Latest ArticlesThe oxygen evolution reaction (OER) is the bottleneck in the overall photocatalytic splitting of water. The active sites (terminal titanium or bridging oxygen) and active species (molecular or dissociative water) of the initial step of the photocatalyzed OER on the prototypical photocatalyst TiO2, remain debatable. Herein, the photocatalytic chemistry of monolayer water on oxygen-pretreated TiO2(110) (o-TiO2(110)) and reduced TiO2(110) (r-TiO2(110)) surfaces initiated by 400 nm light illumination was investigated by time-dependent two-photon photoemission spectroscopy (TD-2PPE). The photoinduced reduction of the H2O/o-TiO2(110) interface rather than the H2O/r-TiO2(110) interface was detected by TD-2PPE. The difference in 2PPE originated from the presence of the terminal hydroxyl anions (OHt¯) on H2O/o-TiO2(110), as identified by X-ray photoelectron spectroscopy and temperature-programmed desorption. Therefore, the evolution of the electronic structure of H2O/o-TiO2(110) was attributed to the photocatalyzed oxidation of the terminal hydroxyl anions, which most likely formed gaseous •OH radicals, reducing the interface. This work suggested that the oxidation of hydroxyl anions on top of the terminal titanium ions on TiO2, which were excluded previously in solution, need to be considered in the mechanistic studies of the photocatalyzed OER.
Gel-based sensors have provided unprecedented opportunities for bioelectric monitoring. Until now, sensors for underwater applicants have remained a notable challenge, as most sensors work effectively in air but swell underwater leading to functional failure. Herein, we introduce an innovative amphibian-inspired high-performance ionogel, where multiple supramolecular interactions in the ionogel's network confer good stretchability, elasticity, conductivity, and the hydrophobic C-F bonds play a key role in diminishing water molecule hydration and provide outstanding environmental stability. These unique properties of ionogels make them suitable as wearable amphibious flexible sensors, and the sensors are capable of highly sensitive and stable human motion monitoring in air and underwater. Integration of the designed sensor into an artificial intelligence drowning alarm system, which recognizes the swimmer's movement status by monitoring the amplitude and frequency, especially in the drowning status for real-time alarms. This work provides novel strategies for motion recognition and hazard monitoring in amphibious environments, meeting the new generation of wearable sensors.
Metal-organic framework (MOF) has been widely applied in photocatalysis, which is significant for addressing energy crises and environmental issues. Based on density functional theory calculations, the performances of Cu-BTC, a copper-based MOF, and its derivatives CuTM-BTC via the substitution of transition metal (TM) elements at the Cu site for photocatalytic overall water splitting (POWS) have been studied. POWS of Cu-BTC suffers from the sluggish hydrogen evolution reaction due to the large overpotential of 2.02 V and limited solar utilization due to a wide HOMO-LUMO gap of 4.11 eV. Via TM substitution, the HOMO-LUMO gap narrows but still satisfies the redox potentials when taken 3d-TM of Cr, Fe, Co or Ni, 4d-TM of Rh or Pd, or 5d-TM of Re or Pt into consideration, benefiting for the light absorption. Furthermore, Cr and Re could serve as active sites for hydrogen evolution with remarkably lowered overpotentials of 0.79 V and 0.28 V, respectively; similarly, oxygen evolution activities could be enhanced by Fe, Co and Rh because of their reduced overpotentials which are less than 0.5 V. Therefore, our findings pave guidance for designing Cu-BTC derivatives in overall water splitting.
Acute lung injury (ALI) is a critical respiratory disorder with a high mortality rate and is caused by several factors. Addressing oxidative stress and inflammation is a pivotal strategy for ALI treatment. In this study, we introduced a novel nanotherapeutic approach involving a curcumin-loaded ceria nanoenzyme delivery system tailored to counteract the multifaceted aspects of ALI. This system leverages the individual and combined effects of the components to provide a comprehensive therapeutic solution. The dual-action capability of this nanosystem was manifested by mitigating mitochondrial oxidative stress in lung epithelial cells and inhibiting the transient receptor potential melanosome-associated protein 2 (TRPM2)-NOD-like receptor thermal protein domain associated protein 3 (NLRP3) signaling pathway, offering a highly effective therapeutic approach to ALI. Our findings reveal the underlying mechanisms of this innovative nanodelivery system, showcasing its potential as a versatile strategy for ALI treatment and encouraging further exploration of nanoenzyme-based therapies for ALI.
Prostaglandin E2 (PGE2) serves as the ultimate mediator of fever induced by inflammatory factors. In contrast to cyclooxygenase inhibitors that suppress arachidonic acid metabolism, antipyretic herbs possess a well-established clinical history in effectively managing fever. However, the specific mechanisms underlying their efficacy remain unclear. Following the screening for lead compounds that inhibit PGE2 from antipyretic herbs, alkynylated active molecule probes were designed and synthesized to track and identify potential targets. The target investigation revealed that three antipyretic compounds, namely cinnamaldehyde, 2,4-decadienal, and perillaldehyde, containing α,β-unsaturated aldehyde groups irreversibly targeted the microsomal PGES1-TM4 helix (mPGES1-TM4) at Ser139. This specific interaction effectually inhibited PGE2 production in the cerebral vasculature, leading to exert potent antipyretic effects. α,β-Unsaturated aldehydes targeting mPGES1-TM4 offer a new approach for antipyretic effects with significant potential for various applications.
Metallabenzenes, a type of aromatic compound that includes metal atoms, have opened up new avenues for creating materials with unique properties. A distinctive feature of metallabenzenes is the significant deviation of their metal atoms from the planar configuration of the C5 ring, a phenomenon that paradoxically enhances their aromatic character. In this investigation, we propose that this counterintuitive increase in aromaticity upon geometric distortion is governed by the interactions of frontier orbitals in the σ-space. This insight not only corroborates the previously suggested role of σ-space orbitals in inducing geometric non-planarity in metallabenzenes but also underscores their pivotal contribution to the compounds' enhanced aromaticity. As a result, this work broadens the scope of the σ-control mechanism, highlighting its usefulness for the rational design of functional metalla-aromatic materials.
Sulfates are always promising short-wave ultraviolet (UV) nonlinear optical (NLO) candidates, if their birefringence could be greatly improved. Here, in terms of the insufficient birefringence, the unity of heteroleptic tetrahedral groups and triangular ones was proposed and implemented. Thus, a new semi-organic crystal, [C(NH2)3]S3O6 (G2S3O6), was obtained, which is composed of [S3O6]2− and [C(NH2)3]+ groups. It exhibits excellent optical properties with a short absorption cutoff edge of 218 nm, a strong NLO response of 1.4 × KH2PO4, and more especially, a large birefringence of 0.097@546 nm. This birefringence leap makes the G2S3O6 crystal achieve a phase-matching behavior under a 532 nm laser. Thus, the synergy of [S3O6]2− and [C(NH2)3]+ groups results in excellent optical performances. This finding opens a new horizon for exploring novel UV NLO crystals.
Chitin is an abundant aminopolysaccharide found in insect pests and phytopathogenic microorganisms but absent in higher plants and vertebrates. It is crucial for mitigating threats posed by chitin-containing organisms to human health, food safety, and agriculture. Therefore, targeting the chitin biosynthesis-associated bioprocess holds a promise for developing human-safe and eco-friendly antifungal agents or pesticides. Chitin biosynthesis requires chitin synthase and associated factors, which are involved in the modification, regulation, organization or turnover of chitin during its biosynthesis. A number of enzymes such as chitinases, hexosaminidases, chitin deacetylases are closely related and therefore are promising targets for designing novel agrochemicals that target at chitin biosynthesis. This review summarizes the advances in understanding chitin biology over the past decade by our research group and collaborates, specifically regarding essential proteins linked to chitin biosynthesis that can be exploited as promising pesticide targets. Examples of small bioactive molecules that against the activity of these targets are given.
The Fenton method is an effective technology for the removal of organic materials from wastewater. In this work, an induced catalyst Fe3O4 was synthesized by a hydrothermal method, and the modulation of the chemical composition of Fe3O4 crystals was achieved under the microwave shock method with the same effect as that of calcination treatment. Fe3O4 catalyst for the removal of the dye Rhodamine B (RhB) from polluted wastewater under microwave (MW), H2O2 system. The results showed that Fe3O4 nanomicrospheres prepared by microwave shock exhibited superior catalytic activity under the conditions of 500 W, 0.4 mol/L H2O2 and10 mg/L RhB, and the removal rate of RhB reached 98.5% after 10 min. The Fe3O4 catalysts also exhibited good stability and degradation efficiency. Electron paramagnetic resonance experiments confirmed that •OH plays a major role in the rapid degradation of RhB. Under microwave action, the catalyst produces electron-hole pairs, in which the holes react with OH− produced by water ionisation to form •OH, and the microwave-treated Fe3O4 produces more active species. Fe3+ and Fe2+ serve as microwave catalytic activity centers and Fenton catalytic activity centers, respectively. This research demonstrates that optimizing the Fe2+/Fe3+ ratio significantly enhances the degradation efficiency of RhB. This study presents novel views regarding the mechanism of microwave synergistic catalyst-induced Fenton.
Constructing high-performance electrocatalysts for oxygen evolution reaction (OER) using a simple and economical strategy is considerably meaningful yet still challenging. Herein, Co(OH)2/Mo2TiC2Tx (where T represents the surface functional groups, -O, -OH and -F) hetero-nanosheets were facilely prepared by the in situ topochemical transformation at room temperature towards efficient OER. The integrity of Co(OH)2 nanosheets and Mo2TiC2Tx nanosheets affords interfacial coupling to optimize the electronic structures of Co and Mo ions, which endows the high electron transfer efficiency and rapid reaction kinetics. As a result, the Co(OH)2/Mo2TiC2Tx hetero-nanosheets exhibit excellent OER performances with low overpotentials of 283 mV on glass-carbon electrode, and 227 mV on nickel foam at 10 mA/cm2. Furthermore, the decent anti-alkali ability underpins superior operational stability exceeding 100 h, demonstrating grand potential in practical applications. This work provides a new insight for the synthesis of efficient and cost-effective two-dimensional (2D) material-based electrocatalysts.
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