Constructing a Cs₃Sb₂Br₉/g‐C₃N₄ Hybrid for Photocatalytic Aromatic C(sp³)H Bond Activation

Abstract

Utilizing halide perovskites for photocatalytic aromatic C(sp3)H bond activation remains a great challenge due to the serious recombination of photogenerated charge carriers and slow reaction dynamics of the materials themselves. Herein, a lead‐free perovskite‐based hybrid of Cs3Sb2Br9/g‐C3N4 nanosheet is constructed and applied for photocatalytic aromatic C(sp3)H bond activation, which shows enhanced photocatalytic performance. By introducing ultrathin g‐C3N4 nanosheets as the heterogeneous nucleation sites, size‐reduced and well‐dispersed Cs3Sb2Br9 nanocrystals can be obtained. The as‐formed close contact and high‐quality heterointerface between Cs3Sb2Br9 and g‐C3N4 provides pathways for fast charge transfer which is beneficial to improve the separation efficiency of photogenerated electron−hole pairs. Under visible light irradiation, the Cs3Sb2Br9/g‐C3N4 hybrid photocatalyst can effectively oxidize toluene toward benzaldehyde and benzyl alcohol with a total conversion rate of 8346.8 μmol g−1 h−1, which is 26.6‐ and 6.0‐fold that of pure g‐C3N4 and Cs3Sb2Br9, respectively. This work demonstrates the potential of all‐inorganic lead‐free halide perovskite‐based heterostructures for photocatalytic organic reactions.

Sb-Substituted Cs2AgBiBr6/g-C3N4 Composite for Photocatalytic C(sp3)–H Bond Activation in Toluene

“…71 Consistently, the binding energy of Cs 3d, Bi 4f, Ag 3d, and Sb 3d in 20%-CN/CASBB shifted to higher binding energies relative to CASBB, indicating that the electrons migrate from CASBB to g-C 3 N 4 (Figure 2b−f). 25,72,73 These results imply strong interaction between the perovskite and g-C 3 N 4 in the composite that will favor charge carrier separation. 24 Meanwhile, the obvious shift to smaller wavenumbers of two Raman peaks found at 134 and 178 cm −1 in the 20%-CASBB/CN composite, in comparison to CASBB (Figure S4), further confirmed the strong interaction between the two components.…”

“…However, Sn- and Ge-based perovskites are restricted by the problem of poor stability due to the rapid oxidation of Sn 2+ and Ge 2+ . Hence, replacing Pb 2+ with trivalent low-toxic metals to form an A 3 B 2 X 9 stoichiometry perovskite, particularly Cs 3 Bi 2 Br 9 and Cs 3 Sb 2 Br 9 , has been widely reported to produce good candidates for photocatalysis, including recent reports on photocatalytic C­(sp 3 )–H activation. − However, A 3 B 2 X 9 perovskites exhibit low structural dimensionality to maintain charge neutrality, leading to unfavorable properties such as a relatively wide band gap and large charge carrier effective mass, which restrict their effectiveness in photocatalysis …”

Efficient All‐Perovskite White Light‐Emitting Diodes Made of In Situ Grown Perovskite‐Mesoporous Silica Nanocomposites

“…We envisage that the passivation of surface defects achieved with in situ growth strategy can reduce the nonradiative recombination rate of carriers. [39] To further interrogate the interaction between CsPbBr 3 QDs and SBA-15, Fourier transforms infrared spectroscopy (FT-IR) measurements were performed (Figure 2d). A slight shift of the OH peak of the CsPbBr 3 /SBA-15 composites was recorded compared to the SBA-15 alone, indicating the formation of H-bonds between the dangling functional groups presented in the mesopores and the halide anions in the perovskite crystals.…”

Band Gap Tuning Through Cation and Halide Alloying in Mechanochemical Synthesized Cs3(Sb1-xBix)2Br9 and Cs3Sb2(I1-xBrx)9 Solid Solutions

“…39 Cs3Sb2Br9 and Cs3Sb2I9 revealed also to be suitable candidates for photocatalytic applications and in this respect have been, for example, applied in the photocatalytic carbon dioxide reduction, water splitting, and in aromatic C-H bond activation. [40][41][42][43][44] Some efforts has been also applied in the possible use of these defect-ordered perovskites in the manufacturing of solar cells. Cs3Sb2I9 has been preferentially used in for PV due to its suitable band gap around 2 eV, providing good stability but relatively low efficiencies around 2-3%.…”