Nanomaterials
·
2019
·Vol. 9
·期 12
·1676
·
IF 4.034
Pianpian Ma,Na Lei,Bo Yu,Yongkun Liu,Guohua Jiang,Jianming Dai,Shuhong Li,Qiuling Lu
La-based perovskite-type oxide is a new type of supercapacitor electrode material with great potential. In the present study, LaMnO3/MnO (LMO/MnO) nano-arrays supported by carbon cloth are prepared via a simple one-step electrodeposition as flexible supercapacitor electrodes. The structure, deposit morphology of LMO/MnO, and the corresponding electrochemical properties have been investigated in detail. Carbon cloth-supported LMO/MnO electrode exhibits a specific capacitance of 260 F·g−1at a current density of 0.5 A·g−1in 0.5 M Na2SO4aqueous electrolyte solution. The cooperative effects of LMO and MnO, as well as the uniform nano-array morphology contribute to the good electrochemical performance. In addition, a symmetric supercapacitor with a wide voltage window of 2 V is fabricated, showing a high energy density of 28.15 Wh·kg−1at a power density of 745 W·kg−1. The specific capacitance drops to 65% retention after the first 500 cycles due to the element leaching effect and partial flaking of LMO/MnO, yet remains stable until 5000 cycles. It is the first time that La-based perovskite has been exploited for flexible supercapacitor applications, and further optimization is expected.Keywords:perovskite-type LaMnO3/MnO;supercapacitor flexible electrode;electrochemical properties;carbon cloth;electrodeposition
研究领域:
材料科学
·
电化学
✓ 已验证
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2019
·
IF 14.229
Yuxian Wang,Lulu Chen,Hongbin Cao,Zhaoxu Chi,Chunmao Chen,Xiaoguang Duan,Yongbing Xie,Fei Qi,Weiyu Song,Jian Liu,Shaobin Wang
La-based perovskites are catalytically active owing to the oxygen vacancies, redox metal centers of B sites and surface hydroxyl groups. Nevertheless, the insights into these active centers on environmental catalysis are still insufficient. In this study, hierarchical mixed oxides perovskite microspheres were synthesized for catalytic ozonation over oxalic acid and benzotriazole. LaMn 4 O x , with LaMnO 3-δ as the dominant crystal phase, demonstrated superior catalytic activity to Mn 2 O 3 and LaMnO 3 synthesized from citric acid sol-gel method. Temperature-programmed desorption of NH 3 (NH 3 -TPD) and pyridine-Fourier transform infrared spectroscopy (pyridine-FTIR) tests proved Lewis acid as the main acid type. Temperature-programmed reduction of H 2 (H 2 -TPR), O 2 -TPD and X-ray photoelectron spectroscopy (XPS) analysis indicated the presence of oxygen vacancies and mixed valences of Mn in the crystal structure facilitated the catalytic process. Moreover, the content of oxygen vacancy was calculated by iodometric titration method. With the aid of theoretical calculations, oxygen vacancies were found to exhibit a strong affinity toward ozone adsorption, where ozone molecules spontaneously dissociated into reactive oxygen species (ROS) such as O 2 − and 1 O 2 . The B site of Mn facilitated ozone decomposition by extending the O O bond of ozone due to the electron transfer from Mn 3+ /Mn 4+ redox cycle. In-situ EPR and quenching tests confirmed the contribution of O 2 − and 1 O 2 in benzotriazole degradation along with OH. This study stepped further to unveil the ozone adsorption/decomposition and ROS generation on nanoscale perovskite-based composites.
研究领域:
环境科学
·
材料科学
✓ 已验证
DOI
高影响因子
RSC Advances
·
2016
·Vol. 6
·期 74
·69855-69860
·
IF 3.289
Baohuai Zhao,Rui Ran,Li Sun,Xingguo Guo,Xiaodong Wu,Duan Weng
The perovskite oxides LaMnO3+δ were prepared by a citrate method and then etched by acid solution with different times. After etching, the perovskite structures of all the catalysts remained, the surface area enlarged apparently, and the NO catalytic oxidation activities were obviously promoted by increasing the etching time. Long-term experiments revealed the acceptable stability of the etched catalysts. The favorable activities of the etched LaMnO3+δ catalysts were mainly due to their high specific surface area, abundant activated oxygen species and vacancies, as well as the higher valence state of Mn ions resulting from the loss of La3+ in the perovskite structure.
研究领域:
材料科学
·
环境催化
✓ 已验证
产品关联
DOI
高影响因子
APPLIED SURFACE SCIENCE
·
2019
·
IF 5.155
Fawei Lin,Jiaming Shao,Hairong Tang,Yan Li,Zhihua Wang,Guanyi Chen,Dingkun Yuan,Kefa Cen
NO x control by catalytic oxidation combined with wet absorption has been a promising technology for the flue gas treatment of industrial boiler and furnace. LaMnO 3+δ perovskites were investigated as catalysts for NO oxidation. The comparison between metal substitution of La and Mn cations was researched. The activity results indicated that La site substitution was more favorable for NO oxidation than Mn site substitution. LaCoMnO exhibited the highest activity in NO oxidation with maximum value of 83.74% at 250 °C. That value further increased to 89.96% after acid etching (LaCoMnO-A), and closely, such high value of 89.78% was achieved at 220 °C. The surface area was significantly improved by acid etching, i.e., from 47.0 m 2 /g to 212.0 m 2 /g, Tremendous changes in crystalline structure and morphology were taken place, i.e., perovskites phase disappeared and MnO 2 was detected instead; compact amorphous particle morphology was replaced by multiple layer structure. Even more, Mn 4+ ions and oxygen vacancies accumulated on the surface were improved. Deservedly, the redox property was enhanced enormously, especially at low temperature. Subsequently, SO 2 poisoning tests were conducted at 250 °C under 20 ppm SO 2 . Interestingly, no decrease was observed for LaCoMnO-A within 480-min SO 2 poisoning test, which was totally contrasted with the nearly complete deactivation results of LaCoMnO. In-situ DRIFTS measurements validated nitrate disappeared and replaced by sulfate formation on the catalyst surface. Merely, under low-concentration SO 2 atmosphere, the monodentate nitrate and bidentate nitrate were destroyed, while the free nitrates exhibited higher resistance. Overall, the acid etching improved the catalyst resistance to SO 2 , which may have the potential to apply in the flue gas treatment of low-sulfur and sulfur-free fuel fired boiler and furnace.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ELECTROANALYTICAL CHEMISTRY
·
2022
·
IF 4.598
Zhiyang Zhong,Aijuan Xie,Jie Pan,Menglu Li,Jiaojie Wang,Shixin Jiang,Jiaqi Lin,Shichao Zhu,Shiping Luo
A novel core–shell p-p homotype heterojunction based on NiO@LaMnO 3 and multi-walled carbon nanotubes (NiO@LaMnO 3 /MWCNTs) has been designed and synthesized via electrostatic self-assembly method. The phase compositions and morphology were verified by X-ray diffraction (XRD), scanning electron microscope (SEM), transmission electron microscope (TEM). A series of electrochemical tests showed that NiO@LaMnO 3 /MWCNTs modified electrode had a magnifying effect on the electrochemical response signal of ascorbic acid (AA) detection. The current response is linearly increased in the range of 2.60–36.44 μmol/L with the linear regression equation being I (μA) = 0.5902 C (μmol/L) + 1.4407 (R 2 = 0.9909), and the detection limit (S/N = 3) being 2.41 μmol/L. Moreover, NiO@LaMnO 3 /MWCNTs/GCE electrochemical sensor presented satisfying selectivity, stability, repeatability, and can be used to analyze the AA concentration in real daily drinks. The relatively excellent electrocatalytic activity should be attributed to high electroactive surface area, well-matched core–shell structure and synergetic effect of p-p homotype heterojunction. This work offer applicable guidelines for the design of core–shell p-p heterojunction electrode materials for the application of electrochemical sensor.
研究领域:
材料科学
·
分析化学
·
生物医学工程
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF POWER SOURCES
·
2019
·
IF 7.467
Yajing Wang,Yane Zheng,Yuhao Wang,Hua Wang,Xing Zhu,Yonggang Wei,Yaming Wang,Lihong Jiang,Zhiyuan Yang,Kongzhai Li
Chemical looping reforming of methane (CLRM) technology is a new approach for syngas and pure hydrogen generation . During the whole reaction, methane is first partially oxidized to syngas by the lattice oxygen of the oxygen carrier, and then the lattice oxygen of the reduced oxygen carrier is recovered by thermal water splitting, with pure hydrogen produced. LaMnO 3 is used as an oxygen carrier for the CLRM. It obtains a high resistance to carbon deposition , while a lower CH 4 conversion due to the unstable structure. Fe ion substitution in LaMnO 3 can be used to improve its reactivity and thermal stability. La 1-x MnFe x O 3 /LaMn 1-x Fe x O 3 (x = 0.05, 0.1, 0.15, 0.2) oxygen carriers own higher reactivity and better resistance to carbon deposition, producing high purity syngas and hydrogen. La 0.85 MnFe 0.15 O 3 sample exhibits the highest CO selectivity (~99%), syngas productivity (3.78 mmol g −1 ) and H 2 productivity (1.76 mmol g −1 ) due to the higher oxygen vacancy concentration, and its H 2 /CO molar ratio is maintained at the ideal ratio of 2.0 (1.93–2.07) during the whole process. Notably, no carbon deposition is generated over LaMnO 3 , La 0.85 MnFe 0.15 O 3 and LaMn 0.9 Fe 0.1 O 3 oxygen carriers even after 20 redox cycles, and La 0.85 MnFe 0.15 O 3 exhibits superior resistance to carbon deposition due to the better structural and thermal stability.
研究领域:
材料科学
·
能源工程
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Materials Chemistry B
·
2018
·Vol. 6
·期 37
·5931-5939
·
IF 4.776
Lifei Song,Yun Zhu,Zezhou Yang,Ce Wang,Xiaofeng Lu
Nanomaterials with ABX3-type perovskite structure have attracted considerable and increasing attention due to their unique physical and chemical properties as well as promising applications in various fields. In this work, we have developed a simple electrospinning followed by a calcination process to prepare ABO3-type perovskite LaMnO3+δ nanofibers as efficient oxidase mimics for the detection of L-cysteine. The oxidase-like catalytic activity of the prepared LaMnO3+δ nanofibers is heavily dependent on the calcination temperature which results in different sizes of the LaMnO3+δ crystals and their crystallinity, and the maximum activity is achieved at the calcination temperature of 700 °C. Based on the high oxidase-like catalytic activity of the as-prepared perovskite LaMnO3+δ nanofibers, a simple and accurate colorimetric detection method towards L-cysteine has been developed. The detection limit is as low as 109.8 nM and an excellent selectivity for L-cysteine detection with common substances in human blood as interferents is also achieved. In addition, the LaMnO3+δ nanofibers can be retained as a monolithic membrane after the calcination process, making them an oxidase mimic for on-demand colorimetric sensing. This work reveals the promising prospects for the perovskite LaMnO3+δ materials in biosensing, medical diagnosis, food safety and environmental monitoring.
研究领域:
生物传感
·
医学诊断
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食品安全
·
环境监测
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CHEMICAL ENGINEERING JOURNAL
·
2023
·
IF 15.1
Aihua Xu,Runshi Chen,Wenpei Zhao,Jiajin Lin,Rongrong Hu,Aimal Khan,Wei Li,Xiaoxia Li,Shuaiqi Zhao,Yongcai Qiu
Modifying the surface structure of catalysts is critical for facilitating peroxymonosulfate (PMS) activation. Here, we present a quenching approach to effectively modify the surface chemistry of LaMnO 3 nanocatalysts, in which the optimal catalyst obtained by quenching displays higher catalytic degradation performance for levofloxacin (LEVO). The experimental results demonstrates that the increased intrinsic catalytic activity is directly connected to the quenching-induced exposed facets transition and synergistic effect of Cu/Co ions. Meanwhile, density functional theory calculations (DFT) further reveal the aforementioned modifications to surface structure result in an upward shift of d-band centre, which optimizes the adsorption of PMS and makes it easier for the transfer of electron between Mn sites and PMS, thereby facilitating the reduction of Mn 4+ and enhancing catalytic activity for PMS activation and LEVO degradation. This study presents new ideas for controlling surface structure of perovskite metal oxide catalysts and broadens applicability of quenching chemistry in heterogeneous catalysis.
研究领域:
环境科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2021
·
IF 5.316
Yue Chen,Jing Ma,Donghai Li,Chengxian Zhu,Wei Zhang,Chunyang Miao
Flexible supercapacitors are of tremendous interest to power future wearable electronics. The performance of a flexible supercapacitor strongly depends on the properties of electrode materials. In addition to the electrochemical performance, flexible electrodes must be mechanically robust or even stretchable during operation. Electrically conductive hydrogels (ECHs) are an ideal framework for flexible electrode design and construction, owing to their three-dimensional conductive network, toughness, and scalable synthesis. In this work, we synthesized modified LaMnO 3 (MLMO) perovskites with porous tubular skeleton structure by a typical sol-gel method, and integrated the MLMO nanoparticles into a double network (DN) hydrogel, where the MLMO perovskites are uniformly dispersed in polyacrylamide (PAM)/polyvinyl alcohol (PVA) matrixes. The mechanical properties of this new composite hydrogel dramatically increase, with a remarkable enhanced tensile strength of 1.81 MPa and a high breaking elongation of over 440%. In addition, the composite hydrogel electrode shows exceptional capacitive characteristics, including a high gravimetric specific capacitance of 392 F g − 1 (at 1 A/g) and robust cycling stability (90% capacitance retention over 10,000 cycles). Our manufacturing strategy opens the opportunity to design flexible and stretchable supercapacitors with ideal nanostructures and outstanding hydrogel electrodes.
研究领域:
材料科学
·
能源技术
✓ 已验证
DOI
高影响因子
Nano Energy
·
2017
·
IF 12.343
Long Kuai,Erjie Kan,Wei Cao,Marko Huttula,Sami Ollikkala,Taru Ahopelto,Ari-Pekka Honkanen,Simo Huotari,Wenhai Wang,Baoyou Geng
Oxygen reduction reaction (ORR) is the key reaction in various electrochemical energy devices. This work reports an inexpensive mesoporous LaMnO 3+δ perovskite for ORR with remarkable activity, synthesized by a facile aerosol-spray assisted approach. The mesoporous LaMnO 3+δ material shows a factor of 3.1 higher activity (at 0.9 V vs. RHE) than LaMnO 3 obtained from co-precipitation method (LMO-CP). Based on results of x-ray absorption near-edge spectroscopy (XANES), x-ray photoelectron spectroscopy (XPS) and Brunauer–Emmett–Teller (BET) analysis, we conclude that the chemical state of surface Mn and the high surface area are the sources to the notably enhanced activity. The study of Zn-air batteries device further confirmed a Pt/C comparable performance in the practical devices with the novel mesoporous LaMnO 3+δ catalyst, where the power density at 200 mA/cm 2 is only 2.1% lower than in the battery with same-loaded Pt/C catalyst. Therefore, the high mass activity and low-cost of Mn/La may make LaMnO 3+δ further approach to the application of electrochemical devices .
研究领域:
材料科学
·
电化学
·
能源技术
✓ 已验证
产品关联
DOI
高影响因子
Surfaces and Interfaces
·
2025
·
IF 6.3
Yi Cao,Pengcheng Lu,Xiaobing Hu,Zhong Li,Qiyun Pan,Dabei Wu,Huang He,Wenfeng Qiu
Recently, although perovskite-type LaMnO3 was an auspicious material for energy storage, it still suffered from unsatisfactory conductivity. To address this issue, we proposed compounding it with a conductive polymer, such as PEDOT: PSS, which could act both as a binding agent and an active material. In this study, the feasibility of the design was initially verified by analyzing the interface reaction process based on calculations based on first principles. Subsequently, the PEDOT: PSS was assembled on the surface of LaMnO 3 nanofibers prepared via the electrostatic method, denoted as P@LMO. Due to the strong van der Waals interaction and charge transfer at the interface, a covalent bond between Mn and S was formed, thus facilitating ion and electron transport and increasing oxygen vacancy concentration. However, characterizations also indicated that excessive polymer coverage induced by over-addition could affect anion adsorption. Finally, P@LMO-20 sample was considered as a more appropriate option owing to its comparable specific capacitance (465.5 F g −1 ) to the maximum value (486.5 F g −1 ) and its better rate capability. Moreover, the symmetrical supercapacitor (P@LMO-20//P@LMO-20) without additional binder exhibited excellent specific capacitance, superior energy density , and remarkable cyclic stability, revealing the practicality, and application potential of this composite materials.
研究领域:
材料科学
·
电化学
·
纳米科技
·
能源存储
·
功能材料
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2025
·
IF 6.3
Senyang Wang,Xin Li,Mengyu Liu,Pi Wang,Jingyi Qi,Ling Li
Considering the instability of quantum dot sensitized solar cells (QDSSCs) due to the leakage and volatileness of polysulfide electrolyte. We explored the possibility of applying Ce doping LaMnO 3 ceramic hole transport material (LaMnCe) inside QDSSCs. LaMnO 3 oxides possess high electronic conductivity. Doping of Ce can adjust the band position of materials to match Zn-Cu-In-Se (ZCISe) QDSSCs. LaMnCe was added to the photoanode by spin method and further constructed into the quasi-solid state QDSSCs. The QDSSCs can achieve the PCE of 9.15 % (V oc is 0.66 V, J sc is 24.49 mA·cm −2 , FF is 57.80), which is 33 % higher than the standard liquid QDSSCs. The average electron lifetime of quasi-solid-state QDSSCs prepared with LaMnCe is 5 % higher than that of liquid QDSSCs, and the stability performance of the QDSSCs has been raised significantly.
研究领域:
材料科学
·
能源科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）