Highly Enhanced Visible‐light Photocatalytic Activity via a Novel Surface Structure of CeO₂/g−C₃N₄ toward Removal of 2,4‐dichlorophenol and Cr(VI)

Abstract

Photocatalysis is an efficient and eco-friendly method of solving the environmental problems, but the low charge separation efficiency of photocatalysts limits their application. Herein, we report the fabrication of CeO 2 /gÀ C 3 N 4 composites via an in-situ growth of CeO 2 on the dispersed gÀ C 3 N 4 sheets (CNÀ OH) in an strong KOH condition, and the resultant CeO 2 /CNÀ OH composites set up a new interface structure, which demonstrate a dramatically boosted the photocatalytic activity compared with CeO 2 /gÀ C 3 N 4 composites by conventional two-step combination method. The decomposition efficiency of CeO 2 /CNÀ OH for 2,4-dichlorophenol (2,4-DCP) degradation comes up to 6 times of bare CeO 2 or gÀ C 3 N 4 . Compared to conventional CeO 2 / gÀ C 3 N 4 , the CeO 2 /CNÀ OH showed 65.9 % and 23.2 % improvement for 2,4-DCP and Cr(VI) removal, respectively. The significantly enhanced photodegradation ascribe to the alkaline modified CNÀ OH and the fabrication of CeO 2 /CNÀ OH n-n type heterojunction, both can improve the charge separation efficiency and increase the reaction active sites. Furthermore, the probable pathway and concreted photocatalytic mechanism for 2,4-DCP degradation are proposed based on the detected intermediate products.

CeO2 Structure Adjustment by H2O via the Microwave–Ultrasonic Method and Its Application in Imine Catalysis

“…After calcination at 500°C for 1 h, most of the organic groups were removed, and only a small amount of C=O (1,300–1,650 cm −1 ) and C-O (1,060 cm −1 ) groups can be observed besides the OH group at c.a. 3,500 cm −1 ( Guo et al, 2021 ), indicating a relatively clean surface. These groups may be caused by the adsorption of CO 2 and H 2 O from the air, which can be further confirmed by XPS results in Figure 5 .…”

Removal of 3,4-dichlorophenol from water utilizing ferrate(vi): kinetic and mechanistic investigations and effects of coexisting anions

“…In fact, tetrahydroxybenzene has also been identified during the degradation process of other chlorinated phenols, such as the Fe( vi ) oxidation of 2,6-DCP, 25 hydroxyl-based photocatalytic degradation of 2,4-DCP, 52 and decomposition of 2,4-DCP catalyzed by CN-OH/CeO 2 -NP composite. 53…”

“…In fact, tetrahydroxybenzene has also been identified during the degradation process of other chlorinated phenols, such as the Fe(VI) oxidation of 2,6-DCP, 25 hydroxyl-based photocatalytic degradation of 2,4-DCP, 52 and decomposition of 2,4-DCP catalyzed by CN-OH/CeO 2 -NP composite. 53 Pathway (B) is related to the substitution of a Cl group of 3,4-DCP. This is not strange because the chlorine atom attached to the benzene ring of phenolic compounds is susceptible to be substituted by a hydroxyl group under electrophilic attack of the oxidant.…”

Enhanced Cr(VI) Photocatalysis Reduction by Layered N‐doped TiO2 Sheets from Template Free Solvothermal Method

“…successfully synthesized ultra‐thin black TiO 2 nanosheet‐assembled microspheres (diameter of about 1 μm) with high‐thermal stability, which exhibited an excellent solar‐driven photocatalytic hydrogen evolution rate (6.54 mmol ⋅ h −1 ⋅ g −1 ) [9b] . Materials with nanosheets assembly have attracted widely attention, because the sheet structure can provide abundant exposed reactive sites due to its high surface area, and always with excellent catalytic activities, [9b,15] especially in the Cr(VI) photocatalytic reduction [15d–f] …”