In order to overcome the shuttling effect of soluble polysulfides in lithium–sulfur (Li–S) batteries, we have designed and synthesized a creative MoS2–MoO3/carbon shell (MoS2–MoO3/CS) composite by a H2O2-enabled oxidizing process under mild conditions, which is further used for separator modification. The MoS2–MoO3 heterostructures can conform to the CS morphology, forming two-dimensional nanosheets, and thus shorten the transport path of lithium ion and electrons. Based on our theoretical calculations and experiments, the heterostructures show strong surface affinity toward polysulfides and good catalytic activity to accelerate polysulfide conversion. Benefiting from the above merits, the Li–S battery with a MoS2–MoO3/CS modified separator exhibits good electrochemical performance: it delivers a high discharge capacity of 1531 mAh g–1 at 0.2 C; the initial capacity can be maintained by 92% after 600 cycles at 1 C, and the discharge capacity decay rate is only 0.0135% per cycle. Moreover, the MoS2–MoO3/CS battery still achieves good cycling stability with 78% capacity retention after 100 cycles at 0.2 C with a high sulfur loading of 5.9 mg cm–2. This work offers a facile design to construct the MoS2–MoO3 heterostructures for high-performance Li–S batteries, and may also improve one’s understanding on the heterostructure contribution during polysulfide adsorption and conversion.

Suffering from sluggish charge transfer kinetics, carbon‐based perovskite solar cells (C‐PSCs) lag far behind the Ag/Au‐based normal PSCs in power conversion efficiency (PCE). Herein, the use of defective multi‐walled CNT (D‐MWCNT) is demonstrated to tune the charge transfer kinetics regarding hole transport layer (HTL) and the interface between HTL and carbon electrode. Benefiting from the electrostatic dipole moment interaction between the terminal oxygen‐containing groups of D‐MWCNT and 2,2′,7,7′‐tetrakis(N,N‐di‐p‐methoxyphenylamine)‐9,9′‐spirobifluorene, an interface coupling at molecular level is established and in turn, allows rapid charge transfer by edge effect induced electron redistribution and 1D hyper‐channels. Meanwhile, a seamless connection between HTL and carbon electrode is achieved in a novel modular C‐PSCs due to D‐MWCNT induced interface coupling with graphene at nanometer scale. Based on this strategy, high PCEs up to 22.07% (with a certified record PCE of 21.9% to date for C‐PSCs) and excellent operational stability have been achieved.

Solution processability enables perovskite solar cells (PSCs) as a potentially advantageous candidate over the conventional vacuumbased photovoltaic technologies. Nevertheless, the stability issue of the metal halide perovskite (MHP) precursor colloids seriously retards the future industrialization of PSCs. Herein we elucidate the key role of organoaminesdeprotonated organoamine cationsin the degradation of the most commercially promising formamidinium/methylammonium (FA + /MA + ) mixed cation MHP precursor and determine that the aminecation reaction of FA-MA + , rather than MA-FA + , is the main route triggering the irreversible degradation process. Subsequently, based on Schiff-base reactions, aldehydes (such as formaldehyde, benzaldehyde, and 3-thenaldehyde) are used to eliminate organoamines for effective suppression of the irreversible degradation of precursors and passivation of H-vacancy traps in the resultant MHP thin films. Furthermore, the optimal benzaldehyde can lead to reduced grain-boundary density to enhance the power conversion efficiency of PSCs from 20.7% to 23.3% with simultaneous improvement in the operational stability.