Hydrogen-Bond-Mediated Self-Assembly of Carbon-Nitride-Based Photo-Fenton-like Membranes for Wastewater Treatment

Abstract

Graphitic carbon nitride has emerged as a promising material for high-performance membranes with both filtration and catalytic abilities. However, the scalable construction of carbon-nitride-based membranes is seriously restricted by the poor ability to tailor the structure and poor solvent solubility of bulk nanostructures. Herein, carbon nitride sol was prepared in high yield and used as a precursor to assemble photo-Fenton-like membranes. Intermolecular hydrogen-bond interactions between carbon nitride nanofibers were found to be vitally important for the repolymerization of hydrolyzed molecules into dense and solid membranes. Intercalated Fe-containing polyoxometalates (Fe-POMs) not only acted as molecular linkers to construct carbon nitride membranes but also provided new opportunities for the catalytic functionality. Benefiting from the hydrophobic nanocapillaries in 2D carbon nitride for ultralow water–carbon friction, self-assembled membranes effectively rejected pollutant molecules with high water permeation flux. The integration of carbon nitride photocatalysts with Fenton-like Fe-POMs contributed to the in situ degradation of retained pollutants. Thus, our work manifested a facile bottom-up strategy to construct photo-Fenton-like membranes with antifouling abilities for wastewater treatment.

Recent Progress of Photocatalytic Fenton-Like Process for Environmental Remediation

“…Due to the simple synthesis method, good physical and chemical stability and earth abundant characteristics, graphite carbonitride (g-C 3 N 4 ) has attracted scientists attention in terms of energy conversion and environmental remediation (Lan et al, 2019). As to homogeneous Fe 2+ /H 2 O 2 Fenton process, the water-soluble Fe 2+ catalyzed H 2 O 2 to produce hydroxyl radical; however, traditional homogeneous catalysts will be constrained by the following drawbacks: (1) low decomposition efficiency of H 2 O 2 ;…”

“…Successively, g-C 3 N 4 coupled with various types of Fe-based materials were explored for removing recalcitrant organic pollutants via photo-Fenton process, including of iron minerals (He et al, 2017), Fe(III) (Hu et al, 2016), single molecule iron complex (Chen et al, 2010;Banić et al, 2011), and iron oxide etc. Moreover, carbon nitride-based nanomaterials could serve as photo-Fenton-like membranes (Yu et al, 2018;Lan et al, 2019). Except of above mentioned, Li et al (2016) constructed solid-gasinterfacial Fenton reaction over alkalinized-C 3 N 4 photocatalyst in isopropanol photodegradation.…”

Membrane processes

“…In a study by Lan et al. (2019), carbon nitride solvent was used as a precursor to assemble photo‐Fenton‐like membranes. Fe‐containing polyoxometalates (Fe‐POMs) functioned as molecular linkers in construction of membranes and at the same time exhibited catalytic characteristics.…”

A Review of Manganese(III) (Oxyhydr)Oxides Use in Advanced Oxidation Processes

“…AOPs are able to remove and mineralize most unbiodegradable pollutants into harmless compounds, such as CO 2 , , and inorganic ions [ 13 ]. Based on various reaction conditions, AOPs can be classified into different categories, including Fenton reaction [ 14 ], Fenton-like reaction [ 15 , 16 ], photochemical oxidation [ 17 , 18 ], ultrasonic oxidation [ 19 , 20 ], electrochemical oxidation [ 21 , 22 ], ozone oxidation [ 23 , 24 ], and sulfate radical-based AOPs (SR-AOPs) [ 25 , 26 , 27 ]. Among them, the application of SR-AOPs for the removal of stubborn pollutants has received increasing attention due to their advantages.…”