Red Carbon Mediated Formation of Cu2O Clusters Dispersed on the Oxocarbon Framework by Fehling's Route and their Use for the Nitrate Electroreduction in Acidic Conditions.

The oligomers of carbon suboxide, known as red carbon, exhibit a highly conjugated structure and semiconducting properties. Upon mild heat treatment, it transforms into a carbonaceous framework rich in oxygen surface terminations, called oxocarbon. In this study, the abundant oxygen functionalities are harnessed as anchors to create oxocarbon-supported nanohybrid electrocatalysts. Starting with single atomic Cu (II) strongly coordinated to oxygen atoms on red carbon, the Fehling reaction leads to the formation of Cu2O clusters. Simultaneously, a covalent oxocarbon framework emerges via cross-linking, providing robust support for Cu2O clusters. Notably, the oxocarbon support effectively stabilizes Cu2O clusters of very small size, ensuring their high durability in acidic conditions and the presence of ammonia. The synthesized material exhibits a superior electrocatalytic activity for nitrate reduction under acidic electrolyte conditions, with a high yield rate of ammonium (NH4 +) at 3.31 mmol h-1 mgcat -1 and a Faradaic efficiency of 92.5% at a potential of -0.4 V (vs RHE).

Au (III) cross-linked hollow organosilica capsules from 3-aminopropyltriethoxysilane.

Hollow organosilica capsules have received extensive interest due to their application potentials in catalyst, sensor, drug delivery etc. In this work, we demonstrate a novel strategy to fabricate hollow organosilica capsules based on coordination interaction, by using 3-aminopropyltriethoxysilane (APTES) as precursor and Au (III) as cross-linker. In this approach, stable APTES droplets are first formed in water with the presence of Au (III) due to the coordination effect between Au (III) and the amino groups of APTES located on the surface of the droplets. Subsequently, the self-catalyzed hydrolysis/condensation of APTES allows for the formation of hollow organosilica capsules, in which the droplets of APTES themselves act as soft template and the Au (III) as cross-linker. The formation mechanism of the capsules was investigated, and potential of the as-prepared Au (III) cross-linked hollow organosilica capsules as glutathione (GSH) sensitive drug carriers was evaluated. In addition, Au particle embedded hollow capsules are further obtained by in-situ reduction of the Au (III) in the shell, which showed excellent stability towards the cyclic catalytic reductions of p-nitroaniline.

Direct observation of highly effective hydrogen isotope separation at active metal sites by in situ DRIFT spectroscopy.

In situ diffuse reflectance infrared Fourier transform (DRIFT) spectroscopy was developed for the first time to observe the hydrogen isotope separation behavior at active CuI sites within CuI-MFU-4l, and clear evidence of the preferential adsorption of D2 over H2 was directly captured. More importantly, our results show direct spectral proof to clarify the chemical affinity quantum sieving mechanism of hydrogen isotope separation within porous adsorbents.

Au Nanoflowers for Catalyzing and In Situ Surface-Enhanced Raman Spectroscopy Monitoring of the Dimerization of p-Aminothiophenol.

In this work, we demonstrated a facile approach for fabrication of Au nanoflowers (Au NFs) using an amino-containing organosilane, 3-aminopropyltriethoxysilane (APTES), as a shape-directing agent. In this approach, the morphology of the Au particles evolved from sphere-like to flower-like with increasing the concentration of APTES, accompanied by a red shift in the localized surface plasmon resonance peak from 520 to 685 nm. It was identified that the addition of APTES is profitable to direct the preferential growth of the (111) plane of face-centered cubic gold and promote the formation of anisotropic Au NFs. The as-prepared Au NFs, with APTES on their surface, presented effective catalytic and surface-enhanced Raman scattering (SERS) performances, as evidenced by their applications in catalyzing the dimerization of p-aminothiophenol and monitoring the reaction process via in situ SERS analysis.

Platinum Single Atoms Supported on Nanoarray-Structured Nitrogen-Doped Graphite Foil with Enhanced Catalytic Performance for Hydrogen Evolution Reaction.

Platinum-based single-atom catalysts (SACs) are among the most promising candidates for the practical applications of electrochemical hydrogen evolution reaction (HER), but their catalytic efficiency remains to be further enhanced. Herein, a well-designed nanoarray-structured nitrogen-doped graphite foil (NNGF) substrate is introduced to support Pt SACs in Pt-N4 construction (Pt1/NNGF) for HER. Within NNGF, the constructed nanoarray-structured surficial layer for supporting Pt SACs could enhance the exposure of active sites to the electrolyte and improve the reaction and diffusion kinetics; meanwhile, the retained graphite structures in bulk NNGF provide not only the required electrical conductivity but also the mechanical stability and flexibility. Because of such double-layer structures of NNGF, stable Pt-N4 construction, and binder-free advantages, the Pt1/NNGF electrode exhibits a low overpotential of 0.023 V at 10 mA cm-2 and a small Tafel slope of 29.1 mV dec-1 as well as an excellent long-term durability.

One-Step Synthesis of NiFe Layered Double Hydroxide Nanosheet Array/N-Doped Graphite Foam Electrodes for Oxygen Evolution Reactions.

Developing cost-effective and highly efficient oxygen evolution reaction (OER) electrocatalysts is vital for the production of clean hydrogen by electrocatalytic water splitting. Here, three dimensional nickel-iron layered double hydroxide (NiFe LDH) nanosheet arrays are in-situ fabricated on self-supporting nitrogen doped graphited foam (NGF) via a one-step hydrothermal process under an optimized amount of urea. The as prepared NiFe LDH/NGF electrode exhibits a remarkable activity toward OER with a low onset overpotential of 233 mV and a Tafel slope of 59.4 mV dec-1 as well as a long-term durability. Such good performance is attributed to the synergy among the doping effect, the binder-free characteristic, and the architecture of the nanosheet array.

Radiochemical reaction of DT/ T2 and CO under high pressure.

For both fuel cycle design and safety evolution of tritium (T) in fusion reactor, it is important to study irradiation-induced reactions between T2 and various molecular species produced from nuclear-fusion fuel cleanup systems. The radiochemical reactions between deuterium-tritium/tritium and carbon monoxide of different concentrations under 1.0 MPa were elucidated in this work. The products and the process of radiochemical reactions of T2/CO and D2-T2/CO mixed system with different tritium concentrations were analyzed by mass spectrometry and gas chromatography. The evolution of the product composition in 300 min. was monitored at room temperature with a rapid decrease of tritium concentration and pressure. It was found that, in T2/CO and D2-T2/CO mixed system, only tritium was involved in the reaction of CO. Under the ß irradiation of tritium, the reaction products were mainly composed of tritiated formaldehyde (CT2O) and tiny amount of CO2, C(DT)4, C3(DT)8. The concentration of products rose with the increase of CO concentration in reaction system.

Structural and Kinetic Hydrogen Sorption Properties of Zr0.8Ti0.2Co Alloy Prepared by Ball Milling.

The effects of ball milling on the hydrogen sorption kinetics and microstructure of Zr0.8Ti0.2Co have been systematically studied. Kinetic measurements show that the hydrogenation rate and amount of Zr0.8Ti0.2Co decrease with increasing the ball milling time. However, the dehydrogenation rate accelerates as the ball milling time increases. Meanwhile, the disproportionation of Zr0.8Ti0.2Co speeds up after ball milling and the disproportionation kinetics is clearly inclined to be linear with time at 500°C. It is found from X-ray powder diffraction (XRD) results that the lattice parameter of Zr0.8Ti0.2Co gradually decreases from 3.164 Å to 3.153 Å when the ball milling time extends from 0 h to 8 h, which is mainly responsible for the hydrogen absorption/desorption behaviors. In addition, scanning electron microscope (SEM) images demonstrate that the morphology of Zr0.8Ti0.2Co has obviously changed after ball milling, which is closely related to the hydrogen absorption kinetics. Besides, high-resolution transmission electron microscopy (HRTEM) images show that a large number of disordered microstructures including amorphous regions and defects exist after ball milling, which also play an important role in hydrogen sorption performances. This work will provide some insights into the principles of how to further improve the hydrogen sorption kinetics and disproportionation property of Zr0.8Ti0.2Co.