In-situ growth behavior of FAPbBr3 on two-dimensional materials for photocatalytic reaction to controllable products

Interface Engineering, Charge Carrier Dynamics, and Solar-Driven Applications of Halide Perovskite/2D Material Heterostructured Photocatalysts

Halide perovskites (HPs), renowned for their intriguing optoelectronic properties, such as robust light absorption coefficient, long charge transfer distance, and tunable band structure, have emerged as a focal point in the field of photocatalysis. However, the photocatalytic performance of HPs is still inhibited by rapid charge recombination, insufficient band potential energy, and limited number of surface active sites. To overcome these limitations, the integration of two-dimensional (2D) materials, characterized by shortened charge transfer pathways and expansive surface areas, into HP/2D heterostructures presents a promising avenue to achieve exceptional interfacial properties, including extensive light absorption, efficient charge separation and transfer, energetic redox capacity, and adjustable surface characteristics. Herein, a comprehensive review delving into fundamentals, interfacial engineering, and charge carrier dynamics of HP/2D material heterostructures is presented. Numerous HP/2D material photocatalysts fabricated through diverse strategies and interfacial architectures are systematically described and categorized. More importantly, the enhanced charge carrier dynamics and surface properties of the HP/2D material heterostructures are thoroughly investigated and discussed. Finally, an analysis of the challenges faced in the development of HP/2D photocatalysts, alongside insightful recommendations for potential strategies to overcome these barriers, is provided.

Comparative Study of the Electrorheological Properties of Various Halide Perovskites

Although perovskite-structured materials have primarily been widely employed in solar cell applications, limited studies have been conducted in the field of electrorheology (ER). In this study, various halide perovskite materials, including FAPbBr3, FAPbI3, MAPbBr3, MAPbI3, CsPbBr3, and CsPbI3 were synthesized for the first time to evaluate their applicability in ER for the first time. Initially, the morphological and chemical properties of these materials were characterized to confirm the successful formation of the perovskite structures. In addition, the as-synthesized halide perovskite materials were dispersed in silicone oil (3.0 wt %) to evaluate their suitability as dispersants in ER fluids. Among these, the CsPbI3-based ER fluid exhibited the optimal dielectric properties and the greatest dispersion stability of the various systems examined. In ER applications, the CsPbI3-based ER fluid demonstrated the highest ER performance, achieving a shear stress of 99.4 Pa, owing to the synergistic effects of its intrinsic rod-like structure and dielectric properties, which promoted polarization. The aspect ratios of the CsPbI3 rods were further controlled by modifying the synthetic process, resulting in the generation of both shorter and longer rods. Notably, ER fluids based on CsPbI3 synthesized via a hydrothermal method yielded rod-like structures with a high aspect ratio of 20, leading to an enhanced ER activity of 128.0 Pa. These results highlight the potential of halide perovskite materials for use in ER applications.

Structural Modification Strategies, Interfacial Charge-Carrier Dynamics, and Solar Energy Conversion Applications of Organic-Inorganic Halide Perovskite Photocatalysts

Over the past few decades, organic-inorganic halide perovskites (OIHPs) as novel photocatalyst materials have attracted intensive attention for an impressive variety of photocatalytic applications due to their excellent photophysical (chemical) properties. Regarding practical application and future commercialization, the air-water stability and photocatalytic performance of OIHPs need to be further improved. Accordingly, studying modification strategies and interfacial interaction mechanisms is crucial. In this review, the current progress in the development and photocatalytic fundamentals of OIHPs is summarized. Furthermore, the structural modification strategies of OIHPs, including dimensionality control, heterojunction design, encapsulation techniques, and so on for the enhancement of charge-carrier transfer and the enlargement of long-term stability, are elucidated. Subsequently, the interfacial mechanisms and charge-carrier dynamics of OIHPs during the photocatalytic process are systematically specified and classified via diverse photophysical and electrochemical characterization methods, such as time-resolved photoluminescence measurements, ultrafast transient absorption spectroscopy, electrochemical impedance spectroscopy measurements, transient photocurrent densities, and so forth. Eventually, various photocatalytic applications of OIHPs, including hydrogen evolution, CO2 reduction, pollutant degradation, and photocatalytic conversion of organic matter.

The Development of iDPC-STEM and Its Application in Electron Beam Sensitive Materials

The main aspects of material research: material synthesis, material structure, and material properties, are interrelated. Acquiring atomic structure information of electron beam sensitive materials by electron microscope, such as porous zeolites, organic-inorganic hybrid perovskites, metal-organic frameworks, is an important and challenging task. The difficulties in characterization of the structures will inevitably limit the optimization of their synthesis methods and further improve their performance. The emergence of integrated differential phase contrast scanning transmission electron microscopy (iDPC-STEM), a STEM characterization technique capable of obtaining images with high signal-to-noise ratio under lower doses, has made great breakthroughs in the atomic structure characterization of these materials. This article reviews the developments and applications of iDPC-STEM in electron beam sensitive materials, and provides an outlook on its capabilities and development.

CsPbBr3 perovskite quantum dots as a visible light photocatalyst for cyclisation of diamines and amino alcohols: an efficient approach to synthesize imidazolidines, fused-imidazolidines and oxazolidines

We report the synthesis of highly stable CsPbBr3QD based photocatalysts using dibromoisocyanuric acid (DBI) as a benign non-toxic bromide precursor.