# Development of hybrid nanoparticles based on Zr(iv) and perylene-3,4,9,10-tetracarboxylic acid with visible-light photoredox activity

## TL;DR

This paper describes a new hybrid nanoparticle that can perform visible-light-driven redox reactions, useful for dehalogenation and hydrogen peroxide production.

## Contribution

A novel Zr–perylene hybrid nanoparticle with visible-light photoredox activity is developed and characterized.

## Key findings

- The ZIPER material shows strong visible light absorption and intense photoluminescence.
- ZIPER enables visible-light photoredox catalysis for reductive dehalogenation and H2O2 production.
- Photoexcitation leads to electron transfer from organic linkers to Zr clusters.

## Abstract

Herein, we investigate perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) as a linker in Zr-clusters. The photostable, 3D metal–organic nanomaterial obtained by a solvothermal synthesis procedure in the presence of formic acid as modulator, named ZIPER, shows strong absorption in the visible (400–560 nm) and an intense photoluminescence (PL) in the 600–700 nm range. PL quenching experiments strongly indicate that the ZIPER excited state (ZIPER*) behaves primarily as a strong oxidant and a mild reductant with redox couples E(ZIPER*/ZIPER˙−) = 1.8–1.2 V and E(ZIPER˙+/ZIPER*) = −0.44–−0.48 V (vs. NHE). Amine quenching of ZIPER* PL led to a strong reductant (ZIPER˙−) with E(ZIPER/ZIPER˙−) <−0.6 V vs. NHE. This reactivity was exploited to drive the reductive dehalogenation of model polychlorinated compounds, such as carbon tetrachloride and trichloroacetic acid, through visible-light photoredox catalysis in aqueous suspension. In contrast, under air-saturated conditions, the system predominantly produces substantial amounts of H2O2. A detailed analysis of the results suggests that photoexcitation of the organic linkers is followed by electron transfer to the Zr cluster. Charge-separated states are mainly stabilized in the presence of suitable electron donors or acceptors; otherwise, the system relaxes radiatively, emitting strong orange fluorescence.

Zr–perylene hybrid suspensions enable solar-driven photocatalytic redox reactions.