New Insights In‐Plane Porous Defects Formation Mechanism of Single‐Layer Graphitic Carbon Nitride by Tetrahydrofuran Etching Reaction

Defect engineering is an effective way to accelerate catalytic yield of graphitic carbon nitride (g‐C 3 N 4 ). Herein, bulk g‐C 3 N 4 is synthesized under two calcination atmospheres, argon and air, which significantly influence the incorporation of oxygen into the g‐C 3 N 4 structure and the formation of nitrogen vacancy. The oxygen doping and nitrogen vacancy play an essential role in promoting the creation of in‐plane porous defects by etching reaction with tetrahydrofuran (THF), while the in‐plane porous defect contents are controlled by optimization of the reaction temperature. The best CN‐200‐Pt sample achieves an excellent photocatalytic hydrogen evolution of 7806.6 μmol g −1 h −1 , and an optimal photocurrent density reached 1.8 μA cm −2 , representing 11 times and 9 times enhancements over the nondefective BCN–Ar–Pt sample, respectively. These results demonstrate that the controlled introduction of in‐plane porous defects can effectively modulate the charge separation process, number of catalytic active sites, band structure, and Pt 2+ /Pt 0 cocatalyst sites, directly enhancing the photocatalytic and photoelectrochemical water‐splitting performance of g‐C 3 N 4 . Along with density functional theory and molecular dynamics calculations, this study suggests the role of oxygen doping and nitrogen vacancy for the formation of in‐plane porous defects in the 2D g‐C 3 N 4 nanosheets in the etching reaction by THF, thus highlighting its potential in practical applications.