Doped Graphitic Carbon Nitride: Insights from Spectroscopy and Electrochemistry

Photocatalytic use of the neat graphitic carbon nitride, g-C3N4, is usually restricted by unsatisfactory efficiency due to low solar light absorption and rapid recombination of photogenerated charge carriers. The introduction of metal ions into g-C(3)N(4)structure can effectively reduce the recombination rate of photogenerated charges, expand the light absorption range and in consequence improve overall photocatalytic efficiency. The series of graphitic carbon nitride based materials, doped with metals cations (iron, bismuth, cobalt, zinc), has been prepared. The doping-caused changes of band gap energy, flat band potential, photocurrent generation, and photoactivity range have been studied using spectroscopic and electrochemical techniques. Moreover, based on the photocatalytic activity tests the efficiency of change recombination has been estimated. Presented studies proved multifarious positive effects of doping on g-C3N4, such as extended light absorption, an improved yield of electron-hole pairs separation, suppressed recombination of charge carriers, reduced electron transport resistance, and improved photocatalytic efficiency of dye decomposition.