Rapid Catalytic Reduction of 4-Nitrophenol and Clock Reaction of Methylene Blue using Copper Nanowires

• Main Authors: Aina Shasha Hashimi, Muhammad Amirul Nazhif Mohd Nohan, Siew Xian Chin, Sarani Zakaria, Chin Hua Chia
• Format: Article
• Language: English
• Published: MDPI AG 2019-06-01
• Series: Nanomaterials
• Subjects: catalytic activity; clock cycle; acetic acid treatment; metal nanowires; <i>p</i>-nitrophenol; reduction of nitro compounds
• Online Access: https://www.mdpi.com/2079-4991/9/7/936

Copper nanowires (CuNWs) with a high aspect ratio of ~2600 have been successfully synthesized by using a facile hydrothermal method. The reductions of 4-nitrophenol (4-NP) to 4-aminophenol (4-AP) and methylene blue (MB) to leucomethylene blue (LMB) by using sodium borohydride (NaBH₄) were used as models to test the catalytic activity of CuNWs. We showed that by increasing the CuNWs content, the rate of reduction increased as well. The CuNWs showed an excellent catalytic performance where 99% reduction of 4-NP to 4-AP occurred in just 60 s by using only 0.1 pg of CuNWs after treatment with glacial acetic acid (GAA). The rate constant (k_app) and activity factor (K) of this study is 18 and ~10¹⁰ fold in comparison to previous study done with no GAA treatment applied, respectively. The CuNWs showed an outstanding catalytic activity for at least ten consecutive reusability tests with a consistent result in 4-NP reduction. In clock reaction of MB, approximately 99% of reduction of MB into LMB was achieved in ~5 s by using 2 &#956;g CuNWs. Moreover, the addition of NaOH can improve the rate and degree of recolorization of LMB to MB.