The synergistic effects of the B heteroatomic energy levels, abundant oxygen vacancies, and acid sites, combined with the strong localized surface plasmon resonance effect of the B-doped defect-rich Fe₃O₄@B-CeO₂/Au photocatalyst, enhance its utilization of visible light, improve the adsorption and activation of O₂ and BA, and accelerate the transfer of interfacial charges, thereby significantly enhancing its photocatalytic performance.

Selective oxidation of aromatic alcohols to their corresponding carbonyl compounds under mild conditions holds significant promise for industrial applications. However, the performance of photocatalysts is notably hindered by limited visible-light absorption, low charge separation and transfer efficiency, as well as weak adsorption and activation of aromatic alcohols and O₂. Herein, a boron-doped (B-doped) defect-rich Fe₃O₄@B-CeO₂/Au photocatalyst is successfully synthesized for the selective oxidation of benzyl alcohol (BA) to benzaldehyde (BAD) under visible light. Experimental results and density functional theory calculations demonstrate that boron doping not only introduces a heteroatomic energy level that acts as “intermediate springboards,” significantly broadening the absorption range of visible light, but also creates abundant oxygen vacancies and acidic sites, benefiting the adsorption and activation of O₂ and BA. Furthermore, the localized surface plasmon resonance effect of Au further improves the transport of interfacial photogenerated electrons. Due to these combined advantages, the selectivity of the Fe₃O₄@B-CeO₂/Au photocatalyst for BAD reaches 100%, and the conversion rate of BA is as high as 98.96% after 8 h of reaction under visible light. Moreover, owing to the magnetic properties of the Fe₃O₄ core, the photocatalyst exhibits excellent operational and cyclic stability.