FUNDAMENTALS AND PRINCIPLES OF PHOTOCATALYSIS

Photocatalysis provides a renewable platform to address both environmental and energy problems by converging air cleaning or less harmful products. This chapter overviews the principles of gas-phase photocatalysis, highlighting mechanistic similarities and differences between oxidative pollutant degradation and reductive pollutant conversion. Photocatalytic oxidation of major pollutants including volatile organic compounds (VOCs), nitrogen oxides (NOX), and sulfur oxides (SOX). The reductive reactions provide transferable insights for carbon dioxide (CO2) reductions. CO2 photoreduction is highlighted, with discussion devoted to mechanistic insight, material design pathways including defect engineering, doping, heterojunction engineering, cocatalyst loading and organic interlayers, and control of selectivity and product proof standards. Case studies are included to show recent progress in increasing efficiency and stability. This chapter concludes by providing a critical account of current limitations and suggesting potential futures for developing scalable photocatalytic systems capable of sustaining simultaneously both clean technologies for air and sustainable CO2 utilization.