Design and Construction of Carbon-Coated Bimetallic Selenide Heterostructures Loaded on Reduced Graphene Oxide Substrate for Superior Lithium-Ion Storage.

In this work, carbon-coated bimetallic tin-nickel selenide heterostructures loaded on reduced graphene oxide composites were prepared through a metal-organic framework-assisted strategy. The carbon coating mitigates the volume expansion and maintains the structural stability, while the introduction of reduced graphene oxide and heterojunction enhances electrical conductivity and reaction kinetics, thereby together contributing to the enhanced lithium-ion storage performance. As expected, the optimal material delivers excellent lithium-ion storage performance in terms of a high reversible capacity of 1033.4 mAh g-1 at 0.2 A g-1, outstanding rate capability, and long-term cyclability with the capacity of 726.2 mAh g-1 after 500 cycles at 1.0 A g-1 and 452.4 mAh g-1 after 1000 cycles at 2.0 A g-1. Furthermore, the electrochemical reaction mechanism of the composite is analyzed.

Construction of Bimetallic-Anchored Two-Dimensional Nanosheets on COF for Rechargeable Zinc-Air Batteries.

The preparation of carbon materials by doping bimetallic oxides into triazine frameworks (COFs) is a promising electrocatalyst with the potential to replace precious metals in energy storage systems. In this experiment, a covalent triazine framework (COF) was synthesized by 1,4-dicyanobenzene (DCB) and zinc chloride, in which the COF and transition metals were used as carbon, nitrogen, cobalt, and iron sources. According to the properties of this COF, the destruction of the catalyst during pyrolysis can be prevented. The enhanced catalytic performance of the catalysts can be seen by testing all of the samples of catalysts in an alkaline medium. The high half-wave potential (E1/2) of 0.86 V is comparable to Pt/C and also shows excellent durability by testing. Zinc-air batteries were assembled using the prepared catalysts, and the batteries were tested for specific capacity (548 mAh g-1) and power density (189 mW cm-2). This work provides a new direction for COF-derived catalysts for carbon materials.

Aqua-bis-(4-chloro-benzoato)-κ(2) O,O';κO-bis-(pyridine-κN)cobalt(II).

In the title compound, [Co(C7H4ClO2)2(C5H5N)2(H2O)], the Co(II) atom is six-coordinated by three O atoms from a bidentate and a monodentate 4-chloro-benzoate ligand, two N atoms from two pyridine ligands and a water O atom, giving a distorted octa-hedral geometry. In the crystal, the complex mol-ecules are connected by O-H⋯O hydrogen bonds and π-π interactions between the benzene rings [centroid-centroid distance = 3.8924 (17) Å] into a chain along [010]. Between adjacent chains, π-π inter-actions occur between the pyridine rings [centroid-centroid distance = 3.898 (2) Å], giving an overall two-dimensional architecture.

Preparation and Enhanced Photocatalytic Properties of 3D Nanoarchitectural ZnO Hollow Spheres with Porous Shells.

By using ginkgo leaves (GL) as template and Zn(CH3COO)2∙2H2O as Zn source, a series of ZnO samples with special morphology were prepared via a template-assisted two-steps method without adding any other additives. The degradation of the dye MB was used to evaluate the photocatalytic property of the as-prepared samples. The results showed that when a proper amount of the template was used, a 3D nanoarchitectural ZnO hollow sphere with porous sphere shell assembled by well-distributed nanoparticles was obtained and its photocatalytic activity was much higher than that of ZnO nanoparticles. The special morphology of the sample was herein considered to be very helpful for highly efficient adsorption and activation of reactant molecules by multi-times adsorption-desorption-adsorption, efficient absorption of irradiation light by repeated absorption-reflection-absorption, and efficient separation of the photogenerated e--h⁺ pairs. In addition, the formation of 3D structure of sample ZnO was also discussed.

Highly Efficient Photocatalytic Hydrogen Production of Flower-like Cadmium Sulfide Decorated by Histidine.

Morphology-controlled synthesis of CdS can significantly enhance the efficiency of its photocatalytic hydrogen production. In this study, a novel three-dimensional (3D) flower-like CdS is synthesized via a facile template-free hydrothermal process using Cd(NO3)2•4H2O and thiourea as precursors and L-Histidine as a chelating agent. The morphology, crystal phase, and photoelectrochemical performance of the flower-like CdS and pure CdS nanocrystals are carefully investigated via various characterizations. Superior photocatalytic activity relative to that of pure CdS is observed on the flower-like CdS photocatalyst under visible light irradiation, which is nearly 13 times of pure CdS. On the basis of the results from SEM studies and our analysis, a growth mechanism of flower-like CdS is proposed by capturing the shape evolution. The imidazole ring of L-Histidine captures the Cd ions from the solution, and prevents the growth of the CdS nanoparticles. Furthermore, the photocatalytic contrast experiments illustrate that the as-synthesized flower-like CdS with L-Histidine is more stable than CdS without L-Histidine in the hydrogen generation.

Photodegradation of textile dye Rhodamine B over a novel biopolymer-metal complex wool-Pd/CdS photocatalysts under visible light irradiation.

A novel biopolymer-metal complex wool-Pd/CdS photocatalysts were prepared and exhibited high activity for photodegradation of Rh B under visible light irradiation. The wool-Pd could not only enhance the utilization rate of noble metal Pd but also significantly improve the activity of dye degradation. Wool-Pd was able to introduce Pd and PdS to effectively prohibit the recombination of photogenerated electrons and holes. The optimal weight percentage of wool-Pd in the photocatalyst was found to be 0.5wt%, which resulted in a good result of degradation of Rh B under visible light. It is obviously better in the catalyst efficiency than pure CdS. The photocatalysts were characterized by X-ray diffraction, diffuse reflectance UV-vis spectroscopy, energy-dispersive X-ray spectroscopy (EDX), X-ray photoelectron spectroscopic (XPS) studies, transmission electron microscopy (TEM). In a word, the prepared novel biopolymer-metal complex wool-Pd/CdS photocatalysts not only improve the degradation efficiency of Rh B, but also has a good advantage of recycling and cost-effective. It will have a good application prospect. In addition, the possible degradation pathway of Rh B was proposed in this paper.