Modulating nanoceria bandgap via CoO/Pd heterostructure hybrids for efficient light-driven Suzuki–Miyaura coupling reaction

Abstract

The addition of metal oxides as impurities to generate an intermediary energy band near the conduction or valence band to reduce the bandgap is the most distinctive approach to improve the photo-absorption characteristics of the material. Herein, we have reported the synthesis of nanohybrid bimetallic heterostructures by linking the interface of CeO₂ and CoO, which narrows the electronic band structure of CeO₂ from 2.85 eV to 1.5 eV and modulates the distribution of charges at the active sites. The resulting CeO₂/CoO hybrid support enhances the dispersion and stability of Pd NPs, resulting in lowering the activation energy (E_a) barrier of the coupling reaction, thereby significantly enhancing its catalytic efficacy. The E_a value of CeO₂/CoO/Pd (53.7 kJ mol⁻¹) is much lower compared to that of CeO₂/Pd (68.6 kJ mol⁻¹), with excellent catalytic activities (yield: 98%) and exhibiting long-term stability for 5 continuous cycles without any significant loss in activity. Overall, the CeO₂/CoO/Pd hybrid system effectively utilized the photothermal effect to facilitate an effective electron transfer, thereby enhancing the rate of the Suzuki–Miyaura coupling reaction. This study offers a feasible and encouraging prospect to use the heterostructured metal oxide-based catalytic system for efficient Suzuki–Miyaura cross-coupling reaction.