Lithiophilic and Eco-Friendly Nano-Se Seeds Unlock Dendrite-Free and Anode-Free Li-Metal Batteries.

A 3D host design for lithium (Li)-metal anodes can effectively accommodate volume changes and suppress Li dendrite growth; nonetheless, its practical applicability in energy-dense Li-metal batteries (LMBs) is plagued by excessive Li loading. Herein, we introduced eco- and human-friendly Se seeds into 3D carbon cloth (CC) to create a robust host for efficient Li deposition/stripping. The highly lithiophilic nano-Se endowed the Se-decorated CC (Se@CC) with perfect Li wettability for instantaneous Li infusion. At an optimal Li loading of 17 mg, the electrode delivered an unprecedentedly long life span of 5400 h with low overpotentials <36 mV at 1 mA cm-2/1 mAh cm-2 and 1500 h at 5 mA cm-2/5 mAh cm-2. Furthermore, the uniform Se distribution and strong Li-Se binding allowed for further reduction in Li loading to 2 mg via direct Li electrodeposition. The corresponding LiNi0.8Co0.1Mn0.1O2 (NCM811)-based full cell afforded a high capacity retention rate of 74.67% over 300 cycles at a low N/P ratio of 8.64. Finally, the initial anode-free LMB using a NCM811 cathode and a Se@CC anode current collector demonstrated a high electrode-level specific energy of 531 Wh kg-1 and consistently high CEs >99.7% over 200 cycles. This work highlights a high-performance host design with excellent tunability for practical high-energy-density LMBs.

Electrocatalytically inactive copper improves the water adsorption/dissociation on Ni3S2 for accelerated alkaline and neutral hydrogen evolution.

Nickel dichalcogenides, especially Ni3S2, present inferior alkaline and neutral hydrogen evolution activity due to their sluggish water dissociation kinetics. Although these materials hold promise as non-noble metal-based electrocatalysts for the hydrogen evolution reaction (HER) in acidic media, developing efficient strategies to enhance the water dissociation processes of nickel dichalcogenides in alkaline and neutral solutions is also an important area of research. The present work discloses an electrocatalytically inactive copper doping strategy to promote the water adsorption and dissociation process of Ni3S2 (Cu-Ni3S2) nanoparticles supported on nickel foam (NF) towards improving the alkaline and neutral hydrogen evolution reactions. Based on combined density functional theory calculations and electrochemical characterizations, the doping of Cu can accelerate the Volmer step and therefore strengthen the water adsorption/dissociation on the respective Ni sites and S sites during the HER process. As a result, the electrocatalyst exhibits superior and stable HER performance in both 1 M KOH and 1 M phosphate-buffered saline (PBS) solutions, with much lower overpotentials of 121 and 228 mV at a current density of 10 mA cm-2, respectively, in comparison to bare Ni3S2. We therefore conclude that the tailored control of the water adsorption/dissociation capability of Ni3S2 will open significant opportunities for the rational design of alkaline and neutral electrocatalysts from earth-abundant and stable materials.

Assembling of Bi atoms on TiO2 nanorods boosts photoelectrochemical water splitting of semiconductors.

Low photoconversion efficiency, high charge transfer resistance and fast recombination rate are the bottlenecks of semiconductor nanomaterials in photoelectrochemical (PEC) water splitting, where the introduction of an appropriate co-catalyst is an effective strategy to improve their performance. In the present study, we have purposely designed atomic-scale dispersed bismuth (Bi) assembled on titanium dioxide nanorods (TiO2), and demonstrated its effective role as a co-catalyst in enhancing the PEC water splitting performance of TiO2. As a result, functionalized Bi/TiO2 generates a high photocurrent intensity at 1.23 VRHE under simulated solar light irradiation, which is 4-fold higher than that of pristine TiO2, exhibiting a significantly improved PEC performance for water splitting. The strategy presented in this study opens a new window for the construction of non-precious metals dispersed at atomic scales as efficient co-catalysts for realizing sustainable solar energy-driven energy conversion and storage.

Organic-inorganic hybrid (CH3NH3)2FeCuI4Cl2 and (CH3NH3)2InCuI6 for ultraviolet light photodetectors.

Photodetectors play a key role in the military, aerospace, communications, bio-imaging, etc. In this study, we fabricate photodetector devices based on (CH3NH3)2FeCuI4Cl2 (MA2FeCuI4Cl2) and (CH3NH3)2InCuI6 (MA2InCuI6) for the first time. We find that the device based on MA2InCuI6 is highly selective for ultraviolet light (880 nA mW-1) and shows high anti-interference for visible-light (20-50 nA mW-1). The electrochemical impedance results indicate that the value (480 ± 10 Ω) of the resistance based on the MA2InCuI6 photodetector device is much smaller than that (1 ± 0.001 MΩ) based on the MA2FeCuI4Cl2 photodetector device, which in turn proves the difference in photoelectric response.

Recent Progress in Two-Dimensional Layered Double Hydroxides and Their Derivatives for Supercapacitors.

High-performance supercapacitors have attracted great attention due to their high power, fast charging/discharging, long lifetime, and high safety. However, the generally low energy density and overall device performance of supercapacitors limit their applications. In recent years, the design of rational electrode materials has proven to be an effective pathway to improve the capacitive performances of supercapacitors. Layered double hydroxides (LDHs), have shown great potential in new-generation supercapacitors, due to their unique two-dimensional layered structures with a high surface area and tunable composition of the host layers and intercalation species. Herein, recent progress in LDH-based, LDH-derived, and composite-type electrode materials targeted for applications in supercapacitors, by tuning the chemical/metal composition, growth morphology, architectures, and device integration, is reviewed. The complicated relationships between the composition, morphology, structure, and capacitive performance are presented. A brief projection is given for the challenges and perspectives of LDHs for energy research.

Semi-Transparent and Stable Solar Cells for Building Integrated Photovoltaics: The Confinement Effects of the Polymer Gel Electrolyte inside Mesoporous Films.

The semi-transparent solar cells are promising to be applied in building integrated photovoltaic (BIPV) and tandem solar cells. In this study, we fabricate semi-transparent and stable solar cells for BIPV by utilizing a poly (ethylene oxide) electrolyte and controlling the size of TiO2 nanoparticles and the thickness of the TiO2 film. The power conversion efficiency of the semi-transparent (over 50% transmittance at 620-750 nm) and quasi-solid solar cells is 5.78% under standard AM1.5G, 100 mW cm-2. The higher conductivity and smaller diffusion resistance of the quasi-solid electrolyte inside the mesoporous TiO2 film indicate the confinement effects of the polymer electrolyte inside a mesoporous TiO2 film. The unsealed semi-transparent and quasi-solid solar cell retains its initial efficiency during 1000 h irradiation in humid air.

Enlarged Interlayer Spacing in Cobalt-Manganese Layered Double Hydroxide Guiding Transformation to Layered Structure for High Supercapacitance.

Cobalt-manganese layered double hydroxide (CoMn-LDH) has been known as a highly desired cathode material used with an alkaline electrolyte. However, the layered double hydroxide structure is unstable and changes almost instantly in alkaline solution due to the instability of a manganese(III) ion. Thus, it is important to investigate the true active phase for designing efficient electrode materials. In this work, the metal-organic framework is used as a templating precursor to derive CoMn-LDH from three different manganese solutions, namely, MnSO4, Mn(NO3)2, and MnCl2. Anions in the solutions participate in the derivation process and strongly affect the layer structure, phase transformation process, and charge storage properties of the resulting materials. CoMn-LDH synthesized from manganese sulfate solution exhibits the largest interlayer spacing of 1.08 nm, and more interestingly, the layered structure can well be retained in KOH solution, while the other two synthesized from manganese chloride and nitrate solutions transform into the spinel structure. As a cathode material, it delivers a high areal capacity of 582.07 mC/cm2 at 2 mA/cm2, which is about 100% higher than those of the other two samples. The present work explores the active phase of CoMn-LDH in the alkaline electrolyte and proposes a potential mechanism of the phase transformation, which provides insights into understanding and designing of the active electrode materials for stable and high-performing supercapacitors in an alkaline environment.

Progesterone maintains the status of granulosa cells and slows follicle development partly through PGRMC1.

Progesterone receptor membrane component 1 (PGRMC1) mediates antimitotic and antiapoptotic actions of progesterone in granulosa cells, which indicates that PGRMC1 may play a key role in maintaining the status of granulosa cells. The current study investigated the effects of progesterone on intracellular signaling involved in differentiation, follicle development, inflammatory responses, and antioxidation, and determined the role of PGRMC1 in these processes. Our results demonstrated that progesterone slowed follicle development and inhibited p-ERK1/2, p-p38, caspase-3, p-NF-κB, and p-IκB-α signals involved in differentiation, steroidogenesis, and inflammatory responses in granulosa cells. Progesterone inhibited the steroidogenic acute regulatory protein and the cholesterol side-chain cleavage enzyme and decreased pregnenolone production. A PGRMC1 inhibitor and a PGRMC1 small interfering RNA ablated these inhibitory effects of progesterone. Interfering with PGRMC1 functions also decreased cellular antioxidative effects induced by an oxidant. These results suggest that PGRMC1 might play a critical role in maintaining the status of granulosa cells and balancing follicle numbers.

Synthesis and antitumour activity of arctigenin amino acid ester derivatives against H22 hepatocellular carcinoma.

Arctigenin (ARG) is famous in its abundant pharmacological activity. However, many researches in it entered the bottleneck period because of its poor water solubility. The derivatives of ARG have been synthesised with five amino acids which have t-Butyloxy carbonyl (BOC) as a protective group. We examined the effects of removing BOC. The results showed that the amino acid derivatives without protective group have better water solubility and nitrite-clearing ability than ARG. Based on these results, ARG6' and ARG9' were selected at a dosage of 40 mg/kg to evaluate their antitumour activity. The percentage inhibition rate of ARG6' and ARG9' were 55.87 and 51.40, respectively, which was twice as much as ARG. Furthermore, they could increase liver and kidney indexes and produce less damage in these organs. In brief, this study provides a basis for new drug development.

Progesterone amplifies oxidative stress signal and promotes NO production via H2O2 in mouse kidney arterial endothelial cells.

The role of progesterone on the cardiovascular system is controversial. Our present research is to specify the effect of progesterone on arterial endothelial cells in response to oxidative stress. Our result showed that H2O2 (150 µM and 300 µM) induced cellular antioxidant response. Glutathione (GSH) production and the activity of Glutathione peroxidase (GPx) were increased in H2O2-treated group. The expression of glutamate cysteine ligase catalytic subunit (GCLC) and modifier subunit (GCLM) was induced in response to H2O2. However, progesterone absolutely abolished the antioxidant response through increasing ROS level, inhibiting the activity of Glutathione peroxidase (GPx), decreasing GSH level and reducing expression of GClC and GCLM. In our study, H2O2 induced nitrogen monoxide (NO) production and endothelial nitric oxide synthase (eNOS) expression, and progesterone promoted H2O2-induced NO production. Progesterone increased H2O2-induced expression of hypoxia inducible factor-α (HIFα) which in turn regulated eNOS expression and NO synthesis. Further study demonstrated that progesterone increased H2O2 concentration of culture medium which may contribute to NO synthesis. Exogenous GSH decreased the content of H2O2 of culture medium pretreated by progesterone combined with H2O2 or progesterone alone. GSH also inhibited expression of HIFα and eNOS, and abolished NO synthesis. Collectively, our study demonstrated for the first time that progesterone inhibited cellular antioxidant effect and increased oxidative stress, promoted NO production of arterial endothelial cells, which may be due to the increasing H2O2 concentration and amplified oxidative stress signal.

In vitro controlled release of vitamin C from Ca/Al layered double hydroxide drug delivery system.

A new drug delivery system for vitamin C (VC), Ca/Al layered double hydroxide (LDH), is demonstrated in this work. VC anions were intercalated successfully in the Ca/Al LDH gallery by a coprecipitation method. The interlayer space of 9.8Å suggests that VC anions are vertical to the LDH layers in the form of interdigitated bilayer. The loading of VC in LDH is 36.4wt.%. The thermal stability of VC is significantly enhanced after intercalation. In vitro VC release results show that the release time of VC in a phosphate buffer at pH7.4 was significantly extended, and the maximal percentage of VC released is 80% of the total. The Avrami-Erofe'ev equation most satisfactorily explains the release kinetics of VC, which is that the release of VC is mainly dominated by the ion-exchange reaction.

Enhanced luminescence of europium-doped layered double hydroxides intercalated by sensitiser anions.

Four sensitising anions naphthalene-1,5-disulfonate (15-NDS), naphthalene-2,6-dicarboxylate (26-NDC), benzoate (BA) and terephthalate (TA) were intercalated into a Eu(3+)-doped Zn/Al layered double hydroxide. The carboxylate anions enhanced the red luminescence of Eu(3+) much more strongly than the sulfonate, in the descending order TA > 26-NDC > BA > 15-NDS.