To keep pace with the rapid evolution of nowadays technology-driven world, an efficient method for solar light harvesting has been proven to be absolutely necessary for providing sustainable solutions in research and industry. The current simultaneous growth of industry and technology for a better tomorrow is associated with the inevitable side effects such as increasing production of chemical pollutants. This poses an immediate threat to civilization by polluting natural resources like air and potable water. In this context, elaborate research, aiming at the removal of such pollutants in an efficient manner, should be among the prime goals of the scientific community. The use of photocatalysis has already proved to be one potent technique for this purpose. Over the years, the harvesting of solar light for environmental restoration has gathered a lot of interest, and several promising photocatalysts have been discovered over the last decade. In this chapter, an outline has been provided on how to efficiently harness the complete range of solar wavelengths to eliminate contaminants. In order to accomplish this objective, various instances involving both practical experiments and fundamental principles have been employed to establish and forecast material compositions with the capability to eliminate pollutants by utilizing distinct segments of the solar spectrum. To achieve this goal, a combination of experimental approach and first-principles tools has been used to identify and predict material compositions that can remove pollutants by utilizing different parts of the solar spectrum. Those engineered photocatalysts were designed in accordance with their efficacy under diverse light irradiations from UV-Vis to near-infrared (NIR). With a brief discussion of the photocatalysis process and mechanism for the developed novel materials, their charge transfer processes and band structure modulations have been elaborated in this chapter.