Photocatalytic environmental remediation supplies the most environmentally-friendly and lowest energy-cost approach to eliminate contaminants and thus has attracted extensive attention.^1,2  Although this topic involves various environmental applications, such as degradation of organic contaminant, antibacterial, removal of toxic ions and heavy metal ions, and so on, most of the reported studies are directly relevant to organic-pollutant degradation based on semiconductor induced photocatalysis. As presented in Figure 11.1, a semiconductor-based photocatalytic degradation for organic contaminants (O.C.) includes (a) light absorption to generate electrons and holes, (b) carrier separation and migration to surface, (c) surface redox reactions, and an accompanying but disadvantageous process (s) carrier recombination.^1,3  To overcome the thermodynamic and kinetic limitations related to the above-mentioned processes to enhance the photodegradation efficiency, many efforts have been made to design and synthesize new materials, which will be introduced in this chapter in depth.