Iterative laser-induced dual-component covalent patterning of graphene

Achieving spatial control over the chemical identity and density of covalent addends on graphene remains a key challenge in two-dimensional materials chemistry. Herein, we present an advanced iterative laser-based strategy for the covalent functionalization of graphene, enabling high-precision control over the chemical identity, spatial positioning, and functionalization density within the patterned graphene domains. Applying dibenzoyl peroxide (DBPO) as a model precursor reagent, we demonstrate that sequential laser-triggered functional group grafting allows for a controlled, multi-level modification of monolayer graphene. The Raman spectroscopic analysis confirms that the achieved degree of functionalization is primarily governed by the cumulative laser parameters rather than by the sequence of individual ‘writing’ steps. Building on this concept, bis -(4-chlorodibenzoyl) peroxide (Cl-DBPO) was introduced as a second reagent, allowing for a spatially resolved incorporation of chemically distinct moieties on a single graphene sheet. Kelvin probe force microscopy allowed us to verify the chemical differentiation of these patterned domains based on local surface potential variations. This combined approach enabled the first laser-triggered covalent patterning of multiple functional entities in adjacent and intersecting geometries. Overall, the presented laser-induced functionalization strategy provides a flexible platform for programmable chemical structuring of graphene and may contribute to the development of multifunctional graphene-based materials with spatially defined properties.