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As the power‐conversion efficiency (PCE) of organic–inorganic lead halide perovskite solar cells (PSCs) is approaching the theoretical maximum, the most crucial issue concerns long‐term ambient stability. Here, the application of PCN‐224 quantum dots (QDs) is reported, a typical Zr‐based porphyrinic metal–organic framework (MOF), to enhance the ambient stability of PSCs. PCN‐224 QDs with abundant Lewis‐base groups (e.g., CO, C−N, CN) contribute to high‐quality perovskite films with enlarged grain size and reduced defect density by interaction with under‐coordinated Pb2+. Meanwhile, PCN‐224 QDs enable the well‐matched energy level at the perovskite/hole transport layer (HTL) interface, thereby facilitating hole extraction and transport. More importantly, PCN‐224 QDs‐treated HTL can capture Li+ from bis(trifluoromethanesulfonyl)imide additive, leading to the reduced aggregation and less direct contact with moisture for hygroscopic Li‐TFSI. Moreover, PCN‐224 QDs mitigated Li+ ion migration into the perovskite layer, thus avoiding the formation of deleterious defects. The resultant devices yield a champion PCE of 22.51%, along with substantially improved durability, including humidity, thermal and light soaking stabilities. The findings provide a new approach toward efficient and stable PSCs by applying MOF QDs. [ABSTRACT FROM AUTHOR]

Extraordinary electronic and photonic features (e.g., tunable direct bandgap, high ambipolar carrier mobility) render few‐layer black phosphorus (BP) nanosheets/quantum dots an important optoelectronic material. However, most of the BP applied in metal halide perovskite solar cells (PSCs) are produced by sonication‐assisted liquid exfoliation, which inevitably brings inferior electronic properties, thus leading to limited beneficial effects. Furthermore, this study uncovers that the intrinsic instability of BP nanosheets sandwiched between (CsFAMA)Pb(BrI)3 perovskite and spiro‐OMeTAD has a deleterious effect on the performance stabilization of PSCs. To address the above constraints, a feasible strategy herein is developed by introducing high‐quality fluorinated BP (F‐BP) nanosheets synthesized by one‐step electrochemical delamination. In addition to P‐Pb coordination, there is a strong hydrogen bond between F− and MA+/FA+ as well as an ionic bond between F− and Pb2+ for the perovskite/F‐BP interface, thus leading to fewer interfacial traps than perovskite/BP, which is responsible for the highest power conversion efficiency (22.06%) of F‐BP devices. More importantly, F‐BP devices exhibit significantly improved humidity and shelf‐life stabilities due to the excellent ambient stability of F‐BP, resulting from the antioxidation and antihydration behavior of fluorine adatoms. Overall, the findings provide a promising strategy to simultaneously enhance the photovoltaic performance and long‐term stability of BP‐based PSCs. [ABSTRACT FROM AUTHOR]

UiO‐66‐NH2/black phosphorus quantum dots (MOF/BPQDs) heterojunctions are anchored on the carboxyl cellulose nanofiber (CNF) aerogel with high porosity (>98%) to fabricate high‐efficiency uranium adsorbents (BP@CNF‐MOF). CNF aerogels possess abundant carboxyl groups, which can serve as nucleation centers to in situ synthesize UiO‐66‐NH2 with smaller crystal size, high mass loading, and good adhesion. BP@CNF‐MOF demonstrates good mechanical flexibility and minimal MOF loss from the CNF aerogel, both of which result from the mutual physical interactions and entanglements of CNFs as well as strong binding interactions between MOF crystals and CNF aerogel. Owing to the excellent heterogeneous photocatalytic activity of MOF/BPQDs, on one hand, marine bacteria can be effectively destroyed by reactive oxygen species (ROS). On the other hand, the photocatalytic U(VI) reduction to insoluble U(IV) could be facilitated, thereby allowing more binding sites on the MOF crystals for further U(VI) adsorption. Consequently, compared with dark conditions, the adsorption efficiency of the light irradiated BP@CNF‐MOF increases by 55.3%, reaching up to 6.77 mg‐U per g‐Ads after 6 weeks of exposure to natural seawater. The intrinsic instability of BPQDs can be overcome by MOF coating layer simultaneously. The strategy applied in this work could also be applicable to other superior MOF crystals. [ABSTRACT FROM AUTHOR]