Extensive research continues to optimize and widen the spectrum of potential applications of semiconductor photocatalysis. The applications are based on photooxidation, photoreduction, photosterilization and photoinduced superhydrophilicity phenomena or a combination thereof, and related with air and water treatment, active surfaces, green chemistry and energy conversion. The commercial potential of photocatalysis is extensive, including hygiene and sanitation; architecture and construction; automotive, food, chemical and textile industries; or environmental protection. All while working and harmony with our environment and produces zero waste and pollution discharge. It is THE future for a better and healthier planet.