Fengyu Li

Bio: Fengyu Li is an academic researcher from Inner Mongolia University. The author has contributed to research in topics: Density functional theory & Monolayer. The author has an hindex of 25, co-authored 54 publications receiving 2648 citations. Previous affiliations of Fengyu Li include Dalian University of Technology & University of Puerto Rico, Río Piedras.

Semiconducting Group 15 Monolayers: A Broad Range of Band Gaps and High Carrier Mobilities

Abstract: Optoelectronic applications require materials both responsive to objective photons and able to transfer carriers, so new two-dimensional (2D) semiconductors with appropriate band gaps and high mobilities are highly desired. A broad range of band gaps and high mobilities of a 2D semiconductor family, composed of monolayer of Group 15 elements (phosphorene, arsenene, antimonene, bismuthene) is presented. The calculated binding energies and phonon band dispersions of 2D Group 15 allotropes exhibit thermodynamic stability. The energy band gaps of 2D semiconducting Group 15 monolayers cover a wide range from 0.36 to 2.62 eV, which are crucial for broadband photoresponse. Significantly, phosphorene, arsenene, and bismuthene possess carrier mobilities as high as several thousand cm2 V−1 s−1. Combining such broad band gaps and superior carrier mobilities, 2D Group 15 monolayers are promising candidates for nanoelectronics and optoelectronics.

Exploration of High-Performance Single-Atom Catalysts on Support M1/FeOx for CO Oxidation via Computational Study

Abstract: Inspired by the recently discovered highly active CO oxidation catalyst Pt1/FeOx [Qiao, B.; Wang, A.; Yang, X.; Allard, L. F.; Jiang, Z.; Cui, Y.; Liu, J.; Li, J.; Zhang, T. Nat. Chem. 2011, 3, 634–641], we systemically examined various single-atom catalysts M1/FeOx (M = Au, Rh, Pd, Co, Cu, Ru and Ti) by means of density functional theory (DFT) computations, aiming at developing even more efficient and low-cost nanocatalysts for CO oxidation. Our computations identified five single-atom catalysts, namely the oxygen-defective Rh1/FeOx and Pd1/FeOx, Ru1/FeOx with or without oxygen vacancy, and vacancy-free Ti1/FeOx and Co1/FeOx, which exhibit improved overall catalytic performance compared to Pt1/FeOx for the CO oxidation via a Langmuir–Hinshelwood (LH) mechanism. These theoretical results provide new guidelines to design even more active and/or cost-effective heterogeneous catalysts for CO oxidation.

Fe-Anchored Graphene Oxide: A Low-Cost and Easily Accessible Catalyst for Low-Temperature CO Oxidation

Abstract: By means of first-principles computations, we investigated the catalytic capability of the Fe-anchored graphene oxide (Fe–GO) for CO oxidation with O2. The high-energy barrier of Fe atom diffusion on GO and the strong binding strength of Fe anchored on GO exclude the metal clustering problem and enhance the stability of the Fe–GO system. The Fe-anchored GO exhibits good catalytic activity for CO oxidation via the favorable Eley–Rideal (ER) mechanism with a two-step route, while the Langmuir–Hinshelwood (LH) mechanism is not kinetically favorable. The low-cost Fe-anchored GO system can be easily synthesized and serves as a promising green catalyst for low-temperature CO oxidation.

SiC2 silagraphene and its one-dimensional derivatives: where planar tetracoordinate silicon happens.

Abstract: The periodic systems containing planar tetracoordinate silicon (ptSi), SiC(2) silagraphene, nanotubes, and nanoribbons, were predicted by means of density functional theory (DFT) computations. In SiC(2) silagraphene, each silicon atom is bonded by four carbon atoms in a pure plane, representing the first anti-van't Hoff/Lebel species in the Si-containing extended system. SiC(2) nanotubes, rolled up by the SiC(2) silagraphene, exhibit excellent elastic properties. All these ptSi-containing nanomaterials are metallic, regardless of the chirality, tube diameter, or ribbon width. The high stabilities of these systems strongly suggest the feasibility for their experimental realizations.

B80 and B101-103 clusters: remarkable stability of the core-shell structures established by validated density functionals.

Abstract: Prompted by the very recent claim that the volleyball-shaped B(80) fullerene [X. Wang, Phys. Rev. B 82, 153409 (2010)] is lower in energy than the B(80) buckyball [N. G. Szwacki, A. Sadrzadeh, and B. I. Yakobson, Phys. Rev. Lett. 98, 166804 (2007)] and core-shell structure [J. Zhao, L. Wang, F. Li, and Z. Chen, J. Phys. Chem. A 114, 9969 (2010)], and inspired by the most recent finding of another core-shell isomer as the lowest energy B(80) isomer [S. De, A. Willand, M. Amsler, P. Pochet, L. Genovese, and S. Goedecher, Phys. Rev. Lett. 106, 225502 (2011)], we carefully evaluated the performance of the density functional methods in the energetics of boron clusters and confirmed that the core-shell construction (stuffed fullerene) is thermodynamically the most favorable structural pattern for B(80). Our global minimum search showed that both B(101) and B(103) also prefer a core-shell structure and that B(103) can reach the complete core-shell configuration. We called for great attention to the theoretical community when using density functionals to investigate boron-related nanomaterials.

Heterogeneous single-atom catalysis

Abstract: Single-atom catalysis has arguably become the most active new frontier in heterogeneous catalysis. Aided by recent advances in practical synthetic methodologies, characterization techniques and computational modelling, we now have a large number of single-atom catalysts (SACs) that exhibit distinctive performances for a wide variety of chemical reactions. This Perspective summarizes recent experimental and computational efforts aimed at understanding the bonding in SACs and how this relates to catalytic performance. The examples described here illustrate the utility of SACs in a broad scope of industrially important reactions and highlight the advantages these catalysts have over those presently used. SACs have well-defined active centres, such that unique opportunities exist for the rational design of new catalysts with high activities, selectivities and stabilities. Indeed, given a certain practical application, we can often design a suitable SAC; thus, the field has developed very rapidly and afforded promising catalyst leads. Moreover, the control we have over certain SAC structures paves the way for designing base metal catalysts with the activities of noble metal catalysts. It appears that we are entering a new era of heterogeneous catalysis in which we have control over well-dispersed single-atom active sites whose properties we can readily tune. Single-atom catalysts are heterogeneous materials featuring active metals sites atomically dispersed on a surface. This Review describes methods by which we prepare and characterize these materials, as well as how we can tune their catalytic performance in a variety of important reactions.

Ab initio calculation of vibrational absorption and circular dichroism spectra using density functional force fields

Abstract: : The unpolarized absorption and circular dichroism spectra of the fundamental vibrational transitions of the chiral molecule, 4-methyl-2-oxetanone, are calculated ab initio. Harmonic force fields are obtained using Density Functional Theory (DFT), MP2, and SCF methodologies and a 5S4P2D/3S2P (TZ2P) basis set. DFT calculations use the Local Spin Density Approximation (LSDA), BLYP, and Becke3LYP (B3LYP) density functionals. Mid-IR spectra predicted using LSDA, BLYP, and B3LYP force fields are of significantly different quality, the B3LYP force field yielding spectra in clearly superior, and overall excellent, agreement with experiment. The MP2 force field yields spectra in slightly worse agreement with experiment than the B3LYP force field. The SCF force field yields spectra in poor agreement with experiment.The basis set dependence of B3LYP force fields is also explored: the 6-31G* and TZ2P basis sets give very similar results while the 3-21G basis set yields spectra in substantially worse agreements with experiment. jg

Are MXenes Promising Anode Materials for Li Ion Batteries? Computational Studies on Electronic Properties and Li Storage Capability of Ti3C2 and Ti3C2X2 (X = F, OH) Monolayer

Abstract: Density functional theory (DFT) computations were performed to investigate the electronic properties and Li storage capability of Ti3C2, one representative MXene (M represents transition metals, and X is either C or/and N) material, and its fluorinated and hydroxylated derivatives. The Ti3C2 monolayer acts as a magnetic metal, while its derived Ti3C2F2 and Ti3C2(OH)2 in their stable conformations are semiconductors with small band gaps. Li adsorption forms a strong Coulomb interaction with Ti3C2-based hosts but well preserves its structural integrity. The bare Ti3C2 monolayer exhibits a low barrier for Li diffusion and high Li storage capacity (up to Ti3C2Li2 stoichiometry). The surface functionalization of F and OH blocks Li transport and decreases Li storage capacity, which should be avoided in experiments. The exceptional properties, including good electronic conductivity, fast Li diffusion, low operating voltage, and high theoretical Li storage capacity, make Ti3C2 MXene a promising anode material for...

Cocatalysts for Selective Photoreduction of CO2 into Solar Fuels.

Abstract: Photoreduction of CO2 into sustainable and green solar fuels is generally believed to be an appealing solution to simultaneously overcome both environmental problems and energy crisis. The low selectivity of challenging multi-electron CO2 photoreduction reactions makes it one of the holy grails in heterogeneous photocatalysis. This Review highlights the important roles of cocatalysts in selective photocatalytic CO2 reduction into solar fuels using semiconductor catalysts. A special emphasis in this review is placed on the key role, design considerations and modification strategies of cocatalysts for CO2 photoreduction. Various cocatalysts, such as the biomimetic, metal-based, metal-free, and multifunctional ones, and their selectivity for CO2 photoreduction are summarized and discussed, along with the recent advances in this area. This Review provides useful information for the design of highly selective cocatalysts for photo(electro)reduction and electroreduction of CO2 and complements the existing reviews on various semiconductor photocatalysts.