The mixed marriage of copper and carbon ring-g-C_3N_4 nanosheet: A visible-light-driven heterogeneous Fenton-like catalyst

摘要

Effective photogenerated charge separation and rapid Cu(II)/Cu(I) redox cycling is still challenging for photocatalytic reactions and copper-based Fenton-like process, respectively. Herein, a novel heterogeneous Fenton-like catalyst of copper incorporated carbon ring-g-C3N4 (Cu-C-CN) was prepared through a facile calcination method. The carbon ring could be intimately connected with g-C3N4 via sp(2)-hybridized C-N bonds to form an in-plane p-conjugated structure. The carbon ring spliced g-C3N4 (C-CN) can serve as an effective electron-hole separator owing to the varied electron affinity of two domains (e.g. carbon-ring and g-C3N4). The copper species were further introduced to the framework of g-C3N4 via the Cu-N bonds to act as acceptors of conduction-electrons from g-C3N4 and H2O2 activators. Taking the photodegradation of methylene blue (MB) as a model reaction, the decomposition efficiency over Cu-C-CN is 5.5 times higher than that of pristine g-C3N4, and would nearly linearly increase with pH. The notable enhancement in photodegradation efficiency could be ascribed to the synergetic collaboration between photocatalysis process and Fenton-like process to generate abundant center dot OH and e(-). The Cu-C-CN catalyst shows high recycling stability with negligible Cu leaching due to the strong affinity of Cu2+ to g-C3N4 framework. The strategy of coupling Fenton-like catalysts, electron-deficient domains (e.g. carbon-ring) into semiconductor-based photocatalysis provides a facile and promising solution to the remediation of water pollution with solar energy.