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Active tether and transportation of cargoes on cytoskeletal highway enabled by molecular motors is key for accurate delivery of vesicles and organelles in the complex intracellular environment. Here, a hybrid system composed of colloidal motors and self-assembled lipid tubes is designed to mimic the subcellular traffic system in living cells. The colloidal motors, composed of gold-coated hematite, display light-activated self-propulsion tunable by the light intensity and the concentration of hydrogen peroxide fuel. Importantly, the motors show light-switchable binding with lipid cargoes and attachment to the lipid tubes, whereby the latter act as the motor highways. Upon assembly, the colloidal motor/lipid tube system demonstrates directional delivery of lipid vesicles, emulating intracellular transportation. The assembly and function of the hybrid system are rationalized by a cooperative action of light-triggered electrophoretic and hydrodynamic effects, supported by finite element analysis. A synthetic analog of the biological protein motor/cytoskeletal filament system is realized for the manipulation and delivery of different matter at the microscale, which is expected to be a promising platform for various applications in materials science, nanotechnology, microfluidics, and synthetic biology.

Ammonia is the main precursor for the production of fertilizers, a hydrogen energy carrier and an emerging clean fuel that plays a crucial role in sustaining life on the globe. Herein, hybrid MoSe2@g-C3N4 micro/nanostructures are described that can serve as photoelectrochemical (PEC) catalysts to fix N2 into NH3 in a basic electrolyte at a low potential (−0.3 V vs. RHE) under ambient conditions. In situ functionalization of the hierarchical micro/nanoflowers of MoSe2 with exfoliated g-C3N4 nanosheets dramatically boosts the faradaic efficiency and yield rate up to 28.91% and 7.72 μmol h−1 cm−2 respectively. The high PEC activity can be attributed to the hierarchical architecture, light-harvesting capability, tunable active sites and formation of heterojunctions, as confirmed by various characterization and density functional theory (DFT) calculations. Therefore, this work not only develops an effective procedure to obtain hierarchical heterojunction catalysts towards a high-efficiency NRR but also provides a deep understanding of artificial N2 fixation at the MoSe2@g-C3N4 interface.

We reported the fabrication of an electrochemical sensor for uric acid (UA) monitoring using metal-free electrode based on heteroatoms (S, N, P, and O) doped carbon (HADC) nanoparticles, derived fr...

Light-powered fuel-free colloidal motors possess significant potential for practical applications ranging from nanomedicine to environmental remediation. However, current light-powered colloidal motors often require the incorporation of expensive metals or high concentrations of toxic chemical fuels, which is a severe limitation for their practical applications. Integrating highly ordered and porous materials with a large surface area into colloidal motors is a promising strategy for upsurging their self-propelled speed and adsorption, which will benefit many applications. Here, highly efficient, fuel-free, and light-activated metal organic framework (MOF)-3-trimethoxysilyl propyl methacrylate Janus colloidal motors with a hierarchical morphology are reported. These colloidal motors can be driven by UV or visible light, with a self-propelled speed tuned by the light intensity. The speed can be further enhanced by morphology optimization or by the addition of H2O2 as a fuel. The colloidal motors display a superior efficiency in removing heavy metal ions of Hg, which is up to ∼90% within 40 min from the contaminated water, attributed to their high surface area, hierarchical morphology, large number of active sites, and high mobility. This work not only offers a facile approach to incorporate a versatile MOF family into the design of fuel-free and light-powered Janus colloidal motors, but also demonstrates their potential for real-life applications such as environmental remediation.

The synergy between nitrogen (N) and sulfur (S) in quaternary heteroatom-doped carbons is rarely probed, although these elements can significantly alter the performance of the oxygen evolution reac...

Covalent inorganic–organic hybrid frameworks (CIOFs) composed of inorganic heterocycles covalently linked to organic building blocks are a relatively unexplored and fertile area of research compared to the covalent organic frameworks. Herein, we report the selective light responsive CIOFs prepared by considering energy gaps (Egs) of the inorganic heterocycle (P3N3Cl6) (Eg 5.745 eV), organic building block (4,4-sulfonyldiphenol) (Eg 4.05 eV), and triazine heterocycle (1,3,5-triazine-2,4,6-triamine) (Eg 4.79 eV) under mild reaction conditions (by P–O–C and P–NH–C bond formation). The morphology of CIOF-I (prepared from hexachlorocyclotriphosphazene and 4,4-sulfonyldiphenol) is micro-spherical (diameter, ca. 0.6–1 μm), whereas that of CIOF-II (prepared from hexachlorocyclotriphosphazene and 1,3,5-triazine-2,4,6-triamine) is micro-spherical (diameter, ca. 0.5–1 μm) as well as tubular. The X-ray diffraction (XRD) analysis showed that these CIOFs are amorphous in nature. The luminescence studies of both CIOFs have shown a selective response to different lights; when excited under UV light at a wavelength of 365 nm, the CIOFs showed cyan emission, while under visible region 420 nm and 546 nm excitations, the emission shifts to green and red, respectively. CIOF-I demonstrated maximum emission at 454 nm (Ex. 365 nm), 487 nm (Ex. 420 nm), and 708 nm (Ex. 546 nm), while CIOF-II exhibited maximum emission at 460 nm (Ex. 365 nm), 478 nm (Ex. 420 nm), and 604 nm (Ex. 546 nm). The density functional theory (DFT) studies were performed based on Gaussian 09 (B3LYP/6-311+G (d,p)) for the core structure of CIOFs’ HOMO and LUMO levels (CIOF-I −6.54 eV, −2.62 eV and CIOF-II −6.44 eV, −2.55 eV), and Egs (3.92 eV and 3.84 eV) which are in good agreement with the experimental values. The mechanism behind the demonstration of similar emission colors by two different chemical structures is also underpinned. The selective response towards different lights is ascribed to the aggregation/clustering-induced/triggered emission (AIE/CTE) and restricted rotation emission (RRE) due to the crosslinking of the wider energy gap inorganic heterocycle and organic linkers. This study may grab the attention of researchers to study the inorganic heterocycle centered selective light responsive materials due to their extensive application prospects.

The utilization of solar energy is an epitome towards water splitting for hydrogen generation and environmental remediation. For efficient use of solar energy, photocatalysts capable of light-harvesting, with appropriate band energetics, that are inexpensive, stable, and scalable, are desired. Herein, a prototypical cyclotriphosphazene (P3N3)-based covalent inorganic–organic hybrid framework (CIOF) is designed with highly crosslinked aggregation that can produce hydrogen fuel from photocatalytic water splitting, as well as the degradation of industrial waste-water pollutant (rhodamine B). The P3N3-CIOF was synthesized by the aggregation, self-assembly, and subsequent polycondensation of hexachlorocyclotriphosphazene, tris(4-hydroxyphenyl)ethane and pyridine, in one-pot under ultrasonication. Morphology and structure of the newly synthesized P3N3-CIOF are characterized through scanning electron microscopy, Fourier transform infrared spectroscopy, solid-state 31P and 13C nuclear magnetic resonance spectroscopy, X-ray photoelectron microscopy, UV-visible absorbance, photoluminescence, and micro-spectrophotometry. The P3N3-CIOF shows selective response to the UV-visible light by emitting bright green (Ex. 365 nm), yellow (Ex. 420 nm), and red (Ex. 546 nm) colors. Moreover, the onset bandgap (2.14 eV) and the potential of the conduction band (−0.26 eV) and valence band (+1.88 eV) straddle the potential range for photocatalytic water splitting and dye degradation. The as-synthesized P3N3-CIOF continuously produced hydrogen fuel (24.5 μmol g−1 h−1) during photocatalytic water splitting for a period of 16 h, using Pt (3 wt%) and triethanolamine as the co-catalyst and holes scavenger, respectively. It also showed photodegradation ability to rhodamine B as a proxy dye to industrial waste-water pollutants. The plausible photocatalytic mechanism is also proposed based on the energetics of the photogenerated excitons, and scavenging experiments. These findings exemplify a critical first step towards photocatalytic hydrogen generation and remediation of organic pollutants through P3N3-CIOF, as well as motivation to engineer new materials based on aggregation-induced phenomena.

Herein, we demonstrated poly(diaryloxy)phosphazene (PDPP) which has inherent thermal stability and flame retardancy, is used as a matrix material for the fabrication of novel thermal conductive composites (TCCs) with variety of thermal conductive fillers including aluminum oxide (Al2O3), boron nitride (BN), silicon carbide (SiC) and expended graphite (EG) with different particle size and volume fraction by special processing method. Thermogravimetric analysis (TGA) and limit oxygen index (LOI) results indicated that the TCCs own excellent thermal stability and flame retardancy. SEM analyses of the as-prepared materials showed high orientation degree of flake-like fillers after processing. The thermal conductivity (TC) of the TCCs measurements implied that the EG is the most effective filler to enhance the TC. TC measured in-plane direction reaches a highest value 7.05 Wm−1 K−1 for EG filled samples, which is times higher than PDPP matrix. This work explored a great potential of polyphosphazenes as a matrix material for TCCs.

Polyphosphazenes have grabbed focal attention in materials research due to their structural diversity, intrinsic backbone stability, and capability to form hybrid molecules. Herein, for the first time, we report morphology-controlled cross-linked hybrid nanotubes and microspheres composed of a novel iron-containing poly(ferrocenedimethano)cyclotriphosphazene synthesized via a facile polycondensation between 1,1'-ferrocenedimethanol and hexachlorocyclotriphosphazene. The morphology was tuned by introducing two sets of mixed solvent systems that are tetrahydrofuran:acetonitrile and acetone:toluene mixtures, for the growth of nanotubes and microspheres, respectively. A growth mechanism for nanotubes and microspheres has been proposed. The nanotubes exhibited intrinsic paramagnetic properties (saturation magnetization of 53 emu/g and coercivity of 19.6) and fluorescence emission (2450 au) as compared to microspheres owing to their remarkable cross-linked structure. Both nanotubes and microspheres demonstrated significant potential to absorb negatively charged hazardous methyl orange dye, and their adsorption capacities came out under the range of 880-2235 and 737-2125 mg g

Poly(aryloxyphosphazenes) are thermally stable, insulative, fire proof, and ablative resistant in extreme combustion, and can be applied as an insulated covering of high voltage cable and thermal shielding material for aircraft and spacecraft. However, being an elastomer, its higher glass transition temperature (Tg above −15 °C) limits the application in certain aspects. Therefore, adjustment of the Tg of poly(aryloxyphosphazenes) has become a research focus to improve overall performance. Introducing substituents such as alkoxy groups has been identified as an effective approach to lower the polymer Tg. In this study, based on the introduction of the different ratios of the ethoxy substituents in poly(bisphenoxyphosphazene), a series of simulations and experimental studies have been carried out for predicting the Tg of polyphosphazenes, along with establishing the relationships among synthesis, structure, and Tg. Molecular dynamics (MD) simulations using COMPASS force field and empirical Flory-Fox equation have been used to predict the Tg of the polymers and confirm the compatibility with the experimental data. Overall, the simulation results are noted to be in good agreement with the experimental values, and the Tg of the polymers gradually decreases with an increase in the ethoxy content. The proposed methods are efficient for the prediction of the Tg values of polyphosphazenes and can also be used for the structure prediction via the desired Tg, which is likely to have broad application for targeted polyphosphazenes synthesis.

Herein, we reported the organocyclophosphazenes (OCP) microspheres with excitation wavelength tunable fluorescence (EWTF) emission by reacting hexachlorocyclotriphosphazene and 4,4′-methylenedianiline via one-pot facile method. The as-prepared microspheres exhibit blue (λex 280 nm), green (λex 365/420 nm) and red (λex 546 nm) tunable fluorescence emissions in the ultraviolet (UV) and visible region. The microspheres have shown broadband semiconductors like absorptions in UV and visible regions indicate the multiple bandgaps in the microspheres. The role of the crosslinked structure and property demonstrated that stable interactions are conceivable in microspheres than branched polymer, which imparted EWTF property. This study explored the cyclotriphosphazene as a platform for the synthesis of EWTF materials, and their potential utilization in the full spectrum tunable fluorescence and other light related technologies.