Graphitic Carbon Nitrides: Modifications and Applications in Environmental Purification

Semiconductor photocatalytic technology can be used for decomposition, conservation and mineralization of environmental pollutants, so it is a long-term effective approach to purify environmental pollution. Polymer semiconductor graphitic carbon nitride (g-C3N4), a new-type metal-free functional material, possesses distinct electronic structure and chemical property, and has attracted a wide spread attention in clean energy conversation and chemical synthesis using solar power. In recent years, the development of g-C3N4 makes further progress of environmental purification research using semiconductor photocatalytic technology. In this review, some important advances using g-C3N4 as novel photocatalysts for environmental pollutants treatment have been reviewed, including degradation of aqueous organic pollutant, inactivation of bacteria, removal of atmospheric contaminant, detoxication of heavy metal ion, and reduction or conversation of CO2. High efficiency and stability can be maintained during photocatalytic reaction process. For further improve the catalytic efficiency of g-C3N4 many works for structure optimization have been researched. Taking the utilization in degradation of organic pollutant as examples, the modifications of g-C3N4 for photocatalytic performance optimization are summarized, including structure optimization, surface and doping modification, composite semiconductor. The photocatalytic reaction mechanisms of g-C3N4 for pollutants degradation and CO2 reduction are elucidated. In addition, the prospects for the development of g-C3N4 based semiconductor materials and application in environment pollutants treatment are also discussed.