Crystals
·
2021
·Vol. 11
·期 5
·547
·
IF 2.589
Zengguang Tang,Liujiang Zhang,Zhenhuang Su,Zhen Wang,Li Chen,Chenyue Wang,Guoping Xiao,Xingyu Gao
In this article, CsPbI2Br perovskite thin films were spin-coated on FTO, on which CuPc was deposited by thermal evaporation. The electronic structure at the CsPbI2Br/CuPc interface was examined during the CuPc deposition by in situ X-ray photoelectron spectroscopy (XPS) and ultraviolet photoelectron spectroscopy (UPS) measurements. No downward band bending was resolved at the CsPbI2Br side, whereas there is ~0.23 eV upward band bending as well as a dipole of ~0.08 eV identified at the molecular side. Although the hole injection barrier as indicated by the energy gap from CsPbI2Br valance band maximum (VBM) to CuPc highest occupied molecular orbital (HOMO) was estimated to be ~0.26 eV, favoring hole extraction from CsPbI2Br to CuPc, the electron blocking barrier of ~0.04 eV as indicated by the offset between CsPbI2Br conduction band minimum (CBM) and CuPc lowest unoccupied molecular orbital (LUMO) is too small to efficiently block electron transfer. Therefore, the present experimental study implies that CuPc may not be a promising hole transport material for high-performance solar cells using CsPbI2Br as active layer.
研究领域:
材料科学
·
光伏器件
·
表面科学
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DOI
高影响因子
CERAMICS INTERNATIONAL
·
2020
·Vol. 46
·期 10
·16524-16532
·
IF 3.83
Muhammad Yousaf,Asma Noor,Shuai Xu,Majid Niaz Akhtar,Baoyuan Wang
Yttrium iron garnet (YIG) nanoparticles (NPs) doped with rare earth (RE) metal ions (Y 2.5 Sm 0.5 Fe 5 O 12 , Y 2.5 Nd 0.5 Fe 5 O 12 ) were successfully synthesized by sol-gel auto combustion approach. The cubic crystalline structure and morphology of the prepared garnet ferrite NPs were analyzed by X-ray diffractometer (XRD) and field emission scanning electron microscopy (FESEM). The cubic crystalline garnet phase of the synthesized YIG, Sm-YIG and Nd-YIG samples was successfully achieved at 950 °C sintering temperature . The force constant and absorption bands were estimated by using Fourier transform infrared spectroscopy (FTIR). The doping effect of RE metal ions on the chemical states of YIG were examined by x-ray photoelectron microscopy (XPS). The valence band (from 12.63 eV to 13.22 eV), conduction band (from 10.89 eV to 11.34 eV) edges and optical bandgap values of RE doped YIG samples were calculated using UV–Vis spectroscopy and ultraviolet photo electron spectroscopy (UPS). The magnetic analysis of the prepared NPs was studied using vibrating sample magnetometer (VSM). The XPS analysis of RE doped YIG samples exhibit the existence of RE (Sm +3 , Nd +3 ) contents on the surface of YIG ferrite by decreasing the oxygen lattice in garnet structure. The optical bandgap (from 1.74 eV to 1.88 eV) explains the semiconducting nature of the synthesized NPs. The UPS results confirm the valence band position of YIG doped samples. The saturation magnetization and remanence of RE doped garnet ferrite samples increased from 13.45 to 18.83 emu/g and 4.06–6.53 emu/g, respectively.
研究领域:
材料科学
·
纳米科技
·
固体物理
·
无机化学
·
功能材料
✓ 已验证
DOI
高影响因子
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
·
2020
·
IF 6.444
Qianfan Zhou,Kunpeng Qian,Jianhui Fang,Miao Miao,Shaomei Cao,Xin Feng
With the mushrooming of smart electronic devices, ultrathin Ti 3 C 2 T x MXene based EMI shielding materials with long term durability have aroused much interest. Herein, 2D Ti 3 C 2 T x /g-C 3 N 4 heterojunction films were firstly assembled using cellulose nanofibrils (CNF) as green binder via a solution-based pressured-filtration process. The heterojunction film with Ti 3 C 2 T x /g-C 3 N 4 mass ratio of 5:1 (28.20 µm in thick) exhibited distinguished performance with EMI shielding effectiveness of 42.99 dB in X-band and high tensile strength of 23.85 MPa. Specially, the generation of photo-electrons from g-C 3 N 4 nanosheets reduced TiO 2 into lower valence states under 365 nm UV light-irritation, resulting in lower loss on electrical conductivity as well as EMI shielding performance compared to their unilluminated counterparts. The reduction on TiO 2 offered by the g-C 3 N 4 enables the heterojunction film to be considered as a promising alternative EMI shielding material for future potential applications, because it can run long time just need UV light modulation.
研究领域:
材料科学
·
电子工程
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产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2019
·Vol. 7
·期 26
·15722-15730
·
IF 10.733
Xiao-Lei Li,Li-Li Gao,Bin Ding,Qian-Qian Chu,Zhen Li,Guan-Jun Yang
A key challenge in the eco-friendly optoelectronic materials field is to find highly stable and nontoxic perovskite materials. Here, we report the optoelectronic properties and stability of the (C6H5NH3)BiI4 perovskite material. Using an eco-friendly gas pump treatment technique, a dense and pinhole-free (C6H5NH3)BiI4 film was fabricated. Remarkably, a large-area (>20 cm2) Bi-based perovskite film was obtained, which is the largest Bi-based perovskite film ever reported. Besides, the (C6H5NH3)BiI4 perovskite exhibits good solubility in ethanol, which is a safe and eco-friendly solvent. Thermogravimetric analysis results show the beginning of weight loss at ∼184 °C, suggesting excellent heat stability of this material. Most importantly, the (C6H5NH3)BiI4 material can tolerate continuous moisture exposure for 334 days in ambient air owing to the presence of a hydrophobic organic chain. To the best of our knowledge, this is the longest moisture stability reported for lead-free perovskite materials so far. This work paves the way for realizing highly stable and nontoxic perovskite materials for potential optoelectronic applications.
研究领域:
材料科学
·
环境科学
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产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2023
·
IF 9.9
Yanning Qu,Jie Ren,Dongfeng Sun,Yuan Yu
Black phosphorus quantum dots (BPQDs)-based materials possess excellent photocatalytic efficiency; however, they often present a loss of photo-induced carriers and random active sites in electron transfer of heterojunctions , thus restricting the enhancement of hydrogen (H 2 ) evolution and their potential application. In this study, a micro-nano ZnIn 2 S 4 /BPQDs (MN-ZISBP) composite is constructed to enable specific orientation and self-distribution of photoelectrons transferred from ZnIn 2 S 4 (ZIS) to BPQDs. The relationship between photoelectron transfer and H 2 evolution efficiency is investigated via experiments and density functional theory (DFT) calculations. MN-ZISBP with a nanorod-like structure presents an H 2 evolution rate of 1207 μmol/g/h and is higher than that of the sheet-shaped (S-ZISBP, 1023 μmol/g/h) and flower-like composites (F-ZISBP, 744 μmol/g/h) under visible light irradiation. The MN-ZISBP composite with a lower conduction band level and larger specific surface area increases the number of active sites on BPQDs via “self-distribution” for H 2 evolution. Finally, the electron transfer direction and bonding orbitals of MN-ZISBP are calculated using the work function and density of states results to verify the above conclusions. The novel construction technique and photocatalytic mechanism of MN-ZISBP reported in this study provide significant insights into the BPQDs-based photocatalysts for H 2 evolution.
研究领域:
材料科学
·
能源科学
·
纳米技术
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Nanomaterials
·
2024
·Vol. 14
·期 14
·1189
·
IF 4.4
Jian Yu,Zhaokang Zheng,Aiwu Wang,Muhammad Humayun,Yasser A. Attia
Molybdenum trioxide (MoO3) is an attractive semiconductor. Thus, bandgap engineering toward photoelectronic applications is appealing yet not well studied. Here, we report the incorporation of sulfur atoms into MoO3, using sulfur powder as a source of sulfur, via a self-developed hydrothermal synthesis approach. The formation of Mo-S bonds in the MoO3material with the synergistic effect of sulfur doping and oxygen vacancies (designated as S-MoO3−x) is confirmed using Fourier-transform infrared (FTIR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and electron paramagnetic resonance (EPR). The bandgap is tuned from 2.68 eV to 2.57 eV upon sulfur doping, as confirmed by UV-VIS DRS spectra. Some MoS2phase is identified with sulfur doping by referring to the photoluminescence (PL) spectra and electrochemical impedance spectroscopy (EIS), allowing significantly improved charge carrier separation and electron transfer efficiency. Therefore, the as-prepared S-MoO3−xdelivers a sensitive photocurrent response and splendid cycling stability. This study on the synergistic effect of sulfur doping and oxygen vacancies provides key insights into the impact of doping strategies on MoO3performance, paving new pathways for its optimization and development in relevant fields.
研究领域:
材料科学
·
半导体物理
✓ 已验证
产品关联
DOI
PubMed
高影响因子
Progress in Natural Science-Materials International
·
2012
·
IF 1.099
Delong Li,Chunxu Pan
A process to fabricate a kind of novel micro–nano scaled TiO 2 /CuS composite fibers by electrospinning technique and chemical precipitation method was developed in the present study. The microstructures and photoelectronic properties of the fibers were characterized using SEM, FT-IR, UV–vis and fluorescence spectroscopy. The results revealed that the TiO 2 portion in the composite fibers was a mixture rutile and anatase phases while TiO 2 and CuS had been fully composite. The fibers had smooth surface with a diameter of 50–300 nm. Comparing with pure TiO 2 fiber, the TiO 2 /CuS micro–nano-scaled composite fibers exhibited a strong absorption in the visible light region and the efficiency of photo-induced charge separation were enhanced. This composite system is of widely potential applications in the areas such as solar cells, supercapacity, photocatalysis, etc.
研究领域:
材料科学
·
纳米技术
✓ 已验证
产品关联
DOI
高影响因子
RSC Advances
·
2013
·Vol. 3
·期 33
·13782-13788
·
IF 2.562
Zhongfu An,Qingyang Wu,Jianjian Xiao,Runfeng Chen,Jun Yin,Huifang Shi,Ye Tao,Yang Wang,Zhixiang Wang,Huanhuan Li,Hongmei Zhang,Xinhui Zhou,Yi Zhao,Wei Huang
A series of ternary asymmetric triazines with tunable singlet and triplet excited states were successfully synthesized on the basis of σ-spacer methodology and a facile synthetic route. The optoelectronic properties are dominated by the conjugated donor–acceptor (D–A) backbone of peripheral carbazoles (D) and triazine core (A), and can be further modulated via the partially interrupted conjugation between the core and the third substituents by the σ spacers of N–CH3, NH, O, S and OSO, which offers new opportunities to fine tune the electronic structures and properties of triazines.
研究领域:
有机化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
MICROCHEMICAL JOURNAL
·
2019
·
IF 3.206
Yajun Zhang,Xiaoliang Zeng,Xiaofang Jiang,Hanjiao Chen,Zhou Long
The cerium (Ce)-based UiO-66 metal-organic frameworks were employed for the first time as an effective catalyst for both oxidation and reduction. On one hand, selenium (Se)(VI) was efficiently photo-reduced to volatile species derived from the low lying of Ce 4f orbital and efficient generation of photo-electrons through the frameworks of UiO-66(Ce); on the other hand, the chromogenic substrate, 3, 3′, 5, 5′-tetramethylbenzydine (TMB), was oxidized based on the oxidase-like behavior of UiO-66(Ce) derived from the Ce 4+ /Ce 3+ spontaneous redox couple. The photo-reduced Se(VI) was determined by atomic fluorescence spectrometry , with a linear range of 5.0–200.0 μg/L − 1 , correlation coefficient of 0.998, and detection limit of 1.5 ng/mL − 1 obtained. The colorimetric sensing of mercury (Hg)(II) was accomplished based on the inhibition of TMB oxidation via Hg (II)-TMB interaction, with two linear ranges of 0.1–2.0 μM and 2.25–4.1 μM obtained, and a correlation coefficient of 0.993 and 0.995 obtained, respectively. The catalytic activity of UiO-66(Ce) was demonstrated to be satisfactory for both oxidation and reduction, which further explored the application of UiO-66(Ce) in the field of catalysis.
研究领域:
分析化学
·
材料科学
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF CHEMICAL PHYSICS
·
2012
·Vol. 137
·期 12
·
IF 3.333
Guan Jiwen,Hu Yongjun,Zou Hao,Cao Lanlan,Liu Fuyi,Shan Xiaobin,Sheng Liusi
In present study, photoionization and dissociation of acetic acid dimers have been studied with the synchrotron vacuum ultraviolet photoionization mass spectrometry and theoretical calculations. Besides the intense signal corresponding to protonated cluster ions (CH 3 COOH) n ·H + , the feature related to the fragment ions (CH 3 COOH)H + ·COO (105 amu) via β-carbon-carbon bond cleavage is observed. By scanning photoionization efficiency spectra, appearance energies of the fragments (CH 3 COOH)·H + and (CH 3 COOH)H + ·COO are obtained. With the aid of theoretical calculations, seven fragmentation channels of acetic acid dimer cations were discussed, where five cation isomers of acetic acid dimer are involved. While four of them are found to generate the protonated species, only one of them can dissociate into a C–C bond cleavage product (CH 3 COOH)H + ·COO. After surmounting the methyl hydrogen-transfer barrier 10.84 ± 0.05 eV, the opening of dissociative channel to produce ions (CH 3 COOH) + becomes the most competitive path. When photon energy increases to 12.4 eV, we also found dimer cations can be fragmented and generate new cations (CH 3 COOH)·CH 3 CO + . Kinetics, thermodynamics, and entropy factors for these competitive dissociation pathways are discussed. The present report provides a clear picture of the photoionization and dissociation processes of the acetic acid dimer in the range of the photon energy 9–15 eV.
研究领域:
化学物理学
·
光谱学
·
计算化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
CRYSTENGCOMM
·
2014
·Vol. 16
·期 16
·3403-3413
·
IF 3.858
Enyan Guo,Longwei Yin,Luyuan Zhang
We report on solar cells based on CdS QD sensitized anatase TiO2 hierarchical nanostructures prepared via a facile and controlled hydrothermal process. To adjust the size of CdS QDs, the TiO2 surfaces were first treated with thiolactic acid which provides a binding site for Cd2+ ions. CdS QDs with controllable size are grown onto the TiO2 hierarchical nanostructures. The CdS QDs/TiO2 hierarchical heterojunction nanocomposites display a red shift from the ultraviolet to the visible light region with a longer wavelength for the absorption edge. The matching of band edges between CdS and TiO2 to form a semiconductor heterojunction plays an important role in effective separation of light induced electrons and holes, providing a promising photoanode for its wide absorption spectrum, high electron injection efficiency, and fast electron transference. Under UV-vis irradiation, both CdS and TiO2 are excited. Under visible light irradiation, photons are captured by CdS QDs, with the photogenerated electron–hole pairs rapidly separated into electrons and holes at the interface between TiO2 and CdS QDs. In addition to this, more photoelectrons are generated from TiO2 by harvesting UV photons. TiO2 collects the photoelectrons from CdS and passes them through to the back contact. The holes (from both CdS and TiO2) generated in the process are transferred to the solid–liquid interface. Under one sun illumination, the solar cells based on CdS QDs/TiO2 hierarchical heterojunction nanocomposites with a smaller average size of 7.6 nm for CdS QDs show a maximum short circuit current density of 6.09 mA cm−2 and a conversion efficiency of 3.06%. The performance improvement of the solar cells based on CdS QDs/TiO2 hierarchical nanostructures can be attributed to the unique microstructure characteristics and the bandgap energy matching between the CdS QDs and TiO2.
研究领域:
材料科学
·
纳米技术
·
光伏技术
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2021
·
IF 8.128
Naseeb Ullah,Zhaoqi Song,Wei Liu,Chi-Ching Kuo,Aymeric Ramiere,Xingke Cai
Controlled synthesis of noble metal nanoparticles with well-defined size and good dispersion on supports has been a long-standing challenge in heterogeneous catalysis. Here we report a facile photo-assisted H 2 in situ reduction process to synthesize monodispersed Pd nanoparticles with 2–4 nm size on photo-insensitive Sm 2 O 3 rare-earth metal oxide with nanorod morphology. Thanks to the contribution of UV irradiation, the photoelectrons generation in the Sm 2 O 3 support accelerates the H 2 reduction of Pd 2+ ions into Pd 0 and stabilize the growth of very small Pd nanoparticles homogeneously dispersed on the support. The homogeneous distribution of the Pd NPs on the surface of Sm 2 O 3 is most likely attributed to the profuse nucleation sites created by the UV irradiation and the abundance of hydroxyl groups on the support. The hydrogenation of styrene to ethylbenzene was studied as a model reaction. As a result, the UV radiated sample shows an excellent TOF value of 7419 h −1 , which is quadruple of the sample without UV irradiation, under the condition of 0.1 MPa H 2 at a content of 1.0 wt% Pd. Besides, UV radiated sample shows a negligible performance degradation during the repeated cycling process. This photo-promoted H 2 reduction process provides a convenient and straightforward route for assembling materials with novel structures and functions for nanotechnology applications.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
危险品化学品经营许可证（带存储）