An environment-friendly route to synthesize pyramid-like g-C3N4 arrays for efficient degradation of rhodamine B under visible-light irradiation

Pyramid-like g-C3N4 arrays (PCNA) were successfully prepared for the first time by ultra-rapid microwave heating method. The as-synthesized PCNA was investigated by comprehensive analytical techniques. The ultraviolet- visible (UV-Vis) spectrum of PCNA had an absorption edge located in the visible-light region at approximately 450 nm, corresponding to band gap of approximately 2.76 eV. Subsequently, the photocatalytic activity of PCNA was evaluated by the photodegradation of rhodamine B (RhB) in aqueous solution under visible-light (lambda > 420 nm) irradiation. Result indicated that the decolorization ratios of RhB reached up to 99.5% after the degradation reaction catalyzed by PCNA for 30 min. The first-order kinetics rate constant of photodegradation RhB for PCNA was 10 times as large as that of bulk g-C3N4. Moreover, PCNA still maintained an outstanding photocatalytic activity after consecutive 4 times recycling.