Design and fabrication of graphitic carbon nitride incorporated zinc silicate hybrid nanocomposite for effective degradation of eriochrome black T dye as water pollutant under sunlight irradiations

Abstract

This paper presents an approach to prepare zinc silicate (Zn2SiO4) and its nanocomposites with graphitic carbon nitride (g-C3N4) for enhanced photocatalytic performance. Zn2SiO4 was synthesized using a simple and cost-effective sonochemical method, followed by the fabrication of Zn2SiO4/g-C3N4 through an ultrasonic-assisted co-precipitation method. The characterization of Zn2SiO4 and its nanocomposites was carried out using various techniques such as XRD, FTIR, EDS, SEM, TEM, BET, and DRS. The main focus of this study was to investigate the photocatalytic efficiency of g-C3N4, Zn2SiO4, and different Zn2SiO4 nanocomposites for the degradation of eriochrome black T (EBT) and erythrosine (ER). It is worth noting that this is the first time Zn2SiO4 has been combined with carbon nitride, which resulted in excellent photocatalytic performance. The experimental results revealed that several factors influenced the efficiency of the photocatalytic process, including the content of Zn2SiO4 in the nanocomposite, catalyst loading, and initial concentration of EBT. Among all the tested compositions, Zn2SiO4/g-C3N4 with 10 % Zn2SiO4 exhibited the best performance. Specifically, when 70 mg of 10 % Zn2SiO4/g-C3N4 was used as a catalyst, it achieved a remarkable degradation efficiency of 75.5 % for 10 ppm EBT. This finding highlights the potential application of Zn2SiO4/g-C3N4 nanocomposites as efficient photocatalysts for environmental remediation. The results of scavenger test indicated that superoxide radicals and positive holes played significant roles in driving the photodegradation reactions. Furthermore, a kinetics study was performed to determine the rate constant (k) associated with the photocatalytic process. It was observed that a higher rate constant (k = 0.011 min−1) corresponded to a higher efficiency of 75.5 %. This finding suggests that the Zn2SiO4/g-C3N4 nanocomposites possess excellent photocatalytic activity and can effectively degrade organic pollutants.