A Review on Halide Perovskite-Based Photocatalysts: Key Factors and Challenges

Abstract

A growing number of research articles have been published on the use of halide perovskite materials for photocatalytic reactions. These articles extend these materials' great success from solar cells to photocatalytic technologies such as hydrogen production, CO 2 reduction, dye degradation, and organic synthesis. In the present review article, we first describe the background theory of photocatalysis, followed by a description on the properties of halide perovskites and their development for photocatalysis. We highlight key intrinsic factors influencing their photocatalytic performance, such as stability, electronic band structure, and sorption properties. We also discuss and shed light on key considerations and challenges for their development in photocatalysis, such as those related to reaction conditions, reactor design, presence of degradable organic species, and characterization, especially for CO 2 photocatalytic reduction. This review on halide perovskite photocatalysts will provide a better understanding for their rational design and development and contribute to their scientific and technological adoption in the wide field of photocatalytic solar devices.

Cs3Bi2Br9/g-C3N4 Direct Z-Scheme Heterojunction for Enhanced Photocatalytic Reduction of CO2 to CO

“…Higher photocurrents in the composites, especially in the 40% Cs 3 Bi 2 Br 9 composite, indicate that composites offer superior charge separation when photoinduced charges are generated. This increased charge separation favors photocatalytic processes, since it mitigates electron–hole charge recombination. , …”

“…5,6 Currently, the most heavily researched lead halide perovskites are CsPbBr 3 or CH 3 NH 3 PbI 3 owing to their abundant elements. 7 However, perovskites with Pb 2+ cations in their structure pose the risk of releasing the toxic element to the environment, since photocatalysts are not encapsulated like solar cells. 8,9 To address this challenge, researchers have been testing perovskite-inspired materials that substitute lead with a combination of cations that preserve charge neutrality.…”

Nanostructured Metal Chalcohalide Photocatalysts: Crystal Structures, Synthesis, and Applications

“…Inorganic semiconducting nanostructured materials have been extensively studied for decades as heterogeneous photocatalysts for solar energy harvesting. − Among these, carbon-based materials, − metal–organic frameworks, − metal oxides, ,− chalcogenides, − chalcopyrites, − kesterites, − perovskites, − and oxyhalides − remained in the forefront. Developments of such new materials, along with studies of their crystal structures and optical bandgaps, are also continuing, in order to meet the current challenges of harvesting energy while providing environmental remedies.…”

The Dark Side of Lead-Free Metal Halide Nanocrystals: Substituent-Modulated Photocatalytic Activity in Benzyl Bromide Reduction

“…Moreover, the photogenerated charges are trapped at different surface sites to conduct redox reactions with electron acceptors and donors. 15 Indeed, APbX 3 NCs have been explored as photocatalysts in the oxidative degradation of photosensitizers, 16 CO 2 reduction, 17,18 and organic transformations, such as alcohol oxidation, 19 C(sp 3 )-H activation, 20 oxidative palladium Suzuki coupling reactions, 21 and C−C, C−O, and C−N bond formation. 22 In particular, the Csp 3 −Csp 3 bond formation via C−H activation of aldehydes by CsPbBr 3 NCs required the consumption of a cocatalyst and a base to drive forward the reaction.…”

“…In detail, lead halide perovskite NCs (APbX 3, A = CH 3 NH 3 + , Cs + ; X = Cl – , Br – , I – ) have been spotted as optimal photocatalysts (for solar energy capture) thanks to their appealing optoelectronic properties, such as a strong absorption in the UV–visible range, long excited-state lifetimes, effective charge separation and transport, and ultrafast charge transfer processes, − together with their simple preparation from earth-abundant materials. Moreover, the photogenerated charges are trapped at different surface sites to conduct redox reactions with electron acceptors and donors . Indeed, APbX 3 NCs have been explored as photocatalysts in the oxidative degradation of photosensitizers, CO 2 reduction, , and organic transformations, such as alcohol oxidation, C­(sp 3 )-H activation, oxidative palladium Suzuki coupling reactions, and C–C, C–O, and C–N bond formation .…”