An uncomplicated and stable photocatalytic reaction platform for organic water treatment: Floating graphite-like carbon nitride film fixed by transparent double-sided adhesive tape

Immobilizing the photocatalyst on solid substrates is considered a state-of-the-art technical requirement, which can address the separation problem for the reuse of nano photocatalytic materials. Graphite-like carbon nitride (g-C 3 N 4 ) shows excellent properties as an unconventional photocatalyst, but the surface with inert functional groups makes it difficult to produce strong adhesion to the substrate surface. Herein, nano g-C 3 N 4 was fixed on the transparent substrate with double-sided adhesive tape (DSAT), forming an uncomplicated and stable photocatalytic reaction platform for organic wastewater treatment. g-C 3 N 4 film is located at the outer bottom side of the platform, which can avoid the shading effect of sewage turbidity on the photocatalyst. Furthermore, the substrate and DSAT are transparent, thus the influence on the light absorption of g-C 3 N 4 can be negligible. The prepared g-C 3 N 4 film (520 nm) consists of one layer of the dispersed g-C 3 N 4 particles (590 nm). At low catalyst dosage (62.5 ppm), the absorption of g-C 3 N 4 film exceeds 90 % in 200–800 nm. The normalized photocatalytic degradation rate constant of the suspended g-C 3 N 4 and g-C 3 N 4 film are 0.280 h −1 and 0.423 h −1 for 80 mL Rhodamine B solution (10 mg/L), respectively. When the rotation speed increased from 0 RPM to 250 RPM, the rate constant could increase 3 times from 0.139 h −1 to 0.608 h −1 . Besides, the film's photocatalytic activity could be retained after 20 times of reuse, which shows the film has good recyclability. Compared with the suspended g-C 3 N 4 , the prepared film has obvious advantages in light absorption utilization, the photocatalytic performance and recovery.