Green preparation of silver nanocluster composite AgNCs@CF--PAA and its application: 4-NP catalytic reduction and hydrogen production.

4-Nitrophenol (4-NP) is a serious organic environmental pollutant. Conversion of 4-nitrophenol to 4-aminophenol (4-AP) by catalytic hydrogenation is an effective solution. In this work, a catalyst (AgNCs@CF--PAA) loaded with silver nanoclusters (AgNCs) was prepared by radiation technique. Firstly, the template polyacrylic acid (PAA) was grafted onto the cotton fiber (CF) by radiation grafting technique to obtain a solid template (CF--PAA). After that, AgNCs were synthesized on CF--PAA by radiation reduction, and the composite material AgNCs@CF--PAA was obtained directly. AgNCs@CF--PAA has an obvious photoluminescence phenomenon, which is attributed to the stable AgNCs binding to the carboxyl on the PAA molecular chain. Due to the extremely small size of AgNCs, AgNCs@CF--PAA has good catalytic characteristics. The prepared AgNCs@CF--PAA catalyst has a very high catalytic rate for the hydrogenation of 4-NP. Even at high concentrations of 4-NP, AgNCs@CF--PAA can still maintain a high catalytic rate. At the same time, the AgNCs@CF--PAA catalyst can also be used to catalyze the rapid hydrolysis of sodium borohydride, which is conducive to hydrogen production. In summary, we have prepared a practical catalyst AgNCs@CF--PAA with high catalytic performance based on cheap raw materials and a simple synthesis route, which provides a catalyst candidate for the treatment of water contaminant 4-NP and the production of hydrogen from sodium borohydride.