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)WO 3) 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 C N terminal of CCN framework in the synthesized CCN-WO 3 composites. The introduction of more WO 3 has shifted the optical property of the CCN-WO 3 composites to higher wavelength. The TEM and FESEM analyses on CCN-WO 3 revealed the presence of WO 3 in needle like shape decorated on the surface of CCN. Among, material CCN-(0.25)WO 3 has exhibited the highest photocatalytic degradation of phenol which was 1.5 and 15 times higher than bare CCN and WO 3 within 6 h exposure of visible light, respectively. The synergistic effect by co-existence of CCN and WO 3 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-WO 3. The radical scavenger studies confirmed that the synthesized CCN-WO 3 composite was an excellent visible light driven photocatalyst for phenol degradation. [Display omitted] • New tungsten oxide modified heptazine-based crystalline carbon nitride composites are synthesized. • The composites have broad light absorption, low electron-hole recombination and high electron-transfer rate constant. • The CCN-0.25 wt% WO 3 composite is an excellent visible light driven photocatalyst for phenol degradation. [ABSTRACT FROM AUTHOR]