To overcome current serious energy and environmental issues, photocatalytic water splitting holds great promise because it requires only solar energy as an energy input to produce hydrogen. Two-dimensional (2D) semiconductors and heterostructures possess several inherent advantages which are more suitable for boosting solar energy than their bulk counterparts. In this work, by performing high-throughput first-principles calculations combined with a semiempirical van der Waals dispersion correction, we first provided the periodic table of band alignment type for van der Waals heterostructures when packing any two of the 260 semiconductor monolayers obtained from our 2D semiconductor database (2DSdb) (https://materialsdb.cn/2dsdb/index.html). Based on the rules of thumb for photocatalytic water splitting, we have further screened dozens of potential semiconductors and thousands of heterostructures which are promising for photocatalytic water splitting. The resulting database would provide a useful guidance for experimentalists to design suitable 2D vdWHs and photocatalysts according to desired applications.
High throughput theoretical methods are increasingly used to identify promising photocatalytic materials for hydrogen generation from water as a clean source of energy. While most promising water splitting candidates require co-catalyst loading and electrical biasing, computational costs to predict them apriori becomes large. It is therefore important to identify bare, bias-free semiconductor photocatalysts with small initial hydrogen production rates, often in the range of tens of nano-mols per hour, as these can become highly efficient with further co-catalyst loading and biasing. Here we re…
The production of hydrogen fuels, via water splitting, is of practical relevance for meeting global energy needs and mitigating the environmental consequences of fossil-fuel-based transportation. Water photoelectrolysis has been proposed as a viable approach for generating hydrogen, provided that stable and inexpensive photocatalysts with conversion efficiencies over 10% can be discovered, synthesized at scale, and successfully deployed (Pinaud et al., Energy Environ. Sci., 2013, 6, 1983). While a number of first-principles studies have focused on the data-driven discovery of photocatalysts, i…
SrTiO$_3$ is a highly efficient photocatalyst for the overall water splitting reaction under UV irradiation. However, an atomic-level understanding of the active surface sites responsible for the oxidation and reduction reactions is still lacking. Here we present a unified experimental and computational account of the photocatalytic activity at the SrO- and TiO$_2$- terminations of aqueous-solvated [001] SrTiO$_3$. Our experimental findings show that the overall water-splitting reaction proceeds on the SrTiO$_3$ surface only when the two terminations are simultaneously exposed to water. Our si…
The improved photocatalytic water splitting using 2D materials has technological importance for economically viable renewable energy. The present study focuses on the effect of uniaxial, biaxial, and vertical strain on the energy gap and band edge positions of C2N/MoS2 van der Waals heterostructures through first-principles density functional theory using PBE and SCAN functionals. The calculations establish that SCAN functional provides comparatively much better results as compared to the PBE for the band gap and band alignment study. The heterostructure exhibits a type- II band alignment whic…
Using first principles calculations, the energetic stability of two-dimensional (2D) binary compounds $XY$ is investigated, where $X$ and $Y$ indicate the metallic element from Li to Pb in the periodic table. Here, 1081 compounds in the buckled honeycomb (BHC), buckled square, B2, L1$_0$, and B$_h$ structures are studied. For the compounds that have negative formation energy in the BHC structure or the compounds that can have the B$_h$ structure, the phonon dispersions of the 2D structures are also calculated. We demonstrate that (i) a negative formation energy is neither a sufficient nor nece…
We present the result of an \textit{ab initio} search for new Dirac materials among inverse perovskites. Our investigation is focused on the less studied class of lanthanide antiperovskites containing heavy $f$-electron elements in the cation position. Some of the studied compounds have not yet been synthesized experimentally. Our computational approach is based on density functional theory calculations which account for spin-orbit interaction and strong correlations of the $f$-electron atoms. We find several promising candidates among lanthanide antiperovskites which host bulk Dirac states cl…
Escaping the Hydrolysis Trap: An Agentic Workflow for Inverse Design of Durable Photocatalytic Covalent Organic Frameworks
Luxembourg Institute of Science and Technology (LIST)（卢森堡科学与技术研究院）；Department of Physics and Materials Science, University of Luxembourg（卢森堡大学物理与材料科学系）
Imaging nanoscale photocarrier traps in solar water-splitting catalysts
California Institute of Technology（加州理工学院）；University of California, Irvine（加州大学尔湾分校）；Center for Nanoscale Materials, Argonne National Laboratory（阿贡国家实验室纳米材料中心）；Irvine Materials Research Institute (IMRI), University of California, Irvine（加州大学尔湾分校欧文材料研究所）；Sandia National Laboratories（桑迪亚国家实验室）；Tokyo University of Science（东京科学大学）
In search of high performance anode materials for Mg batteries: computational studies of Mg in Ge, Si, and Sn
我们目前的从头算研究的结构，能量学，和扩散性能的Mg在Si，Ge和Sn金刚石结构，以评估其潜在的插入型阳极材料的镁电池。我们表明，Si可以提供最高的比容量（3817毫安时g-1）和最低的平均插入电压（~0.15 eV vs. Mg）的Mg存储。然而，由于其显著的晶格膨胀百分比（~216%）和缓慢的Mg扩散，Sn和Ge更有吸引力;两种阳极具有比Si更低的晶格膨胀（分别为~ 120%和~ 178%）和扩散势垒（对于单Mg扩散，分别为~0.50和~0.70 eV）。我们表明，镁-镁相互作用在不同阶段的充电可以显着降低扩散势垒相比，单原子扩散，高达0.55 eV。
Finding low-energy molecular conformers is challenging due to the high dimensionality of the search space and the computational cost of accurate quantum chemical methods for determining conformer structures and energies. Here, we combine active-learning Bayesian optimization (BO) algorithms with quantum chemistry methods to address this challenge. Using cysteine as an example, we show that our procedure is both efficient and accurate. After only one thousand single-point calculations and approximately thirty structure relaxations, which is less than 10% computational cost of the current fastes…
Semiconductors offer a promising platform for physical implementation of qubits, but their broad adoption is presently hindered by limited scalability and/or very low operating temperatures. Learning from the nitrogen-vacancy centers in diamond, our goal is to find equivalent optically active point defect centers in crystalline silicon, which could be advantageous for their scalability and integration with classical devices. Transition metal (TM) impurities in silicon are common paramagnetic deep defects, but a comprehensive theoretical study of the whole 3$d$ series that considers generalized…
Physics-Informed Tree Search for High-Dimensional Computational Design
Department of Mechanical and Industrial Engineering, University of Illinois, Chicago（机械与工业工程系，伊利诺伊大学芝加哥分校）；Center for Nanoscale Materials, Argonne National Laboratory（纳米材料中心，阿贡国家实验室）；Mathematics and Computer Science Division, Argonne National Laboratory（数学与计算机科学部，阿贡国家实验室）
Adaptive Pruning for Increased Robustness and Reduced Computational Overhead in Gaussian Process Accelerated Saddle Point Searches
Rohit Goswami Institute IMX and Lab-COSMO（Rohit Goswami 实验室IMX和Lab-COSMO）；École polytechnique fédérale de Lausanne (EPFL)（联邦理工学院洛桑校区）；Science Institute & Faculty of Physical Sciences University of Iceland（冰岛大学科学研究院及物理科学学院）
Transition metal nitrides have attracted much interest of the scientific community for their intriguing properties and technological applications. Here we focus on yttrium dinitride (YN$_{2}$) and its formation and structural transition under pressure. We employed a fixed composition USPEX search to find the most stable polymorphs. We choose yttrium as a proxy for the lanthanide series because it has only $+3$ oxidation state, contrary to most transition metals. We then computed thermodynamic and dynamical stability of these structures compared to the decomposition reactions and we found that …
