Rational Design of Metal Halide Perovskite Nanocrystals for Photocatalytic CO₂ Reduction: Recent Advances, Challenges, and Prospects

Abstract

Metal halide perovskite nanocrystals (MHP NCs) have attracted much scientific interest in photocatalysis. Various types of MHP photocatalysts have been intensively explored in photocatalytic CO 2 reduction in the past few years. However, some key issues, such as severe charge recombination, low stability, and the origin of products, have created bottlenecks in developing MHP photocatalysts. Therefore, the rational design of MHPs is worthwhile to deepen our understanding of the above issues and develop efficient photocatalysts. This Focus Review highlights the recent advances in MHP photocatalysts regarding design principles toward photocatalytic CO 2 reduction. Various modification strategies are clarified, and an outlook on future challenges and prospects is also provided to point out the possible research directions in MHP photocatalysts. It is anticipated that this Focus Review can provide guidance on the design of MHP-based photocatalysts and help uncover some common issues encountered by the scientific community when studying MHP photocatalysts.

Lead Halide Perovskite Cube Coupled Star Nanocrystal Photocatalysts

“…Moreover, moisture instability remained the major hurdle for these nanocrystals for their dispersion in polar medium, , and hence, catalytic reactions could not be explored widely for these nanocrystals. Some organic reactions in nonpolar medium and also reduction of CO 2 in limited ethyl acetate and water medium are a few of the recent successes for these halide perovskite nanocrystal catalysts. − However, these are limited, and more reaction paths and understanding details of the catalytic processes as well as designing robust and appropriate structures of these nanocrystals need to be further explored.…”

“…These intriguing Cd doped and undoped CsPbBr 3 star nanocrystals were further explored for photocatalytic CO 2 reduction. The reported ethyl acetate/water medium was adopted here as the model approach to test the catalytic activities of these larger size star nanocrystals with a catalytic amount of water (V/V = 1000:1). − Even though the use of ethyl acetate/water and the involved redox processes for the halide perovskite catalysts in the evolution of CO and CH 4 are under debate, still these are widely accepted as the products of CO 2 reduction. − , Hence, this was also extended here for both doped and undoped star nanocrystals and their catalytic activities were compared with standard cube shaped nanostructures. Details of these catalytic measurements and electrode preparations are provided in the Supporting Information.…”

“…52−59 Even though the use of ethyl acetate/water and the involved redox processes for the halide perovskite catalysts in the evolution of CO and CH 4 are under debate, still these are widely accepted as the products of CO 2 reduction. [45][46][47]57 Hence, this was also extended here for both doped and undoped star nanocrystals and their catalytic activities were compared with standard cube shaped nanostructures. Details of these catalytic measurements and electrode preparations are provided in the Supporting Information.…”

Highly stable halide perovskites for photocatalysis via multi-dimensional structure design and in situ phase transition

“…Lead halide perovskite nanomaterials have been proved to be promising candidates for photocatalysis as they embody several desirable physical traits such as a tunable band gap width and outstanding light absorption ability. 1,2 So far, they have shown great potential in photocatalytic hydrogen (H 2 ) generation 3,4 and carbon dioxide (CO 2 ) reduction, [5][6][7] among which CsPbBr 3 quantum dots (QDs) are key research targets owing to their simple and low-cost preparation and better crystalline stability compared with other halide perovskites. However, unlike other photocatalysts such as metallic oxide, CsPbBr 3 QDs represent rather poor long-term stability in photocatalysis due to their liquid-like ionic properties.…”

Surface Halogen Compensation on CsPbBr3 Nanocrystals with SOBr2 for Photocatalytic CO2 Reduction

“…With the ever-increasing concerns on fossil fuel consumption and carbon dioxide (CO 2 ) overproduction, the scientific community has been searching for a solution to decrease CO 2 emission and utilize CO 2 in a sustainable way. − Photocatalytic CO 2 reduction is a potential capstone technology to convert CO 2 into high-value-added chemicals. − However, a grand challenge still remains in achieving an efficient photocatalytic system for CO 2 reduction. Concerning the excellent photoelectrical properties, , such as strong light harvesting ability, tunable band gaps, and low exciton binding energy, metal halide perovskite nanocrystals (MHP NCs) are regarded as an ideal candidate for photocatalysis. − However, the photocatalytic performance of most MHP NCs is largely limited by severe charge recombination . To overcome this problem, various semiconductor or metal cocatalysts were coupled with MHP NCs to form heterojunctions for suppressing undesired charge recombination. − The charge transfer efficiency in heterojunctions is highly dependent on the interfacial interactions between MHP NCs and nearby cocatalysts. , However, high-quality and monodispersed MHP NCs, generally prepared by hot-injection or ligand-assisted reprecipitation methods, , are capped with long-chain organic ligands, which impede the electronic coupling between MHP NCs and cocatalysts .…”