Preparation of floating PDMS sponge catalysts embedded with copper oxide(s): A prelude to the study of its application toward the effective rhodamine B degradation by sonochemical method

Abstract

In this study, copper oxide (s) embedded polydimethylsiloxane (PDMS) sponge catalysts have been prepared and demonstrated as an efficient heterogeneous catalyst for the Fenton-type degradation of rhodamine B (RB) in an aqueous solution, in which RB was selected as a representative pollutant. Each Cu2O, CuO, and a mixture of Cu2O and CuO embedded with the PDMS sponge were synthesized by respective copper oxides onto a sugar template, followed by the addition of PDMS with an elastomer, degassing, curing, removing sugar templates, and drying in a hot air oven. The resulting catalysts were characterized using FTIR, SEM-EDS, and ICP-OES methods. The as-synthesized catalysts were used to degrade RB utilizing normal stirring and sonochemical methods under a diverse range of reaction conditions. The sonochemical method effectively removed RB (> 98% of 125 mg L–1) from the aqueous solution. Moreover, RB degradation follows relatively faster kinetics (3–9 h) with 750 µL volume of H2O2, and degradation remains consistent with different optimized pH conditions (4–7). This degradation process followed a first order kinetic model with higher r2 values. Experimental results suggest that RB degradation is linked to the interplay among all reagents and coincides with previously reported degradation mechanisms. This sonochemical degradation process followed a first-order kinetic model and the materials were reusable for more than 10 cycles. The facile synthesis, high catalytic performance, reusability, durability, and easy recoverability of the as-prepared catalyst are promising for environmental catalytic pollutant degradation applications in the treatment of organic pollutants at diverse operating conditions.