The performance degradation of high-sulfur-loading cathodes caused by the migration of polysulfide intermediates from cathode to anode seriously impedes the practical use of lithium-sulfur batteries. This work presents a lightweight, porous nitrogen-doped carbon nanosheet modified commercial separator with a high polysulfide-entrapping ability, which can significantly improve the capacities, rate capabilities, and cycling stability of the high-sulfur-loading cathodes made of commercial carbon materials. This study provides useful insight into the design of low-cost and high-energy-density Li-S batteries.

Two-dimensional (2D) nanosheets (NSs) of a Ni-S coordination polymer have been successfully synthesized with the use of 2D Ni(OH) 2 NSs grown on conductive carbon cloth as the template and 1,4-benzenedithiol as the ligand. In situ X-ray absorption spectroscopy revealed that the as-prepared catalyst was entirely transformed into ultrathin Ni NSs under alkaline reductive conditions. The in-situ-generated catalysts exhibited superior activity toward the hydrogen evolution reaction (HER) with an overpotential of 80 mV to reach 10 mA cm À2 . Studies revealed that the large-area ultrathin Ni NSs served as active sites for H 2 generation, and the trace sulfur adsorbed on the Ni surface promoted water dissociation. This work has developed a templating approach for preparing highly active HER electrocatalysts and identified the real active sites under electrocatalytic conditions.

Perovskite solar cells (PSCs) have reached certified efficiencies of up to 23.7% but suffered from frailness and instability when exposed to ambient atmosphere. Zinc oxide (ZnO), when used as electron transport layer (ETL) on PSCs, gives rise to excellent electronic, optic, and photonic properties, yet the Lewis basic nature of ZnO surface leads to deprotonation of the perovskite layer, resulting in serious degradation of PSCs using ZnO as ETL. Here, we report a simple but effective strategy to convert ZnO surface into ZnS at the ZnO/perovskite interface by sulfidation. The sulfide on ZnO–ZnS surface binds strongly with Pb2+ and creates a novel pathway of electron transport to accelerate electron transfer and reduce interfacial charge recombination, yielding a champion efficiency of 20.7% with improved stability and no appreciable hysteresis. The model devices modified with sulfide maintained 88% of their initial performance for 1000 h under storage condition and 87% for 500 h under UV radiation. ZnS is demonstrated to act as both a cascade ETL and a passivating layer for enhancing the performance of PSCs.

How to exert the energy density advantage is a key link in the development of lithium–sulfur batteries. Therefore, the performance degradation of high-sulfur-loading cathodes becomes an urgent problem to be solved at present. In addition, the volumetric capacities of high-sulfur-loading cathodes are still at a low level compared with their areal capacities. Aiming at these issues, two-dimensional carbon yolk-shell nanosheet is developed herein to construct a novel self-supporting sulfur cathode. The cathode with high-sulfur loading of 5 mg cm−2 and sulfur content of 73 wt% not only delivers an excellent rate performance and cycling stability, but also provides a favorable balance between the areal (5.7 mAh cm–2) and volumetric (1330 mAh cm–3) capacities. Remarkably, an areal capacity of 11.4 mAh cm–2 can be further achieved by increasing the sulfur loading from 5 to 10 mg cm–2. This work provides a promising direction for high-energy-density lithium–sulfur batteries.

Air-stable atomically thick copper nanosheets are prepared and used for selective electrochemical reduction of CO2 into CO.

No abstract

Electrochemical conversion of CO into fuels using electricity generated from renewable sources helps to create an artificial carbon cycle. However, the low efficiency and poor stability hinder the practical use of most conventional electrocatalysts. In this work, a 2D hierarchical Pd/SnO structure, ultrathin Pd nanosheets partially capped by SnO nanoparticles, is designed to enable multi-electron transfer for selective electroreduction of CO into CH OH. Such a structure design not only enhances the adsorption of CO on SnO , but also weakens the binding strength of CO on Pd due to the as-built Pd-O-Sn interfaces, which is demonstrated to be critical to improve the electrocatalytic selectivity and stability of Pd catalysts. This work provides a new strategy to improve electrochemical performance of metal-based catalysts by creating metal oxide interfaces for selective electroreduction of CO .

An effective strategy is developed to synthesize high‐nuclearity Cu clusters, [Cu53(RCOO)10(C≡CtBu)20Cl2H18]+ (Cu53), which is the largest CuI/Cu0 cluster reported to date. Cu powder and Ph2SiH2 are employed as the reducing agents in the synthesis. As revealed by single‐crystal diffraction, Cu53 is arranged as a four‐concentric‐shell Cu3@Cu10Cl2@Cu20@Cu20 structure, possessing an atomic arrangement of concentric M12 icosahedral and M20 dodecahedral shells which popularly occurs in Au/Ag nanoclusters. Surprisingly, Cu53 can be dissolved in diethyl ether and spin coated to form uniform nanoclusters film on organolead halide perovskite. The cluster film can subsequently be converted into high‐quality CuI film via in situ iodination at room temperature. The as‐fabricated CuI film is an excellent hole‐transport layer for fabricating highly stable CuI‐based perovskite solar cells (PSCs) with 14.3 % of efficiency.