ACKNOWLEDGEMENTS

27 Nov 2024

Submitted by (Bold are A*STAR Staff): Haimei Wang, Hao Yuan, Wanwan Wang, Lei Shen, Jianguo Sun, Ximeng Liu, Jing Yang, Xingyang Wang, Tuo Wang, Ning Wen, Yulin Gao, Kepeng Song, Dairong Chen, Shijie Wang, Yong-Wei Zhang, John Wang

Research Institute: IHPC, IMRE

Title of Paper: Asymmetric Polarization Modulation of d–p Hybridization-Enhanced Bidirectional Sulfur Redox Kinetics with Heteronuclear Dual-Atom CatalystsClic

Publish in: ACS Nano

Abstract: Lithium sulfur batteries (LiSBs) represent a highly promising avenue for future energy storage systems, offering high energy density and eco-friendliness. However, the sluggish kinetics of the sulfur redox reaction (SRR) poses a significant challenge to their widespread applications. To tackle this challenge, we have developed an efficient heteronuclear dual-atom catalyst (hetero-DAC) that leverages surface charge polarization to enhance the asymmetric adsorption of sulfur intermediates. This study investigates how asymmetric electronic redistribution of CoFe DACs modulates the d–p orbital hybridization with sulfur intermediates, revealing the mechanisms of moderate adsorption dynamics with enhanced catalytic performance. The dynamic switching between mono and dual adsorption sites, enabled by the heteronuclear polarized configuration, fine-tunes the orbital hybridization, boosting the bidirectional rate-determining steps, that is, the solid–solid conversion of Li2S2 to Li2S and the reverse dissociation of Li2S. Consequently, the thus-designed CoFe DACs cathode delivers impressive rate performance, achieving a high initial specific capacity of 703.9 mA h g–1 at 3 C, with a negligible decay rate of only 0.031% over 1000 cycles, demonstrating sustained long-term cycling stability. This work bridges geometric configurations and electronic structures, elucidating the mechanisms of asymmetric trapping and conversion enabled by hetero-DACs and offering fresh perspectives for catalyst design in LiSBs and beyond.

URL:  https://pubs.acs.org/doi/10.1021/acsnano.4c09637

05 Nov 2024

Submitted by (Bold are A*STAR Staff): Damien K. J. Lee, Teck Leong Tan, Man-Fai Ng

Research Institute: IHPC

Title of Paper: Machine Learning-Assisted Bayesian Optimization for the Discovery of Effective Additives for Dendrite Suppression in Lithium Metal Batteries

Publish in: ACS Applied Materials & Interfaces

Abstract: In the pursuit of enhancing the performance and safety of lithium (Li)-metal batteries, the discovery of effective electrolyte additives to suppress Li dendrites has emerged as a paramount objective. In this study, we employ an inverse design strategy to identify potential additives for dendrite mitigation. Two key mechanisms, namely, the formation of robust solid electrolyte interphase layers and the leveling mechanism, serve as the foundation for our investigation. Our inverse design strategy is guided by molecular properties such as the lowest unoccupied molecular orbital energy and interaction energy upon Li surface adsorption. An active learning process utilizing Bayesian optimization (BO) was utilized to identify potential molecules with ideal properties. Through this screening process, we uncover a collection of 62 molecules with the potential to act as SEI-forming additives, along with 106 molecules for leveling additives, both surpassing the performance of established additives reported in the literature. This work highlights the potential of BO methods in computationally based inverse design of materials for many applications, and the discovered additives could potentially boost the commercialization of Li–metal batteries.

URL:  https://doi.org/10.1021/acsami.4c16611

30 Oct 2024

Submitted by (Bold are A*STAR Staff): Yuanjian Li, Xiang Feng, Gaoliang Yang, Wei Ying Lieu, Lin Fu, Chang Zhang, Zhenxiang Xing, Man-Fai Ng, Qianfan Zhang, Wei Liu, Jun Lu & Zhi Wei Seh 

Research Institute: IMRE, IHPC

Title of Paper: Toward waterproof magnesium metal anodes by uncovering water-induced passivation and drawing water-tolerant interphases

Publish in: Nature Communications

Abstract: Magnesium (Mg) metal is a promising anode candidate for high-energy and cost-effective multivalent metal batteries, but suffers from severe surface passivation in conventional electrolytes, especially aqueous solutions. Here, we uncover that MgH2, in addition to the well-known MgO and Mg(OH)2, can be formed during the passivation of Mg by water. The formation mechanism and spatial distribution of MgH2, and its detrimental effect on interfacial dynamics and stability of Mg anode are revealed by comprehensive experimental and theoretical investigations. Furthermore, a graphite-based hydrophobic and Mg2+-permeable water-tolerant interphase is drawn using a pencil on the surface of Mg anodes, allowing them to cycle stably in symmetric (> 900 h) and full cells (> 500 cycles) even after contact with water. The mechanistic understanding of MgH2-involved Mg passivation and the design of pencil-drawn waterproof Mg anodes may inspire the further development of Mg metal batteries with high water resistance.

URL:  https://doi.org/10.1038/s41467-024-53796-z

30 Oct 2024

Submitted by (Bold are A*STAR Staff): Thathsara D. Maddumapatabandi, Fabio Bussolotti, Wei Fu, Hiroyo Kawai, Kuan Eng Johnson Goh

Research Institute: IMRE, IHPC

Title of Paper: Influence of Substrate Defects on the Electronic Properties of the WS2 Monolayer/Highly Oriented Pyrolytic Graphite Heterostructure

Publish in: ACS Applied Electronic Materials

Abstract: This study investigates the influence of local defects introduced in highly oriented pyrolytic graphite (HOPG) substrates on the electronic properties of two-dimensional transition-metal dichalcogenides (TMDs). Utilizing a combination of X-ray photoelectron spectroscopy (XPS) and angle-resolved photoemission spectroscopy (ARPES), we studied the changes in energy level alignment and interface charge transfer phenomena at the HOPG/WS2 interface. While XPS did not detect significant spectral changes for defect densities up to ∼7%, ARPES line shape analysis revealed that the increased defect density in the HOPG interfacing the WS2 monolayer significantly shortened carrier lifetimes. This provides crucial guidance for the study and optimization of devices wherein TMDs are interfaced with a HOPG or graphene.

URL:  https://doi.org/10.1021/acsaelm.4c01330

17 Oct 2024

Submitted by (Bold are A*STAR Staff): Zaohong Zhang, Kaihui Xu, Jing Yang, Zhuoyu Ji , Yunchen Ge, Zhicong Shi, Yongwei Zhang, Kai Zhang, Chuan Wu, and Jia Hong Pan

Research Institute: IHPC

Title of Paper: Versatility of π-d Conjugated Coordination Nickel Metal-Organic Frameworks as Electrode Materials of Metal-Ion Batteries

Publish in: Energy Material Advances

Abstract: Metal–organic frameworks have emerged as promising electrode materials for metal-ion batteries due to their superior structural customizability. However, they face challenges such as poor reversibility and easy degradation during electrochemical redox processes. Here, we report the synthesis of π-d conjugated coordination polymers through NH3-vapor-assisted self-polymerization of NiCl2·6H2O with 1,2,4,5-benzenetetramine tetrahydrochloride (namely, Ni-BTA). The synthesized Ni-BTA exhibits an open lattice structure that enhances the capacity for metal-ion diffusion, ensuring prolonged electrochemical cycling stability. Moreover, electrochemical characterizations reveal that Ni-BTA functions as a bifunctional material, serving as both cathode and anode materials for lithium-ion batteries (LIBs). After 1,000 cycles at 1.0 A g−1, the cathode and anode show high discharge capacities of 199.7 and 338.4 mAh g−1, respectively. Additionally, symmetrical all-organic batteries constructed with Ni-BTA exhibit a high specific capacity of 30.6 mAh g–1 and an ultrastable coulombic efficiency of approximately ≈100% after 6,000 cycles at 1.0 A g−1. Furthermore, Ni-BTA exhibits versatility as a robust cathode for aluminum ion batteries (AIBs), delivering a discharge capacity of 18.7 mAh g−1 after 10,000 cycles at 1.0 A g−1. These findings highlight the potential of Ni-BTA as a versatile and durable electrode materials for both LIBs and AIBs.

URL:  https://spj.science.org/doi/10.34133/energymatadv.0126

14 Oct 2024

Submitted by (Bold are A*STAR Staff): Choon Wee Kee, Jia’E Zheng, Wei Jie Yap, Roy Ou Yong and Yan Liu 

Research Institute: ISCE2

Title of Paper: Thermal and Sono—Aqueous Reforming of Alcohols for Sustainable Hydrogen Production

Publish in: Molecules 

Abstract: Hydrogen is a clean-burning fuel with water as its only by-product, yet its widespread adoption is hampered by logistical challenges. Liquid organic hydrogen carriers, such as alcohols from sustainable sources, can be converted to hydrogen through aqueous-phase reforming (APR), a promising technology that bypasses the energy-intensive vaporization of feedstocks. However, the hydrothermal conditions of APR pose significant challenges to catalyst stability, which is crucial for its industrial deployment. This review focuses on the stability of catalysts in APR, particularly in sustaining hydrogen production over extended durations or multiple reaction cycles. Additionally, we explore the potential of ultrasound-assisted APR, where sonolysis enables hydrogen production without external heating. Although the technological readiness of ultrasound-assisted or -induced APR currently trails behind thermal APR, the development of catalysts optimized for ultrasound use may unlock new possibilities in the efficient hydrogen production from alcohols.

URL:  https://doi.org/10.3390/molecules29204867

28 Aug 2024

Submitted by (Bold are A*STAR Staff): Mudi Li, Yaxi Ding, Prof. Siwen Zhang, Minghui Liu, Jiazhuo Li, Ying Sun, Dr. Lingfeng Zhu, Dr. Hui Li, Prof. Zhi Gen Yu, Prof. Yong-Wei Zhang, Prof. Hongge Pan, Prof. Bosi Yin, Prof. Tianyi Ma

Research Institute: IHPC

Title of Paper: Organic-Inorganic Coupling Strategy: Clamp Effect to Capture Mg2+ for Aqueous Magnesium Ion Capacitor

Publish in: German Chemical Society

Abstract: The rapid transport kinetics of divalent magnesium ions are crucial for achieving distinguished performance in aqueous magnesium-ion battery-based energy storage capacitors. However, the strong electrostatic interaction between Mg2+ with double charges and the host material significantly restricts Mg2+ diffusivity. In this study, a new composite material, EDA-Mn2O3, with double-energy storage mechanisms comprising an organic phase (ethylenediamine, EDA) and an inorganic phase (manganese sesquioxide) was successfully synthesized via an organic–inorganic coupling strategy. Inorganic-phase Mn2O3 serves as a scaffold structure, enabling the stable and reversible intercalation/deintercalation of magnesium ions. The organic phase EDA adsorbed onto the surface of Mn2O3 as an elastic matrix, works synergistically with Mn2O3, and utilizes bidentate chelating ligands to capture Mg2+. The robust coordination effect of terminal biprotonic amine in EDA enhances the structural diversity and specific capacity characteristics of the composite material, as further corroborated by density functional theory (DFT) calculations, ex situ XRD, XPS, and Raman spectroscopy. As expected, the EDA-Mn2O3 composite achieved an outstanding specific discharge capacity of 188.97 mAh/g at 0.1 A/g. Additionally, an aqueous magnesium ion capacitor with EDA-Mn2O3 serving as the cathode can reach 110.17 Wh/kg, which stands out among the aqueous magnesium ion capacitors that have been reported thus far. The abundant reversible redox sites are ensured by the strategic design concept based on the synergistic structure and composition advantages of organic and inorganic phases. This study aimed to explore the practical application value of organic-inorganic composite electrodes with double-energy storage mechanisms.

URL:  https://doi.org/10.1002/anie.202412735

21 Aug 2024

Submitted by (Bold are A*STAR Staff): Syed Zulfiqar Hussain Shah, Zainul Aabdin, Weng Weei Tjiu, Wei Nong, Jose Recatala-Gomez, Vijila Chellappan, Wenhao Zhai, Durga Venkata Maheswar Repaka, Gang Wu, Kedar Hippalgaonkar, Iris Nandhakumar, Pawan Kumar

Research Institute: IMRE, IHPC

Title of Paper: Thermoelectric Property Enhancement of Tellurium Nanowires by Surface Passivation

Publish in: ACS Applied Materials & Interfaces

Abstract: The pursuit of high-performance thermoelectric materials is of paramount importance in addressing energy sustainability and environmental concerns. Here, we explore the multifaceted impact of sulfur passivation in the matrix of tellurium nanowires (TeNWs), encompassing environmental control, thermoelectric properties, and charge carrier mobility. In this study, we present the facile production of TeNWs using an aqueous solution synthesis approach. The synthesized TeNWs were subsequently subjected to surface modification involving sulfur moieties. Our findings demonstrate that sulfur passivation not only effectively safeguards the nanowires from environmental degradation but also significantly augments their thermoelectric properties. Notably, the highest recorded values were achieved at 560 K for passivated tellurium nanowires, exhibiting a Seebeck coefficient of 246 μV/K, an electrical conductivity of 14.2 S/cm, and power factors of 86.7 μW/m-K2. This strategy presents a promising avenue for the development of advanced thermoelectric materials for applications in energy harvesting, waste heat recovery, and sustainable energy conversion technologies.

URL:  https://pubs.acs.org/doi/10.1021/acsami.4c02469

15 Aug 2024

Submitted by (Bold are A*STAR Staff): Yuanyuan Feng, Jing Yang, Maykel Manawan, Huiyun Gan, Dongwei Ma, Zhuoyu Ji, Zhicong Shi, Zhongzhu Liu, Yong-Wei Zhang, Chuan Wu, Jia Hong Pan

Research Institute: IHPC

Title of Paper: Comparative insight into crystal evolutions of monodisperse MNb2O6 (M = Ni, Cu, Zn) spheres during electrochemical cycling in Li/Al-ion batteries

Publish in: Energy Storage

Abstract: Niobates have emerged as advanced anode materials for lithium-ion batteries, owing to their inherently higher voltage and the occurrence of multiple one-electron redox reactions. However, there is a lack of comprehensive comparative analysis regarding their performance in lithium-ion and aluminum-ion battery applications. In this study, a facile solvothermal process is developed to synthesize uniform submicrospheres of three niobates: NiNb2O6, CuNb2O6, and ZnNb2O6 with large specific surface area and narrow size distribution. Their superior textural properties consisting of interconnected nanograins offer numerous active sites, delivering enhanced capacity and rate performance for the constructed half and full cells. Our in-situ XRD analysis reveals that all three niobates exhibit ultralow crystal volume expansion (< 6 %). But they exhibit distinct ion storage mechanisms: CuNb2O6 undergoes a phase transition to LiNb3O8 and NbO2 upon cyclic insertion of Li+ ions; NiNb2O6 mainly involves a classic hybrid-controlled process, facilitating easy ion insertion/extraction into/from the crystal lattices, especially at low sweep rates; while ZnNb2O6 stores charges via a pseudocapacitive-controlled process. Density functional theory (DFT) calculation and ex-situ XRD analysis confirm that CuNb2O6 outperforms the others, displaying the best electrochemical performance and holding promise as a high-energy electrode material thanks to favorable phase conversion, enhanced transport channels, porous structure and spherical morphology.

URL:  https://doi.org/10.1016/j.est.2024.113187

14 Aug 2024

Submitted by (Bold are A*STAR Staff): Song Lin Zhang, Yuke Li, Jintao Zhang, Wanwan Wang, Nguk Neng Tham, Bing Li, Jia Zhang, Zhaolin Liu

Research Institute: IHPC, IMRE

Title of Paper: Anchoring Metal–Nitrogen Sites on Porous Carbon Polyhedra with Highly Accessible Multichannels for Efficient Oxygen Reduction

Publish in: ACS Applied Materials & Interfaces

Abstract: Transition metal–nitrogen-carbon complexes, featuring single metal atoms embedded in a nitrogen-doped carbon matrix, emerge as promising alternatives to traditional platinum-based catalysts, offering cost-effectiveness, abundance, and enhanced catalytic performance. This work introduces a novel method for the etching and doping of zeolitic imidazolate frameworks (ZIFs) with transition metals, creating a uniform distribution of secondary metal centers on ZIF surfaces. By disrupting the crystalline symmetry of ZIFs through synthetic defect engineering, we gain access to their entire internal volume, creating multichannel pathways. The absorption of metal ions is theoretically simulated, demonstrating their thermodynamically spontaneous nature. The selective removal of defect channels under Lewis acidic conditions, induced by metal ion alcoholysis/hydrolysis, facilitates the introduction of metal atoms into ZIF cavities. The resulting single-atom catalyst, after pyrolysis, features a three-dimensional (3D) multichannel structure, high surface area, and uniformly dispersed metal atoms within the N-doped carbon matrix, establishing it as an exceptional catalyst for the oxygen reduction reaction (ORR). Our findings highlight the potential of using metal etching in defect-engineered metal–organic frameworks (MOFs) for single-atom catalyst preparation, paving the way for the next generation of high-performance, cost-effective ORR catalysts in sustainable energy systems.

URL:  https://doi.org/10.1021/acsami.4c07385

06 Aug 2024

Submitted by (Bold are A*STAR Staff): Miao Tian, Jing Lyu, Ran Su, Xu Zhang, Kexin Wang, Xiang Lv, Dawei Zhang, Shuo-Wang Yang, John Hon Kay Yip, Zhongkai Hao, Guo Qin Xu

Research Institute: IHPC

Title of Paper: Harnessing the Power of Nano-Ferroelectrics: BaTiO3/MXene (Ti3C2Tx) Composites for Enhanced Lithium Storage

Publish in: Advanced Energy Materials

Abstract: 2D Ti3C2Tx MXene is a desirable electrode material for advanced lithium-ion batteries (LIBs) in the pursuit of high energy and power densities, owing to its extensive reactive area and surface-induced pseudo-capacitance. Here, a novel synergistic strategy for fortifying lithium storage capability is first proposed, by in-situ anchoring BaTiO3 ferroelectric nanoparticles on few-layered Ti3C2Tx nanosheets (BT/f-Ti3C2Tx) using a hydrothermal method. The uniform BaTiO3 nanoparticles effectively prevent the restacking of Ti3C2Tx nanosheets, successfully deplete metastable Ti atoms, and intriguingly form a thin and well-adhered solid electrolyte interface layer, enhancing the aggregation-resistant, oxidation-resistant, and electrochemical properties of Ti3C2Tx. Simultaneously, the internal electric fields, originating from the spontaneous polarization of BaTiO3 ferroelectric nanoparticles, can augment the adsorption of Li+, boosting the lithium storage capacity and reaction kinetics. The resulting composite electrode displays a remarkable charge capacity of 84 mAh g−1 at 10 A g−1, almost five times that of pristine Ti3C2Tx electrode. The excellent rate performance and cyclability make BT/f-Ti3C2Tx composites highly attractive for LIBs. Furthermore, this synthetic approach presented here is scalable and can be extended to other Ti-based materials. This strategy is expected to underscore the considerable potential of ferroelectric composites for integration into high-performance LIBs.

URL:  https://doi.org/10.1002/aenm.202401988

03 Aug 2024

Submitted by (Bold are A*STAR Staff): Ganna Petruk , Jitka Petrlova, Firdaus Samsudin, Peter J. Bond, Artur Schmidtchen

Research Institute: BII

Title of Paper: Thrombin-derived C-terminal peptides bind and form aggregates with sulfated glycosaminoglycans

Publish in: Heliyon

Abstract: Glycosaminoglycans (GAGs) such as heparin and heparan sulfate (HS) play crucial roles in inflammation and wound healing, serving as regulators of growth factors and pro-inflammatory mediators. In this study, we investigated the influence of heparin/HS on thrombin proteolysis and its interaction with the generated 11 kDa thrombin-derived C-terminal peptides (TCPs). Employing various biochemical and biophysical methods, we demonstrated that 11 kDa TCPs aggregate in the presence of GAGs, including heparin, heparan sulfate, and chondroitin sulfate-B. Circular dichroism analysis demonstrated that 11 kDa TCPs, in the presence of GAGs, adopt a β-sheet structure, a finding supported by thioflavin T1 (ThT) fluorescence measurements and visualization of 11 kDa TCP-heparin complexes using transmission electron microscopy (TEM). Furthermore, our investigations revealed a stronger binding affinity between 11 kDa TCPs and GAGs with higher sulfate group contents. Congruently, in silico simulations showed that interactions between 11 kDa TCPs and heparin/HS are predominantly electrostatic in nature. Collectively, our study suggests that 11 kDa TCPs have the capacity to aggregate in the presence of GAGs, shedding light on their potential roles in inflammation and wound healing.

URL:  https://doi.org/10.1016/j.heliyon.2024.e35703

28 Mar 2023

Submitted by (Bold are A*STAR Staff): Naythan Z. X. Yeo, Dillon W. P. Tay, Shi Jun Ang

Research Institute: ISCE2,IHPC

Title of Paper: Benchmarking tandem mass spectra of small natural product molecules via ab initio molecular dynamics

Published in: ChemRxiv

Abstract: Natural products have proven to be valuable, particularly in the fields of drug discovery and chemogenomics. Tandem mass spectrometry, along with reference mass spectral libraries, has been frequently used to assist the characterization of natural products present in unknown complex mixtures. As current spectral libraries only contain a small percentage of known natural products, their continual expansion is crucial for accurate molecular identification. However, doing so through experimental means is often expensive and time-consuming. This study explores the use of ab initio molecular dynamics simulations (AIMD) based on the lightweight GFN2-xTB semiempirical Hamiltonian, to generate mass spectra for small natural products molecules. Through this approach, more than 2,700 unique mass spectra were generated and analysed in relation to the Global Natural Products Social Molecular Networking (GNPS) database. This study found that AIMD performs relative well (mean cosine similarity score of 0.68), with improved performance observed in aromatic molecules but limitations found when applied to molecules with carboxylic acid groups. Other key findings relating to experimental and simulated conditions also led to several recommendations for future work in this area. Overall, AIMD proved to have huge potential to be used to develop a putative natural product mass spectral library.

URL: https://doi.org/10.26434/chemrxiv-2023-7k5x8