Noble metal deposited graphitic carbon nitride based heterojunction photocatalysts

The photoinduced charge carrier separation and significant band gap response spanning the solar spectrum is indispensable for designing the functional photocatalysts towards wastewater purification. Although modified titania are still promising, the upsurge of alternative nanomaterials has continued to inspire the materials chemistry research community due to their excellent structure-electronic properties. In this context, polymeric g-C3N4 (GCN) is in the focus of strenuous research mainly ascribed to its inherent advantages such as narrow band gap and favorable band edge positions that are conducive to trigger the desired redox reactions. Despite these paramount importance, GCN suffers from intrinsic drawbacks such as narrow visible light response and high degree of charge carrier recombination. Among the various strategies investigated, depositing the noble metal over the GCN surface appears to be effective approach to modify the photon harvesting capacity and to increase the charge carrier separation kinetics. In this focused review article, performance of GCN towards many probe reactions via noble metal deposition (Au, Pd, Pt & Ag) under visible light illumination is presented. The decoration of single metal atom clusters, bimetallic deposition and ternary heterostructure of GCN associated with noble metal and semiconductor is discussed to understand the role of metal islands in these composite systems. The preparation method, degradation mechanism of few probe reactions combined with charge carrier dynamics are emphasized at the relevant places. We are positive that our review article furnish the sufficient information on the metal-GCN heterostructure and pave the way for better photocatalytic applications.