Nanostructured DyFeO3 photocatalyst: an authentic and effective approach for remediation of industrial and pharmaceutical wastewater

Abstract

The persistent issue of water contamination by industrial dyes and pharmaceutical residues has created an urgent need for advanced photocatalytic materials to effectively address environmental remediation. Despite ongoing research, developing novel photocatalysts with ideal band structures, high quantum yields, and strong stability remains a considerable challenge. In this study, we report the synthesis and detailed characterization of nanostructured dysprosium orthoferrite (DyFeO₃) nanoparticles, designed with a porous architecture featuring an average pore size of 3.41 nm and a surface area of 23.25 m² g⁻¹ to enhance photocatalytic efficiency under solar irradiation. Using Inverse Fast Fourier Transform (FFT) analysis on selected areas of TEM images, we gained deeper insights into the formation and internal structure of these nanoparticles. DyFeO₃ nanoparticles exhibit a direct band gap of 2.1 eV, making them particularly effective for solar light absorption. Comprehensive spectroscopic analyses, including Mott–Schottky measurements and valence band XPS, confirmed their n-type semiconducting nature and revealed an electronic band structure that supports efficient oxygen reduction and oxidation reactions. Additionally, time-resolved photoluminescence spectroscopy demonstrated a charge carrier lifetime of 2.43 ns, indicating efficient separation and transport of photogenerated charge carriers. The photocatalytic performance of DyFeO₃ was evaluated through degradation experiments using two model pollutants: Rhodamine B (RhB) and Levofloxacin (LFX). The nanoparticles successfully degraded both the colored RhB and the colorless LFX, eliminating concerns of dye sensitization. Furthermore, the presence of DyFeO₃ significantly reduced the activation energy for RhB degradation from 55.87 kJ mol⁻¹ K⁻¹ to 34.58 kJ mol⁻¹ K⁻¹ and for LFX from 38.4 kJ mol⁻¹ K⁻¹ to 34.1 kJ mol⁻¹ K⁻¹, demonstrating its catalytic efficiency. With apparent quantum yield values of 28.94% for RhB and 32.83% for LFX, these nanoparticles demonstrate exceptional solar energy harvesting capabilities. The high degradation efficiency, quantum yield, and stability of the single-structured DyFeO₃ nanoparticles highlight their potential for large-scale applications in photocatalytic and environmental remediation technologies.