Highly efficient and recoverable Ag-Cu bimetallic catalyst supported on taro-rhizome powder applied for nitroarenes and dyes reduction

Abstract

Every day, the risk of water pollution grows. According to the World Health Organization (WHO), approximately half of the population of poor countries suffers from health problems linked to chemically or microbially contaminating drinkable water. Here in the present study, powder of taro-rhizome was used for preparation of supported bimetallic catalyst (Ag-Cu/TP). Characterization techniques used for analysis were XRD, TEM, SEM, FTIR and EDS. The prepared catalyst was then used in the catalytic reduction of chemical pollutants, including 4-nitrophenol (4-NP), 2,4,6-trinitrophenol (TNP), 2-nitrophenol (2-NP), methyl orange (MO), Acid Red 27 or amaranth (AM), Congo red (CR), Rhodamine B (RhB) and methyl red (MR). Turnover frequency was calculated for nitrophenol reductions, which were 0.98 min−1 for 2-NP and 3.45 min−1 for 4-NP. The Ag-Cu/TP catalyst shows outstanding performance and 99.4% of 4-NP was reduced just in 5 min with pseudo-first order constant of 5.24 × 10−3s−1, while 97% reduction of 2-NP took 17 min with the pseudo-first order constant of 1.01 × 10−3s−1. The prepared Ag-Cu/TP catalyst was packed into a glass column and organic dyes containing water were filtered through it to test the cleaning effectiveness of water from dyes. Excellent dye reduction was achieved. The prepared column reactor works excellent in the remediation of dyes and reduces about 68.7% CR. In addition, stability and reusability study showed exceptional reusability up to 5 times with very small loss of activity and was stable for up to 10 days.

Keywords

• Bimetallic supported catalyst
• Pseudo first-order kinetic
• Dyes reduction
• Reusability
• Stability of catalyst