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Metal halide perovskites represented by methylamine lead iodine (MAPbI3) have attracted extensive attention for their excellent performance in the field of photoelectric catalysis. However, the catalytic performance of MAPbI3 is limited due to the severe recombination of electrons and holes. Here, we synthesized hollow MoS2 (H-MoS2) microspheres by the template method and then supported it on the surface of MAPbI3 by electrostatic coupling to obtain H-MoS2/MAPbI3 composites, which showed excellent performance in photocatalytic hydrogen production. Among them, the 15% H-MoS2/MAPbI3 composite showed the highest photocatalytic hydrogen evolution performance, which was 399 μmol h−1, about 260 times that of MAPbI3 (1.53 μmol h−1). The long-term cycling experiments showed that the H-MoS2/MAPbI3 composite retains its activity for at least 16 h. The excellent performance of H-MoS2/MAPbI3 composites was attributed to the efficient shunting of photogenerated electrons and holes by H-MoS2 as a cocatalyst. The results of our study provided a reference for the construction of MAPbI3-based composite heterostructures for efficient photocatalytic hydrogen production. [ABSTRACT FROM AUTHOR]

All‐inorganic metal halide perovskite quantum dots (QDs) have attracted attention from researchers with their fascinating optoelectronic properties. However, blue‐emitting perovskite QDs typically have low photoluminescence quantum yield (PLQY). For potential commercial applications, it is preferable to replace Pb with an element having low toxicity. Here, Pb‐free Cs3Bi2Br9@BiOBr perovskite QDs were anchored on the surface of NHx‐rich monodisperse silica (A−SiO2) via N−Bi chemical bonding to isolate QDs from each other, thus enhancing efficient surface passivation and suppressing optical decay. Compared to unanchored QDs, Cs3Bi2Br9@BiOBr QDs/A−SiO2 composites exhibited significantly enhanced blue emission performance, the PLQY of which increased from 16.62 % to 77.26 %, in addition to good water and environmental stability. Finally, the novel composites as photocatalysts were used to drive the oxidation of toluene, a template reaction of C(sp3)−H bond activation and demonstrated astonishing conversion rates (4317 μmol g−1 h−1) with high selectivity (around 87 %). [ABSTRACT FROM AUTHOR]

Lead halide perovskite nanocrystals (NCs) have been regarded as a promising potential photocatalyst, owing to their high molar extinction coefficient, low economic cost, adjustable light absorption range, and ample surface active sites. However, the toxicity of lead and its inherent instability in water and polar solvents could hinder their wide application in the field of photocatalysis. Herein, with α‐alkylation of aldehydes as a model reaction, C−C bond‐forming is demonstrated in high yield by using lead‐free double perovskite Cs2AgSbCl6 NCs under visible light irradiation. Moreover, the photocatalytic performance is simply improved by rational control of the surface ligands and a reaction mechanism involving a radical intermediate is proposed. Although the stability requires further amelioration, the results indicate the enormous potential of lead‐free double perovskite NC photocatalysts for organic synthesis and chemical transformations. [ABSTRACT FROM AUTHOR]

Metal halide perovskites, such as iodine methylamine lead (MAPbI3), have received extensive attention in the field of photocatalytic decomposition of HI for hydrogen evolution, due to their excellent photoelectric properties. In this paper, a new MAPbI3-based composite, MoC/MAPbI3, was synthesized. The results show that 15 wt% MoC/MAPbI3 has the best hydrogen production performance (38.4 μmol h−1), which is approximately 24-times that of pure MAPbI3 (1.61 μmol h−1). With the extension of the catalytic time, the hydrogen production rate of MoC/MAPbI3 reached 165.3 μmol h−1 after 16 h due to the effective separation and transfer of charge carriers between MoC and MAPbI3, showing excellent hydrogen evolution rate performance under visible light. In addition, the cycling stability of MoC/MAPbI3 did not decrease in multiple 4 h cycle tests. This study used the non-precious metal promoter MoC to modify MAPbI3, and provides a new idea for the synthesis of efficient MAPbI3-based composite catalysts. [ABSTRACT FROM AUTHOR]

Lead halide perovskite quantum dots have drawn worldwide attention due to their quantum confinement effect and excellent optical gain properties. It is worth noting that due to the toxicity of lead ions and the inherent instability of organic groups, research on all-inorganic lead-free metal halide perovskite quantum dots (ILFHPQDs) has become a hot spot in recent years. This paper summarizes the latest research progress of ILFHPQDs, analyzes the sources and limitations affecting the performance of ILFHPQDs, and provides the improvement methods. Firstly, the typical synthesis strategies of ILFHPQDs are discussed, followed by a focus on the structural characteristics, optoelectronic properties and stability of each type of ILFHPQD. Next, the applications of ILFHPQDs in devices are investigated. Finally, the challenges, solutions and future application directions of ILFHPQDs are prospected. [ABSTRACT FROM AUTHOR]

Novel all-inorganic Sb-based lead-free double perovskite Cs2AgSbX6 (X = Cl, Br or I) quantum dots exhibiting excellent air stability and strong blue emission with photoluminescence quantum yields of 31.33% were synthesized for the first time using a surfactant-assisted method. The ligand, oleic acid, could control the crystallization of the pure perovskite phase and significantly passivate the surface. [ABSTRACT FROM AUTHOR]

Highly photoluminescent all-inorganic copper based perovskite Cs2CuX4 (X = Cl, Br, and Br/I) quantum dots (QDs) were facilely synthesized and investigated for the first time. These perovskite QDs exhibited high quantum yield for blue-green light and excellent stability, while the particle size and photoluminescence wavelength could be tuned via the molar ratio of the raw materials. [ABSTRACT FROM AUTHOR]

Cs3Bi2Br9 quantum dots (QDs) with photoluminescence quantum yields (PLQYs) of up to 22% were prepared through the steady binding of octylammonium bromide and oleic acid. Excellent thermal stability and good luminescence properties have been achieved as intrinsic features of the inorganic halide perovskites, as well as the effective passivation of surface trap-states. [ABSTRACT FROM AUTHOR]

• The specific composite composed of carbon nanotubes (CNTs) tightly wrapped perovskite-CsPbBr 3 (CsPbBr 3 @CNTs) was synthesized by a simplified co-precipitation method. • The CsPbBr 3 @CNTs was applied as anode in lithium ion batteries for the first time. • The CsPbBr 3 @CNTs composite showed excellent lithium storage capacity supplied with surface dominating pseudocapacitive contribution. All-inorganic halide perovskites have recently made remarkable achievements in the field of photo-electrochemistry, but rarely been applied in energy storage devices, especially, in lithium-ion batteries (LIBs). In this article, the specific composite composed of carbon nanotubes (CNTs) tightly wrapped perovskite-CsPbBr 3 (CsPbBr 3 @CNTs) was synthesized by a simplified co-precipitation method. Attributed to the specific morphology, the CsPbBr 3 @CNTs composite supplied short pathways for the transport of both electrons and lithium ions, along with the interface for pseudocapacitive behavior. The synergistic effects of CsPbBr 3 and CNTs enhanced the pseudocapacitive effect, thus, CsPbBr 3 @CNTs exhibited high cycling stability and rate capability. The prominent lithium storage capabilities were exhibited then, with first reversible capacity of 644.6 mA h g−1/100 mA g−1 and maintained at 470.2 mA h g−1 after 200 cycles. Moreover, under the large current density of 600 mA g−1, it kept a stable capacity of 203.8 mA h g−1. This study, for the very first time, proved the great application potential of all-inorganic perovskite composite materials with surface dominating pseudocapacitive contribution in LIBs. Image, graphical abstract [ABSTRACT FROM AUTHOR]