Facile fabrication of oxygen-doped carbon nitride with enhanced visible-light photocatalytic degradation of methyl mercaptan

Element doping has demonstrated an effective strategy for enhancing photocatalytic performance of carbon nitride (CN). Herein, we reported that oxygen-doped CN (OCN) was successfully prepared by molten urea as the only raw precursor, in which thermal copolymerization of urea and in situ formed biuret can effectively incorporate oxygen in the CN network. The introduction of oxygen into CN network greatly improved the visible-light absorption capability, increased the charge carrier mobility and inhibited the electron–hole pairs recombination. In addition, the incorporation of the elemental oxygen with strong electronegativity into CN matrix afforded OCN with more structural base sites, which benefited for the adsorption of CH3SH. As expected, OCN exhibited an enhanced photocatalytic performance toward CH3SH degradation and mineralization under visible-light irradiation. This study demonstrates that a simple precursor pretreatment strategy can achieve the incorporation of beneficial foreign atoms into the CN framework, which provides some guidance for the design and synthesis of high-efficiency CN photocatalyst with peculiar feature.Graphical abstractO-doped carbon nitride prepared by thermal polymerization of molten urea exhibited an enhanced visible-light-driven photocatalytic performance for CH3SH degradation.