Enhanced sunlight-driven photocatalytic activity in assembled ZrO2/g-C3N4 nanocomposite

In recent years, solar energy photocatalysis has been extensively used for the removal of organic pollutants and it is desirable to have a plethora of materials with high photocatalytic efficiency to treat a wide variety of organic pollutants. The semiconducting metal oxides are a class of materials with high photocatalytic activity and structural stability that can be potential candidates to treat industrial effluents. Though ZrO 2 has been investigated for its photocatalytic activity, the wide bandgap has limited its application in sunlight photocatalytic degradation. In an attempt to tune the bandgap of ZrO 2 , a heterogeneous ZrO 2 /g-C 3 N 4 photocatalyst has been synthesized via a simple hydrothermal method at different weight proportions. The structural characteristics were ascertained by the XRD and FTIR which confirms the formation of the ZrO 2 /g-C 3 N 4 composite. The dye degradation characteristics were investigated for g-C 3 N 4 , ZrO 2 and ZrO 2 /g-C 3 N 4 composite and their photocatalytic kinetics were studied. The photocatalytic activity degraded 65%, 41%, 89% of methylene blue (MB) and 60%, 38%, 77% of xylenol orange (XyO) dyes in 75 min under solar light irradiation. Further, the ZrO 2 /g-C 3 N 4 (1:1 wt%) nanocomposite improves the photocatalytic rate five times for MB and three times for XyO. In addition, band gap tuning, surface morphology, and pore formation were ascertained by optical absorption, SEM and BET analysis. The optical absorption spectrum reveals that the ZrO 2 /g-C 3 N 4 (1:1 wt%) nanocomposite tunes the bandgap of ZrO 2 from 3.67 to 2.87 eV. BET surface analysis confirms the enhancement of the surface area upon the nanocomposite formation. These results suggest that a high photocatalytic activity has been achieved via bandgap tuning for efficient charge carrier generation and enhancement of surface area for efficient charge transfer in ZrO 2 /g-C 3 N 4 . Also, the ZrO 2 /g-C 3 N 4 nanocomposite has good reusability and structural stability toward the degradation of MB and XyO. In an essence, ZrO 2 /g-C 3 N 4 nanocomposite with improved photocatalytic characters can serve as an apt material for environmental remediation application.