Multifunctional Luminescent 3D Ln-MOFs with High Sensitivity for Trace Detection of Micronutrients.

The synthesis of two versatile fluorescent metal-organic frameworks (MOFs), [Eu(4-NCP)(1,4-bdc)]n·0.5H2O (1) and [Eu(4-NCP)(4,4'-bpdc)]n·0.75H2O (2) (HNCP = 2-(4-carboxyphenyl)imidazo(4,5-f)-(1,10)phenanthroline, 1,4-H2bdc = benzene-1,4-dicarboxylic acid, 4,4'-H2bpdc = 4,4'-biphenyldicarboxylic acid), was carried out using a hydrothermal method. These MOFs were characterized through various advanced technologies to determine their structural information. The results indicate that both MOFs exhibited 3D network structures with specific topologies. Furthermore, these MOFs demonstrated exceptional thermal stabilities and adsorption capabilities. Additionally, complex 2 was utilized for studying the fluorescence sensing properties of various micronutrients including metal ions, nitro aromatic compounds, and biological small molecules. Notably, complex 2 showed promising potential as a multifunctional sensor for selectively detecting Fe3+, nitrobenzene, and ascorbic acid in aqueous solutions through fluorescence quenching with low limits of detection (LODs ∼ 10-7 M) and high quenching constants (Ksv ∼ 103 M-1). Moreover, the detection mechanism of complex 2 was further investigated by using experimental methods and DFT calculations.

Direct C-H Arylation Derived Ternary D-A Conjugated Polymers: Effects of Monomer Geometries, D/A Ratios, and Alkyl Side Chains on Photocatalytic Hydrogen Production and Pollutant Degradation.

Donor-acceptor (D-A) conjugated polymer (CP) featuring high charge mobility and widely tunable energy bands have shown promising prospects in photocatalysis. In this work, a library of ternary D-A CPs (22 polymers) based on benzothiadiazole, bithiophene, and fluorene derivatives (i.e., fluorene [Fl], 9,9-dihexylfluorene [HF], and 9,9'-spirobifluorene [SF]) with and without alkyl side chains, and with 3D geometry are designed and synthesized via atom-economical direct C-H arylation polymerization to explore the synergetic effects of stereochemistry, D/A ratio, and alkyl chains on the properties and photocatalytic performances, which reveal that 1) the cross-shaped 3D spirobifluorene (SF) building block shows the highest hydrogen evolution rates (HER) owing to the sufficient photocatalytic active sites exposed, 2) the alkyl-free linear polymer (FlBtBT0.05 ) exhibit the highest photocatalytic pollutant degradation performance owing to its superior charge separation, and 3) the alkyl side chains are redundances that will exert detrimental effects on the aqueous photocatalysis owing to their insulating and hydrophobic property. The structure-property-performance correlation results obtained will provide a desirable guideline for the rational design of CP-based photocatalysts.

Kinetically and Thermodynamically Favorable Ni-Al Layered Double Hydroxide/Ni-Doped Zn0.5Cd0.5S S-Scheme Heterojunction Triggering Photocatalytic H2 Evolution.

Layered double hydroxide (LDH)-based photocatalysts have attracted more attention in photocatalysis due to their low cost, wide band gaps, and adjustable photocatalytic active sites; however, their low photogenerated carrier separation efficiency limits their photocatalytic efficiency. Herein, a NiAl-LDH/Ni-doped Zn0.5Cd0.5S (LDH/Ni-ZCS) S-scheme heterojunction is rationally designed and constructed from kinetically and thermodynamically favorable angles. The 15% LDH/1% Ni-ZCS displays comparable photocatalytic hydrogen evolution (PHE) activity with a rate of 6584.0 µmol g-1 h-1, which exceeds by ∼6.14- and ∼1.73-fold those of ZCS and 1% Ni-ZCS, respectively, and outperforms most of the previously reported LDH-based and metal sulfide-based photocatalysts. In addition, the apparent quantum yield of 15% LDH/1% Ni-ZCS reaches 12.1% at 420 nm. In situ X-ray photoelectron spectroscopy, photodeposition, and theoretical calculation reveal the specific transfer path of photogenerated carriers. On this basis, we propose the possible photocatalytic mechanism. The fabrication of the S-scheme heterojunction not only accelerates the separation of photogenerated carriers but also decreases the activation energy of H2 evolution and improves the redox capacity. Moreover, there are huge amounts of hydroxyl groups distributed on the surface of photocatalysts, which is highly polar and easy to combine with H2O with a large dielectric constant to form a hydrogen bond, which can further accelerate PHE.

Fluorinated Polyimide/Allomelanin Nanocomposites for UV-Shielding Applications.

A series of highly fluorinated polyimide/allomelanin nanoparticles (FPI/AMNPs) films were prepared with FPI as the matrix and AMNPs as the filler. Due to the formation of hydrogen bonds, significantly reinforced mechanical and UV-shielding properties are acquired. Stress-strain curves demonstrated a maximum tensile strength of 150.59 MPa and a fracture elongation of 1.40% (0.7 wt.% AMNPs), respectively, 1.78 and 1.56× that of pure FPI. The measurements of the UV-vis spectrum, photodegradation of curcumin and repeated running tests confirmed the splendid UV-shielding capabilities of FPI/AMNPs films. The enhancement mechanisms, such as synergistic UV absorption of the charge transfer complexes in FPI and AMNPs and photothermal conversion, were the reasons for its exceptional UV shielding. The excellent comprehensive properties above enable FPI/AMNPs nanocomposites to be potential candidates in the field of UV shielding.

Interior and Surface Synergistic Modifications Modulate the SnNb2O6/Ni-Doped ZnIn2S4 S-Scheme Heterojunction for Efficient Photocatalytic H2 Evolution.

Interior and surface synergistic modifications can endow the photocatalytic reaction with tuned photogenerated carrier flow at the atomic level. Herein, a new class of 2D/2D SnNb2O6/Ni-doped ZnIn2S4 (SNO/Ni-ZIS) S-scheme heterojunctions is synthesized by a simple hydrothermal strategy, which was used to evaluate the synergy between interior and surface modifications. Theoretical calculations show that the S-scheme heterojunction boosts the desorption of H atoms for rapid H2 evolution. As a result, 25% SNO/Ni0.4-ZIS exhibits significantly improved PHE activity under visible light, roughly 4.49 and 2.00 times stronger than that of single ZIS and Ni0.4-ZIS, respectively. In addition, 25% SNO/Ni0.4-ZIS also shows superior structural stability. This work provides advanced insight for developing high-performance S-scheme systems from photocatalyst design to mechanistic insight.

Boosting H2 Production over C60 -Mediated NH2 -MIL-125(Ti)/Zn0.5 Cd0.5 S S-Scheme Heterojunction via Enhanced Interfacial Carrier Separation.

Improving greatly the separation efficiency of interfacial charge carrier is a major challenge in photocatalysis. Herein, a new class of C60 -mediated NH2 -MIL-125(Ti)/Zn0.5 Cd0.5 S S-scheme heterojunction with enhanced interfacial charge carrier separation is designed and synthesized. The constructed S-scheme heterojunction thermodynamically favors photocatalytic H2 evolution because of the large driving force resulting from its strong redox abilities. As a consequence, the optimum proportion of C60 -mediated NH2 -MIL-125(Ti)/Zn0.5 Cd0.5 S S-scheme heterojunction displays comparable H2 evolution activity with a rate of 7825.20 µmol h-1 g-1 under visible light irradiation, which is about 93.05 times, 6.38 times and 2.65 times higher than that of 2% C60 /NH2 -MIL-125(Ti), Zn0.5 Cd0.5 S and 45% NH2 -MIL-125(Ti)/Zn0.5 Cd0.5 S, and outperforms the majority of the previously reported MOFs-based photocatalysts. Spectroscopic characterizations and theory calculations indicate that the S-scheme heterojunction can powerfully promote the separation of photogenerated carriers. This work offers a new insight for future design and development of highly active MOFs-based photocatalysts.

The preparation of heparin-like hyperbranched polyimides and their antithrombogenic, antibacterial applications.

1,3,5-Tris(4-aminophenoxy) benzene (TAPOB) and 2,2-bis [4-(3,4-dicarboxyphenoxy) phenyl] propane dianhydride (BPADA) were used to synthesize an amino-terminated hyperbranched polyimide (AM-HBPI). Then, the 2-methacryloyloxyethyl phosphorylcholine-modified hyperbranched polyimide (HBPI-MPC) was obtained through the graft modification of MPC onto AM-HBPI by Michael addition. The infrared spectroscopy and X-ray photoelectron spectroscopy spectra showed MPC molecules were successfully grafted onto the HBPI molecules. The HBPI-MPC films exhibited slightly decreased thermal stabilities with 5% weight loss temperature in the range of of 418-483 °C in nitrogen, compared with the pure HBPI film. With the increase of MPC grafting amount, the static water contact angles decreased from average 84.0° of the pure HBPI film to average 45.0° of the HBPI-MPC film with 20% MPC. Meanwhile, the increased surface roughness of the HBPI-MPC films increased the contact areas with the platelets, enhancing their anticoagulant efficiency. The number of platelet adhesion declined and the shape of platelet changed from flat to round. The recalcification times grew from average 300 s of pure HBPI to average 551 s of the HBPI-MPC film with 20% MPC, indicating improved anticoagulant properties and biocompatibility. Bacterial adhesion test also demonstrated the number of bacterial adhesion was significantly reduced and antibacterial properties were improved. Thus, the HBPI-MPC films have great application prospects as biomedical anticoagulant materials.

Lattice capacity-dependent activity for CO2 methanation: crafting Ni/CeO2 catalysts with outstanding performance at low temperatures.

In the pursuit of understanding lattice capacity threshold effects of oxide solid solutions for their supported Ni catalysts, a series of Ca2+-doped CeO2 solid solutions with 10 wt% Ni loading (named Ni/CaxCe1-xOy) was prepared using a sol-gel method and used for CO2 methanation. The lattice capacity of Ca2+ in the lattice of CeO2 was firstly determined by the XRD extrapolation method, corresponding to a Ca/(Ca + Ce) molar ratio of 11%. When the amount of Ca2+ in the CaxCe1-xOy supports was close to the CeO2 lattice capacity for Ca2+ incorporation, the obtained Ni/Ca0.1Ce0.9Oy catalyst possessed the optimal intrinsic activity for CO2 methanation. XPS, Raman spectroscopy, EPR and CO2-TPD analyses revealed the largest amount of highly active moderate-strength alkaline centers generated by oxygen vacancies. The catalytic reaction mechanisms were revealed using in situ IR analysis. The results clearly demonstrated that the structure and reactivity of the Ni/CaxCe1-xOy catalyst exhibited the lattice capacity threshold effect. The findings offer a new venue for developing highly efficient oxide-supported Ni catalysts for low-temperature CO2 methanation reaction and enabling efficient catalyst screening.

Correction: Critical role of hydrogen bonding between microcrystalline cellulose and g-C3N4 enables highly efficient photocatalysis.

Correction for 'Critical role of hydrogen bonding between microcrystalline cellulose and g-C3N4 enables highly efficient photocatalysis' by Zhaoqiang Wang et al., Chem. Commun., 2024, 60, 204-207, https://doi.org/10.1039/D3CC04800D.

Renewable hemicellulose-based materials for value-added applications.

The importance of renewable resources and environmentally friendly materials has grown globally in recent time. Hemicellulose is renewable lignocellulosic materials that have been the subject of substantial valorisation research. Due to its distinctive benefits, including its wide availability, low cost, renewability, biodegradability, simplicity of chemical modification, etc., it has attracted increasing interest in a number of value-added fields. In this review, a systematic summarizes of the structure, extraction method, and characterization technique for hemicellulose-based materials was carried out. Also, their most current developments in a variety of value-added adsorbents, biomedical, energy-related, 3D-printed materials, sensors, food packaging applications were discussed. Additionally, the most recent challenges and prospects of hemicellulose-based materials are emphasized and examined in-depth. It is anticipated that in the near future, persistent scientific efforts will enable the renewable hemicellulose-based products to achieve practical applications.

One-step photodeposition of spatially separated CuOx and MnOx dual cocatalysts on g-C3N4 for enhanced CO2 photoreduction.

The rapid recombination of photogenerated carriers of photocatalysts greatly limits their actual application in CO2 conversion into valuable chemicals. Herein, dual CuOx and MnOx cocatalysts are decorated on g-C3N4 nanosheets via a one-step photodeposition strategy. Benefiting from the repulsion between Cu2+ and Mn2+ cations, a novel g-C3N4-based heterostructure loaded with spatially separated CuOx and MnOx nanoparticle dual cocatalysts has been successfully fabricated. Cu favors the trapping of electrons, while MnOx tends to collect holes. Moreover, the Cu2O/g-C3N4 p-n heterojunction also accelerates the charge separation. As a result, the photogenerated holes and electrons flow into and out of the photocatalyst, respectively, resulting in enhanced charge separation for achieving efficient CO2 photoreduction over CuOx/g-C3N4/MnOx. Accordingly, the optimized CuOx/g-C3N4/MnOx exhibits an improved CO production rate of 5.49 µmol g-1 h-1, which is 27.5 times higher than that of bare g-C3N4.

Size effect of ruthenium nanoparticles on water cracking properties with different crystal planes for boosting electrocatalytic hydrogen evolution.

Small size ruthenium (Ru) nanoparticles have shown remarkable potential for electrocatalytic hydrogen evolution reaction (HER). Nevertheless, the complicated preparation and relatively low activity of small size Ru nanoparticles are two key challenges. In this work, carbon nanotubes supported Ru nanoparticles catalysts (cnts@NC-Ru t °C) with different sizes were prepared via using the combination of L-3,4-dihydroxyphenylalanine (l-dopa) self-polymerization oxidation reaction and different high temperature annealing to study the variation of particle activity with size. Electrochemical test results showed that the optimized cnts@NC-Ru 700 °C catalyst exhibited a very low overpotential at 10 mA/cm2 (21 mV) and tafel slope of 34.93 mV/dec when the mass loading of precious metal per unit area was merely 12.11 µg/cm2 that surpassed most recently reported high-performance Ru based catalyst. The results of density functional theory (DFT) calculation showed that small Ru nanoparticles had abundant active sites, and the H2O dissociation on small Ru nanoparticles (110) surface is quite easy than other surfaces, while (111) surface of small Ru nanoparticles is beneficial for Tafel step of HER. The synergy between (110) and (111) surfaces on the Ru cluster contributes to its outstanding HER performance. This study provides a novel design idea in promoting the preparation method and uncovering the reason of high activity of small size Ru nanoparticles.

Recent Advances in LDH/g-C3N4 Heterojunction Photocatalysts for Organic Pollutant Removal.

Environmental pollution has been decreased by using photocatalytic technology in conjunction with solar energy. An efficient method to obtain highly efficient photocatalysts is to build heterojunction photocatalysts by combining graphitic carbon nitride (g-C3N4) with layered double hydroxides (LDHs). In this review, recent developments in LDH/g-C3N4 heterojunctions and their applications for organic pollutant removal are systematically exhibited. The advantages of LDH/g-C3N4 heterojunction are first summarized to provide some overall understanding of them. Then, a variety of approaches to successfully assembling LDH and g-C3N4 are simply illustrated. Last but not least, certain unmet research needs for the LDH/g-C3N4 heterojunction are suggested. This review can provide some new insights for the development of high-performance LDH/g-C3N4 heterojunction photocatalysts. It is indisputable that the LDH/g-C3N4 heterojunctions can serve as high-performance photocatalysts to make new progress in organic pollutant removal.

A tunable fluorescent probe for superoxide anion detection during inflammation caused by Treponema pallidum.

Syphilis, caused by Treponema pallidum (T. pallidum), is associated with the oxidative stress due to its inflammation-like symptom, and detecting the reactive oxygen species (ROS) is crucial for monitoring the infectious process. Herein, we design and synthesize a perylene-based tunable fluorescent probe, PerqdOH, which can detect endogenous O2˙- during T. pallidum infection. The fluorescence peak shifted from 540 nm to 750 nm with increasing O2˙- levels. Besides, both decreased green fluorescence and enhanced red fluorescence could be observed simultaneously during the in vitro infection, providing the real-time monitoring of intracellular O2˙- caused by T. pallidum. Furthermore, the probe exhibited a remarkable signal in the treponemal lesions on the back of a rabbit model. Taken together, our synthesized PerqdOH holds great potential for application in clarifying the infectious process caused by T. pallidum in real time.

Critical role of hydrogen bonding between microcrystalline cellulose and g-C3N4 enables highly efficient photocatalysis.

Developing a highly efficient photocatalyst for energy and environmental applications is urgently required. Herein, graphitic carbon nitride (CN) coupled with microcrystalline cellulose (MCC) (denoted as MCC-X/CN) shows excellent photocatalytic performance for tetracycline (TC) degradation and H2 evolution. And the optimized MCC-0.05/CN shows an improved TC degradation rate (Kapp = 0.019 min-1) and H2 evolution rate (642.71 µmol g-1 h-1), which are 1.9 and 22 times higher than those of pure CN, respectively. This improvement primarily results from hydrogen bonding (H-bonding) between CN and MCC, which enables excellent charge separation and migration, leading to the outstanding photoelectrochemical properties of MCC-0.05/CN.

Manganese-based hollow nanoplatforms for MR imaging-guided cancer therapies.

Theranostic nanoplatforms integrating diagnostic and therapeutic functions have received considerable attention in the past decade. Among them, hollow manganese (Mn)-based nanoplatforms are superior since they combine the advantages of hollow structures and the intrinsic theranostic features of Mn2+. Specifically, the hollow cavity can encapsulate a variety of small-molecule drugs, such as chemotherapeutic agents, photosensitizers and photothermal agents, for chemotherapy, photodynamic therapy (PDT) and photothermal therapy (PTT), respectively. After degradation in the tumor microenvironment (TME), the released Mn2+ is able to act simultaneously as a magnetic resonance (MR) imaging contrast agent (CA) and as a Fenton-like agent for chemodynamic therapy (CDT). More importantly, synergistic treatment outcomes can be realized by reasonable and optimized design of the hollow nanosystems. This review summarizes various Mn-based hollow nanoplatforms, including hollow MnxOy, hollow matrix-supported MnxOy, hollow Mn-doped nanoparticles, hollow Mn complex-based nanoparticles, hollow Mn-cobalt (Co)-based nanoparticles, and hollow Mn-iron (Fe)-based nanoparticles, for MR imaging-guided cancer therapies. Finally, we discuss the potential obstacles and perspectives of these hollow Mn-based nanotheranostics for translational applications. Mn-based hollow nanoplatforms such as hollow MnxOy nanoparticles, hollow matrix-supported MnxOy nanoparticles, Mn-doped hollow nanoparticles, Mn complex-based hollow nanoparticles, hollow Mn-Co-based nanoparticles and hollow Mn-Fe-based nanoparticles show great promise in cancer theranostics.

Recent advances in near-infrared-II hollow nanoplatforms for photothermal-based cancer treatment.

Near-infrared-II (NIR-II, 1000-1700 nm) light-triggered photothermal therapy (PTT) has been regarded as a promising candidate for cancer treatment, but PTT alone often fails to achieve satisfactory curative outcomes. Hollow nanoplatforms prove to be attractive in the biomedical field owing to the merits including good biocompatibility, intrinsic physical-chemical nature and unique hollow structures, etc. On one hand, hollow nanoplatforms themselves can be NIR-II photothermal agents (PTAs), the cavities of which are able to carry diverse therapeutic units to realize multi-modal therapies. On the other hand, NIR-II PTAs are capable of decorating on the surface to combine with the functions of components encapsulated inside the hollow nanoplatforms for synergistic cancer treatment. Notably, PTAs generally can serve as good photoacoustic imaging (PAI) contrast agents (CAs), which means such kind of hollow nanoplatforms are also expected to be multifunctional all-in-one nanotheranostics. In this review, the recent advances of NIR-II hollow nanoplatforms for single-modal PTT, dual-modal PTT/photodynamic therapy (PDT), PTT/chemotherapy, PTT/catalytic therapy and PTT/gas therapy as well as multi-modal PTT/chemodynamic therapy (CDT)/chemotherapy, PTT/chemo/gene therapy and PTT/PDT/CDT/starvation therapy (ST)/immunotherapy are summarized for the first time. Before these, the typical synthetic strategies for hollow structures are presented, and lastly, potential challenges and perspectives related to these novel paradigms for future research and clinical translation are discussed.

Renewable plant-derived lignin for electrochemical energy systems.

Lignin, as one of the most abundant natural polymers, has been proved to be a promising material for the construction of high-performance electrochemical energy systems, including electrodes, electrolytes, and separators, because of their low-cost and sustainable natures and unique structure with abundant functional group. In this review article, we outline some key contributions in this field such as fundamental principles and various electrochemical energy systems including rechargeable batteries, supercapacitors, solar cells, and fuel cells. At the same time, we also point out the significant scientific discussion and critical barriers for lignin-based materials for electrochemical energy systems and also provides feasible strategies for preparing new sustainable energy materials.

Hyaluronic-Acid-Coated Chitosan Nanoparticles for Insulin Oral Delivery: Fabrication, Characterization, and Hypoglycemic Ability.

Oral administration of insulin faces multiple biological challenges, such as varied digestive environments, mucin exclusion, and low epithelial cells' absorption. In the present study, a hyaluronic acid (HA)-coated chitosan (CS) nanoparticle (HCP) delivery system is fabricated for insulin oral delivery. It is hypothesized that the developed nanoparticles will protect insulin from digestive degradation, promote intestinal epithelial cell absorption, and exert strong in vivo hyperglycemic ability. Nanoparticles formulated by CS and sodium tripolyphosphate (TPP) are optimized to form the core nanoparticles (CNPs). HA is further applied to coat CNP (HCP) to improve stability, reduce enzymatic degradation, and promote absorption of insulin. HCP promotes insulin uptake by Caco-2 cells, absorbs less mucin, and improves intestinal absorption. Moreover, an in vivo test demonstrates that oral administration of insulin-loaded HCP exerts strong and continuous hyperthermia effect (with a pharmacological availability (PA) of 13.8%). In summary, HCP is a promising delivery platform for insulin oral administration in terms of protecting insulin during digestion, facilitating its absorption and ultimately promoting its oral bioavailability.

MOF(Fe)-derived composites as a unique nanoplatform for chemo-photodynamic tumor therapy.

Fe-based metal-organic frameworks (MOFs) can be used for chemodynamic therapy (CDT) for tumors due to their unique Fenton-like effects and porous and biodegradable nature. The adsorption and transport of small molecule drugs by their structure has attracted much attention. Herein, MnO2@NH2-MIL101(Fe)@Ce6-F127 nanoparticles (MNMCF NPs) were synthesized using a facile solvothermal strategy. The small molecule photosensitizer Ce6 was adsorbed by MOFs to improve the biocompatibility of Ce6 and give it high bioavailability when injected intravenously. When the MNMCF NPs reached the tumor site, Fe-based MOFs exhibited Fenton-like properties, producing ˙OH and showing CDT effects. MnO2 could specifically respond to produce O2 in a tumor microenvironment, thereby improving the tumor hypoxia state and enhancing the efficacy of photodynamic therapy (PDT) by Ce6. Both the in vitro and in vivo experiments showed that the MNMCF-guided CDT/PDT combination therapy could effectively ablate tumors without the drawbacks of poor tolerability and potential long-term side effects. Therefore, the prepared MNMCF NPs can be used as promising candidates for synergistic CDT/PDT tumor therapy.