Hydrophobic Metal Halide Perovskites for Visible‐Light Photoredox C−C Bond Cleavage and Dehydrogenation Catalysis

Abstract

Two‐dimensional lead and tin halide perovskites were prepared by intercalating the long alkyl group 1‐hexadecylammonium (HDA) between the inorganic layers. We observed visible‐light absorption, narrow‐band photoluminescence, and nanosecond photoexcited lifetimes in these perovskites. Owing to their hydrophobicity and stability even in humid air, we applied these perovskites in the decarboxylation and dehydrogenation of indoline‐2‐carboxylic acids. (HDA)2PbI4 or (HDA)2SnI4 were investigated as photoredox catalysts for these reactions, and quantitative conversion and high yields were observed with the former.

Recent Progress in Engineering Metal Halide Perovskites for Efficient Visible‐Light‐Driven Photocatalysis

“…Despite this exciting progress, limited stability in polar solvents and the toxicity of lead may still hinder their large‐scale implementation. Although some water‐resistant MHPs were reported, the development of general polar‐solvent‐tolerant and acid‐/alkali‐resistant MHP‐based materials may still be the key for broadly exploring new photocatalytic organic reactions with high reactivity and selectivity. On the other hand, the current yields of MHP‐driven C(sp 3 )−H bond activation are still relatively low, especially for the selective oxidation of alkanes or aliphatic compounds (Table ), although reaction conversion is very important and promising.…”

A Supported Bismuth Halide Perovskite Photocatalyst for Selective Aliphatic and Aromatic C–H Bond Activation

“…As eries of photocatalysts consisting of lead-free Cs 3 Bi 2 Br 9 nanoparticles confined in am atrix of mesoporous SBA-15 silica have been prepared. Thewell-dispersed halide perovskite nanoparticles (2-5 nm) lead to better charge separation, more accessible active sites,a nd close contact with hydrocarbons,w hich facilitate the activation of CÀH bonds in hydrocarbons.U nder visible light irradiation, the supported Cs 3 Bi 2 Br 9 /SBA-15 photocatalysts efficiently oxidize C(sp 3 ) À Hbonds of various hydrocarbons (from C 5 to C 16 including aromatic and aliphatic alkanes) to their corresponding oxygenates (mainly aldehydes/ketones) with aconversion rate of up to 32 900 mmol g cat À1 h À1 and high selectivity of > 99 %. We believe this work could provide ap romising direction for exploring halide perovskite photocatalysis in more challenging organic transformation reactions.…”

“…[9] Following the first report using MAPbI 3 for photocatalytic hydrogen evolution, [10] lately toxic lead-based perovskites (for example,C sPbBr 3 and CsPbI 3 )h ave been used for photocatalytic reactions such as dye degradation, [11] CO 2 reduction, [8b, 12] and various organic transformations including C(sp 3 ) À Hb ond activation, [7i] alcohol oxidation, [13] aldehyde alkylation, [14] thiol reaction, [15] C À Cc leavage,a nd dehydrogenation. [16] Moreover,C sPbBr 3 nanocrystals have successfully driven other organic synthesis such as CÀC, CÀO, and CÀNb ond-forming reactions. [17] In comparison, cheap, low-toxic,a nd air-stable bismuth-based counterparts such as Cs 3 Bi 2 X 9 [18] and Cs 2 AgBiX 6 [19] showed af ew applications in photocatalysis (CO 2 reduction, [19e] ring-opening reactions, [20] and dye degradation [21] ).…”

Photoelectrochemical Cells for Artificial Photosynthesis: Alternatives to Water Oxidation

“…The powder XRD patterns of the HDA‐based perovskites before and after exposure to moist environments then demonstrated the increased stability of these hydrophobic perovskites in protic media and solvents, since the data from the sample stirred in water was essentially indistinguishable from that of pristine (HDA) 2 PbI 4 (Figure c). There were also few changes to the photoemissive properties of (HDA) 2 PbI 4 , which was remarkably photoluminescent with a maximum at 500 nm (Figure d) after excitation at 350 nm …”

“…(e) Application of the Pb and Sn 2D perovskites as photocatalysts for the decarboxylation and dehydrogenation reactions of indoline‐2‐carboxylic acids. This figure was adapted from reference 48a …”