Butea monosperma aided green synthesis of α-MoO3 nanoparticles: Biosensing and photocatalytic activity towards hazardous dyes and rangoli colorants

Abstract

Increasing environmental pollutants and the need for efficient photocatalytic and biosensing materials have led to the development of novel green synthesis methods. In this study, MoO₃ nanoparticles (NPs) were successfully synthesized by using green chemistry approach. In that respect, Butea monosperma leaf powder was used as a novel fuel. Structural parameters, optical properties, shape and morphology of MoO₃ NPs are examined using XRD, FTIR, UV–Vis spectrophotometer, Photoluminescence (PL), SEM - EDAX and TEM analysis. The use of MoO₃ NPs as a dusting agent in fingerprint applications results in improved fingerprint visibility, which is useful in forensic investigation. In this study, we modified the GCE electrode surface with MoO₃ NPs to develop a highly sensitive dopamine (DA) sensor. Electrochemical impedance spectroscopy (EIS), cyclic voltammetry (CV), and differential pulse voltammetry (DPV) were used to investigate the electrochemical behaviour and electrocatalytic property of the MoO₃ NPs. The synthesized NPs have excellent performance for detection of highly sensitive biologically active DA. The sensor exhibits a low detection limit of 0.45 μM. Additionally, it shows good stability, simplicity, and selectivity for the rapid detection of DA. MoO₃ NPs shows good photocatalytic activity under UV light for the degradation of important textile industries dye such as methylene blue (MB) and harmful rangoli colors which are available in local shops of Tumkur, Karnataka. The photocatalyst exhibits a remarkable 97 % degradation efficiency for MB dye. Coumarin studies ensure the effective generation of OH radicals on the surface of the photocatalyst, leading to the degradation of organic dyes. Additionally, the MoO₃ NPs reusability was examined, and even after four cycles, the level of photocatalytic activity did not drop much. Therefore, it is a potential photocatalyst for the processing of organic colours.