ChemPhysMater最新文献

The key challenges in aqueous zinc-manganese dioxide batteries (MnO₂//Zn) are their poor electrochemical kinetics and stability, which are mainly due to low conductivity and the inevitable dissolution of MnO₂. A synergistic combination of a Co-doped σ-MnO₂ electrode (Co-MnO₂) and a Co(CH₃COO)₂•4H₂O (CoAc) electrolyte additive is here developed to design a high-performance aqueous MnO₂//Zn battery (denoted as a Co-MnO₂//Zn battery with CoAc). The introduction of Co ions (Co³⁺/Co²⁺) into the σ-MnO₂ electrode is achieved via a facile one-step electrodeposition method. Benefitting from the synergistic coupling effect of the Co-MnO₂ electrode and the CoAc electrolyte additive, the fabricated Co-MnO₂//Zn battery with CoAc shows a commendable discharge capacity of 313.8 mAh g⁻¹ at 0.5 A g⁻¹, excellent rate performance, excellent durability over 1000 cycles (∼ 92% capacity retention at 1.0 A g⁻¹) and admirable energy density (439.3 Wh kg⁻¹), which is a significant improvement compared with an un-doped σ-MnO₂//Zn battery.

Partial oxidation of methane is a promising alternative strategy for methanol production under mild reaction conditions; however, significant challenges hinder the development of appropriate catalysts. In this study, based on first-principles calculations, we demonstrate that a single Fe atom supported on anatase TiO₂(001) provides double active sites (Fe and Ti_5C) to activate gas-phase O₂ and form O-assisted intermediates. The triple state Fe-O/TiO₂(001) system exhibited better activity for methane activation (ΔG_max = 1.02 eV). Our findings offer new insights into the design of non-noble-3d transition metal single-atom catalysts on TiO₂(001) for partial methane oxidation via an inexpensive O₂ oxidant under mild reaction conditions.

A series of new nanobiotechnology-based methods have been developed toward achieving safe and efficient cancer treatment. Gold nanorods (AuNRs) have attracted increasing attention owing to their unique optical characteristics, good biocompatibility, and low toxicity, and they have thus been widely used in tumor treatment. In this study, an AuNR-based system was designed by attaching microRNA-192 (miR-192) to polydopamine-coated AuNRs (AuNR@PDA) to explore the possibility of combining genetic and photothermal therapies. RNA/AuNR@PDA exhibited an excellent thermal conversion efficiency under near-infrared (NIR) laser irradiation and excellent biocompatibility. Thus, photothermal therapy (PTT) was combined with gene therapy, which was effected by miR-192, a genetic drug that inhibits cancer cell growth. The combinatory treatment approach entailing the AuNRs-based drug carrier system exhibited encouraging antitumor efficacy.

Photoelectrochemical (PEC) active interfaces exhibiting visible-light responses and good electron-transfer capabilities are key to the development of PEC biosensors. In this study, bioinspired polydopamine (PDA)–polyethyleneimine (PEI) hybrid films were designed to engineer inorganic semiconductors and construct PEC biosensing interfaces. The charge-transfer capability and visible-light-response property of PDA were combined with the electron-attracting ability of PEI to produce a synergistic PEC-enhancement effect. The achieved PEC-enhancement effect was versatile for photoanode and photocathode semiconductors. Further, the role of PEI doping was revealed via electrochemical investigations. Compared with the PDA sensing platform, the hybrid sensing interface offered by the PDA–PEI film exhibited enhanced analytical performances toward ascorbic acid (AA), achieving a larger detection range and a lower limit of detection.

Silicon (Si) anodes with extremely high theoretical capacities are considered indispensable for next-generation high-energy lithium-ion batteries (LIBs). However, several intractable problems, including pulverization, poor electrical contact, and continuous side reactions caused by the large volume change of Si during lithiation/delithiation, lead to a short cycle life and poor rate capability, thus hindering the commercial use of Si anodes in LIBs. Two-dimensional (2D) Si with a unique graphene-like structure has a short ion diffusion pathway, small volume change during lithiation, and efficient redox site utilization, making it more promising than bulk Si or Si with other versatile structures for use in LIBs. Theoretical analysis demonstrated that the low energy barrier on the surface of 2D Si accelerates the transport of Li⁺. However, the issues surrounding 2D Si, including the tedious and user-unfriendly synthesis, ease of restacking, and atmospheric sensitivity, limit its practical applications, which are discussed in this review. Furthermore, possible solutions to these remaining challenges and new directions are provided, with the aim of designing practical and high-performance 2D Si anodes for next-generation LIBs.

The microstructural evolution and corrosion behavior of Ni₆₂Nb₃₃Zr₅ bulk metallic glasses (BMGs) after annealing treatment (AT) at different crystallization temperatures and cryogenic treatment (CT) at −100 ℃ are experimentally investigated. Appropriate AT and CT can both improve the thermal stability and comprehensive corrosion resistance of as-cast BMG in 3.5 wt.% NaCl solution. The annealed and cryo-treated BMGs exhibit one more finite diffusion layer loop in the electrical equivalent circuit than the as-cast BMG, indicating the complexity of the corrosion behavior. Superior corrosion resistance is obtained in the cryo-treated BMG because the high degree of amorphization caused by CT reduces the structural inhomogeneity. Lower C_d and higher R_d values are obtained for the cryo-treated BMG, revealing the formation of a more stable passive film. Among the annealed BMGs, the fully crystallized sample exhibits a higher anti-corrosion performance owing to the existence of Nb-rich oxides in the crystallization products. The passive film is found to be composed mainly of Nb₂O₅ and ZrO₂, demonstrating that Nb and Zr are conducive to reacting with oxygen to form a passive film. Based on the goal of maintaining a fully amorphous phase, appropriate CT causing structural homogeneity of the BMG is a simple and effective means to improve the comprehensive corrosion resistance.

Polyoxometalates (POMs) have drawn broad and intense interest due to their unique structure-dependent properties. The assembly of POM molecules into nanoarchitectures and superstructures can bridge the gap between micro-molecule and bulk POM materials and integrate the merits of molecule and materials that are widely used in catalysis, energy conversion, electronics, and bioapplications. The synthetic methodologies and applications of multiscale POM assemblies have been widely studied. In this review, we survey the POM-based multiscale assembly focusing on two aspects: the strategies for multiscale assembly of POMs and the emerging applications of POM assemblies. For the multiscale assembly, we focus on the methods of POMs assembly including templated synthesis and self- and co-assembly of POMs into nanoarchitectures and superstructures. For the applications, we review the applications of POM assemblies in energy, catalysis, and functional materials. Finally, we present the prospects for the future synthetic design and applications of POM assemblies.

The energetic disorder $\sigma$ describes the energy state distribution in organic semiconducting materials. In organic solar cells (OSCs), energetic disorder is an important parameter for evaluating the charge transport behavior, and it is strongly correlated with the device performance. Thus far, a widely used approach for extracting energetic disorder values in OSCs is the Gaussian disorder model (GDM), in which the disorder values can be extracted by fitting the slope of $\text{ln}\mu \sim \frac{1}{T^2}$, where $\mu$ is the charge mobility and $T$ is the temperature. Herein, we demonstrate the potential of the percolation approach to evaluate the energetic disorder values in OSCs and compare them with the data obtained using the GDM approach. Two typical non-fullerene acceptor (NFA)-based bulk heterojunction (BHJ) films, with PTB7-Th:ITIC and PM6:Y6, were selected as the model systems. When the percolation models were adopted in the two BHJ films, the energetic disorder values extracted from the Grünewald/Thomas and Nenashev percolation models gave similar results for electron transport in the PTB7-Th:ITIC and PM6:Y6 BHJ films. This work successfully demonstrates the feasibility of microresistance analysis in BHJ systems and the application potential of the percolation model for extracting energetic disorders in OSCs.

Photosynthesis is the basis for the survival of organisms in nature; consequently, the fabrication of artificial light-harvesting systems (LHSs) that simulate natural photosynthesis is of significant interest. Recently, a variety of artificial LHSs have been successfully constructed using fluorescence resonance energy transfer (FRET). However, it is crucial to fabricate artificial LHSs with a sequential energy transfer process when considering that the natural photosynthetic process involves a multistep sequential energy transfer process rather than a simple one-step energy transfer. Moreover, many previously reported LHSs have been used as imaging agents for cell labeling and bioimaging or as catalysts in photocatalytic reactions, showing promise for applications simulating natural photosynthesis. In this review, we have summarized recently published representative work on artificial LHSs. In addition, the application of LHSs in photocatalysis and cell labeling has been described in detail.

Developing highly conductive, stable, and active hydrogen evolution reaction (HER) catalysts is a critical step towards establishing the hydrogen economy. However, there are few catalysts, except for noble metals, that can meet all the requirements. Recently, two-dimensional (2D) transition metal carbon/nitride (MXene) materials have shown excellent performance in catalysis, and have attracted wide attention from researchers. In this study, the effectiveness of non-metal element (B, C, N, P, and S)-doped Ti₃C₂O₂ MXene in the electrocatalytic hydrogen evolution reaction was investigated using density functional theory (DFT) calculations. Non-metal atoms as electron donors can provide additional electrons to the O functional group on the catalyst surface, thereby reducing charge transfer from H to O and the interaction between H and O. The Gibbs free energy (∆G_H) of non-metal element-doped Ti₃C₂O₂ is closer to 0 than that of pristine Ti₃C₂O₂, demonstrating better hydrogen evolution performance. Furthermore, in the hydrogen evolution path, the desorption process is more inclined to the Heyrovsky mechanism, and doping greatly reduces the energy barrier of the reaction, thereby improving the catalytic efficiency. The present results prove that doping with non-metallic elements is an effective means of improving the catalytic activity of Ti₃C₂O₂ for hydrogen evolution.