Hydroxyl-/Carboxyl-Rich Graphitic Carbon Nitride/Graphene Oxide Composites for Efficient Photodegradation of Reactive Red 195 and Antibacterial Applications

Abstract

In this work, a protonated graphitic carbon nitride (P-g-C3N4)-coated graphene oxide (GO) composite (GO/P-g-C3N4) was prepared via wet-chemistry exfoliation, followed by a freeze-drying process. The GO/P-g-C3N4 composite was found to have an outstanding photodegradation performance effect on the reactive red 195 (RR195) dye and very strong antibacterial properties. Both the GO structure and the dispersed state of P-g-C3N4 were found to play a significant role in enhancing the photocatalytic activity of GO/P-g-C3N4. The GO/P-g-C3N4 obtained via freeze-drying retained a large number of oxygen-containing groups and showed higher catalytic activity and reusability than the reduced GO (rGO)/g-C3N4 obtained via thermal reduction. Characterization of the samples indicates that GO/P-g-C3N4 has a higher specific surface area and photocurrent density than rGO/g-C3N4; it is likely that these properties lead to the superior photocatalytic activity observed in GO/P-g-C3N4. Adsorption energy calculations indicate that O2 can be readily adsorbed onto the GO surface, which results in stronger oxidizing superoxide anion radicals (•O2 –) and holes (h+); these active radicals can rapidly degrade RR195 dyes. Moreover, broad-spectrum antibacterial activity (demonstrated against Staphylococcus aureus and Escherichia coli) was observed in the case of the GO/P-g-C3N4 composite irradiated with visible light. This work offers new insights into the design of cost-effective g-C3N4-based photocatalysts for environmental remediation.

MOF-Derived Hollow Spheres of MIL-100(Fe)-NH2(20) with Well-Developed Hierarchical Mesoporous and Uniform Distribution of Fe and N Active Phases for the Photocatalytic Removal of Organic Dyes

“…Proverbially, the porous structure is beneficial to the diffusion of larger molecules with lower resistance and enhancing the contact between catalytic active sites and reactants. 24,25 Additionally, the main chemical composition of the obtained MIL-100(Fe)-NH 2 (20) was also investigated by EDX, and the consequences are interpreted in Figure 1d. Besides the C, N, and O elements, the Fe element also emerged in the spectrum, and the distributions of C, N, O, and Fe elements were indicated by purple, orange, yellow, and green colors, respectively, which confirms that the amino groups have been successfully introduced.…”

“…After modification, the MIL-100­(Fe)-NH 2 (20) still inherits the hollow microsphere morphology with a uniform structure and regular array of initial MIL-100­(Fe), suggesting that the introduction of amino groups has almost no impact on the topological structure of MIL-100­(Fe). Proverbially, the porous structure is beneficial to the diffusion of larger molecules with lower resistance and enhancing the contact between catalytic active sites and reactants. , …”

Photocatalytic Degradation of Tetracycline Hydrochloride Based on the Structure–Property Exploration of BiOCl

“…However, these complex molecules are difficult to degrade in the environment, and the TC-HCl-contained wastewater from hospital and pharmaceutical industries would cause severe environmental and ecological pollution. Among the various techniques used for TC-HCl removal from wastewater, the photodegradation technique is of great interest due to its sustainable and cost-effective features. − Basically, solar light was used to excite photocatalysts to generate electron/hole couples, which then lead to highly reactive oxygen species (ROS) and degrade TC-HCl into nontoxic molecules. − BiOCl is one of the most promising photocatalysts for water remediation. − Its unique layered structure (Cl–O–Bi–O–Cl) constructs internal electric field along the [001] direction . which could facilitate the separation of photogenerated electrons and holes.…”

Isoelectric Substitution Strategy to Construct a Partially Charged MOF for C2H2 Capture and Selective Dye Adsorption

“…However, it poses a great challenge to construct a MOF with partially charged characteristics as only few examples were reported. Meanwhile, it is very difficult for organic dyes to degrade due to their stability to light or oxidants. − Conventional adsorbents such as activated carbon and wood had been used for the adsorption of organic dyes; however, their poor separation selectivity limited their practical application. , Thus, designing and synthesizing multifunctional materials for gas separation and dye adsorption are effective methods to deal with environmental and energy consumption problems. , …”