A Novel Multifunctional Photocatalytic Separation Membrane Based on Single‐Component Seaweed‐Like g‐C₃N₄

Abstract

Multifunctional separation membrane is usually realized by multi‐component collaborative construction, which makes the membrane preparation method complicated and uncontrollable. Herein, a novel multifunctional photocatalytic separation membrane is prepared by vacuum self‐assembly of single seaweed‐like g‐C3N4 photocatalyst. The seaweed‐like g‐C3N4 gives membrane certain roughness, large specific surface area, excellent hydrophilicity and abundant transport channels. Through a systematic study, the membrane exhibits excellent separation of five oil‐in‐water emulsions with a maximum flux of 3114.0 ± 113.0 L m−2 h−1 bar−1 for 1, 2‐dichloroethane‐in‐water (Dc/W) emulsion and a maximum efficiency of 97.4 ± 0.1% for chloroform‐in‐water (C/W) emulsion. In addition, the seaweed‐like g‐C3N4 with large specific surface area and narrow bandgap render excellent visible light absorption characteristics and accelerate e−‐h+ pairs transport rate, giving the membrane excellent photocatalytic degradation and antibacterial properties. The membrane shows good degradation for eight different pollutants, among which the degradation effect for rhodamine B (RhB), methylene blue (MB), and crystal violet (CV) were ≈100%. The antibacterial efficiency against E. coli and S. aureus is also close to 100%. After 35 consecutive separations of C/W emulsion and 10 consecutive degradations of RhB, the membrane still maintains excellent separation performance. This long‐lasting multifunctional separation membrane exhibits broad application prospects in complex wastewater purification.

Shear Stress Triggers Ultrathin-Nanosheet Carbon Nitride Assembly for Photocatalytic H2O2 Production Coupled with Selective Alcohol Oxidation

“…To assess the ability of ASCN-3 and BCN to produce different free radicals in air under light, EPR trapping experiments were conducted using 5,5-dimethyl-1-pyrroline- N -oxide (DMPO) and 2,2,6,6-tetramethylpiperidine (TEMP). As reported, the energy band structure of C 3 N 4 makes it difficult to produce large amounts of • OH radicals. , Especially, the E VB of ASCN-3 is measured to be 1.66 V (vs RHE), which does not meet the thermodynamics requirement of generating • OH (1.89 V vs RHE) . Thus, the weak characteristic signals related to the DMPO- • OH adduct provide direct evidence of trace • OH (Figure S37a), which is further verified by the hydroxyl radical-trapping experiment using t BuOH as a quencher (Table S5, entry 10).…”

CdS–SH/TiO2 Heterojunction Photocatalyst Significantly Improves Selectivity for C–O Bond Breaking in Lignin Models

“…Lignin is an aromatic polymer consisting of three phenylpropane units connected in a disordered manner by C–C and C–O bonds and is the only renewable aromatic resource that exists in nature. − However, the underutilization and inherent resistance to biodegradation of lignin contribute to environmental pollution and the squandering of valuable renewable sources. , In recent years, many lignin depolymerization processes, including noncatalytic, catalytic pyrolysis, enzymolysis, catalytic depolymerization, and oxidation, have grown rapidly, wherein catalytic chemical conversion with the assistance of various catalysts is a very competitive method due to its exceptional selectivity and conversion efficiency . Photocatalysis strategies that can achieve selective reactions under mild conditions are receiving increasing attention. − The CdS photocatalyst possesses a narrow band gap (2.4 eV) and a wide visible light absorption range, making it a promising semiconductor material for the photocatalytic conversion of lignin. − However, the catalytic performance of the CdS photocatalyst is constrained by its relatively small specific surface area and short carrier lifetime, which limit its overall effectiveness. Several works , have been conducted to explore surface modifications of CdS.…”

Oxygen-Doped Porous g-C3N4 via Oxalic Acid-Assisted Thermal Polycondensation as a Visible Light-Driven Photocatalyst for Bisphenol A Degradation

“…Graphitic phase carbon nitride (g-C 3 N 4 ) exhibits great potential for photocatalytic applications due to its favorable band gap ( E g = 2.7 eV), excellent visible light responsiveness, and high thermal and chemical stability. , However, the photocatalytic performance of g-C 3 N 4 is still constrained by several drawbacks, including low specific surface area, rapid recombination of photogenerated charges, limited utilization of visible light, significant exciton effects, slow carrier migration, and weak electrical conductivity. , These limitations impede the further development and practical application of g-C 3 N 4 , thus necessitating the design of photocatalytic systems that demonstrate elevated catalytic activity for BPA degradation.…”