Guangxi University of Science and Technology

Abstract The absence of two-dimensional (2D) van der Waals (vdW) ferromagnetic crystals with both above-room-temperature strong intrinsic ferromagnetism and large perpendicular magnetic anisotropy (PMA) severely hinders practical applications of 2D vdW crystals in next-generation low-power magnetoelectronic and spintronic devices. Here, we report a vdW intrinsic ferromagnetic crystal Fe 3 GaTe 2 that exhibits record-high above-room-temperature Curie temperature ( Tc , ~350-380 K) for known 2D vdW intrinsic ferromagnets, high saturation magnetic moment (40.11 emu/g), large PMA energy density (~4.79 × 10 5 J/m 3 ), and large anomalous Hall angle (3%) at room temperature. Such large room-temperature PMA is better than conventional widely-used ferromagnetic films like CoFeB, and one order of magnitude larger than known 2D vdW intrinsic ferromagnets. Room-temperature thickness and angle-dependent anomalous Hall devices and direct magnetic domains imaging based on Fe 3 GaTe 2 nanosheet have been realized. This work provides an avenue for room-temperature 2D ferromagnetism, electrical control of 2D ferromagnetism and promote the practical applications of 2D-vdW-integrated spintronic devices.

Two-dimensional materials having a layered structure comprise a monolayer or multilayers of atomic thickness and ultra-low shear strength. Their high specific surface area, in-plane strength, weak layer-layer interaction, and surface chemical stability result in remarkably low friction and wear-resisting properties. Thus, 2D materials have attracted considerable attention. In recent years, great advances have been made in the scientific research and industrial applications of anti-friction, anti-wear, and lubrication of 2D materials. In this article, the basic nanoscale friction mechanisms of 2D materials including interfacial friction and surface friction mechanisms are summarized. This paper also includes a review of reports on lubrication mechanisms based on the film-formation, self-healing, and ball bearing mechanisms and applications based on lubricant additives, nanoscale lubricating films, and space lubrication materials of 2D materials in detail. Finally, the challenges and potential applications of 2D materials in the field of lubrication were also presented.

Safe, inexpensive aqueous zinc-ion batteries (AZIBs) are regarded as promising energy storage devices. However, they still face issues, including dissolution and collapse of the cathode as well as H2 evolution and the growth of Zn dendrites on the Zn anode. Herein, we simultaneously regulate the cations and anions in the electrolyte for high-capacity, high-stability aqueous zinc–vanadium (Zn–V) batteries based on a bimetallic cation-doped Na0.33K0.1V2O5⋅nH2O cathode. We demonstrate that Na+ ​cations suppress cathode dissolution and restrain Zn dendrite growth on the anode via an electrostatic shield effect. We also illustrate that ClO4− anions participate in energy storage at the cathode and are reduced to Cl−, generating a protective layer on the Zn anode surface and providing a stable interface to decrease Zn dendrites and H2 evolution during long-term cycling. When Na+ and ClO4− are introduced into an aqueous ZnSO4 electrolyte, a Zn/Zn symmetric cell shows durable and reversible Zn stripping/plating for 1500 ​h at a current density of 1 ​mA ​cm−2 and with an area capacity of 1 mAh cm−2. Zn/Na0.33K0.1V2O5⋅nH2O full batteries exhibit a high capacity of 600 mAh g−1 at 0.1 ​A ​g−1 and long-term cycling performance for 5000 cycles, with a capacity of 200 mAh g−1 at 20 ​A ​g−1.

The power conversion efficiency of lead halide perovskite solar cells has been elevated to 25.2%. However, the toxicity of lead and the complex fabrication process of those cells considerably hinder the commercial application of such solar cells. Therefore, lead-free solar cells with comparable power conversion efficiency with a much lower environmental impact have recently attracted enormous attention in both academia and industry. This paper presents a theoretical study to assess the energy conversion capacity of lead-free perovskite solar cells with MASnI3 perovskite as its absorber layer using solar cell capacitance simulator (SCAPS). In particular, the effects of materials of the perovskite solar cells’ electron transport layers (ETLs) and hole transport layers (HTLs) on their energy conversion performance are elaborated. Our results show that Cd0.5Zn0.5S and MASnBr3 are the most suitable materials for ETL and HTL, respectively. It is also found from that the solar cell performance can be further enhanced through optimizing the thickness and defect density of its absorber layer. Moreover, the effects of defect densities in interface layers are investigated. In addition, the effects of ETL and HTL doping densities as well as influences of the back-contact work function and operating temperature of the tin-based perovskite solar cells are discussed. Finally, a glass substrate/FTO/Cd0.5Zn0.5S (ETL)/MASnI3/MASnBr3 (HTL)/back-contact solar cell with a power conversion efficiency of 23.86% is recommended for further optimization.

The commercial application of aqueous zinc metal batteries in the field of large-scale energy storage is still suffered from their low-temperature operation, in which the electrochemical behaviors of the electrolyte, electrode materials, and their interfaces will deteriorate at low temperatures. Herein, by considering the significance of this topic, an in-depth comprehensive and systematic summary of low-temperature zinc metal batteries (LTZMBs) with the main challenges and corresponding optimization strategies was provided. Furthermore, the promising perspectives have also been proposed, aiming to guide the scientific future development of LTZMBs.

A double-layered Huygens' unit cell is proposed to design a broadband metasurface lens (meta-lens) for 5G millimeter-wave antennas. The Huygens' unit cell consists of a pair of antisymmetric conducting semicircle arc elements on both surfaces of a thin dielectric substrate. The surface currents flowing at the opposite directions on both conducting elements form an electric current loop to induce the orthogonal magnetic current, and then the Huygens' resonances are stimulated. The Huygens' unit cell provides the transmission phase coverage of over 400° with transmission amplitude better than -2.3 dB. This breaks through the phase shift limitation of a conventional double-layer frequency-selective surface (FSS) element. It shows that induced magnetism makes such a Huygens-based meta-lens very compact with only one printed circuit board. As an example, a double-layered meta-lens on a 1.5 mm-thick dielectric substrate is designed and experimentally verified. The meta-lens antenna achieves the measured peak gain of 30.7 dBi at 26.2 GHz with an aperture efficiency of 42.25% over the 3 dB bandwidth of 15.7% from 24.1 to 28.2 GHz, fully covering the proposed 5G spectrum from 24.25 to 27.5 GHz. This proposed method greatly helps in the application of promoting planar lightweight low-cost broadband lens antennas in the coming 5G systems.

Abstract Although mild aqueous electrolytes endow zinc‐ion batteries with intrinsic security surpassing that of lithium‐ion batteries, whether irreversible zinc deposition and related corrosion on the anode or cathode species dissolution severely circumscribes their cyclic stability, especially at low current density. Here, hydrogen bond‐functionalized massive solvation modules in a maltose‐based hybrid electrolyte are constructed, which is crucial for the stability of bilateral interfaces in the cycling process, to address this infamous issue. The intensive solvated interactions and diffusion hindrance effect yield uniform deposition of zinc at the anode interface, while the hydrogen bond confinement to free water interdicts derived parasitic reactions. As for the cathode interface, the massive solvation modules avoid structural framework collapse from vanadium dissolution and preserve low interfacial activation energy during cycling. The above bilateral interface regulation enables resultant full batteries to unprecedentedly maintain 84.2% of its initial specific capacity after 400 continuous cycles even at a very low current density of 50 mA g –1 . This work provides a new perspective toward economical and eco‐friendly electrolytes for stable aqueous batteries.

Abstract Aqueous Mn 2+ /MnO 2 ‐based batteries have attracted enormous attentions in aqueous energy storage fields, owing to their high working voltage and theoretical capacity (616 mAh g −1 ) brought by the two‐electron reaction (Mn 2+ /Mn 4+ ). However, there are currently several tricky challenges facing Mn 2+ /MnO 2 ‐based batteries: their complicated working mechanisms, existing issues, and optimization strategies. This Perspective aims to provide a mechanistic understanding and an overview of the insufficiency, optimization, and future development for Mn 2+ /MnO 2 ‐based batteries. The existing issues and deficiency in Mn 2+ /MnO 2 ‐based batteries have been systematically analyzed, and optimization strategies have also been rationally summarized and discussed with deep insights. Also, the often‐overlooked optimized objects and aspects have been highlighted with unique perspectives. The proposals of testing methods and performance assessment are presented, containing different degradation mechanisms. Based on the above points, this Perspective will provide guidance and contribute to the further development of aqueous Mn 2+ /MnO 2 ‐based batteries.

ZIF-8, as an important photoresponsive metal–organic framework (MOF), holds great promise in the field of cancer theranostics owing to its versatile physiochemical properties. However, its photocatalytic anticancer application is still restricted because of the wide bandgap and specific response to ultraviolet light. Herein, we developed lanthanide-doped nanoparticles (LDNPs) coated with Fe/Mn bimetal-doped ZIF-8 (LDNPs@Fe/Mn-ZIF-8) for second near-infrared (NIR-II) imaging-guided synergistic photodynamic/chemodynamic therapy (PDT/CDT). The LDNPs were synthesized by encapsulating an optimal Yb3+/Ce3+-doped active shell on the NaErF4:Tm core to achieve dual-mode red upconversion (UC) and NIR-II downconversion (DC) emission upon NIR laser irradiation. At the optimal doping concentration, the UC and DC NIR-II emission intensities of LDNPs were increased 30.2- and 13.2-fold above those of core nanoparticles, which endowed LDNPs@Fe/Mn-ZIF-8 with an outstanding capability to carry out UC-mediated PDT and NIR-II optical imaging. In addition, the dual doping of Fe2+/Mn2+ markedly decreased the bandgap of the ZIF-8 photosensitizer from 5.1 to 1.7 eV, expanding the excitation threshold of ZIF-8 to the visible light region (∼650 nm), which enabled Fe/Mn-ZIF-8 to be efficiently excited by UC photons to achieve photocatalytic-driven PDT. Furthermore, Fe2+/Mn2+ ions could be responsively released in the tumor microenvironment through degradation of Fe/Mn-ZIF-8, thereby producing hydroxyl radicals (·OH) by Fenton/Fenton-like reactions to realize CDT. Meanwhile, the degradation of Fe/Mn-ZIF-8 endowed the nanosystems with tumor self-enhanced NIR-II imaging function, providing precise guidance for CDT/PDT.

Hypercrosslinked pyrrole was synthesized via the Friedel–Crafts reaction and then carbonized to obtain urchin-like nitrogen-doped carbon (UNC). Ultrasmall iron oxide nanoparticles were then supported on UNC, and the composite was used to prepare an electrochemical sensor for detecting uric acid (UA) in human urine. FexOy/UNC was characterized and analyzed via scanning electron microscopy, transmission electron microscopy, energy dispersive spectrometry, X-ray diffraction, and X-ray photoelectron spectroscopy. A glassy carbon electrode (GCE) modified with FexOy/UNC was used as an electrochemical sensor to effectively identify UA. The electrochemical behavior of the FexOy/UNC-based UA sensor was studied using differential pulse stripping voltammetry, and the optimal conditions were determined by changing the amount of FexOy/UNC, pH of the buffer solution, deposition potential, and deposition time. Under optimal conditions, the FexOy/UNC-based electrochemical sensor detected UA in the range of 2–200 μM, where the limit of detection (LOD) for UA was 0.29 μM. Anti-interference experiments were performed, and the sensor was applied to the actual analysis of human urine samples. Urea, glucose, ascorbic acid, and many cations and anions present at 100-fold concentrations relative to UA did not strongly interfere with the response of the sensor to UA. The FexOy/UNC electrochemical sensor has high sensitivity and selectivity for uric acid in human urine samples and can be used for actual clinical testing of UA in urine.

With the development of energy science and electronic technology, interfacial thermal transport has become a key issue for nanoelectronics, nanocomposites, energy transmission, and conservation, etc. The application of thermal interfacial materials and other physical methods can reliably improve the contact between joined surfaces and enhance interfacial thermal transport at the macroscale. With the growing importance of thermal management in micro/nanoscale devices, controlling and tuning the interfacial thermal resistance (ITR) at the nanoscale is an urgent task. This Review examines nanoscale interfacial thermal transport mainly from a theoretical perspective. Traditional theoretical models, multiscale models, and atomistic methodologies for predicting ITR are introduced. Based on the analysis and summary of the factors that influence ITR, new methods to control and reduce ITR at the nanoscale are described in detail. Furthermore, the challenges facing interfacial thermal management and the further progress required in this field are discussed.

Abstract High‐energy electrolytic Zn//MnO 2 batteries show potential for grid‐scale energy storage, but the severe hydrogen evolution corrosion (HEC) caused by acidic electrolytes results in subdued durability. Here, an all‐around protection strategy is reported for achieving stable Zn metal anodes. First, a proton‐resistant Pb‐containing (Pb and Pb(OH) 2 ) interface is constructed on a Zn anode (denoted as Zn@Pb), which in situ forms PbSO 4 during H 2 SO 4 corrosion and protects the Zn substrate from HEC. Second, to improve the plating/stripping reversibility of Zn@Pb, Pb(CH 3 COO) 2 an additive (denoted as Zn@Pb‐Ad) is introduced, which triggers PbSO 4 precipitation and releases trace Pb 2+ that can dynamically deposit a Pb layer on the Zn plating layer to suppress HEC. The superior HEC resistance stems from the low affinity of PbSO 4 and Pb for H + , as well as strong bonding between Pb–Zn or Pb–Pb, which increase the hydrogen evolution reaction overpotential and the H + corrosion energy barrier. Consequently, the Zn@Pb‐Ad//MnO 2 battery runs stably for 630 and 795 h in 0.2 and 0.1 m H 2 SO 4 electrolytes, respectively, which are >40 times better than that of bare Zn. The as‐prepared A h‐level battery achieves a one‐month calendar life, opening the door to the next generation of high‐durable grid‐scale Zn batteries.

Due to the increasing air pollution from diesel engines and the shortage of conventional fossil fuels, many experimental and numerical types of research have been carried out and published in the literature over the past few decades to find a new, sustainable, and alternative fuels. Biodiesel is an appropriate alternate solution for diesel engines because it is renewable, non-toxic, and eco-friendly. According to the European Academies Science Advisory Council, biodiesel evolution is broadly classified into four generations. This paper provides a comprehensive review of the production, properties, combustion, performance, and emission characteristics of diesel engines using different generations of biodiesel as an alternative fuel to replace fossil-based diesel and summarizes the primary feedstocks and properties of different generations of biodiesel compared with diesel. The general impression is that the use of different generations of biodiesel decreased 30% CO, 50% HC, and 70% smoke emissions compared with diesel. Engine performance is slightly decreased by an average of 3.13%, 89.56%, and 11.98% for higher density, viscosity, and cetane, respectively, while having a 7.96% lower heating value compared with diesel. A certain ratio of biodiesel as fuel instead of fossil diesel combined with advanced after-treatment technology is the main trend of future diesel engine development.

Abstract The solid–liquid transition reaction lays the foundation of electrochemical energy storage systems with high capacity, but realizing high efficiency remains a challenge. Herein, in terms of thermodynamics and dynamics, this work demonstrates the significant role of both interfacial H + concentration and Mn 2+ migration steric hindrance for the high‐efficiency deposition/dissolution chemistry of zinc–manganese batteries. Specially, the introduction of formate anions can buffer the generated interfacial H + to stabilize interfacial potential according to the Nernst equation, which stimulates high capacity. Compared with acetate and propionate anions, the formate anion also provides high adsorption density on the cathode surface to shield the electrostatic repulsion due to the small spatial hindrance. Particularly for the solvated Mn 2+ , the formate‐anion‐induced lower energy barrier of the rate‐determining step during the step‐by‐step desolvation process results in lower polarization and higher electrochemical reversibility. In situ tests and theoretical calculations verify that the electrolyte with formate anions achieve a good balance between ion concentration and ion‐migration steric hindrance. It exhibits both the high energy density of 531.26 W h kg ‐1 and long cycle life of more than 300 cycles without obvious decay.

A simple heterovalent metal halide surface treatment enables formation of n/n ⁺ perovskite homojunction, which enlarged built-in electric field and accelerated charge extraction at the perovskite/C ₆₀ interface, achieving a high efficiency of 22.2%.

The band gaps of photonic crystals (PCs) play an important role in light manipulation for many applications, such as reflectors, filters, and lasers. In traditional, one-dimensional all-dielectric PCs, as the angle of incidence increases, the gaps are blueshifted in wavelength for both transverse-electric (TE) and transverse-magnetic (TM) polarizations. However, this work predicts and demonstrates that redshifted gaps can be realized in one-dimensional PCs composed of alternating hyperbolic metamaterials and dielectrics for TM polarization, while for TE polarization the gaps remain blueshifted. This property facilitates the design of polarization selectors working in a wide angle range.

Abstract Aqueous zinc–manganese batteries with low cost, reliable safety, and considerable energy density, show promise for grid‐scale storage. Their durable operation is highly dependent on the reversibility and stability of both electrode interfaces, which is limited by the different requirements of the interfaces of manganese‐based cathodes and zinc anodes. Here, a quasi‐decoupled solid–liquid hybrid electrolyte is proposed, which demonstrates good compatibility and high reversibility for both interfaces with different electrolyte environments, showing quasi‐decoupling characteristics. Such a hybrid electrolyte can endow the anode interface with abundant favorable nucleation sites for achieving uniform zinc platting/stripping, as well as limit the presence of free H 2 O molecules, to suppress side‐reactions. This electrolyte is also adapted to a reversible and stable MnO 2 /Mn 2+ manganese deposition/dissolution reaction at the cathode interface by restricting OH − /H + ion diffusion, preventing formation of irreversible electrochemically inert MnOOH. As a result, the quasi‐decoupled solid–liquid hybrid electrolyte enables Zn||Zn cycling for more than 500 h, and a specific capacity of a Zn||α‐MnO 2 battery up to 348 mAh g −1 at 0.2 A g −1 . It also allows 87% capacity retention after 500 cycles at 0.5 A g −1 . This work provides a new insight into electrolyte design that focuses on the different requirements of differing electrode interfaces.

Abstract Control of ferromagnetism is of critical importance for a variety of proposed spintronic and topological quantum technologies. Inducing long-range ferromagnetic order in ultrathin 2D crystals will provide more functional possibility to combine their unique electronic, optical and mechanical properties to develop new multifunctional coupled applications. Recently discovered intrinsic 2D ferromagnetic crystals such as Cr 2 Ge 2 Te 6 , CrI 3 and Fe 3 GeTe 2 are intrinsically ferromagnetic only below room temperature, mostly far below room temperature (Curie temperature, ~20–207 K). Here we develop a scalable method to prepare freestanding non-van der Waals ultrathin 2D crystals down to mono- and few unit cells (UC) and report unexpected strong, intrinsic, ambient-air-robust, room-temperature ferromagnetism with T C up to ~367 K in freestanding non-van der Waals 2D CrTe crystals. Freestanding 2D CrTe crystals show comparable or better ferromagnetic properties to widely-used Fe, Co, Ni and BaFe 12 O 19 , promising as new platforms for room-temperature intrinsically-ferromagnetic 2D crystals and integrated 2D devices.

Abstract As an integral part of all‐solid‐state lithium (Li) batteries (ASSLBs), solid‐state electrolytes (SSEs) must meet requirements in high ionic conductivity, electrochemical/chemical stability toward the electrode. The ionic conductivity of the Li super ionic conductor (LISICON) is limited, and the thio‐LISICON is improved by replacing O 2− in the LISICON with S 2− . Currently, the ionic conductivity of Li 10 GeP 2 S 12 (LGPS) has exceeded 10 mS cm −1 , which meets the demands of commercial ASSLBs. However, poor stability of SSEs, baneful interfacial reactions, Li dendrite growth, and other factors have impeded the development of ASSLBs. Hence, this review first traces the development progress of thio‐/LISICON and LGPS‐type SSEs, analyzes the complicated ion transport mechanism, and summarizes the effective strategies for improving ionic conductivity. Moreover, exciting methods focusing on electrode interface engineering are outlined separately. As to SSE/anode interface, poor chemical or electrochemical compatibility, poor interfacial contact, and the mechanisms of dendrite formation are discussed. For the SSE/cathode interface, poor interfacial stability and non‐intimate solid–solid contact are daunting challenges. Then, effective methods to improve interface stability and electrochemical performance of ASSLBs with LGPS‐type SSEs are introduced. Finally, combined with the present chances and challenges, the possible future developing directions of LGPS‐based ASSLBs and the perspectives are proposed.

Abstract Alterations in energy metabolism are associated with depression. However, the role of glycolysis in the pathogenesis of depression and the underlying molecular mechanisms remain unexplored. Through an unbiased proteomic screen coupled with biochemical verifications, we show that the levels of glycolysis and lactate dehydrogenase A (LDHA), a glycolytic enzyme that catalyzes L-lactate production, are reduced in the dorsomedial prefrontal cortex (dmPFC) of stress-susceptible mice in chronic social defeat stress (CSDS) model. Conditional knockout of LDHA from the brain promotes depressive-like behaviors in both male and female mice, accompanied with reduced L-lactate levels and decreased neuronal excitability in the dmPFC. Moreover, these phenotypes could be duplicated by knockdown of LDHA in the dmPFC or specifically in astrocytes. In contrast, overexpression of LDHA reverses these phenotypic changes in CSDS-susceptible mice. Mechanistic studies demonstrate that L-lactate promotes neuronal excitability through monocarboxylic acid transporter 2 (MCT2) and by inhibiting large-conductance Ca 2+ -activated potassium (BK) channel. Together, these results reveal a role of LDHA in maintaining neuronal excitability to prevent depressive-like behaviors.