Heterojunction‐Type Photocatalytic System Based on Inorganic Halide Perovskite CsPbBr 3 †

Recent progress of metal halide perovskite materials in heterogeneous photocatalytic organic reactions

Photocatalytic technology is widely regarded as an important way to utilize solar energy and achieve carbon neutrality, which has attracted considerable attentions in various fields over the past decades. Metal halide perovskites (MHPs) are recognized as "superstar" materials due to their exceptional photoelectric properties, readily accessible and tunable structure, which made them intensively studied in solar cells, light-emitting diodes, and solar energy conversion fields. Since 2018, increased attention has been focused on applying the MHPs as a heterogeneous visible light photocatalyst in catalyzing organic synthesis reactions. In this review, we present an overview of photocatalytic technology and principles of heterogeneous photocatalysis before delving into the structural characteristics, stability, and classifications of MHPs. We then focus on recent developments of MHPs in photocatalyzing various organic synthesis reactions, such as oxidation, cyclization, C-C coupling etc., based on their classifications and reported reaction types. Finally, we discuss the main limitations and prospects regarding the application of metal halide perovskites in organic synthesis.

All-inorganic lead halide perovskites for photocatalysis: a review

Nowadays, environmental pollution and the energy crisis are two significant concerns in the world, and photocatalysis is seen as a key solution to these issues. All-inorganic lead halide perovskites have been extensively utilized in photocatalysis and have become one of the most promising materials in recent years. The superior performance of all-inorganic lead halide perovskites distinguish them from other photocatalysts. Since pure lead halide perovskites typically have shortcomings, such as low stability, poor active sites, and ineffective carrier extraction, that restrict their use in photocatalytic reactions, it is crucial to enhance their photocatalytic activity and stability. Huge progress has been made to deal with these critical issues to enhance the effects of all-inorganic lead halide perovskites as efficient photocatalysts in a wide range of applications. In this manuscript, the synthesis methods of all-inorganic lead halide perovskites are discussed, and promising strategies are proposed for superior photocatalytic performance. Moreover, the research progress of photocatalysis applications are summarized; finally, the issues of all-inorganic lead halide perovskite photocatalytic materials at the current state and future research directions are also analyzed and discussed. We hope that this manuscript will provide novel insights to researchers to further promote the research on photocatalysis based on all-inorganic lead halide perovskites.

Lead-Free Cs2 AgSbCl6 Double Perovskite Nanocrystals for Effective Visible-Light Photocatalytic C-C Coupling Reactions

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 Cs₂ AgSbCl₆ 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.

Application of Metal Halide Perovskites as Photocatalysts in Organic Reactions

This review summarizes the current status of the application of metal halide perovskites (MHPs) as photocatalysts in organic syntheses/transformations. It is shown that the optimal and unique electronic properties of MHPs can be advantageously used in several reaction types providing pros with respect to traditional photocatalysts. While still being at infancy, such field of application of MHPs as effective photocatalysts will for sure become a central research topic in the forthcoming years, thanks also to their rich structural and chemical tunability, which may provide tailored materials for most of the envisaged organic reactions.

Recent Progress in Designing Halide-Perovskite-Based System for the Photocatalytic Applications

The halide perovskite material has attracted vast attention as a versatile semiconductor in the past decade. With the unique advantages in physical and chemical properties, they have also shown great potential in photocatalytic applications. This review aims at the specific design principles triggered by the unique properties when employing halide-perovskite-based photocatalytic systems from the following perspectives: (I) Design of photoelectrocatalytic device structures including the n-i-p/p-i-n structure, photoelectrode device encapsulation, and electrolyte engineering. (II) The design of heterogeneous photocatalytic systems toward the hydrogen evolution reaction (HER) and CO2 reduction reaction, including the light management, surface/interface engineering, stability improvement, product selectivity engineering, and reaction system engineering. (III) The photocatalysts for the environmental application and organic synthesis. Based on the analyses, the review also suggests the prospective research for the future development of halide-perovskite-based photocatalytic systems.