PART I: VISIBLE LIGHT ACTIVE PHOTOCATALYSIS - RESEARCH AND TECHNOLOGICAL ADVANCEMENTS Research frontiers in solar light harvesting Recent advances on photocatalysis for water detoxification and CO2 reduction Fundamentals of photocatalytic water splitting (Hydrogen and oxygen evolution) Photoredox catalytic activation of carbon-halogen bonds PART II: DESIGN AND DEVELOPMENTS OF VISIBLE LIGHT ACTIVE PHOTOCATALYSTS Black TiO2: The New Generation Photocatalyst Effect of Modification of TiO2 with Metal Nanoparticles on its Photocatalytic Properties Studied by Time Resolved Microwave Conductivity Glassy photocatalysts: New trend in solar photocatalysis Visible-Light-Active Photocatalysis: Nanostructured Catalyst Design, Mechanisms, and Application Conducting Polymers Nanostructures as Novel Materials for Efficient Solar Light Harvesting PART III: VISIBLE LIGHT ACTIVE PHOTOCATALYSIS FOR SOLAR ENERGY CONVERSION AND ENVIRONMENTAL PROTECTION Sensitization of TiO2 by dyes: a way to extend the range of photocatalytic activity of TiO2 to the visible region Recent progress in novel photocatalysts for detoxification Metal-free Organic Semiconductors for Visible Light Photocatalytic Water Splitting Solar Photochemical Splitting of Water Visible Light Photoredox Catalysis by Organic Dyes for Organic Synthesis Visible Light Heterogeneous Catalysts for Photocatalytic CO2 Reduction PART IV: MECHANISTIC STUDIES OF VISIBLE LIGHT ACTIVE PHOTOCATALYSIS Band-gap engineering of photocatalysts: Optical, electronic, and catalytic Modifications Roles of the active species generated during photocatalysis Visible-Light-Active Photocatalysis: Nanostructured Catalyst Design, Mechanisms, and Applications PART V: CHALLENGES AND PERSPECTIVES OF VISIBLE LIGHT ACTIVE PHOTOCATALYSIS FOR LARGE SCALE APPLICATIONS Quantum Effects in Modeling Photocatalytic Processes An overview of solar photocatalytic reactor designs and their broader impact on the environment Conclusions and Future work sakriti opis