needs while signifi cantly reducing battery cost. For this reason, the combination of lithium and sulfur has been considered as one of the most promising battery chemistries for full electrifi cation of vehicles. [ 3 ] Despite these advantages, Li S batteries have a few critical barriers to be overcome. Besides the insulating properties of sulfur and polysulfi des, Li S batteries also suffer from dramatic (i.e., ≈76%) volume change of sulfur during cycling and shuttling effect of polysulfi des that sulfur species transport back and forth between electrodes. These lead to the destruction of sulfur cathodes and the corrosion of lithium anode resulting in short battery life.In a traditional Li S cell, a typical sulfur electrode consists of three components, i.e., the electrochemically active sulfur material, the conductive carbon additive, and the polymeric binder. [ 4 ] Through the syntheses of nanoarchitectured carbon additives, the electrochemical performance and cycle life of Li S batteries have been successfully improved. [ 5 ] Although signifi cant achievements have been made in designing nanostructured carbon/sulfur composites for cycle life improvement of Li S batteries, these processes are commonly sophisticated, high cost, and not suitable for large-scale manufacturing.The sulfur cathode in traditional lithium-sulfur batteries suffers from poor cyclability due to polysulfi de shuttling effect as well as large volume change during charge/discharge processes. Gum arabic (GA), a low cost, nontoxic, and sustainable natural polymer from Acacia senegal , is adopted as a binder for the sulfur cathode to address these issues. The excellent mechanical properties of GA endow the cathode with high binding strength and suitable ductility to buffer volume change, while the functional groups chemically and physically confi ne sulfur species within the cathode to inhibit the shuttling effect of polysulfi des. Additionally, GA shifts the electrode fabrication process from the organic solvent process to an aqueous process, eliminates the use of toxic organic solvents, and achieves uniformly distributed electrode with lower impedance. A remarkable cycling performance, i.e., 841 mAh g −1 at low current rate of C /5, is achieved throughout 500 cycles due to the bifunctions of the GA binder.

α-Fe(2)O(3) nanoparticle-loaded carbon nanofiber composites were fabricated via electrospinning FeCl(3)·6H(2)O salt-polyacrylonitrile precursors in N,N-dimethylformamide solvent and the subsequent carbonization in inert gas. Scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, X-ray diffraction, and elemental analysis were used to study the morphology and composition of α-Fe(2)O(3)-carbon nanofiber composites. It was indicated that α-Fe(2)O(3) nanoparticles with an average size of about 20 nm have a homogeneous dispersion along the carbon nanofiber surface. The resultant α-Fe(2)O(3)-carbon nanofiber composites were used directly as the anode material in rechargeable lithium half cells, and their electrochemical performance was evaluated. The results indicated that these α-Fe(2)O(3)-carbon nanofiber composites have high reversible capacity, good capacity retention, and acceptable rate capability when used as anode materials for rechargeable lithium-ion batteries.

Nonoxidative coupling of methane (NOCM) is a highly important process to simultaneously produce multicarbons and hydrogen. Although oxide-based photocatalysis opens opportunities for NOCM at mild condition, it suffers from unsatisfying selectivity and durability, due to overoxidation of CH4 with lattice oxygen. Here, we propose a heteroatom engineering strategy for highly active, selective and durable photocatalytic NOCM. Demonstrated by commonly used TiO2 photocatalyst, construction of Pd–O4 in surface reduces contribution of O sites to valence band, overcoming the limitations. In contrast to state of the art, 94.3% selectivity is achieved for C2H6 production at 0.91 mmol g–1 h–1 along with stoichiometric H2 production, approaching the level of thermocatalysis at relatively mild condition. As a benchmark, apparent quantum efficiency reaches 3.05% at 350 nm. Further elemental doping can elevate durability over 24 h by stabilizing lattice oxygen. This work provides new insights for high-performance photocatalytic NOCM by atomic engineering.

No abstract