Metal Halide Perovskite/Chalcohalide Heterojunctions for the Photoinduced Oxidative Coupling of p‑Substituted Thiophenols

TL;DR

Researchers developed a new semiconductor junction that efficiently catalyzes chemical reactions using visible light.

Contribution

A tunable perovskite/chalcohalide heterojunction was optimized for visible-light-driven oxidative coupling of thiophenols.

Findings

CsPbBr3/Pb4S3Br2 achieved 94% selectivity for disulfide formation from p-OCH3 thiophenol.

The system reached a turnover number of 14,300 under visible light without a sacrificial electron donor.

Type-II heterojunctions enhance charge separation and electron delocalization for efficient catalysis.

Abstract

The introduction
of a semiconductor–semiconductor
junction
is an effective strategy to enhance the photocatalytic performance
of perovskite nanocrystal-based systems. Herein, we optimized the
synthesis of CsPbX3/Pb4S3Y2 (X, Y = Cl, Br, I) perovskite/chalcohalide heterostructures, whose
band alignment can be tuned by the halide composition. As a proof-of-concept,
we evaluated the photooxidative coupling of p-substituted
thiophenols at room temperature, under visible light, in air, and
without a sacrificial electron donor. Notably, CsPbBr3/Pb4S3Br2 achieved up to 94% selectivity
toward disulfide (p-OCH3 thiophenol with
a turnover number of 14 300), highlighting the crucial role
of the type-II heterojunction in promoting charge separation and efficient
electron delocalization across the junction.

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