Nanoscopic mass/ion transport through heterogeneous nanostructures with various physicochemical environments occurs in both natural and artificial systems. Concentration gradient-driven mass/ion transport mechanisms, such as diffusioosmosis (DO), are primarily governed by the structural and electrical features of the nanostructures. However, these phenomena under various electrical and chemical conditions have not been adequately investigated. In this study, we fabricated a pervaporation-based particle-assembled membrane (PAM)-integrated micro-/nanofluidic device that facilitates easy tuning of the surface charge heterogeneity in nanopores/nanochannels. The nanochannels in the device consisted of two heterogeneous and in-series PAMs. The device was used to quantitatively measure electric signals generated by DO within the nanochannels with a single electrolyte or a combination of two electrolytes. Then, we characterized ion transport by changing surface charge heterogeneity and applying various electrolytic conditions, characterizing the concentration-driven power generation under these conditions. We found that not only does the charge heterogeneity provide additional resistance to ion transport but also the manipulation of the heterogeneity enables the effective modulation of ion transport and optimization of concentration-driven power generators regarding ion selectivity. In conjunction with the surface charge heterogeneity, the electrolytic conditions significantly affected the net flux of ion transport by enhancing or even negating the ion selectivity. Hence, we anticipate that both the platform and results will provide a deeper understanding of ion transport in nanostructures within complex environments by optimizing and improving practical concentration-driven applications, such as energy conversion/harvesting, molecular focusing/separation, and ionic diodes and memristors.
Moiré superlattices, arising from the periodic Moiré patterns formed by two-dimensional (2D) materials stacked with a slight lattice mismatch, have attracted significant attention due to their unique electronic and optical performances. This review provides an overview of recent advances in Moiré superlattices, highlighting their formation mechanisms, structural characteristics, and emergent phenomena. First, we discuss the theoretical basis and experimental techniques employed in fabricating Moiré superlattices. Then we outline various characterization methods that enable the investigation of the structural and electronic performance of Moiré superlattices at the atomic scale. Afterward, we review the diverse range of emergent phenomena exhibited in Moiré superlattices. These phenomena include the appearance of electronic band engineering, unconventional superconductivity, and topologically nontrivial state. We explore how these phenomena arise from the interplay between the original electronic properties of the constituent materials and the Moiré pattern-induced modifications. Furthermore, we examine the potential applications of Moiré superlattices in fields such as electronics, optoelectronics, and quantum technologies. Finally, we summarize the challenges and directions in Moiré superlattice research, which include exploring more complex Moiré patterns, understanding the role of twist angle and strain engineering, and developing theoretical frameworks to describe the behaviors of Moiré systems. This review aims to provide a comprehensive understanding of the recent progress in Moiré superlattices, shedding light on their formation, performance, and potential applications. The insights gained from this research are expected to pave the way for the design and development of next-generation functional Moiré superlattices.
This study investigates the application of trioctylphosphine oxide (TOPO) and triphenylphosphine oxide (TPPO) as an additive to enhance the performance of all-inorganic CsPbBr3 perovskite solar cells (PSCs). The addition of TOPO and TPPO passivates surface defects, increases grain size, and reduces surface trap states, leading to better light absorption and accelerated carrier transport. These modifications lead to an optimized energy level distribution, resulting in a significant increase in power conversion efficiency from 5.14 to 9.21% with TOPO and from 5.14% to 7.28% with TPPO. Furthermore, the long alkyl chains in TOPO provide effective isolation from air and water, significantly enhancing device stability for over 2400 h without packaging. The findings demonstrate that oxygen phosphine additives with long alkane chains are more effective in improving PSCs than those with aromatic hydrocarbons, offering new insights for the use of passivators in perovskite solar cells.
The complex microenvironment of persistent inflammation and bacterial infection is a major challenge in chronic diabetic wounds. The development of nanozymes capable of efficiently scavenging reactive oxygen species (ROS) is a promising method to promote diabetic wound healing. However, many nanozymes show rather limited antioxidant activity and ROS-dependent antibacterial effects under certain circumstances, further weakening their ability to scavenge ROS. To meet these challenges, electronically regulated bioheterojunction (E-bio-HJ) nanozyme hydrogels derived from metal-organic frameworks (MOFs) were designed and prepared via an interface engineering strategy. Owing to the electron transfer and redistribution effects of the abundant and highly dispersed Cu-O-Zn sites at the heterogeneous interface, the E-bio-HJ nanozymes exhibited catalase (CAT)-like activity with ultrahigh hydrogen peroxide affinity (Km = 25.76 mM) and sustained ROS consumption. In addition, owing to the enhanced interfacial effect of E-bio-HJ and the good biocompatibility and cell adhesion of the methacryloylated gelatin (Gel) hydrogel, the E-bio-HJ gelatin hydrogel (E-bio-HJ/Gel) further reduced inflammation by inducing macrophage transformation to the M2 phenotype, accompanied by excellent antimicrobial properties and enhanced cell migration, angiogenesis, and collagen deposition, which synergistically promoted diabetic wound healing. This highly effective and comprehensive strategy offers a new approach for the rapid healing of diabetic wounds.
In this work, we introduce twenty-six phenothiazine derivatives (PTZs) that were designed and synthesized as visible light photoinitiators. These compounds, in combination with an amine [ethyl 4-(dimethylamino)benzoate (EDB)] and an iodonium salt [di-tert-butylphenyl iodonium hexafluorophosphate (Iod)], could furnish high-performance three-component (PTZs/EDB/Iod) photoinitiating systems that were employed for the free radical polymerization of thick films of a low-viscosity model acrylate resin, namely, trimethylolpropane triacrylate (TMPTA) under visible light and sunlight exposure. A commercial thioxanthone, i.e., isopropylthioxanthone (ITX) was selected to design a reference ITX/EDB/Iod photoinitiating system. Double bond conversions of 87% and 76% were measured for the developed and synthesized photoinitiating systems under 405 and 450 nm light-emitting diode irradiation, respectively, and a conversion as high as 70% could be determined under sunlight irradiation─about 23 times higher than the conversion obtained with the comparable system prepared with the commercial photoinitiator. The relevant photoinitiation abilities and photochemical mechanisms are comprehensively investigated by a combination of techniques including real-time Fourier transform infrared spectroscopy, UV-visible absorption spectroscopy, fluorescence spectroscopy, steady-state photolysis, cyclic voltammetry, and electron paramagnetic resonance. Notably, the exceptional performance of the photoinitiators enabled the fabrication of 3D objects with precise morphology and superior resolution through 3D printing and direct laser write techniques. These findings not only provide opportunities for efficient polymerization under artificial and natural light conditions but also pave the way for scalable, cost-effective, environmentally sustainable, and green chemistry-driven curing applications.
Implant-associated infections frequently complicate orthopedic surgeries, resulting in challenging issues. The current therapy of antibiotic treatment and surgical debridement often leads to drug resistance and bone defect. The development of pH-responsive antimicrobial and pro-osteogenic materials is a promising approach to controlling infections and repairing infected bone defects, especially given the weakly acidic pH of the bacterial infection area. Solid peroxides have the potential to provide a sustained release of hydrogen peroxide (H2O2), rendering them applicable for antimicrobial purposes. Additionally, their chemical properties render them inherently responsive to pH. Here, we propose a novel GelBA/PVA/MgO2 hydrogel composed of gelatin (Gel), benzeneboronic acid (BA), poly(vinyl alcohol) (PVA), and magnesium peroxide (MgO2) with self-healing ability and pH-responsiveness. The borate ester bond formed between PVA and BA is a dynamic chemical bond with properties of dynamic formation and dissociation, making the hydrogel both self-healable and pH-responsive. Meanwhile, the addition of MgO2 improves the network structure of the hydrogel and gives the hydrogel the ability to perform sustained release of H2O2 and Mg2+. Experimentally, the GelBA/PVA/MgO2 hydrogel exhibits controlled and pH-dependent H2O2 and Mg2+ release, sustained over time at physiological pH (7.4) and significantly increased at infection pH (5.5). In vitro and in vivo outcomes revealed that this hydrogel is able to inhibit Staphylococcus aureus growth and accelerate bone regeneration, improving bone healing without cytotoxic effects on normal tissues. These findings suggest that the GelBA/PVA/MgO2 hydrogel is a unique and efficient approach for anti-infection and therapeutic implant-associated infections.