Novel ZnCo2O4 embedded with S, N-CQDs as efficient visible-light photocatalyst

The increasing demand for the modern treatment of organic pollutants has led to the development of environment-friendly photocatalytic methods. This paper reports a novel carbon quantum dots-based photocatalyst for the first time. It includes S, N co-doped carbon quantum dots (S, N-CQDs) embedded onto ZnCo2O4 nanoparticles to obtain a potential photocatalyst for the degradation of acid blue 113 (AB 113) under visible light irradiation. The prepared samples were characterized using FE-SEM, EDX, XRD and DRS analyses. The particle size of the prepared samples was seen to be strongly controlled by the amount of capping agent, and the average particle size was found to be 76 nm and 47 nm using 2.0 mL and 4.0 mL PEG, respectively. The DRS and photocatalytic experiments revealed that the S, N-CQDs had a remarkable effect on the band gap and hence the photoactivity of the ZnCo2O4 composite. Minimum band gap was about 2.62 eV for the S, N-CQDs/ZnCo2O4 nanocomposite. After 120 min of visible light illumination, a high level of photodegradation (93 %) was obtained for AB 113 using the combination of S, N-CQDs with ZnCo2O4 nanoparticles. In addition, the prepared S, NCQDs/ZnCo2O4 photocatalyst showed great stability with only 23 % loss of activity after 6 reaction cycles. The photocatalytic mechanism was studied using different radical scavenging agents. This new photocatalyst pro vides a promising alternative for organic pollutant degradation applications.