# Spatial and temporal control over photoresponsive nanoclusters

## TL;DR

Researchers developed a method to control the structure and size of nanoclusters in solid materials using light, enabling precise spatial and temporal transformations.

## Contribution

A novel Cu-based nanocluster pair with comparable photoinduced conversion efficiencies was introduced for spatial control in solid-state transformations.

## Key findings

- Cu18 and Ag1Cu17 nanoclusters undergo efficient photoinduced transformations in both solution and solid states.
- Photoconversion efficiency is comparable between Cu18 and Ag1Cu17, monitored through time-dependent characterizations.
- Femtosecond cold laser and UV irradiation enable micrometer-scale spatial and temporal control of cluster transformations.

## Abstract

Although cluster species undergo efficient photoresponsive transformations in dilute solutions, their solid-state materials suffer from severely impeded responsiveness due to insufficient motional freedom. Here, we present a photochemical approach that enables spatial and temporal control over nanocluster structure/size conversions in the crystalline state. The Cu18 nanocluster, whether in solution or in solid form, undergoes a photoinduced transformation when exposed to 365-nm light, resulting in a size-reduced Cu14 nanocluster. The single-atom alloy counterpart, Ag1Cu17, possesses a remarkably enhanced efficiency towards the photoinduced conversion to form the same cluster product. The comparable photoinduced conversion efficiencies between Cu18 and Ag1Cu17 are monitored by using time-dependent characterizations and further rationalized by using theoretical calculations. The high photoconversion efficiency of crystalline nanocluster materials allows the precise spatial and temporal control of solid-state transformations at the micrometer scale by using femtosecond cold laser technology or by controlling the irradiation time of ultraviolet light. This study introduces a novel pair of clusters with comparable photoinduced conversion characteristics, allowing atomic-level characterizations and an in-depth understanding of the photochemical behavior of metal nanoclusters. Furthermore, the findings in this work are expected to facilitate the design of cluster-based solid-state nanomaterials for downstream photoresponsive applications.

A novel structure-correlated Cu-based nanocluster pair with comparable photoinduced conversion efficiencies was presented, allowing for spatial control over solid-state transformations.