Boron-modulated surface of hollow nickel framework for improved hydrogen evolution

MGT: Machine Learning Accelerates Performance Prediction of Alloy Catalytic Materials

The application of deep learning technology in the field of materials science provides a new method for predicting the adsorption energy of high-performance alloy catalysts in hydrogen evolution reactions and material discovery. The activity and selectivity of catalytic materials are mainly influenced by the properties and positions of active sites and adsorption sites. However, current deep learning models have not sufficiently focused on the importance of active atoms and adsorbates, instead placing more emphasis on the overall structure of the catalytic materials. In this paper, the overall molecular graph and a masked graph, which ignores fixed atoms, are separately input into the Masked Graph Transformer (MGT) network to enhance the model's ability to recognize key sites in catalytic reactions. Second, we introduce a nonlinear message-passing mechanism to improve the dot-product attention in the Transformer and capture the directional information on the relative positions of nodes by integrating molecular geometric information through deep tensor products. Subsequently, we constructed the NLMP-TransNet framework, which combines MPNN and Transformer and optimizes the model's learning and prediction capabilities through weight sharing and residual connections. The MGT achieves an error rate of 0.5447 eV on the small data set OC20-Ni, surpassing existing technologies. Ablation studies confirm the necessity of focusing on site features for accurate adsorption energy prediction. Code is available at https://github.com/KristinSun/OCP-MGT.git.

Facile method to activate substrate for oxygen evolution by a galvanic-cell reaction

NiFe layered double hydroxide (NiFe LDH) is a promising material with multiple functions. In this communication, a novel method is used to prepare NiFe LDH. This synthesis method is achieved via galvanic-cell corrosion between nickel and iron substrates in aqueous solutions containing a halogen group anion (e.g., Cl) at ambient temperature. The as-prepared NiFe LDH electrodes are developed as electrocatalysts for the oxygen evolution reaction (OER) and exhibit excellent catalytic activities and durability. This work provides an energy-efficient, cost-effective, and scaled-up corrosion engineering approach for manufacturing NiFe LDH materials.

Multiple Effects of High Surface Area Hollow Nanospheres Assembled by Nickel Cobaltate Nanosheets on Soluble Lithium Polysulfides

Inhibiting the shuttle effect of soluble polysulfides and improving slow reaction kinetics are key factors for the future development of Li-S batteries. Herein, edelweiss shaped NiCo₂O₄ hollow nanospheres with a high surface area were prepared by a simple template method to modify the separator to realize multiple physical constraints and strong chemical anchoring on the polysulfides. On one hand, the good electrolyte wettability of NiCo₂O₄ promoted the migration of Li-ions and greatly improved the dynamics. On the other hand, mesoporous NiCo₂O₄ nanomaterials provided many strong chemical binding sites for loading sulfur species. The hollow structure also provided a physical barrier to mitigate the sulfur species diffusion. Therefore, the modified separator realized multiple physical constraints and strong chemical anchoring on sulfur species. As a result, the sulfur cathode based on this composite separator showed significantly enhanced electrochemical performance. Even at 4 C, a high capacity of 505 mAh g^-1 was obtained, and about 80.6% could be retained after 300 cycles.

Constructing 1D Boron Chains in the Structure of Transition Metal Monoborides for Hydrogen Evolution Reactions

The forms of boron atoms are many and varied in the structure of transition metal borides (TMBs). The form of boron atoms determines the structure, morphology, and properties of borides. Herein, transition metal monoborides (CrB and WB) with different arrangement of one-dimensional (1D) boron chains were synthesized under high pressures and high temperatures. The 1D boron chains between the interlayers of CrB are parallel to one another, while the 1D boron chains between the interlayers of WB are perpendicular to one another. The morphologies of CrB and WB also show large differences due to the difference in 1D boron chain arrangement. As electrocatalysts for hydrogen evolution reactions (HERs), CrB and WB show good catalysis activity and durability. WB has the smallest overpotential (210 mV) and Tafel slope (90.09 mV dec−1), which is mainly attributed to the intercrossing boron chains improving the electrical properties of WB, as well as the 5d electrons of W being more chemically active. The TOF value of WB is 1.35 s−1, proving that WB has a higher intrinsic catalytic activity during HERs. This work provides a data reference for the development of high-efficiency electrocatalysts.