INTERNATIONAL JOURNAL OF HYDROGEN ENERGY
·
2017
·
IF 3.582
Haidong Chen,Feng Zhang,Xianwen Sun,Weifeng Zhang,Guoqiang Li
We systematically investigated the impact of reaction atmosphere on the Pt cocatalyst photodeposition and hydrogen evolution . A long induction period which is hardly found in close-system appears in the presence of oxygen, and is affected by the concentration of chloroplatinic acid. The Pt cocatalyst is metal state and contributes to the electronic states near Fermi level judging from the valence band X-ray photoelectron spectrum. The cocatalyst metal Pt will reduce the surface photovoltage signals due to the metal feature. The hydrogen evolution rate increased and reached a platform with increasing the Pt coverage on the surface of photocatalyst which is characterized by the Pt:Ti atomic ratio.
研究领域:
材料科学
·
催化化学
✓ 已验证
产品关联
DOI
高影响因子
INORGANIC CHEMISTRY
·
2019
·
IF 4.85
Ailijiang Abudurusuli,Kui Wu,Junjie Li,Alimujiang Yalikun,Zhihua Yang,Shilie Pan
A series of metal chalcogenides, LiBa2MIIIQ4 (MIII = Al, Ga, In; Q = S, Se), have been successfully obtained by the sealed-tube method. LiBa2MIIIQ4 undergoes a special structural transformation from the P21/m (LiBa2AlQ4 and LiBa2GaS4) to the P21/n (LiBa2InQ4) space group, which leads to disparities in electronic states, birefringence, and band gaps. Their structures feature the same zigzag [LiMIIIQ4]4– layers consisting of corner-shared LiQ4 and MIIIQ4 tetrahedra. The Ba atoms serve to bridge the [LiMIIIQ4]4– layers. The structural comparisons show that the radii of MIII and the coordination environments of the Ba atoms (BaQ7 vs BaQ8) cooperatively affect the structural transition from simple mirror m to diagonal glide n in LiBa2MIIIQ4. In addition, a statistical analysis uncovers that the MIII/Ba atomic ratio also plays an important role in regulating the structural transition in Ba- and MIII-based chalcogenides.
研究领域:
材料科学
·
化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
ELECTROCHEMISTRY COMMUNICATIONS
·
2018
·
IF 4.66
Bo Zhang,Lixia Yang,Jia Wang,Wen Luo,Yaqin Wu,Zhenling Wang
To uncover the distinction in the electronic density of states (DOS) near Fermi level at the graphene and metal, we compare the standard rate constant k 0 values for quinone species at graphene and gold nanoelectrodes, which might be affected by the electronic DOS near Fermi level. The experimental result indicates that the k 0 value obtained at the individual graphene flake of nanometer size is very close to that obtained on gold nanoelectrode, and higher than that at large graphene flake. Unlike the high electronic DOS in gold nanoelectrodes, the difference of k 0 values at graphene nanoelectrodes of different sizes will reveal the size-dependent DOS at single graphene flake.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2023
·
IF 9.5
Fengshou Yu,Zhixiang Zhou,Yang You,Jiayu Zhan,Tong Yao,Lu-Hua Zhang
Precise electronic state regulation through coordination environment optimization by metal–support interaction is a promising strategy to facilitate catalysis reaction, while the limited density of functional groups in the bulk substrate restricts the regulation degree. Herein, different sizes of Ti3C2Tx MXene with hydroxyl (−OH) terminal including the MXene layer (ML-OH, 3 μm), the MXene nanosheet (MNS-OH, 600 nm), and the MXene quantum dot (MQD-OH, 8 nm) were prepared to anchor CoPc, and the effect of −OH density on the performance of electrochemical CO2 reduction was systematically investigated. Notably, a linear relationship was established by plotting reactivity vs hydroxyl density. With the highest −OH density, CoPc/MQD-OH exhibits a superior Faradaic efficiency for CO formation (FECO) of ∼100% at −0.9 to −1.0 V vs RHE and a high FECO of >90% over a wide potential window from −0.8 to −1.4 V. The mechanism exploration shows that the axial coordination interaction of the −OH terminal with Co increases the electron density of the Co site, thus promoting the adsorption and activation of CO2. This work provides a new insight into designing of molecular catalysts with high efficiency and tunable structure for other electrochemical conversions.
研究领域:
材料科学
·
电化学
·
催化反应
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF RAMAN SPECTROSCOPY
·
2012
·Vol. 44
·期 3
·440-446
·
IF 3.087
Ming-Xia Liu,Bin-Bin Xie,Ming-Juan Li,Yan-Ying Zhao,Ke-Mei Pei,Hui-Gang Wang,Xuming Zheng
The structural dynamics of thioanisole in the S 2 (ππ*) electronic state that has large oscillator strength was studied by using the resonance Raman spectroscopy. The vibrational assignments were done for thioanisole on the basis of the FT-Raman and FT-IR measurements, the density-functional theory computations and the normal mode analysis. The A- and B-band resonance Raman spectra were obtained in cyclohexane, methanol and acetonitrile, in which ten modes in A’ irreducible representations were observed. The structural dynamics were obtained according to the resonance Raman intensity pattern. The vibroinc-coupling between the S 3 (πσ*) electronic state that has no oscillator strength and the S 2 (ππ*) electronic state were revealed. We discuss the correlation between our present structural dynamics and the previous S 2 (ππ*)/S 3 (πσ*) conical intersectional dynamics revealed by resonant-enhanced two-photon ionization and the photofragment excitation spectroscopic study. Copyright © 2012 John Wiley & Sons, Ltd.
研究领域:
化学物理学
·
光谱学
✓ 已验证
DOI
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2023
·
IF 22.1
Siyuan Hu,Mingzhen Huang,Jingru Li,Jinxin He,Kaiji Xu,Xiaoping Rao,Dongren Cai,Guowu Zhan
Herein, atomic layer deposition (ALD)-Al 2 O 3 films were applied as a medium to modulate the electronic states of the supported Pt. Based on the sacrificial template of ZIF-67, the ternary Co 3 O 4 /Pt/Al 2 O 3 catalyst exhibited better performance in catalytic CO oxidation than the binary Co 3 O 4 /Pt catalyst. Both experimental and calculation results indicate the existence of charge transport between the Pt and the ALD-Al 2 O 3 films, leading to electron-rich Pt, enhanced O 2 affinity, and reduced activation energy. Interestingly, the oxidation resistance of Pt nanoparticles was visualized when annealing Co 3 O 4 /Pt/Al 2 O 3 catalyst at high temperatures. Mechanism studies indicate the typical LH mechanism occurred in CO oxidation , showing that the co-adsorbed CO and O 2 could be converted to carbonate-type *OCOO intermediates via low energy barriers. At low temperatures, CO 2 was mainly produced by the lattice oxygen-mediated M-vK mechanism based on isotope labeling experiments. Our findings provide an alternative way to regulate the electronic states of noble metals by the ALD technique.
研究领域:
催化化学
·
材料科学
·
理论计算
✓ 已验证
产品关联
DOI
高影响因子
ADVANCED FUNCTIONAL MATERIALS
·
2023
·Vol. 33
·期 33
·2302003
·
IF 19
Mingyue Yuan,Hualiang Lv,Hanwen Cheng,Biao Zhao,Guanyu Chen,Jincang Zhang,Renchao Che
0D nanomaterials with high efficiency of atom utilization possess extraordinary tunability over bulk materials. Precise reconstruction of atoms in a 0D nanoparticle toward tuning of crystalline phases and defects is highly desirable but remains a grand challenge. In this study, a crystallization rate-controlled strategy is reported to achieve controllable reconstruction of atoms in situ, which inducts a series of monodisperse 0D molybdenum carbide nanoparticles (Mo x C NP) that anchor on a carbon matrix with adjustable crystalline phases and atom vacancies. Aberration-corrected transmission electron microscopy, electron paramagnetic resonance technique, density functional theory calculation, and electron holography jointly reveal the atomic reconstruction process and confirm its remarkable effects of optimizing the local electronic states and enhancing the heterointerface interactions. As a result, the optimized MoC/Mo 2 C heterostructure on the carbon matrix is shown to enable the promoted dielectric response and generate more than 90% absorption of lower-frequency microwaves (the current 5 th -generation communication band). The control of atomic reconstruction may provide an effective pathway for unlocking tunable dielectric properties of 0D nanomaterials toward various technological applications.
研究领域:
材料科学
·
物理学
·
电子工程
✓ 已验证
产品关联
DOI
高影响因子
Journal of Materials Chemistry A
·
2023
·Vol. 11
·期 35
·18811-18819
·
IF 11.9
Qiang Zhang,Jiadang Li,Nagendra S. Chauhan,Lifei Wang,Zhicheng Huang,Wenhao Fan,Kei Hayashi,Shaoping Chen,Jianfeng Fan,Yuzuru Miyazaki
Grain boundary (GB) scattering has been widely reckoned as a primary restraint on room-temperature (RT) carrier mobility in Mg3Sb2-based materials. In this work, two-dimensional graphene (G) with varied contents was added to single phase Mg3.24Sb1.5Bi0.49Te0.01 materials in order to tailor the highly resistive space-charge region at GBs. The results indicate that introducing G effectively lowers the carrier transport energy barrier Eb from 42 meV (pristine sample) to 18 meV (Mg3.24Sb1.5Bi0.49Te0.01/1.0 vol% G sample), and correspondingly increases the drift mobility by 112.5% from 32 cm2 V−1 s−1 to 68 cm2 V−1 s−1 at RT, leading to an enhanced power factor and thus ZT value. Besides, first-principles calculations were also performed to qualitatively bridge the underlying negative correlation between the electronic density of states (DOS) and GB potential barrier Eb. Moreover, the equivalent nano-particle phonon scattering is also realized through introducing the two-dimensional G, contributing to a moderate reduction in lattice thermal conductivity as quantitatively illustrated based on the Debye–Callaway model. Consequently, the figure of merit ZT for G-added samples is greatly improved in the entire temperature range compared with that of the G-free sample. This study opens up a new avenue for rationally engineering the grain boundary, via regulating interfacial electronic DOS, to optimize electrical transport properties and ZT values.
研究领域:
材料科学
·
物理学
✓ 已验证
产品关联
DOI
高影响因子
Nature Communications
·
2020
·Vol. 11
·期 1
·1-8
·
IF 12.121
Zhang Zhirong,Feng Chen,Liu Chunxiao,Zuo Ming,Qin Lang,Yan Xupeng,Xing Yulin,Li Hongliang,Si Rui,Zhou Shiming,Zeng Jie
Single-atom catalysts (SACs) exhibit intriguing catalytic performance owing to their maximized atom utilizations and unique electronic structures. However, the reported strategies for synthesizing SACs generally have special requirements for either the anchored metals or the supports. Herein, we report a universal approach of electrochemical deposition that is applicable to a wide range of metals and supports for the fabrication of SACs. The depositions were conducted on both cathode and anode, where the different redox reactions endowed the SACs with distinct electronic states. The SACs from cathodic deposition exhibited high activities towards hydrogen evolution reaction, while those from anodic deposition were highly active towards oxygen evolution reaction. When cathodically- and anodically-deposited Ir single atoms on Co 0.8 Fe 0.2 Se 2 @Ni foam were integrated into a two-electrode cell for overall water splitting, a voltage of 1.39 V was required at 10 mA cm −2 in alkaline electrolyte.
研究领域:
材料科学
·
电化学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
APPLIED CATALYSIS B-ENVIRONMENTAL
·
2025
·
IF 21.1
Chunyu Zhang,Guang Yang,Xueqing Gao,Zhiyun Li,Yifan Li,Siyuan Wang,Junyong Wang,Xunhua Zhao,Kai Zhang,Yu Kang,Yi Cui
Surface OH species on electrocatalysts play a pivotal role in affecting the hydrogen evolution reaction (HER). Herein, we highlight the critical role of surface OH basicity in regulating interfacial water structure and OH desorption behavior. By annealing Ru/Ni(OH) 2 at various temperatures, we successfully tailored the electronic state of surface OH species, with the catalyst annealed at 300 °C (Ru-Ni-300) exhibiting superior HER performance, achieving a current density of 100 mA/cm 2 at an exceptionally low overpotential of 71 mV. X-ray photoelectron spectroscopy demonstrates that the electron-rich surface OH species on Ru-Ni-300 exhibit strong Lewis basicity. The enhanced OH basicity facilitates the formation of hydrogen-bond networks with interfacial water through electron donation, which in turn promotes OH desorption kinetics. Quasi-in-situ XPS and density functional theory calculations further elucidated that the increased electron density on surface OH species reduces OH adsorption energy, thus accelerating HER performance. These findings unveil a direct correlation between surface OH basicity and HER efficiency, offering new insights into tailoring surface environments for advanced water-splitting electrocatalysts.
研究领域:
电化学
·
材料科学
✓ 已验证
DOI
高影响因子
ACS Applied Materials & Interfaces
·
2015
·
IF 6.723
Yingpan Song,Huifang Hu,Miao Feng,Hongbing Zhan
The density of electronic states (DOS) is an intrinsic electronic property that works conclusively in the electrochemistry of carbon materials. However, seldom has it been reported how the DOS at the Fermi level influences the electrochemical activity. In this work, we synthesized partially and fully unzipped carbon nanotubes by longitudinally unzipping pristine carbon nanotubes (CNTs). We then studied the electrochemical activity and biosensitivity of carbon materials by means of the CNTs and their derivatives to elucidate the effect of the DOS on their electrochemical performances. Tailoring of the DOS for the CNT derivatives could be conveniently realized by varying the sp2/sp3 ratio (i.e., graphite concentration) through manipulating the oxidative unzipping degree. Despite the diverse electron transfer mechanisms and influence factors of the four investigated redox probes (IrCl62–, [Fe(CN)6]3–, Fe3+, and ascorbic acid), the CNT derivatives exhibited consistent kinetic behaviors, wherein CNTs with a high DOS showed superior electrochemical response compared with partially and fully unzipped carbon nanotubes. For biological detection, the CNTs could simultaneously distinguish ascorbic acid, dopamine, and uric acid, while the three CNT derivatives could all differentiate phenethylamine and epinephrine existed in the newborn calf serum. Moreover, the three CNT derivatives all presented wide linear detection ranges with high sensitivities for dopamine, phenethylamine, and epinephrine.
研究领域:
材料科学
·
电化学
·
生物医学
✓ 已验证
产品关联
DOI
PubMed
高影响因子
MATERIALS RESEARCH BULLETIN
·
2022
·
IF 5.6
Yi Wang,Shaoqi Zhang,Yuxiang Yan,Hengdong Ren,Jian Chen,Lizhe Liu,Xinglong Wu
A series of flower-like BiOCl x Br 1-x (x = 0∼1) with different Cl − doping contents were prepared via a simple co-precipitation method. Experimental results show that BiOCl 0.2 Br 0.8 (20 mg) can decompose tetracycline hydrochloride (20 mg/L) of ∼100% within 30 min, which is far higher than those of the previously reported BiOCl and BiOBr. Microstructural and spectroscopic characterization demonstrates that Cl − doping can effectively change the growth orientation of the layered BiOCl x Br 1-x nanosheets to expose more (102) active surfaces. Density of states calculations and radical trapping experiments reveal that strong coupling between the electronic states of multi-anions adjusts the band structure, which improves light absorption and generation of main active species ⋅O 2 − . Meanwhile, strong polarization caused by anionic doping also promotes separation and migration of the photogenerated carriers to different positions of the active surface. As a result, the photocatalytic activities are improved largely and optimal in BiOCl 0.2 Br 0.8 .
研究领域:
材料科学
·
环境科学
·
化学
✓ 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）