Enhanced Photocatalytic Performance Of Ammonia Self-Etched Holely G-C3n4 Decorated With Anatase Nanoflakes By A Facile Synthesis Process

Graphitic carbon nitride (g-C3N4) nanosheets have attracted extensive attention in the field of photocatalysis due to their superior properties. However, the photocatalytic performance of g-C3N4 is still restricted by the limited active sites and high combination rate of photo-generated carriers. To confront these drawbacks, a facile NH3 self-etching and TiO2 decorating method is employed in this work. The self-released NH3 with high concentration in thermal condensation process etches and exfoliates g-C3N4 into less aggregated nanosheets with abundant nano holes (similar to 2.7 nm). The specific surface area is up to 224 m(2).g(-1), which is higher than the previous reported samples prepared by template-free methods. The formed holes endow g-C3N4 nanosheets with more exposed active edges that greatly accelerate mass exchange and photo-generated carriers transfer. After decorating anatase TiO2 nanoflakes, the composite photocatalyst exhibits a Z-scheme heterojunction behavior and enhances spatial separation efficiency of photo-generated carriers greatly. As a result, the photocatalytic performance is significantly enhanced: the photodegradation rate on rodamine B reaches 99.2% within 8 min and the hydrogen evolution rate reaches as high as 1764 mu mol.g(-1) h(-1). This work provides a facile and low-cost processing method to prepare high active and stable photocatalysts, and show the importance in rational designing the nanomaterials by well-directed preparation process and energy band engineering.