Surfactant-tuned vanadium pentoxide for enhanced photocatalytic degradation of organic dyes: nanosheet <i>vs.</i> microflower morphologies

This study explores the impact of surfactants on the morphology and photocatalytic performance of V₂O₅ materials synthesized <i>via</i> a hydrothermal method, followed by calcination. Two surfactants, Pluronic P123 and cetrimonium bromide (CTAB), were used, leading to the formation of V₂O₅ nanosheets (V₂O₅-P123) and V₂O₅ microflowers (V₂O₅-CTAB), each exhibiting distinct structural characteristics and photocatalytic efficiencies. The prepared nanosheets are of sizes ranging from a few micrometers and thickness of approximately 50-60, and the flower-like structures have an average diameter of approximately 5 micrometers. The photocatalytic degradation of Methylene Blue (MB) and Rhodamine B (RhB) dyes were evaluated under simulated sunlight. The V₂O₅-P123 nanosheets showed superior performance, achieving 96.72% MB degradation in 150 minutes, with a degradation rate constant of 0.92 min^-1, compared to 90.02% for V₂O₅-CTAB microflowers (0.51 min^-1). This enhanced performance was attributed to the larger surface area, higher porosity, and optimized structure of the nanosheets, which promoted better dye adsorption and interaction with reactants. In contrast, the degradation of RhB was lower for both structures, with the V₂O₅-P123 nanosheets achieving only 18% degradation (rate constant: 0.0014 min^-1) and the V₂O₅-CTAB microflowers 46% (rate constant: 0.0071 min^-1). This highlights the challenge of degrading RhB due to its complex molecular structure and higher chemical stability, limiting effective interaction with the catalyst surface. The study emphasizes the significant influence of surfactants on the morphology and photocatalytic performance of V₂O₅ materials, with V₂O₅ nanosheets showing promising potential for environmental remediation, particularly in the degradation of organic pollutants like MB. The findings also suggest that optimizing the photocatalyst design could enhance the degradation of more chemically stable pollutants, thereby expanding the scope of applications for clean energy production and environmental protection.