Consequently, combining TiO 2 with g-C 3N 4 to prepare heterostructured photocatalysts can effectively separate photogenerated electrons and holes and improve the visible-light catalytic performance relative to that of TiO 2 alone (Khan et al., 2020). It is more attractive because the delocalized conjugated π structure of g-C 3N 4 can impede charge recombination and facilitate charge separation (Zhang et al., 2018). It is receiving increasing attention owing to its moderate band gap (2.7 eV), non-toxicity, and easy preparation. G-C 3N 4, which has good visible light response and high chemical stability, is a typical two-dimensional semiconductor conjugated polymer (Tahir et al., 2019a Zhang et al., 2021). Therefore, it is very important to develop visible-light-driven TiO 2-based photocatalysts with low electron–hole recombination rates. However, the considerably large band gap of TiO 2 (~3.2 eV) limits the absorption of visible light, and the high photoexcited electron–hole recombination rate leads to reduced catalytic performance (Umer et al., 2019a Chen et al., 2020a). Hydroxyl radicals are formed by oxidation–reduction reactions, leading to the oxidation of antibiotic pollutants into CO 2 and H 2O (Ji et al., 2018).Īs a promising photocatalyst, TiO 2 has attracted considerable attention in many photocatalysis areas owing to its advantages of non-toxicity, physicochemical stability, low cost, and ease of production (Tahir, 2020 Chen et al., 2020b). The electron–hole pairs are transferred to the surface of the photocatalyst, and oxidation–reduction reactions occur. It mainly depends on electron–hole pairs absorbing light with energy equal to or greater than the energy gap of the photocatalyst. Among these methods, photocatalytic degradation is considered to be one of the most promising methods because of the advantages of speed, low-cost, and high efficiency for the degradation of antibiotics (Yang et al., 2020).

Microwave catalysis has the advantages of selective heating, uniform heating, and a rapid heating rate, but it requires a catalyst that can absorb microwaves (Wang et al., 2020b). Moreover, the adsorption capacity of the adsorbent is limited, and the recovery process of desorption is quite tedious (Wang et al., 2020a). Organic pollutants are only concentrated on the surface of the adsorbent, rather than being degraded, which can easily lead to secondary pollution. However, the adsorption method has disadvantages. Adsorption methods with low cost, high efficiency, and good handleability have also been widely used in water treatment. Antibiotics are difficult to handle owing to their antimicrobial properties (Nie et al., 2020). Biological purification is widely used for wastewater treatment. Various techniques have been applied to remove antibiotics from the environment, including biological purification, adsorption, microwave catalysis, and photocatalytic degradation (Luo et al., 2019 Wang et al., 2019 Guo et al., 2018). Numerous studies have shown that the selection of antibiotic-resistant bacteria poses a potential threat to human health (Chen et al., 2018). Most antibiotics are difficult to absorb and digest by animals and humans therefore, they are discharged through urine and feces into the environment (Dong et al., 2018). The layered mosaic stack structure of g-C 3N 4 and TiO 2 prepared with montmorillonite suggests its potential to serve as an efficient photocatalyst for TC in wastewater treatment, and the method could provide some inspiration for the design and construction of efficient photocatalysts.Īccording to a World Health Organization report, 100,000–200,000 tons of antibiotics are consumed worldwide (Song et al., 2017). Density functional theory (DFT) calculations predicted that the degradation of TC mainly occurred at the boundaries rather than in the interlayer spaces. The photocatalytic degradation rate constant of the optimized composite was 0.058 min −1, which was approximately 6.21 higher than that of g-C 3N 4 (0.009 min −1 ). The degradation rate of TC was 97.0% within 60 min. Benefiting from the layered mosaic stack structure, enhanced visible-light response, and effective charge transfer induced by uniform and compact heterojunctions, the prepared photocatalyst showed excellent photodegradation efficiency to remove tetracycline (TC) pollutants. In this work, natural mineral montmorillonite was used as a hard template to prepare g-C 3N 4 and TiO 2 composite photocatalysts with a layered mosaic stack structure through a double intercalation process for the first time.

Photocatalysis is considered one of the most promising methods for removing antibiotics from wastewater.

Mosaic stack ottoman