Visible-Light Hydrogenation of Aromatic Nitriles and Decarboxylation of Phenylacetic Acids Using a Ag–Ni@α/γ-Fe ₂ O ₃ Magnetic Nanocatalyst

We report a surfactant-free strategy for the synthesis of a phase-hybridized nanocatalyst composed of bimetallic Ag–Ni supported on dual-phase α/γ-Fe 2 O 3 via a simple two-step process. The mixed-phase iron oxide not only provides a robust support but also enhances light absorption and charge separation, while Ag–Ni bimetallic nanoparticles (NPs) offer active catalytic sites with synergistic electron transfer characteristics. The absence of harsh surfactants or capping agents makes the method sustainable and scalable. Comprehensive physicochemical characterizations confirm the formation of the Ag–Ni and mixed-phase Fe 2 O 3 interface. The catalytic performance was evaluated in the visible-light-driven hydrogenation of aromatic nitriles, demonstrating excellent conversion efficiency and selectivity. Additionally, we have tested the multifunctionality by investigating a thermally driven oxidative decarboxylation reaction, which has been shown to efficiently produce carbonyl analogs. Notably, this phase-hybridized composite nanocatalyst is excellently magnetically separable and exhibits outstanding recyclability over multiple cycles without any loss of activity or structural integrity, highlighting its potential for green and sustainable transformations under mild conditions.