Interfacial Growth of TiO₂-rGO Composite by Pickering Emulsion for Photocatalytic Degradation

Abstract

A 2D sandwich-like TiO-rGO composite was fabricated by the Pickering emulsion approach to improve the photocatalytic efficiency. Through an in situ growth of antase-TiO nanoparticles on the interface of O/W type GO Pickering emulsion, TiO nanoparticles were closely and densely packed on the surface of well-exfoliated rGO sheets; meanwhile, many mesoporous voids acting as the adsorption chamber and microreactor were produced. Evaluated by methylene blue (MB) degradation, its photocatalytic activity was prominent compared with the common TiO-based photocatalyst, with the rate constants 5 and 3.1 times higher under visible light and xenon lamp, respectively. When we applied it in the photocatalytic degradation of tetracycline hydrochloride (TCH, such as 10 ppm) under the visible light without adding any oxidants, the total removal efficiency was as high as 94% after 40 min. The mechanism of this good photocatalytic efficiency was illustrated by the scavenger trapping tests, which showed that this unique structure of TiO-rGO composite induced by the Pickering emulsion can significantly enhance the light absorption ability, accelerate the separation rate of electron-hole pairs, increase the adsorption capacity of organic pollutants, and hence improve the photocatalytic efficiency.

Food-Grade Pickering Emulsions: Preparation, Stabilization and Applications

“…), the emulsion will degrade. In food applications, researchers add emulsifiers so that the emulsion is not destroyed before the shelf life of the product [ 2 , 87 ]. However, the degradation trend of the emulsion is inevitable, and it is just a matter of time.…”

Designing Internal Hierarchical Porous Networks in Polymer Monoliths that Exhibit Rapid Removal and Photocatalytic Degradation of Aromatic Pollutants

“…[ 35 ] Also, CDPs can better form Pickering HIPEs at a relatively low concentration in comparison with other solid surfactants, such as MOFs, silica, metal oxides, or other MOPs. [ 13–23,35,36 ] For example, the CDP emulsifier resulted in a stable HIPE system even at 1 wt% with respect to the water phase (Figure 3b), while the solid surfactants generally required 5–50 wt%. [ 8,43–45 ] Furthermore, pristine β‐CD needed even more than ten times greater of weight than CDP (Figure S1a, Supporting Information).…”

“…[ 8 ] Contrarily, solid colloidal particles can also stabilize the interface between two different phases even at a relatively low concentration, leading to a Pickering emulsion. [ 9–12 ] A variety of materials such as silica, [ 13–15 ] metal‐organic‐frameworks (MOFs), [ 16–18 ] graphene oxides, [ 19–21 ] and metal oxides [ 22,23 ] has been used as Pickering emulsifiers; they are well dispersed in a continuous phase and bound to the surface of the interface, which forms stable layers to sustain the internal droplets. In contrast to conventional HIPEs, Pickering HIPEs have some advantages: i) they require a small amount of solid particles to maintain the emulsion system (e.g., below 10 wt%) [ 13–23 ] and ii) the emulsifier particles can be designed using diverse monomeric species or further functionalized via post‐polymerization modification.…”

Facile Fabrication of C–TiO2 Nanocomposites with Enhanced Photocatalytic Activity for Degradation of Tetracycline

“…1−3 However, 70–90% of TC is discharged from the body and ultimately exists in surface water, groundwater, and even drinking water. 4,5 To solve these problems effectively, several techniques have been developed, such as absorption, photocatalysis, membrane separation, and electrolysis. 6−10 Compared with the traditional technology, semiconductor-mediated photocatalysis has become a hot spot in the research of antibiotic residue treatment recently because it is a green and efficient technology.…”