高压相变十分复杂，锐钛矿 TiO 2 纳米晶在高压下可能观察不到 a-PbO 2 结构 [15,23,24] ，也可能在压力作用下发生压制无定形相变 [25] ．Li 等人 [26] 对直径为 50-200 nm 的 TiO 2 纳米线进行了高压研究，认为其相变顺序与尺寸大于 10 nm 的 TiO 2 纳米晶相似．此外，对掺杂 TiO 2 纳米粒子 [8] 和 TiO 2 纳米片 [27] 的高压研究中也观察到了独特的高压特性．但是，对于 TiO 2 体材料和纳米材料的高压研究工作多集中于高压下的结构相变，而对压力作用下材料性质变化的研究较少，尤其是针对高压下锐钛矿 TiO 2 的晶界性质、晶体中缺陷行为等方面的研究更是鲜有报道．随着科技的发展，高压原位阻抗谱测量技术已广泛应用于体材料和纳米材料晶界行为的相关研究 [28][29][30][31][32][33] 检测窗口，详细的金刚石砧面微电路的集成过程参照我们前期的工作 [30] ．为了测量电学及样品内部界面信息，实验中没有使用任何传压介质，实验过程中压力的标定采用红宝石进行标压 [34] ．交流阻抗谱电学测量的频率范围为 10 MHz-0. [35] ．如果在阻抗谱的低频区域，主弧后面观察到一个"尾链"，表明存在电极效应 [36,37] ．在复阻抗平面图中，如果晶界弛豫时间和晶粒弛豫时间相差两个数量级以上，则可以很好地分辨出两条半圆弧 [38] ．如果在谱图中没有观察到两条完整半圆弧(如只有一个不规则圆弧等)，则说明晶粒和晶界的弛豫时间相差小于两个…”

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Effects of defects on electrical transport properties of anatase TiO2 polycrystalline under high pressure: AC impedance measurement

Wang¹,

Bo-Huai²,

Shuang-Long³

et al. 2023

Acta Phys. Sin.

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The electrical transport properties of anatase TiO2 polycrystalline have been systematically investigated using high pressure in-situ impedance spectroscopy measurements. The anomalous behaviors of resistance, parameter factor and relaxation frequency of grain and grain boundary can be found at 6.4, 11.5 and 24.6 GPa. Results indicate that the former two discontinuous points (6.4 and 11.5 GPa) correspond to the phase transitions of TiO2 from anatase to a-PbO2 and then to baddeleyite, respectively. Above 24.6 GPa, TiO2 completely transforms into the baddeleyite phase. Based on the change of grain and grain boundary resistance under pressure, intrinsic defects play a crucial effect on the electrical transport properties of TiO2 at high pressure. At 6.4 GPa, the occurrence of phase transition gives rise to the variation of defects' role, from a deep energy level defect (as a recombination centre) changes into a shallow energy level defect (providing carriers to the conduction and valence bands). In addition, the position of defect in energy band changes with pressure increasing. Furthermore, the phase transition of TiO2 at 6.4 GPa is the rearrangement of TiO6 octahedron, while the other one at 11.5 GPa can be attributed to the migration of oxygen Schottky defects from inner to surface. Combining the packing factor and relaxation frequency, the electrical transport properties of TiO2 under pressure are revealed, the packing factor and the relaxation frequency are closely related to the mobility and the carrier concentration, respectively. The activation energies of grain and grain boundary decrease as the pressure elevating, indicating that the transport of carriers in grain and grain boundary become easier under pressure, and the former is smoother than the latter due to the activation energy of grain is smaller than that of grain boundary in the same pressure range. Moreover, the relaxation frequency ratio of grain and grain boundary of TiO2 decreases with pressure increasing, and the grain boundary effect under high pressure is not obvious.

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Pressure-Induced Mixed Protonic–Electronic to Pure Electronic Conduction Transition in Goethite

Cited by 4 publications

References 30 publications

Debye Temperature Evaluation for Secondary Battery Cathode of α-SnxFe1−xOOH Nanoparticles Derived from the 57Fe- and 119Sn-Mössbauer Spectra

Debye Temperature Evaluation for Secondary Battery Cathode of α-SnxFe1−xOOH Nanoparticles Derived from the 57Fe- and 119Sn-Mössbauer Spectra

Photocatalytic and Cathode Active Abilities of Ni-Substituted α-FeOOH Nanoparticles

Effects of defects on electrical transport properties of anatase TiO<sub>2</sub> polycrystalline under high pressure: AC impedance measurement

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