Novel visible light driven crystalline carbon nitride-tungsten oxide composites for photodegradation of phenol

A series of new tungsten oxide modified heptazine-based crystalline carbon nitride (CCN-(x)WO3) composite materials with different W loading amount (x = 0.1-1.0 wt%) were successfully synthesized via modified ionothermal and wet impregnation methods. The XRD and FTIR analyses results of confirmed the presence of highly ordered heptazine unit and CN terminal of CCN framework in the synthesized CCN-WO3 composites. The introduction of more WO3 has shifted the optical property of the CCN-WO3 composites to higher wavelength. The TEM and FESEM analyses on CCN-WO3 revealed the presence of WO3 in needle like shape decorated on the surface of CCN. Among, material CCN-(0.25)WO3 has exhibited the highest photocatalytic degradation of phenol which was 1.5 and 15 times higher than bare CCN and WO3 within 6 h exposure of visible light, respectively. The synergistic effect by co-existence of CCN and WO3 has induced the formation of highly ordered hepatize subunit of CCN, broadening light absorption in visible region, high surface area, low electron-hole recombination and high electron-transfer rate constant, which in turn enhanced the photocatalytic performance of CCN-WO3. The radical scavenger studies confirmed that the synthesized CCN-WO3 composite was an excellent visible light driven photocatalyst for phenol degradation.