Materials Today最新文献

Interconnected porous materials have recently emerged as hybrid porous materials, comprising (meso/micro)pores with interconnected (micro/meso)porous walls. Benefiting from structural, morphological, and geometrical properties, interconnected porous materials are endowed with high porosity, specific surface area, mass transfer capacity, tailored pore sizes, volume and shape compatibility. These hybrid materials can be synthesized and further functionalized into a wide range of nanomaterials by either modifying conventional strategies or involving novel strategies such as pillared-layer assembly, defect-formation and/or the use of structure-directing agents. Owing to their exceptional properties, functionalized materials have already exhibited remarkable potential in various practical applications including reduction, sensing, purification, detection of gases, harvesting, conversion, and storage of energy, photocatalysis, electrocatalysis, chemical synthesis, as well as non-automotive applications. A brief description of recent advancements in catalysis and energy conversion/storage applications of functionalized interconnected materials as well as prospects is provided in this contribution.

Optical metasurfaces, i.e., subwavelength planar nanostructures, have attracted increasing attention due to their unprecedented capabilities of molding classical light and revolutionized conventional optics by replacing bulky optical components with ultrathin, lightweight, and ultracompact meta-optics. In addition to controlling classical light, meta-optics demonstrate the potential to efficiently manipulate nonclassical light and start to enter the realm of quantum photonics. Here, we briefly overview recent advances in quantum meta-optics for generation and manipulation of nonclassical light, highlighting innovative approaches, and discuss future opportunities in this burgeoning area, ranging from fundamental research to practical applications.

Stainless steel is critical material used in a wide variety of industries. Unfortunately, current development of stainless steel has reached a stagnant stage due to the fundamental limitation of the conventional Cr-based single-passivation mechanism. Here, we show that, by using a sequential dual-passivation mechanism, substantially enhanced anti-corrosion properties can be achieved in Mn-contained stainless steel, with a high breakdown potential of ∼1700 mV (saturated calomel electrode, SCE) in a 3.5 wt% NaCl solution. Specifically, the conventional Cr-based and counter-intuitive Mn-based passivation is sequentially activated during potentiodynamic polarization. The Cr-based passive layer prevents corrosion at low potentials below ∼720 mV(SCE), while the Mn-based passive layer resists corrosion at high potentials up to ∼1700 mV(SCE). The present “sequential dual-passivation” strategy enlarges the passive region of stainless steel to high potentials above water oxidation, enabling them as potential anodic materials for green hydrogen production via water electrolysis.

Excellent color purity and high external quantum efficiency (EQE) are major requirements in the development of deep-blue organic light-emitting diodes (OLEDs). To achieve this, multiple-resonance (MR)–thermally activated delayed fluorescence (TADF) emitters have been considered as promising options. Herein, we suggest a novel expanded MR design strategy to fabricate deep-blue MR–TADF emitters derived from a fused indolo[3,2,1-jk]carbazole framework. The expanded MR structure managed a triplet excited state for the accelerated spin–vibronic coupling-assisted reverse intersystem crossing and increased the emission dipole orientation while maintaining the high efficiency and deep-blue emission color. The rigid and planar structure of the MR core yielded a small full-width at half-maximum (FWHM; less than 16 nm), high photoluminescence quantum yield (over 97%), and high horizontal emitting dipole orientation (over 90%), and facilitated a second-order spin–vibronic coupling-assisted triplet-to-singlet spin crossover. The fabricated MR–TADF OLEDs recorded a high EQE of 24.3% and FWHM of 21 nm at a CIE_y of 0.044, thereby satisfying the BT.2020 blue standard. Additionally, further optimized device architecture provided an EQE of 26.8%.

Neuromorphic computing systems inspired by the human brain emulate biological synapses electronically for information handling and processing. Recently, memristive switching devices so-called ‘memristors’ are emerging as an essential constituent of artificial intelligence (AI) and internet-of-thing (IoT) circuits toward the development of energy-efficient intelligent systems proficient with neuromorphic computing features to huddle up the current limits of the conventional von Neumann computing system. Memristors have gained attention to realizing artificial synapses by altering resistance analogous to biological counterparts. ZnO-based memristors allow the formation of two-terminal crossbar architectures with metal/insulator/metal (MIM) cells (i.e., top electrode/active layer/bottom electrode), and the device’s interactivity can be drastically increased. The availability of multiple resistance states in ZnO-based memristors can lead to high-density data storage capacity and artificial synapse. In this review, we discussed the state-of-art of n-type ZnO-polymer (n-ZnO:Poly) hybrid nanocomposite-based memristors, focusing on their intrinsic mechanisms of resistive switching, progress, advancement, and the challenges to the development of high-performance memristive devices. Additionally, the synaptic functions of n-ZnO:Poly nanocomposite-based memristors are explored as artificial synapses for neural networks to emulate synaptic plasticity. Finally, the key requirements for AI and IoT electronics are highlighted in the future perspectives and opportunities for the development of low-power and high-density memristors as artificial synapses with synaptic weight tunability and reliable synaptic plasticity.

The advent of the Internet of Things and smart applications such as smart cities, smart health care, and smart electronics will require the use of a vast array of sensors. Sensors are a key part of the revolution in interconnected devices. The growing need for sensing, monitoring, and collecting data at scales from small to large will help, for example, prevent future pandemics, elucidate climate change, optimize industrial processes, and train machine learning models. Recent progress in materials science, micro/nano technologies, and integrated circuits has made it possible to reduce the size and cost of sensors while integrating them into more complex machines, ranging from wearable/implantable devices to onboard laboratories for planetary exploration rovers. However, the small dimensions of miniature sensors present some challenges, including power supply, active sensing materials, and material flexibility. In this article, we review microbatteries to power miniature sensors. We discuss materials and architectures for microbatteries and their fabrication methods. We also discuss energy harvesting materials for self-powered miniature sensors. We review in detail advanced materials for active sensing, including organic, inorganic, and composite materials with emphasis on wearable/implantable sensors targeted at humans and animals. In addition, flexible electronics as well as substrates and encapsulation materials and their integration are reviewed. Finally, future perspectives and challenges of these functional materials for next-generation miniature sensors are highlighted.

Despite the impressive strides in the research community, numerous obstacles pose marked challenges in the treatment of central nervous system (CNS) disorders. The limitations of current therapeutics are primarily attributed to the systemic and local barriers, particularly the intact blood–brain barriers (BBB). Nanomedicine represents one promising avenue, which enables safe and effective delivery of neurotherapeutics into the CNS by traversing or bypassing the physical barriers. Here, we provide an overview of recent progress of advanced nanoengineering technologies for delivery of neurotherapeutics and elucidate how the emerging nanotherapeutics overcome the restrictive barriers with enhanced therapeutic implications to CNS diseases. The non-invasive strategies crossing BBB mainly comprise carrier-mediated transport, cell-mediated transport, adsorptive mediated transport, paracellular transport, passive diffusion, and receptor-mediated transport. We briefly discuss the typical paradigms of nanomaterials and their physiochemical factors determining CNS transport efficacy, particularly focusing on the applications of advanced nanotechnology in the management of ischemic stroke, neurodegenerative diseases, infectious diseases, pain, and tumor. The prospects and challenges of neuro-nanotherapeutics toward clinical translation are also analyzed from our point of view.