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Effect of femtosecond pulse profile on excitation and dissociation of the nonadiabatic coupling molecule. Chem Phys Lett 2022. [DOI: 10.1016/j.cplett.2022.139388] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Cao YD, Yin D, Wang ML, Pang T, Lv Y, Liu B, Gao GG, Ma L, Liu H. Pt-Substituted polyoxometalate modification on the surface of low-cost TiO 2 with highly efficient H 2 evolution performance. Dalton Trans 2020; 49:2176-2183. [PMID: 31998895 DOI: 10.1039/c9dt04446a] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In this study, Pt-substituted polyoxometalate was first modified on the surface of commercially available TiO2, forming an efficient photocatalyst with high reactivity for hydrogen evolution. During the photocatalytic process, Pt-polyoxometalates not only increase the mobility rate of electrons but also improve the separation efficiency of photoinduced electrons and holes. After photoreduction, the in situ generated Pt0 species are anchored on the surface of polyoxometalate anion, which prevents further agglomeration. Then, the in situ formed Pt0 species and polyoxometalates synergistically promote the efficiency of photoinduced electron transfer from TiO2 to the protons adsorbed on the Pt0 surface. Although the content of Pt0 in the nanocomposite is only 0.6%, the photocatalytic hydrogen production rate reaches 5.6 mmol g-1 h-1 and remains stable at 4.5 mmol g-1 h-1 after the continuous catalytic process. Due to the modification of TiO2 by Pt-substituted polyoxometalate, this nanocomposite represents a practical model that possesses highly efficient photoelectric conversion performance. The presented work not only extends the family of new TiO2-polyoxometalate-based materials but also takes a further step toward the practical application of commercial TiO2 in photocatalytic hydrogen production.
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Affiliation(s)
- Yun-Dong Cao
- School of Materials Science and Engineering, University of Jinan, 250022, Jinan, China.
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Chen L, Chen WL, Wang XL, Li YG, Su ZM, Wang EB. Polyoxometalates in dye-sensitized solar cells. Chem Soc Rev 2019; 48:260-284. [PMID: 30451261 DOI: 10.1039/c8cs00559a] [Citation(s) in RCA: 158] [Impact Index Per Article: 31.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Dye-sensitized solar cells (DSSCs) are the third generation of photovoltaic cells developed by Grätzel and O'Regan. They have the characteristics of low cost, simple manufacturing process, tunable optical properties, and higher photoelectric conversion efficiency (PCE). With an ever increasing energy crisis, there is an urgent need to develop highly efficient, environmentally benign, and energy-saving cell materials. Polyoxometalates (POMs), a kind of molecular inorganic quasi-semiconductor, are promising candidates for use in different parts of DSSCs due to their excellent photosensitivity, redox, and catalytic properties, as well as their relative stability. Following a brief introduction to the development of DSSCs and the potential virtues of POMs in DSSCs, we attempt to make some generalizations about the energy level regulation of POMs that is the underlying theoretical basis for their application in DSSCs, and then we summarize the research progress of POMs in DSSCs in recent years. This is organized in terms of the properties of POMs, namely, electron acceptor, photosensitivity, redox and catalysis, based on the accumulation of our research into POMs over many years. Meanwhile, in view of the fact that the properties of POMs depend primarily on their electronic structural diversity, we keep this point in mind throughout the article with a view to revealing their structure-property relationships. Finally we provide a short summary and remarks on the future outlook. This review may be of interest to synthetic chemists devoted to designing POMs with specific structures, and researchers engaged in the extension of POMs to photoelectric materials.
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Affiliation(s)
- Li Chen
- Key Laboratory of Polyoxometalate Science of Ministry of Education, Department of Chemistry, Northeast Normal University, Changchun 130024, P. R. China.
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Sun Z, Wang C, Zhao W, Zheng Y, Yang C. Control of photodissociation of the NaI molecule via pulse chirping. Phys Chem Chem Phys 2018; 20:20957-20962. [PMID: 30069561 DOI: 10.1039/c8cp02449a] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A dynamic pump control scheme is proposed to manipulate the predissociation process of NaI molecules in different reaction channels. A linearly chirped pulse is used to excite the NaI molecule, and a time-delayed infrared pulse is employed to modify the molecular potentials in the coupling zone. The predissociation branching ratio of the product from two channels can be controlled by tuning the chirp rate with a proper range of delay times. Furthermore, an additional ultrafast photoionization step is adopted to monitor the wave packet evolution and probe the possible modifications of the electronic potential under the influence of a chirped pump field to reveal the physical mechanism behind the control. Aulter-Townes splitting is observed at a proper chirp rate, and the dressed-state population can be controlled via pulse chirping.
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Affiliation(s)
- Zhaopeng Sun
- School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, China.
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Guo W, Lu X, Wang X. The delay time dependence of the photoelectron spectra and state populations of three-level ladder K2 molecule. RUSSIAN JOURNAL OF PHYSICAL CHEMISTRY A 2017. [DOI: 10.1134/s0036024417020352] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Li YH, Lu XQ, Guo W, Yao HB. Influence of Femtosecond Laser Parameters on Autler-Townes Splitting of Three-Level Ladder Molecules. CHINESE J CHEM PHYS 2015. [DOI: 10.1063/1674-0068/28/cjcp1501006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Guo W, Lu X, Wang X, Yao H. The effect of pump-2 laser on Autler-Townes splitting in photoelectron spectra of K2 molecule. Phys Chem Chem Phys 2014; 16:20755-62. [PMID: 25163761 DOI: 10.1039/c4cp02258k] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
We theoretically investigated Autler-Townes (AT) splitting in the photoelectron spectra of a four-level ladder K2 molecule driven by pump1-pump2-probe pulses by employing the time-dependent wave packet approach. The effect of pump-2 laser intensity and wavelength on AT splitting was studied for the first time. Triple splitting with asymmetric profiles arises because of the non-resonant excitation. The triple splitting transforms to double splitting when pump-2 detuning approaches ±1/2 times of pump-1 Rabi frequency. The splitting between two side band peaks in the triplet or doublet does not change with the pump-2 laser wavelength. The three peaks shift to a lower energy with a different shift as pump-2 wavelength increases. The magnitude of AT splitting increases with increasing pump-2 laser intensity. The asymptotic behavior of AT splitting with the pump-2 laser intensity are interesting at the threshold point of the near resonant region and far-off resonant region.
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Affiliation(s)
- Wei Guo
- School of Electric Engineering, University of South China, Hengyang 421001, P. R. China
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Yao H, Zhao G. Theoretical investigation of the competitive mechanism between dissociation and ionization of H₂⁺ in intense field. J Phys Chem A 2014; 118:9173-81. [PMID: 24806756 DOI: 10.1021/jp5030153] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The competitive mechanism between dissociation and ionization of hydrogen molecular ion in intense field has been theoretically investigated by using an accurate non-Born-Oppenheimer method. The relative yield of fragments indicates that the dissociation and ionization channels are competitive with the increasing laser intensity from 5.0 × 10(13) to 2.0 × 10(14) W/cm(2). In the case of intensity lower than 1.0 × 10(14) W/cm(2), the dissociation channel is dominant, with a minor contribution from ionization. The mechanism of dissociation includes the contributions from the bond softening, bond hardening, below-threshold dissociation, and above-threshold dissociation, which are strongly dependent on the laser intensity and initial vibrational state. Furthermore, the ionization dominates over the dissociation channel at the highest intensity of 2.0 × 10(14) W/cm(2). The reasonable origin of ionization is ascribed as the above-threshold Coulomb explosion, which has been demonstrated by the space-time dependent ionization rate. Moreover, the competition mechanism between dissociation and ionization channels are displayed on the total kinetic energy resolved (KER) spectra, which could be tested at current experimental conditions.
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Affiliation(s)
- Hongbin Yao
- State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences , Dalian 116023, China
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Quasi-classical trajectory study of the reaction N(4S) + H2 and its reverse reaction: Role of initial vibrational and rotational excitations in chemical stereodynamics. J CHEM SCI 2013. [DOI: 10.1007/s12039-013-0429-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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YAO HONGBIN, LIN SHIYING, ZHENG YUJUN. NONADIABATIC EFFECTS IN FEMTOSECOND PHOTOIONIZATION OF NaI MOLECULE. JOURNAL OF THEORETICAL & COMPUTATIONAL CHEMISTRY 2012. [DOI: 10.1142/s0219633611006608] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
In this work, the nonadiabatic effects in the femtosecond photoionization of NaI molecule driven by pump and probe pulses are investigated theoretically using the accurate quantum wave packet method. The calculation with the inclusion of nonadiabatic coupling remarkably improves the agreement with experimental results of Jouvet et al. [J Phys Chen A101: 2555, 1997], indicating the importance of the nonadiabatic effect. Moreover, the dynamical evolutions of wave packets and their corresponding time-resolved photoelectron spectroscopy are presented both on the adiabatic and diabatic potentials. These comparisons contribute to further understanding of the influences of nonadiabatic effects in the femtosecond photoionization of NaI molecule.
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Affiliation(s)
- HONG-BIN YAO
- School of Physics, Shandong University, Jinan 250100, P. R. China
| | - SHI-YING LIN
- School of Physics, Shandong University, Jinan 250100, P. R. China
| | - YU-JUN ZHENG
- School of Physics, Shandong University, Jinan 250100, P. R. China
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Sun Z, Lin SY, Zheng Y. Adiabatic and non-adiabatic quantum dynamics calculation of O(1D) + D2 → OD + D reaction. J Chem Phys 2011; 135:234301. [DOI: 10.1063/1.3668084] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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Kim J, Tao H, White JL, Petrović VS, Martinez TJ, Bucksbaum PH. Control of 1,3-Cyclohexadiene Photoisomerization Using Light-Induced Conical Intersections. J Phys Chem A 2011; 116:2758-63. [DOI: 10.1021/jp208384b] [Citation(s) in RCA: 82] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Affiliation(s)
- Jaehee Kim
- PULSE Institute, Stanford University, Stanford, California 94304, United States
| | - Hongli Tao
- PULSE Institute, Stanford University, Stanford, California 94304, United States
| | - James L. White
- PULSE Institute, Stanford University, Stanford, California 94304, United States
| | | | - Todd J. Martinez
- PULSE Institute, Stanford University, Stanford, California 94304, United States
| | - Philip H. Bucksbaum
- PULSE Institute, Stanford University, Stanford, California 94304, United States
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