Efficient encapsulation of CsPbBr3 and Au nanocrystals in mesoporous metal-organic frameworks towards synergetic photocatalytic CO2 reduction

The severe photogenerated charge carrier recombination and the poor CO2 adsorption capacity are regarded as the two main factors impeding the photocatalytic CO2 reduction performances of metal halide perovskite (PVK) nanomaterials. Herein, a ternary CsPbBr3/Au/PCN-333(Al) hybrid featuring high CsPbBr3 nanocrystal loading, fast charge separation, and good CO2 uptake is designed and fabricated by using Al-based mesoporous metal-organic framework (MOF) particles to encapsulate CsPbBr3 and Au nanocrystals, for synergetic photocatalytic CO2 reduction. A vacuum-assisted pore-filling method is developed to facilitate the permeation of CsPbBr3 precursor solution into PCN-333(Al), which results in a high CsPbBr3 loading of >40 wt%. Detailed heterostructure and photoelectric property analysis reveal that well-dispersed CsPbBr3 and Au nanocrystals inside the MOF matrix can form close contact with each other, which can extract the photogenerated electrons of CsPbBr3 to Au, so as to effectively inhibit the charge recombination and accelerate the CO generation. As a result, the CsPbBr3/Au/PCN-333(Al) hybrid exhibits a significantly improved CO2 reduction performance with the photoelectron consumption yield (R-electron) being 11.5-fold higher than that of single CsPbBr3 nanocrystals and a 100% selectivity for CO. This study demonstrates a new way to design a high-quality PVK/MOF heterostructure catalyst, which may also find application in other photocatalytic reactions.

Automated summary

A ternary hybrid material featuring high CsPbBr3 nanocrystal loading, fast charge separation, and good CO2 uptake is designed and fabricated. By extracting photogenerated electrons to gold nanoparticles, charge recombination is effectively inhibited and CO2 reduction is accelerated.