Gd-doped bismuth ferrite nanocomposite: A promising candidate for piezocatalytic degradation of organic dyes and pathogenic E. coli

This work portrays a detailed depiction of degrading two separate carcinogenic organic dyes (Rhodamine B and Eriochrome black T) along with the ablation of pathogenic E. coli bacteria by employing a gadolinium-doped bismuth ferrite (GBF) piezo catalyst. The piezo catalyst has been prepared by a facile two-step solvothermal route and characterized for structural, morphological, elemental, and overall polarization properties. An irregular cubic structure is found (∼15-50 nm), confirming the nano-scale nature of the synthesized samples. Notably, the synthesized nano powder exhibits high remnant polarization (0.92 μC cm⁻²) which is further confirmed by the density functional theory (DFT). Such tremendously high polarizability has been further exploited to eradicate both dyes. Under the soft ultrasound stimulation (15 kHz), the piezo catalyst (GBF1) shows an extraordinary degradation efficiency (97.6% for RhB and 91.3% for EBT). The reusability of the piezo catalyst has been checked for several cycles, and after the cyclic test, post-analysis of the sample has also been done which indicates the stability of the catalyst very well. Moreover, a remarkable antibacterial activity has been found for the GBF1 sample having a mortality of almost ∼ 99.33% in 30 mins. Additionally, the strong remanent magnetization of the catalyst (10.564×10⁻⁴ emu/g) makes the extraction of the catalyst possible by using a simple magnetic field. This extraction method has significant potential for rapidly cleaning waterbodies to prevent secondary pollution. Henceforth, the as-synthesized piezo catalyst (GBF1) could aid in future water treatment projects and can be translated from the bench to the bedside, if properly improvised.