A Review: TiO2 Based Photoelectrocatalytic Chemical Oxygen Demand Sensors and Their Usage in Industrial Applications

fostered a demand for novel technologies related to water treatment and purification. The oxygen demand of a given water matrix can provide useful information on the presence of organic compounds within a sample and can inform decisions on water use and treatment. Traditional oxygen demand measures are time consuming and require the use of harmful reagents. TiO₂-based photoelectrochemical oxygen demand (PeCOD) methods offer a faster, more efficient, and accurate alternative to traditional analysis processes. These methods use TiO₂-mediated photoelectrocatalysis (PEC) to oxidize organic contaminants. This paper reviews the recent synthesis methods of TiO₂ nanomaterials with respect to electrode preparation in COD sensors, fundamentals of TiO₂ photo/photo-electro-catalysis, TiO₂ based PeCOD sensors, and