Nanoscience News (<front>)

Reconfigurable physical unclonable function (PUF) integrating optical and electrical responses in organic field-effect transistor is developed by using unique optical fingerprint textures and random molecular alignment of the semiconductive smectic liquid crystal. This approach enhances security by enabling hierarchical authentication, providing robust solutions for anticounterfeiting and cryptographic applications.

Abstract

Physical unclonable functions (PUFs)—a hardware-based security device using randomness—have evolved from basic integrated circuit designs to advanced systems using diverse materials and mechanisms. However, most PUFs are limited by single-factor challenges and fixed key generation, making them vulnerable to brute-force attacks. A reconfigurable and multidimensional liquid crystal (LC)-based PUF is presented integrated into an organic field-effect transistor (OFET) to address limitations. This system combines optical and electrical PUFs through unique optical fingerprint textures and random molecular alignment of the semiconductive smectic LC material. The PUF can be reconfigured by a simple heating and cooling process, overcoming the limitations of fixed-structure PUFs. Furthermore, this approach enhances security by enabling hierarchical authentication due to the multi-response factors, providing robust solutions for anticounterfeiting and cryptographic applications.

Indium doping in the inner layer of MoS₂ is introduced to significantly reduce the high surface energy associated with sulfur vacancies, achieving highly active and stable catalysts for enhancing sulfur redox kinetics in high-performance Li–S batteries. The novel In-Vs catalytic sites effectively lower reaction-free energies and diffusion energy barriers, accelerate redox kinetics, ensure stable catalytic performance, and mitigate the shuttling effect.

Abstract

Defect engineering in MoS2 via sulfur vacancies (Vs-MoS2) has shown potential in enhancing lithium–sulfur battery (LSB) performance by mitigating the polysulfide shuttle effect. However, the high surface energy of Vs-MoS2 impedes long-term catalyst stability. Herein, indium (In) doping is introduced into the inner layer of Vs-MoS2 lattice (In-Vs-MoS2), which effectively stabilizes the catalyst by reducing surface energy and enhancing sulfur redox kinetics. Theoretical calculations confirm that In doping, in conjunction with surface vacancies, optimizes charge distribution and generates unpaired electrons near the Fermi level, thus improving polysulfide adsorption and lowering Li2S formation barriers. LSBs with In-Vs-MoS2 separators deliver stable cycling at 0.5 C with a favorable capacity of 1042 mAh g−1 retained after 100 cycles. Moreover, even at high current density (5 C) and high S loading (8.7 mg cm−2) scenario, stable cycling is realized, demonstrating the strategy's effectiveness in advancing LSB electrocatalysis. This work offers a straightforward strategy for practical LSBs and deepens the understanding of vacancy-modulated electrocatalysts for sulfur redox.

A full high vacuum preparation and characterization chain unveils that hydroxyl-induced trap states affect the charge transport in p- and n-channel OFETs similarly. The variable-temperature TLM analysis suggests that the activation energy of charge transport plays a more significant role than the density of trap states. Furthermore, the injection barrier is significantly lower in devices with a hydroxyl-free dielectric.

Abstract

Trap states at the gate dielectric-organic semiconductor (OSC) interface are one of the main sources of extrinsic traps in organic field-effect transistors (OFETs). However, they are often overlooked and their effects on the charge transport are attributed to the exposure of devices to ambient air. Here a first variable-temperature transfer length method characterization of both p- and n-channel OFETs under full high vacuum conditions is reported. By comparing a hydroxylated aluminum oxide (Al2O3) gate dielectric with a hydroxyl-free, tetradecylphosphonic acid-functionalized Al2O3 dielectric, it is shown that hydroxyl-induced trap states reduce the charge carrier mobility in OFETs regardless of the channel type. This observation challenges the common belief that the hydroxyl-induced traps are affecting primarily the n-channel transport. The variable-temperature analysis yields a high activation energy of charge transport as the main effect of a hydroxylated gate dielectric. Moreover, the injection barrier at the interface between the source-drain electrodes and the OSC layer is significantly lower for devices with a hydroxyl-free dielectric and correlates with the activation energy of charge transport. This work identifies previously hidden limitations of charge transport in OFETs, opening opportunities for further improvements in device performance and potential device applications.

Polymer regulation shapes a weakly solvating polymer-stabilized anion-rich Na+ solvation structure and robust dual-layered solid electrolyte interphase, enabling long-life and safe quasi-solid-state anode-free sodium battery with high energy.

Abstract

Anode-free sodium metal batteries (AFSMBs) offer a promising solution to enhance the inherently low energy of sodium-ion batteries (SIBs) while circumventing the challenges in processing highly reactive Na metal anodes. However, their practical viability is severely hindered by short lifespan, driven by accelerated irreversible Na loss in zero-Na-excess cell configurations, alongside safety concerns of liquid electrolyte leakage. Here, a design of long-life quasi-solid-state AFSMBs is demonstrated by leveraging polymer regulation of Na+ solvation behavior and anode interphase chemistry to reduce Na loss while enhancing cell safety. The polyoxymethylene with reduced local steric hindrance and weak Na+ chelation shapes a weakly solvating polymer-stabilized anion-rich Na+ solvation structure. It facilitates Na+ transport and formation of robust inorganic–organic dual-layered solid electrolyte interphase (SEI), enabling smooth Na metal deposition in quasi-solid-state electrolytes. This chemistry yields quasi-solid-state AFSMBs with a long lifespan of 500 cycles and 79% capacity retention at a high rate of 1 C. The 1.2 Ah pouch cells retain 81% capacity over 200 cycles, delivering a volumetric energy of 340 Wh L⁻1, surpassing LiFePO4||graphite lithium-ion batteries, while achieving a comparable gravimetric energy of 190 Wh kg⁻1. Such cells also exhibit high reliability against nail penetration in the open air at a fully charged state.

A major advancement in gel technology is presented with the introduction of “Ionophobic Coordination Reinforcement.”(ICR). This strategy combines ionic liquid-phobic microphase separation with lithium-ion coordination crosslinking, enabling a novel thermoplastic gel network. ICR achieves remarkable mechanical performance, efficient self-healing at room-temperature, and exceptional melt-processability, overcoming key challenges in gel materials.

Abstract

As the key materials for next-generation wearable and flexible electronics, ionogels are expected to combine excellent mechanical performance, efficient room-temperature self-healing, and facile processability. Current ionogels typically face a significant trade-off between mechanical strength and self-healing efficiency, limiting their practical applications. Here, “Ionophobic Coordination Reinforcement” (ICR) is introduced, a strategy that integrates ionic liquid-phobic microphase separation with lithium-ion coordination crosslinking. The ICR design yields a dual glass transition temperature (Tg ): −60.27 °C for maintaining soft phase mobility and 55.33 °C for reinforcing hard phase strength. This architecture achieves simultaneous high mechanical performance (6.4-fold increase in tensile strength, 4-fold increase in toughness, and 35.6-fold increase in Young's modulus) and efficient self-healing at ambient conditions. Furthermore, this dynamic supramolecular architecture also provides exceptional melt-processability, facilitating advanced fabrication techniques such as melt spinning. Taking advantage of the high specific surface area of ionogel fibers, the sensor exhibits enhanced humidity sensitivity and rapid response to respiratory moisture changes compared to film counterparts. Integrated into a wireless platform, it enables real-time, non-invasive respiratory monitoring, while intrinsic self-healing ensures long-term stability. ICR effectively resolves the trade-off between strength and self-healing, offering a new paradigm for high-performance wearable electronics, soft robotics, and adaptive sensors.

Energy Environ. Sci., 2025, Accepted Manuscript
DOI: 10.1039/D5EE02194D, Paper Open Access &nbsp This article is licensed under a Creative Commons Attribution 3.0 Unported Licence.Raul A. Marquez, Jay T. Bender, Ashton M Aleman, Emma Kalokowski, Thuy Vy Le, Chloe L. Williamson, Morten Linding Frederiksen, Kenta Kawashima, Chikaodili Emmanuel Chukwuneke, Andrei Dolocan, Delia Milliron, Joaquin Resasco, Thomas Jaramillo, Charles Mullins
Energy conversion technologies that are key to decarbonization efforts face significant durability challenges due to variable operation. Understanding the impact of variable operation on catalytic stability and identifying the key...
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Advanced Materials, Volume 37, Issue 23, June 12, 2025.

Materials Research at the Hong Kong University of Science and Technology

The Hong Kong University of Science and Technology (HKUST) was established in 1991 as the first research-focused university in Hong Kong to advance learning and knowledge, particularly in science, technology, engineering, management, and business studies, and at the postgraduate level. HKUST has developed significantly in the past 35 years, ranking itself as one of the best among young universities.

Colloidal Quantum Dots

Colloidal quantum dots (QDs) are exceptional photocatalysts due to their unique photophysical properties, tunable surface chemistry, and structural diversity. These properties enable novel photocatalytic organic transformations, overcoming limitations of traditional catalysts. This review highlights recent QD-driven advancements and discusses future research directions in photocatalysis. More details can be found in article number 2409096 by Haipeng Lu and co-workers.

Stretchable Interconnects for Wearable Bioelectronics

As wearable telemedicine advances, stretchable interconnects becomes vital in skin-compatible devices for reliable health signals. Article number 2408456 by Hnin Yin Yin Nyein and co-workers explores various materials and fabrication methods for stretchable interconnects, highlighting their electrical and mechanical traits along with their geometric versatility. The review also showcases successful rigid-soft interfaces, while addressing unresolved challenges and outlining future directions for practical wearable applications.

Materials Research at the Hong Kong University of Science and Technology

The campus in Hong Kong is situated on a hillside that overlooks Clear Water Bay, offering breathtaking views of the bay and the South China Sea. At the heart of the campus, the Red Bird sundial stands as a prominent sculpture of the university. This piece is inspired by one of humanity's earliest scientific achievements: the sundial. Constructed from steel, the sundial is gracefully placed on a paved podium with broad steps, surrounded by a flowing water pool. The podium features a carved mural celebrating 39 notable Chinese contributions to science and technology. Completed on October 8, 1991, the Red Bird sundial, titled “Circle of Time,” has become an enduring symbol of HKUST.

Promotion of C─C Coupling in electrochemical reduction of CO2 to valuable C2+ products is reviewed from microcosmic to macroscopic. The discussed advances and outstanding challenges in the strategies of efficient catalyst design, the influence of local environment in electrolyte, and the design of potential industrial flow cells provided the guidelines for future research in promoted C─C coupling from foundation to application.

Abstract

The electrochemical CO2 reduction reaction (CO2RR) to valuable C2+ products emerges as a promising strategy for converting intermittent renewable energy into high-energy-density fuels and feedstock. Leveraging its substantial commercial potential and compatibility with existing energy infrastructure, the electrochemical conversion of CO2 into multicarbon hydrocarbons and oxygenates (C2+) holds great industrial promise. However, the process is hampered by complex multielectron-proton transfer reactions and difficulties in reactant activation, posing significant thermodynamic and kinetic barriers to the commercialization of C2+ production. Addressing these barriers necessitates a comprehensive approach encompassing multiple facets, including the effective control of C─C coupling in industrial electrolyzers using efficient catalysts in optimized local environments. This review delves into the advancements and outstanding challenges spanning from the microcosmic to macroscopic scales, including the design of nanocatalysts, optimization of the microenvironment, and the development of macroscopic electrolyzers. By elucidating the influence of the local electrolyte environment, and exploring the design of potential industrial flow cells, guidelines are provided for future research aimed at promoting C─C coupling, thereby bridging microscopic insights and macroscopic applications in the field of CO2 electroreduction.

This review focuses on low-dimensional perovskite materials and discusses their applications in light-emitting diodes (LEDs). Special attention is given to the introduction of perovskite quantum wires and nanorods, two unique types of one-dimensional (1D) materials, and their interesting optoelectronic properties. Moreover, the applications of low-dimensional perovskite materials can extend beyond LEDs to others, such as photodetectors and memristors.

Abstract

Perovskite materials, celebrated for their exceptional optoelectronic properties, have seen extensive application in the field of light-emitting diodes (LEDs), where research is as abundant as the proverbial “carloads of books.” In this review, the research of perovskite materials is delved into from a dimensional perspective, with a focus on the exemplary performance of low-dimensional perovskite materials in LEDs. This discussion predominantly revolves around perovskite quantum wires and perovskite nanorods. Perovskite quantum wires are versatile in their growth, compatible with both solution-based and vapor-phase growth, and can be deposited over large areas—even on spherical substrates—to achieve commendable electroluminescence (EL). Perovskite nanorods, on the other hand, boast a suite of superior characteristics, such as polarization properties and tunability of the transition dipole moment, endowing them with the great potential to enhance light extraction efficiency. Furthermore, zero-dimensional (0D) perovskite materials like nanocrystals (NCs) are also the subject of widespread research and application. This review reflects on and synthesizes the unique qualities of the aforementioned materials while exploring their vital roles in the development of high-efficiency perovskite LEDs (PeLEDs).

Implantable devices significantly enhance healthcare but are limited by battery life. Ultrasound power transfer technology offers a promising solution for sustainable operation. This review addresses gaps in current research, particularly in sound field analysis and energy efficiency optimization. It proposes an energy flow diagram, discusses development stages, and explores the potential advancements in ultrasound-based healthcare solutions.

Abstract

Implantable medical devices (IMDs), like pacemakers regulating heart rhythm or deep brain stimulators treating neurological disorders, revolutionize healthcare. However, limited battery life necessitates frequent surgeries for replacements. Ultrasound power transfer (UPT) emerges as a promising solution for sustainable IMD operation. Current research prioritizes implantable materials, with less emphasis on sound field analysis and maximizing energy transfer during wireless power delivery. This review addresses this gap. A comprehensive analysis of UPT technology, examining cutting-edge system designs, particularly in power supply and efficiency is provided. The review critically examines existing efficiency models, summarizing the key parameters influencing energy transmission in UPT systems. For the first time, an energy flow diagram of a general UPT system is proposed to offer insights into the overall functioning. Additionally, the review explores the development stages of UPT technology, showcasing representative designs and applications. The remaining challenges, future directions, and exciting opportunities associated with UPT are discussed. By highlighting the importance of sustainable IMDs with advanced functions like biosensing and closed-loop drug delivery, as well as UPT's potential, this review aims to inspire further research and advancements in this promising field.

This review explores the evolution of AIE materials in bacterial research, highlighting their journey from initial studies of visualizing the unseen bacterial world to uncovering the underlying interaction and antibacterial mechanism. Recent advancements highlight the versatility and potential of AIE materials across a multitude of bacterial applications, showcasing their significant impact in various scientific fields.

Abstract

Bacteria share a longstanding and complex relationship with humans, playing a role in protecting gut health and sustaining the ecosystem to cause infectious diseases and antibiotic resistance. Luminogenic materials that share aggregation-induced emission (AIE) characteristics have emerged as a versatile toolbox for bacterial studies through fluorescence visualization. Numerous research efforts highlight the superiority of AIE materials in this field. Recent advances in AIE materials in bacterial studies are categorized into four areas: understanding bacterial interactions, antibacterial strategies, diverse applications, and synergistic applications with bacteria. Initial research focuses on visualizing the unseen bacteria and progresses into developing strategies involving electrostatic interactions, amphiphilic AIE luminogens (AIEgens), and various AIE materials to enhance bacterial affinity. Recent progress in antibacterial strategies includes using photodynamic and photothermal therapies, bacterial toxicity studies, and combined therapies. Diverse applications from environmental disinfection to disease treatment, utilizing AIE materials in antibacterial coatings, bacterial sensors, wound healing materials, etc., are also provided. Finally, synergistic applications combining AIE materials with bacteria to achieve enhanced outcomes are explored. This review summarizes the developmental trend of AIE materials in bacterial studies and is expected to provide future research directions in advancing bacterial methodologies.

The development of all-solid-state lithium-sulfur batteries offers higher specific energies and lower costs compared to state-of-the-art Li-ion batteries. However, a lack of mechanistic understanding hinders advancement. This review analyzes key electrode parameters, evaluates progress in enhancing ion/electron percolation, and addresses electrochemical-mechanical degradation, offering future research directions.

Abstract

The development of all-solid-state lithium-sulfur batteries (ASSLSBs) toward large-scale electrochemical energy storage is driven by the higher specific energies and lower cost in comparison with the state-of-the-art Li-ion batteries. Yet, insufficient mechanistic understanding and quantitative parameters of the key components in sulfur-based cathode hinders the advancement of the ASSLSB technologies. This review offers a comprehensive analysis of electrode parameters, including specific capacity, voltage, S mass loading and S content toward establishing the specific energy (Wh kg−1) and energy density (Wh L−1) of the ASSLSBs. Additionally, this work critically evaluates the progress in enhancing lithium ion and electron percolation and mitigating electrochemical-mechanical degradation in sulfur-based cathodes. Last, a critical outlook on potential future research directions is provided to guide the rational design of high-performance sulfur-based cathodes toward practical ASSLSBs.

Stretchable interconnects are one of the fundamental components in achieving robust wearable devices, but their importance is often overlooked. This review highlights their importance and provides insightful information on various materials, configurations, and manufacturing approaches being studied for interconnects. Their practical potentials for wearable bioelectronics are also discussed for future research opportunities.

Abstract

Since wearable technologies for telemedicine have emerged to tackle global health concerns, the demand for well-attested wearable healthcare devices with high user comfort also arises. Skin-wearables for health monitoring require mechanical flexibility and stretchability for not only high compatibility with the skin's dynamic nature but also a robust collection of fine health signals from within. Stretchable electrical interconnects, which determine the device's overall integrity, are one of the fundamental units being understated in wearable bioelectronics. In this review, a broad class of materials and engineering methodologies recently researched and developed are presented, and their respective attributes, limitations, and opportunities in designing stretchable interconnects for wearable bioelectronics are offered. Specifically, the electrical and mechanical characteristics of various materials (metals, polymers, carbons, and their composites) are highlighted, along with their compatibility with diverse geometric configurations. Detailed insights into fabrication techniques that are compatible with soft substrates are also provided. Importantly, successful examples of establishing reliable interfacial connections between soft and rigid elements using novel interconnects are reviewed. Lastly, some perspectives and prospects of remaining research challenges and potential pathways for practical utilization of interconnects in wearables are laid out.

Colloidal quantum dots (QDs) have gained significant attention as photocatalysts in organic transformations in recent years. This review highlights QDs’ distinctive features, including the quantum size effect, compositional and structural diversity, tunable surface chemistry, and photophysics. Recent advancements in using QDs as photocatalysts for organic transformations are further summarized and an outlook in this field is provided.

Abstract

Colloidal quantum dots (QDs) have emerged as a versatile photocatalyst for a wide range of photocatalytic transformations owing to its high absorption coefficient, large surface-to-volume ratio, high stability, and efficient charge and energy transfer dynamics. The past decades have witnessed a rapid development of QDs for artificial photocatalysis. In this review, the unique characteristics of QDs are focused on, including quantum size effect, compositional and structural diversity, tunable surface chemistry, and photophysics, that can be utilized for photocatalytic transformations. The recent advancements in photocatalytic organic transformations enabled by QDs photocatalysts are summarized. The unique opportunities of QDs are highlighted to tackle organic reactions that are previously unattainable with small molecule photocatalysts. Lastly, an outlook is provided for future directions in this field.

This review summarizes the current status of microenvironment regulation of catalytic reaction interface, flow electrolyzers design, and the flow electrolyzers derived stepwise approaches for COxRR to alcohol, aiming to provide new insights into the production of alcohols via COxRR.

Abstract

The electrocatalytic reduction of COx (including CO2 and CO) into value-added fuels and chemicals, particularly multi-carbon (C2+) alcohols, presents a significant opportunity to close the manmade carbon cycle and support sustainable energy systems. The catalytic performance of electrochemical reduction reactions of CO2 and CO (COxRR) is strongly correlated with the local microenvironments, the flow electrolyzer, and the catalysis approaches with flow electrolyzers, which contribute to the kinetic and thermodynamic landscape of the reaction, ultimately determining the efficiency and selectivity of the COxRR toward desired reduction products. However, controllable microenvironment construction, rationally designed flow electrolyzers, and matchable flow electrolyzers derived catalysis approaches chosen for improving COxRR-to-alcohol performance still face challenges. Building upon the foundation laid by previous research, this review article will provide an in-depth summary of the regulation of the catalytic reaction interface microenvironment, the design of flow electrolyzers, and the development of derived stepwise catalysis approaches with the flow electrolyzers, which provide a comprehensive and strategic approach to enhancing the COxRR process for alcohol production, offering valuable insights and innovative solutions that can significantly impact the field of COxRR conversion to alcohol and contribute to the development of more sustainable chemical production methods.

Radiative cooling controls surface optical properties for solar and thermal radiation, offering solutions for global warming and energy savings. Despite significant advances, key challenges remain: optimizing optical efficiency, maintaining aesthetics, preventing overcooling, enhancing durability, and enabling scalable production. This review explores advanced solutions in material design and fabrication to guide future research and industrial applications.

Abstract

Radiative cooling is achieved by controlling surface optical behavior toward solar and thermal radiation, offering promising solutions for mitigating global warming, promoting energy saving, and enhancing environmental protection. Despite significant efforts to develop optical surfaces in various forms, five primary challenges remain for practical applications: enhancing optical efficiency, maintaining appearance, managing overcooling, improving durability, and enabling scalable manufacturing. However, a comprehensive review bridging these gaps is currently lacking. This work begins by introducing the optical fundamentals of radiative cooling and its potential applications. It then explores the challenges and discusses advanced solutions through structural design, material selection, and fabrication processes. It aims to provide guidance for future research and industrial development of radiative cooling technology.