Li-Min Liu

• PhD
• PI at Beihang University

The discovery of ferroelectric phases in HfO 2 offers insights into ferroelectricity. Its unique fluorite structure and complex polarization switching pathways exhibit distinct characteristics, challenging conventional analysis methods. Combining group theory and first-principles calculations, we identify numerous unconventional electric polarizati...

Monoatomic-layered carbon materials, such as graphene¹ and amorphous monolayer carbon2,3, have stimulated intense fundamental and applied research owing to their unprecedented physical properties and a wide range of promising applications4,5. So far, such materials have mainly been produced by chemical vapour deposition, which typically requires st...

Bimetallic single‐atom‐dimer (SAD) with unique electronic structures and adsorption properties presents exceptional catalytic performance owing to atomic‐level synergistic effects from direct bonding between different metal atoms. However, inherent characteristics of substrate present great challenges in their synthesis and mechanism investigation....

Recent experiments show that doping a small amount of fluorinated pseudohalides (BF4) into CH3NH3PbI3 (MAPbI3) can enhance the performance of wide-band-gap (WBG) perovskite solar cells. Using time-domain density functional theory and ab initio nonadiabatic molecular dynamics we demonstrate that BF4-doped WBG perovskites not only maintain the high d...

We present the implementation of the Hubbard ($U$) and Hund ($J$) corrected Density Functional Theory (DFT+$U$+$J$) functionality in the Quickstep program, which is part of the CP2K suite. The tensorial and L\"owdin subspace representations are implemented and compared. Full analytical DFT+$U$+$J$ forces are implemented and benchmarked for the tens...

Anisotropy is a significant and prevalent characteristic of materials, conferring orientation-dependent properties, meaning that the creation of original symmetry enables the key functionality that is not found in nature. Even with the advancements in atomic machining, synthesis of separated symmetry in different directions within a single structur...

Improving the absorption of electromagnetic waves at low-frequency bands (2-8 GHz) is crucial for the increasing electromagnetic (EM) pollution brought about by the innovation of the fifth generation (5G) communication technology. However, the poor impedance matching and intrinsic attenuation of material in low-frequency bands hinders the developme...

Despite the low solubility of hydrogen isotopes (HIs) in tungsten (W), their concentration can reach up to ∼10 at.% after low-energy plasma irradiation. This is generally attributed to the vacancies that may accommodate excessive HIs. However, the kinetic energy of incident HIs transferred to W is far below the energy threshold to create a Frenkel...

Nickel-iron (Ni-Fe) hydroxides have received much attention as abundant and efficient electrocatalysts for the oxygen evolution reaction (OER) under alkaline conditions. However, the role of Fe dopants during the reaction...

Although direct generation of high-value complex molecules and feedstock by coupling of ubiquitous small molecules such as CO 2 and N 2 holds great appeal as a potential alternative to current fossil-fuel technologies, suitable scalable and efficient catalysts to this end are not currently available as yet to be designed and developed. To this end,...

Electrochemical carbon dioxide reduction reaction (CO 2 RR) to formate is of great interest in the field of electrochemical energy. Cu‐based material is an appealing electrocatalyst for CO 2 RR. However, retaining Cu ²⁺ under the high cathodic potential of CO 2 RR remains a great challenge, leading to low electrocatalytic selectivity, activity and...

Amorphous materials are metastable solids with only short-range order at the atomic scale, which results from local intermolecular chemical bonding. The lack of long-range order typical of crystals endows amorphous nanomaterials with unconventional and intriguing structural features, such as isotropic atomic environments, abundant surface dangling...

Homogeneous and nanometric metal clusters with unique electronic structures are promising for catalysis, however, common synthesis techniques for metal clusters suffer from large size and even metal nanocrystals attributing to their high surface energy and unsaturated configurations. Herein, a generalized rapid annealing strategy for synthesizing a...

Electrochemical CO2 reduction to C2H4 can provide a sustainable route to reduce globally accelerating CO2 emissions and produce energy-rich chemical feedstocks. However, the poor selectivity in C2H4 electrosynthesis limits its implementation in industrially interesting processes. Herein, we report a composite structured catalyst composed of Ag and...

Catalytic strategies based on main group metals are significantly less advanced than those of transition metal catalysis, leaving untapped areas of potentially fruitful research. We here demonstrate an effective approach for the modulation of Bi 6p energy levels during the construction of atomically dispersed clusters of amorphous BiOx. Bi oxidatio...

Defects play a crucial role in the surface reactivity and electronic engineering of titanium dioxide (TiO2). In this work, we have used an active learning method to train deep neural network potentials from the ab initio data of a defective TiO2 surface. Validations show a good consistency between the deep potentials (DPs) and density functional th...

As one of the most promising materials for next-generation solar cells, organometallic perovskites have attracted substantial fundamental and applied interest. Using first-principles quantum dynamics calculations, we show that octahedral tilting plays an important role in stabilizing perovskite structures and extending carrier lifetimes. Doping the...

Catalytic strategies based on main group metals are significantly less advanced than those of transition metal catalysis, leaving untapped areas of potentially fruitful research. We here demonstrate an effective approach for the modulation of Bi 6p energy levels during the construction of atomically dispersed clusters of amorphous BiOx. Bi oxidatio...

Integrating different reaction sites offers new prospects to address the difficulties in single-atom catalysis, but the precise regulation of active sites at the atomic level remains challenging. Here, we demonstrate a sodium-directed photon-induced assembly (SPA) strategy for boosting the atomic utilization efficiency of single-atom catalysts (SAC...

The interaction of water with TiO 2 surfaces is of crucial importance in various scientific fields and applications, from photocatalysis for hydrogen production and the photooxidation of organic pollutants to self-cleaning surfaces and bio-medical devices. In particular, the equilibrium fraction of water dissociation at the TiO 2 –water interface h...

Compared with layered materials such as graphite and transitional metal dichalcogenides with highly anisotropic in-plane covalent bonds, freestanding metallic two-dimensional (2D) films with atomic thickness are intrinsically more difficult to achieve. The omnidirectional nature of typical metallic bonds prevents the formation of highly anisotropic...

Exploring the transformation/interconversion pathways of catalytic active metal species (single atoms, clusters, nanoparticles) on a support is crucial for the fabrication of high-efficiency catalysts, the investigation of how catalysts are deactivated, and the regeneration of spent catalysts. Sintering and redispersion represent the two main trans...

Two-dimensional Janus MXY materials have been successfully synthesized from their parent species by CVD, SEAR, or PLD techniques. However, their detailed evolution process and underlying atomistic mechanism are far from understood conclusively, which are prompts for further research. Here, taking Janus MoSSe as a representation, the evolution proce...

The Schottky barrier height (ESBH) is a crucial factor in determining the transport properties of semiconductor materials and it directly regulates the carrier mobility in opto-electronics devices. In principle, van der Waals (vdW) Janus heterostructures offer an appealing avenue for controlling the ESBH. However, the underlying atomistic mechanism...

The theoretical capacity of a given electrode material is ultimately determined by the number of electrons transferred in each redox center. The design of multi-electron transfer processes could break through the limitation of one-electron transfer and multiply the total capacity but is difficult to achieve because multiple electron transfer proces...

FAPbI3, as a typical hybrid organic-inorganic perovskite, has attracted considerable interest due to its band gap suitable for visible light absorption and good thermal stability. A barrier to the use of FAPbI3 in commercial, stable devices is its unwanted black-to-yellow (non-perovskite to perovskite, commonly known as delta-to-alpha) phase transi...

Monolayer materials are endowed with an additional degree of freedom to modulate electronic structures and catalytic performances. Here, we report a direct synthesis of monolayer Ni(OH)2 on electrodes by in situ electrochemical conversion and a fundamental investigation of their catalytic activity. The monolayer structure greatly promotes hydrogen...

Owing to highly peculiar properties such as tunable electronic band gaps and coexistence of Rashba, excitonic and piezoelectric effects, low-dimensional Janus transition metal chalcogenides (TMDs) have received growing attention across different research and technological areas. Experimental and theoretical investigations have shown that these emer...

The atomically dispersed dual metal atom catalysts exhibit significant promise for the electrochemical energy conversion technologies. Herein, the hetero-nuclear precious-non-precious (Au-Co) dual atoms have been synthesized and subsequently applied for the acidic oxygen reduction reaction (ORR). The (Au-Co) dual atoms exhibit an outstanding activi...

Although oxygen vacancies (Ov s) play a critical role for many applications of metal oxides, a controllable synthetic strategy for anisotropic Ov s remains a great challenge. Here, a novel strategy is proposed to achieve the regional dual structure with anisotropic Ov s at both the surface and in the interior of TiO2 by constructing amorphous domai...

The excitation of surface-localized polaronic states has recently been discussed as an additional photocatalytic channel to band gap excitation for rutile TiO2. A contribution from photoexcitation of bulk polarons could, in principle, provide a greater contribution because of their higher number and their protection from oxidation. However, determi...

Single atomic Pt catalysts exhibit particularly high hydrogen evolution reaction (HER) activity compared to conventional nanomaterial‐based catalysts. However, the enhanced mechanisms between Pt and their coordination environment are not understood in detail. Hence, a systematic study examining the different types of N in the support is essential t...

Heterostructure is an effective approach in modulating the physical and chemical behavior of materials. Here, the first-principles calculations were carried out to explore the structural, electronic, and carrier mobility properties of Janus MoSSe/GaN heterostructures. This heterostructure exhibits a superior high carrier mobility of 281.28 cm2·V−1·...

Configuring metal single‐atom catalysts (SACs) with high electrocatalytic activity and stability is one efficient strategy in achieving the cost‐competitive catalyst for fuel cells’ applications. Herein, the atomic layer deposition (ALD) strategy for synthesis of Pt SACs on the metal–organic framework (MOF)‐derived N‐doped carbon (NC) is proposed....

Elemental 2D materials with fascinating characteristics are regarded as an influential portion of the 2D family. Iodine is as a typical monoelemental molecular crystal and exhibits great prospects of applications. To realize 2D iodine, not only is it required to separate the weak interlayer van der Waals interactions, but also to reserve the weak i...

Significance Electrochemical water splitting to generate hydrogen and oxygen is proposed as a promising way for building a clean-energy future. One of the challenges facing this scenario is to develop robust electrocatalysts, especially for the kinetically sluggish oxygen evolution reaction (OER) process. In this work, the delafossite analog was pr...

Photoreduction of molecular CO2 by solar light into added-value fuels or chemical feedstocks is an appealing strategy to simultaneously overcome environmental problems and energy challenges. However, multiple reaction steps and a large number of possible products have significantly hindered the development of highly selective catalysts capable to d...

The substantial capacity gap between available anode and cathode materials for commercial Li-ion batteries (LiBs) remains, as of today, an unsolved problem. Oxygen vacancies (OVs) can promote Li-ion diffusion, reduce the charge transfer resistance, and improve the capacity and rate performance of LiBs. However, OVs can also lead to accelerated degr...

Organic–inorganic lead halide perovskite solar cells have attracted great attention due to their high conversion efficiency, easy preparation, and low cost. In spite of impressive development, some fundamental scientific issues regarding perovskites have not been resolved, such as the inclusion of toxic Pb, their poor stability under moisture, oxyg...

Defects and water generally co-exist on the surfaces of reducible metal oxides for heterogeneous photo-catalysis in aqueous environments, which makes quantification and understanding of their coupling essential for development of practical solutions. To this end, here we explore and quantify the coupling between water (H2O) and hydrogen (H) induced...

By combined use of Wide-Angle X-ray Scattering, Thermo-Gravimetric Analysis, Inelastic Neutron Scattering, Density Functional Theory and Density Functional Theory Molecular Dynamics simulations, we investigate the structure, dynamics and stability of the water wetting-layer at single-walled aluminogermanate imogolite nanotubes (SW Ge-INTs): an arch...

Strain engineering has become an emerging strategy to tailor the performance of nanocatalysts. However, current strained catalysts overwhelmingly rely on stresses originated at catalyst-support interfaces. Self-standing strained nanostructures are extremely challenging to produce and thus their impact on catalytic and photocatalytic activities rema...

Single-atom catalysts with unique electronic structures are drawing increasing attention as compared with nano-catalysts. However, subnano-catalysts, falling between the two categories, may match the demands of catalytic reactions better due to their tunable electronic structure, but they have rarely been studied. Here, we report a subnano-rutheniu...

Charge carrier recombination plays a vital role in the CH3NH3PbI3 perovskite solar cell. By investigating a possible synergy between ion migration and charge carrier recombination, we demonstrate that the nonradiative recombination accelerates by an order of magnitude during iodide migration. The migration induces lattice distortion that brings ele...

An amendment to this paper has been published and can be accessed via a link at the top of the paper.

Titanium oxide structures featuring highly reduced TiOx films on top of nearly stoichiometric TiO2 hold promise for applications ranging from photocatalysis to resistance switching devices. Here, we focus on titanium monoxide (TiO) layers on anatase TiO2 (001) and use first principles calculations to investigate their structure and properties as we...

Single atom catalysts exhibit particularly high catalytic activities in contrast to regular nanomaterial-based catalysts. Until recently, research has been mostly focused on single atom catalysts, and it remains a great challenge to synthesize bimetallic dimer structures. Herein, we successfully prepare high-quality one-to-one A-B bimetallic dimer...

The TiO2-Pt-water interface is of great relevance in photocatalysis where Pt is widely used as a co-catalyst for enhancing hydrogen evolution on aqueous TiO2. Using ab initio molecular dynamics, we investigated this interface focusing on Pt single atoms supported on anatase TiO2 (101) in water environment. Based on recent experiments showing a broa...

Sodium tantalate, NaTaO3, has attracted interest as one of the few photocatalysts capable to perform overall water splitting, i.e. simultaneously produce oxygen and hydrogen from water. In particular, an interesting and not fully understood observation is that the efficiency of NaTaO3 increases dramatically in the presence of cation doping. To obta...

Water evaporation is a ubiquitous phenomenon in nature and the essential component in water cycle on the earth. It is appealing to produce high evaporation rate toward application in desalination and sterilization, but remains a great challenge at relatively low temperature under solar irradiation. In this study, free-standing membranes of highly o...

Janus transition metal dichalcogenides (TMDs) have recently emerged as a new class of two-dimensional materials with a vertical dipole moment. Here, using time-domain ab initio simulations, we show that electron-hole recombination can be substantially suppressed via different stacking orientations of bilayer MoSSe. Despite having a larger net dipol...

A major efficiency limit for solution-processed perovskite optoelectronic devices, for example light-emitting diodes, is trap-mediated non-radiative losses. Defect passivation using organic molecules has been identified as an attractive approach to tackle this issue. However, implementation of this approach has been hindered by a lack of deep under...

Methylammonium lead iodide perovskite, CH3NH3PbI3, has attracted particular attention due to its fast increase in efficiency for solid‐state solar cells application. However, little is known about the influence of dipole moments of organic molecules on the electronic structures. In this study, first principles calculations are carried out to invest...

Surfaces, interfaces and grain boundaries are classically known to be sinks of defects generated within the bulk lattice. Here, we report an inverse case by which the defects generated at the particle surface are continuously pumped into the bulk lattice. We show that, during operation of a rechargeable battery, oxygen vacancies produced at the sur...

A crucial obstacle to photoelectrochemical (PEC) water splitting is the scarcity of p-type photocathodes with superior charge separation ability. Nanocrystals with well-defined anisotropic shapes offer an exciting opportunity for tailoring PEC performance of semiconductors. In this paper, varied SnS nanostructures with different dimensions were con...

Much efforts are being pursued in hybridizing TiO2 photocatalysts with graphene-analogue g-C3N4. However, a fundamental understanding on the interfacial behavior of charge carriers is still lacking. In this paper, the impact of exposed facets and structural defects on the charge transfer mechanism around heterostructured interfaces was investigated...

Temperature can govern morphologies, structures and properties of products from synthesis in solution. A reaction in solution at low temperature may result in different materials than at higher temperature due to thermodynamics and kinetics of nuclei formation. Here, we report a low-temperature solution synthesis of atomically dispersed cobalt in a...

The use of electrode additives such as binder and conductive additive (CA) in addition to high pore volume for electrolytes, results in reduced volumetric energy densities of all battery electrodes. In this work, it is proposed to use poly(furfuryl alcohol) (PFA) conductive resin as a trifunctional electrode additive to replace polyvinylidene fluor...

The synergetic contribution of crystal facets and atomic cocatalysts on the photoacitivity of TiO2 was fundamentally investigated. Atomic dispersed Pt and Au were deposited onto 001-faceted and 101-faceted TiO2, respectively. When used as photocatalysts for photocatalytic H2 production, Pt/TiO2-001 showed 1156 and 3 times higher H2 evolution rate t...

It is well known that the size of a catalyst has a huge influence on catalytic activity. Thus, developing an easy and inexpensive way to synthesize nanocatalysts with reduced size is very urgent. Here, we use galvanic replacement between Au and Fe at ultralow temperature to prepare coexisting atomically dispersed Au and small Au nanoparticles. The...

The majority of chemical syntheses involve the use of catalysts, which play a crucial role in the yield and conversion rates of chemical reactions. In view of the increasing demand for chemical commodities and specialties linked to the growth of the world's population and the living standards, highly efficient and low-cost catalysts are urgently re...

We investigate the effect of adsorbates on the structure and photoabsorption of reduced TiO2 by first-principles calculations of rutile TiO2(110) in the presence of both titanium interstitials (Tiints) and adsorbed water or methanol. Our results show that, while Tiints prefer to reside in deep inner layers when the surface is clean, they tend to di...

Transition metal chalcogenides have attracted considerable attention because of their wide applications in solving energy and environmental problems. Here, the electronic structures and optical properties of Janus MoSSe nanotubes are explored by first‐principles calculations. It is shown that the Janus MoSSe nanotubes exhibit versatile electronic p...

We have used two-photon photoemission (2PPE) spectroscopy and first-principles density functional theory calculations to investigate the electronic structure and photoabsorption of the reduced anatase TiO2 (101) and rutile TiO2 (110) surfaces. 2PPE measurements on anatase (101) show an excited resonance induced by reduced Ti3+ species centered arou...

Determination of the atomic structure of inorganic single-walled nanotubes with complex stoichiometry remains elusive due to the too many atomic coordinates to be fitted with respect to X-ray diffractograms inherently exhibiting rather broad features. Here we introduce a methodology to reduce the number of fitted variables and enable resolution of...

The Front Cover shows a novel three‐dimensional Co3O4@NiFe layered double hydroxide core–shell nanoarchitecture that is successfully fabricated on Ni foam. The hierarchical hybrid electrode exhibits excellent electrocatalytic performance in overall water splitting with a low overpotential and long‐term stability. More information can be found in th...