Photocatalytic dye degradation and hydrogen peroxide sensing by a novel copper-Schiff base complex prepared via mechanochemical method

Abstract

ABSTRACT Water pollution, primarily caused due to hazardous organic and inorganic substances, is a cause of concern for human health and development, for it manifests adverse repercussions across health, economic, and social dimensions. The footprints of its adverse effects are also left on aquatic/marine life forms. In the light of the negative impacts of such substances, the development of efficient remediation techniques becomes pertinent. In this article, we report a water-soluble glutamic acid Schiff base copper complex (Cu-GSb) that has been synthesised by taking recourse to a mechanochemical approach, relying upon solid-state reagent interactions in a benign environmental setting, eluding a rigorous refluxing condition and overuse of solvents. The experimental results revealed that the ligand coordinates to the metal centre in a bidentate fashion through the imine nitrogen and carboxylate oxygen, respectively, adopting a distorted square planar geometry. Further, the complex’s utility in mitigating chemical hazards has been demonstrated through the studies involving degradation of organic dyes like methylene blue and bromocresol green, and decomposition/sensing of H2O2. Notably, as a photocatalyst towards the degradation of above-mentioned dyes under visible light irradiation, our study showed the photocatalytic efficiency of Cu-GSb to be ~95% in 50–60 min. The rate of degradation reaction has been found to follow first-order kinetics with rate constant values of 6 × 10−2 and 5.66 × 10−2 min−1 for MB and BCG, respectively. Furthermore, the results of H2O2 sensing evaluation revealed that the complex is capable of potentially decomposing H2O2 in about 20–30 min. The compounds have been routinely characterised by UV–visible spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, and proton nuclear magnetic resonance (1H NMR).