In situ construction of an integrated SyA-Cu MOF/C,N-co doped CuO heterostructure for highly effective and rapid catalytic hydrogenation of 4-nitrophenol†

The separation of catalysts from water is crucial to industrial applications in water treatment and catalytic fields. To improve the practical application and recyclability, herein, we present an efficient integrated SyA-Cu/C,N-CuO heterostructure synthesized via a solvothermal route followed by low-temperature calcination, demonstrating rapid hydrogenation reduction of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP). By optimizing the content of SyA-Cu and C,N-co doped CuO, the SyA-Cu/C,N-CuO heterostructure with sharp tips exhibited outstanding advantages such as high activity, high selectivity, low-cost and simple synthesis and easy separation performance toward the catalytic reduction of 4-NP to 4-AP. And the optimal SyA-Cu/C,N-CuO heterostructure showed the conversion of 4-NP to 4-AP and yield which are both close to 100% within 4 min in the presence of low concentration of NaBH₄, and the reaction rate constant is as high as 0.978 min⁻¹. More importantly, it shows good reusability in six consecutive cycles. The outstanding catalytic performance can be attributed to three factors: (1) its unique morphology and C,N-co-dopants providing abundant active centers for 4-NP adsorption and subsequent hydrogenation, (2) the interfacial structure of spindle-like SyA-Cu MOFs with sharp tips promoting electron transport, and (3) enhanced substrate adsorption at the active sites.