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2D chiral perovskite has greatly boosted the development of optoelectronic devices, ranging from nonlinear optics, spintronics, and ferroelectrics to energy harvesting devices. Despite circularly polarized light (CPL) detection based on chiral perovskite has been achieved, the environmental humidity‐, ultraviolet (UV), and temperature‐induced structural degradation and its large electro‐phonon coupling restrict its commercial application. Here, this study first realizes polymerized chiral perovskite single‐crystal films by combining in situ cross‐linking polymerization with the space‐confined crystallization method. Compared with uncross‐linked chiral perovskites, cross‐linked chiral perovskites exhibit enhanced crystallinity and lattice rigidity, yielding high‐performance circularly polarized photodetectors with a maximum anisotropy factor of 0.22, the responsivity of 1.6 A W−1, and detectivity of 2.17 × 1013 Jones. In addition, flexible circularly polarized photodetectors with extremely high mechanical stability are also realized originating from the polymer‐like behavior of cross‐linked chiral perovskite single‐crystal films. This study opens up new avenues to further enhance the performance and stability of portable and wearable devices based on chiral perovskites. [ABSTRACT FROM AUTHOR]

Developing single‐atom electrocatalysts with high activity and superior selectivity at a wide potential window for CO2 reduction reaction (CO2RR) still remains a great challenge. Herein, a porous NiNC catalyst containing atomically dispersed NiN4 sites and nanostructured zirconium oxide (ZrO2@Ni‐NC) synthesized via a post‐synthetic coordination coupling carbonization strategy is reported. The as‐prepared ZrO2@Ni‐NC exhibits an initial potential of −0.3 V, maximum CO Faradaic efficiency (F.E.) of 98.6% ± 1.3, and a low Tafel slope of 71.7 mV dec−1 in electrochemical CO2RR. In particular, a wide potential window from −0.7 to −1.4 V with CO F.E. of above 90% on ZrO2@Ni‐NC far exceeds those of recently developed state‐of‐the‐art CO2RR electrocatalysts based on NiN moieties anchored carbon. In a flow cell, ZrO2@Ni‐NC delivers a current density of 200 mA cm−2 with a superior CO selectivity of 96.8% at −1.58 V in a practical scale. A series of designed experiments and structural analyses identify that the isolated NiN4 species act as real active sites to drive the CO2RR reaction and that the nanostructured ZrO2 largely accelerates the protonation process of *CO2− to *COOH intermediate, thus significantly reducing the energy barrier of this rate‐determining step and boosting whole catalytic performance. [ABSTRACT FROM AUTHOR]

Abstract: The first utilization of nitrogen‐doped graphdiyne (NGDY) as an efficient catalytic promoter for hydrogen evolution reaction (HER) is reported. X‐ray powder diffraction and X‐ray photoelectron spectroscopy studies indicate the presence of strong interactions between NGDY and MoS2, which should effectively facilitate the charge transport behavior and improvement of the HER kinetics. The creative hybridization of MoS2 and NGDY endows such heterostructure with structural and compositional advantages for boosting the catalytic activity (low overpotential of 186 mV at 10 mA cm−2 and Tafel slope of 63 mV dec−1) and extraordinary stability (higher than all reported MoS2‐based materials and even better than that of commercial Pt and almost all benchmarked electrocatalysts). All of the results not only demonstrate that NGDY can be used as an effective catalytic promoter for hydrogen production, but also provide new strategy for fabricating efficient water‐splitting electrodes. [ABSTRACT FROM AUTHOR]

All‐inorganic metal‐halide perovskites CsPbX3 (X = Cl, Br, I) exhibit higher stability than their organic–inorganic hybrid counterparts, but the thermodynamically instable perovskite α phase at room temperature of CsPbI3 restricts the practical optoelectronic applications. Although the stabilization of α‐CsPbI3 polycrystalline thin films is extensively studied, the creation of highly crystalline micro/nanostructures of α‐CsPbI3 with large grain size and suppressed grain boundary remains challenging, which impedes the implementations of α‐CsPbI3 for lateral devices, such as photoconductor‐type photodetectors. In this work, stable α‐CsPbI3 perovskite nanowire arrays are demonstrated with large grain size, high crystallinity, regulated alignment, and position by controlling the dewetting dynamics of precursor solution on an asymmetric‐wettability topographical template. The correlation between the higher photoluminescence (PL) intensity and longer PL lifetime indicates the nanowires exhibit stable α phase and suppressed trap density. The preferential (100) orientation is characterized by discrete diffraction spots in grazing incidence wide‐angle scattering patterns, suggesting the long‐range crystallographic order of these nanowires. Based on these high‐quality nanowire arrays, highly sensitive photodetectors are realized with a responsivity of 1294 A W−1 and long‐term stability with 90% performance retention after 30‐day ambient storage. Stable α‐CsPbI3 nanowire arrays with high crystallinity, large grain size, and preferential crystallographic orientation are demonstrated on an asymmetric‐wettability topographical template. The suppressed grain boundary and surface trap of these nanowires are reflected by longer photoluminescence lifetime and long‐range crystallographic alignment. These high‐quality nanowires exhibit highly sensitive photodetection with responsivity of 1294 A W−1 and long‐term stability. [ABSTRACT FROM AUTHOR]