Environmentally Friendly Fabrication of High-Efficient Fe-ZnO/Citric Acid-Modified Cellulose Composite and the Enhancement of Photocatalytic Activity in the Presence of H2O2

Abstract

In the present study, a novel Fe-ZnO/citric acid-modified cellulose composite (x%Fe-ZnO-y%CAC) was synthesized using an environmentally friendly hydrothermal method. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), UV−vis diffuse reflectance spectroscopy (DRS), Fourier transform infrared spectroscopy (FTIR), nitrogen physisorption, and electrochemical and photocurrent density analyses. The influence of the additives from the series of x%Fe-ZnO-y%CAC photocatalysts with Fe content from 0 to 5% and CAC content from 0 to 80% on photocatalytic degradation of ibuprofen (IBU) under simulated solar light was investigated. The photocatalyst 0.5%Fe-ZnO-40%CAC showed high photocatalytic activity of 0.0632 min−1 first-order kinetic rate constant and 46% TOC reduction of IBU under simulated solar light irradiation. Additionally, H2O2-assisted photocatalytic process was investigated for facilitating the IBU degradation in the presence of 0.5%Fe-ZnO-40%CAC; the first-order kinetic rate constant was 2.7 times higher compared to the process without addition of H2O2. Moreover, the effect of radical scavengers was examined to explain the degradation mechanism of IBU by synthesized photocatalysts supported with H2O2. The demonstrated system provides a low-cost and green approach to improve the photocatalytic activity of x%Fe-ZnO-y%CAC photocatalysts.

ZrO2 Superhydrophobic Coating with an Excellent Corrosion Resistance and Stable Degradation Performance on Zr-Based Bulk Metallic Glass

“…This indicates that the sample still had an excellent degradation performance after the soaking corrosion. Based on the above experimental results and component analysis, the reaction formula for accelerating the degradation process can be inferred as follows [ 3 , 20 , 21 ]: ZrO 2 + hν → e − + h + h + + H 2 O → •OH +H + e − + O 2 →•O 2 − H 2 O 2 + e − → •OH + OH − •O 2 − + 2H + + 2e − → •OH + OH − H 2 O 2 + hν → •OH •OH + MO → CO 2 + H 2 O …”

“…This indicates that the sample still had an excellent degradation performance after the soaking corrosion. Based on the above experimental results and component analysis, the reaction formula for accelerating the degradation process can be inferred as follows [3,20,21] In order to compare the degradation rate of the MO solution (the volume of MO was 10 mL), the C/C 0 Line chart diagram of the degradation rate is shown in Figure 6a. The curves, which were used to calculate the degradation rate, are shown in Figure S4.…”

ZnO-decorated green-synthesized multi-doped carbon dots from Chlorella pyrenoidosa for sustainable photocatalytic carbamazepine degradation

“…However, certain limitations to common applications, such as the narrow photoresponse range, recombination of photogenerated electron-hole pairs, and low adsorption capacity, have guided extensive studies on appropriate modications to enhance the photoreactivity of ZnO. 10 Therefore, much effort has been devoted to improve the photocatalytic activity of ZnO using e.g., doping with various metals 11,12 and non-metals, 13 formation of hetero-structural composites, 14 noble metals deposition, 15 and coupling with nanocarbon components. 10,16 Zero-dimensional quasi-spherical nanoparticle carbon dots (CDs) have gained global importance in many applications.…”

“…Many studies have conrmed that the oxidizing capability of a photocatalyst can be signicantly improved by the assistance of e.g., hydrogen peroxide (H 2 O 2 ), peroxymonosulphate (PMS) or persulphate (PS). 14,39,40 This enhancement is caused by the activation of these oxidants by photoinduced electrons to generate radicals with a strong oxidation potential, such as hydroxyl (cOH) with a redox potential of 2.8 V or sulphate radicals (SO 4 c − ) with even a higher redox potential (2.5-3.1 V) depending on their activation methods. 39 Additionally, SO 4 c − possesses a higher selectivity and longer half-life than cOH in certain cases.…”

“… 10 Therefore, much effort has been devoted to improve the photocatalytic activity of ZnO using e.g. , doping with various metals 11,12 and non-metals, 13 formation of hetero-structural composites, 14 noble metals deposition, 15 and coupling with nanocarbon components. 10,16 …”