Exploring nanoparticle contributions to enhanced photocatalytic activity of PEO coatings on titanium: A review of the recent advancements

In the current era of industrial advancement, pollution resulting from industrial activities has escalated into a critical issue that demands resolution. Within this spectrum of pollutants, the issue of dye contamination stands out as particularly pressing and in need of immediate attention. Within the field of surface engineering, incorporating nanoparticles into plasma electrolytic oxidation (PEO) solutions is gaining recognition as an effective method to boost the photocatalytic characteristics of the coatings applied to titanium bases. The composition of the PEO electrolyte plays a crucial role in determining the composition, microstructure, and morphology of PEO coatings. Consequently, the addition of particles to the electrolyte leads to modifications in the coatings, affecting factors such as phase composition, pore characteristics, layer thickness, and compactness. A novel strategy involves introducing particles into the electrolyte, aiming for their in-situ integration into PEO coatings during growth. Researchers have successfully produced multifunctional coatings with diverse properties by leveraging particle addition. The properties of the particles themselves, along with the electrical and electrolyte parameters during the PEO process, influence how efficiently the particles are taken up and incorporated into the coatings. This review paper explores the complex interactions between particulate additives in PEO mixtures and their subsequent effects on the photocatalytic efficacy of titanium-based coatings. This thorough investigation acts as an all-encompassing guide to demystifying the intricate association between nanoparticle integration and the photocatalytic effectiveness of titanium coatings, setting the stage for groundbreaking progress in functional surface engineering methods.