Graphitic Carbon Nitride Prepared by Rapid Recrystallization for Photoelectrochemical Anticorrosion

A multilayer homojunction structure of carbon nitride material is successfully realized by a strategy of rapid recrystallization. The evolution of homojunction structures is systematically investigated by SEM, XPS, nitrogen adsorption/desorption measurement, and photoluminescence characterization. The photoelectrochemical cathodic protection performance of graphitic carbon nitride for carbon steel is explored. The results show that the electric field built-in homojunction structure effectively improves the separation efficiency of photoinduced electrons and holes. The photoelectrochemical cathodic protection voltage of homojunction carbon nitride to carbon steel reaches 122 mV, which is 6 times that of bulk material (20 mV). Furthermore, this material exhibits excellent stability and provides as long as at least 3 h protection for carbon steel.