Graphite Coupled with TiO2 Paste Photoelectrodes Well Oriented over COD Photoelectrocatalysis for Rapid Detection of Methylene Blue Organic Dye

Abstract

As an effort to observe the impact of pollution on the aquatic environment, water quality monitoring calls for the development of early detection technologies that are fast, efficient, and inexpensive. Currently, electrochemical sensors are an alternative technology to sensitively analyze pollutants in the aquatic environment. Engineering working electrodes to sense polluting compounds is the target of technology development. This work studies material compositions consisting of graphite carbon with TiO2 nanoparticles as a photoelectrode to analyze chemical oxygen demand (COD) in methylene blue (MB) organic dye wastewater. The materials were prepared by physically mixing the two components and one-pot chemical synthesis, characterizing their microstructure and crystallinity. Then, their analytical performance was assessed by measuring MB dye as a sample against the mass variation of 1:1 (w/w) and 1:2 (w/w) photoelectrodes. The results showed similar 1:1 (w/w) performance with the relevant and theoretical COD. The straightforward synthesis and eco-friendly materials are key factors in the fabrication of COD sensor. This study proposes a technical process for the fabrication and application of photoelectrodes in detecting the chemical oxygen demand (COD) of methylene blue dye. It solves the problems of COD detection in identifying water quality in wastewater, and the problems of long and the problems of dangerous materials used against COD determination. It provides a new understanding of rapid COD detection to measure water quality in wastewater. In practical applications, the fabricated photoelectrode was placed into dye solution and connected to a potentiostat instrument, which was irradiated by ultraviolet (UV) light to initiate the photoelectrocatalytic reaction. The accumulation of organic dye in water will generate the electrical properties (photocurrent) of the photoelectrode, which can the be measured by a multipulse amperometry system. It performs two performance functions at once, namely photoelectrodegradation and COD sensing. In COD sensor performance, the photocurrent response is plotted against the time duration where the photocurrent generated is proportional to the oxidation performance against the organic dye concentration and calculated by the Faraday equation. This research offers several advantages, such as fast response time and real-time detection for COD determination. It also provides more sensitive and accurate measurement of organic pollutants in water. The COD photoelectrocatalysis method can be a practical application for rapid detection of methylene blue organic dye.