Photocatalysis is a process that uses light to accelerate a chemical reaction, typically involving a catalyst. This catalyst, often made from materials like titanium dioxide, absorbs light energy and helps convert reactants into products more efficiently. Photocatalysis is commonly used in applications such as water purification and air cleaning, where it can break down pollutants. In this process, when light hits the catalyst, it generates reactive species that can interact with various substances. This makes photocatalysis a promising technology for environmental remediation and renewable energy, as it can help convert sunlight into usable energy or eliminate harmful contaminants from the environment.