Appropriate purification of the polluted water is a sustainable and significant work. The hydrogenation of 4‐nitrophenol (4‐NP) is an invaluable process by transforming toxic nitrophenol to serviceable industrial raw material 4‐aminophenol (4‐AP). Suffering the limit of high‐cost precious metal as catalyst, the design and exploring cheap and efficient catalyst is urgently needed, to promote this informative process. Here, we propose a simple and economical synthesis route to synthesize spindle‐shaped CuO nanoparticles (S‐CuO NPs). XRD, SEM, HRTEM and ultraviolet‐visible spectroscopy were used to characterize the structure, morphology and catalytic performance of the prepared nanoparticles. In the presence of NaBH4 as a reducing agent, the reduction can be completed in only 90 seconds by using S‐CuO NPs as catalyst, with a good rate constant (k) of 3.774×10−2 s−1. In view of the fact positive surface charge of S‐CuO NPs promotes the occurrence of hydride transfer phenomenon, this mechanism is discussed. The conclusion shows that the prepared S‐CuO NPs have good catalytic activity, can be used as a mild and effective catalyst for the reduction of 4‐NP with good reusability, and have potential applications in catalytic applications.

The catalytic hydrogenation of 4-Nitrophenol (4-NP) can transfer serious toxic 4-NP to invaluable industrial raw materials 4aminophenol (4-AP) in the presence of NaBH 4 , which prevents industrial and agricultural wastewater affecting the health of living beings. It is crucial and meaningful to design costeffective catalysts as alternate to cut down the dependence on precious metals catalysts in the reduction of 4-NP. Metal/ semiconductor composites can be endowed promising costeffective substitution to catalyticly reduce 4-NP. Herein, CuO/ Cu 2 OÀ Ag composite nanoparticles (CNPs) were prepared based on the CuO/Cu 2 O nanocubes by a step method. The morphology and components of the CuO/Cu 2 OÀ Ag CNPs were charac-terized by X-ray diffraction (XRD), scanning electronic microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive X-ray spectroscopy (EDX) respectively. CuO/ Cu 2 OÀ Ag CNPs displayed high catalytic activity in the hydrogenation of 4-NP with pseudo-first-order rate constant of 1.5 × 10 À 2 s À 1 . Notably, a high turnover frequency of 6.44 × 10 À 2 s À 1 was obtained, which expressed much higher than some noblemetal catalysts. Also, CuO/Cu 2 OÀ Ag CNPs exhibited outstanding sustainable catalytic performance, as no distinct activity slump was perceived in continuous 10 cycles with conversion rate exceed 95 %, endowed it potential utility in industrialization.

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4‐Nitrophenol (4‐NP) is one of the most common organic pollutants in industrial waste waters due to its solubility and toxicity. The catalytic degradation of 4‐NP to 4‐aminophenol (4‐AP) is an economical and sustainable process, which transfers waste and toxicity to profitable materials. Fabricating metal nanoparticle based efficient heterogeneous catalysts is crucial to treating these kinds of pollutants. Here in, Cu−W nanoflakes (Cu−W NFs) with thin sheet like structure were prepared by a simple one‐pot method by using polyoxometalate as precursor. The Cu−W NFs served in hydrogenation of 4‐NP reaction as catalyst, achieved high conversion with rate constant (k) of 2.584×10−2 s−1. Notably, the sustainable catalyst Cu−W NFs exhibit no significant degradation of catalytic activity over 16 cycles, manifested good durability and high conversion (>91 %). Also, the reduction of potassium ferricyanide can also be catalyzed by Cu−W NFs with high efficiency. This work provided a concise approach for fabricating highly effective catalyst and was expected to be a potential universal method to obtain sustainable competitive catalyst for utility in treating pollution.

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