Preparation of Carbon-Based Photo-catalyst for Degradation of Phenols

Semiconductor photo-catalyst is one of the most efficient initiatives that can be used for photo-catalytic degradation of organic pollutants in wastewater. However, the recombination of photo-generated electrons and hole pairs can reduce the capability of semiconductor photo-catalysts in the degradation activity. Therefore, carbon quantum dots (CQDs) can be suggested to be one of the carbon-based photo-catalysts that can minimize the recombination of photo-generated electrons and hole pairs due to their nanosizes, high fluorescent intensity, large surface area, strong photo-luminescent, and chemical inertness. Besides, CQDs can be considered as an efficient photo-catalyst in the photo-catalytic degradation of organic pollutants because they possess large band gaps, strong tunable photo-luminescent, and electron reservoir properties. Sustainable raw materials can be used for the fabrication of CQDs because they are cost-effective, eco-friendly, and effective in minimizing waste production. CQDs can be fabricated using laser ablation, microwave irradiation, hydrothermal reaction, electrochemical oxidation, and reflux method. These methods undergo several chemical reactions such as oxidation, carbonization, pyrolysis, and polymerization processes to produce CQDs. Therefore, CQDs-based photo-catalysts are promising nanomaterials that can be used for the photo-catalytic degradation of phenol molecules. This chapter will introduce the properties of CQDs as carbon-based photo-catalysts, the raw materials, and methods used in the fabrication of CQDs as well as their functions and applications in the degradation of phenols. The mechanism of phenol degradation will also be described in this chapter.