Role of Acetaldehyde on Synthesizing Large Surface Area Porous g-C₃N₄Nanosheets with Enhanced Photocatalytic Performance by Using Acetaldehyde–Melamine

Abstract

Large specific surface area porous g-C3N4 nanosheets were prepared by utilizing acetaldehyde-mediated melamine. The synthetic processes adopted two-step thermal treatments which are in N2 and then in an air atmosphere. The introduced acetaldehyde made melamine condensation incompletely and generated body defects in g-C3N4 when heated in N2. Further heating in air realized pores formation at sites of body defects, thus increase the specific surface area of g-C3N4. Notably, the introduction of acetaldehyde is beneficial to generate high concentration defects, which are active sites for thermal oxidative etching, and increase the yield of g-C3N4 by inhibiting the sublimation of melamine. The photocatalytic performance of obtained g-C3N4 was evaluated by the degradation of 2-propanol under visible light irradiation ([Formula: see text][Formula: see text]nm). The porous g-C3N4 exhibits excellent photocatalytic performance than bulk g-C3N4. The addition of trace acetaldehyde significantly increased the specific surface area and enhanced photocatalytic activity, providing a new idea for the development of simple, low-cost and high active g-C3N4 photocatalyst.