Magnetic cobalt-embedded carbon nitride composite derived from one-dimensional coordination polymer as an efficient catalyst for activating oxone to degrade methyltheobromine in water

Synthesis of solar-driven Cu-doped graphitic carbon nitride photocatalyst for enhanced removal of caffeine in wastewater

Caffeine (CaF), a widely consumed compound, has been associated with various harmful effects on human health, including metabolic, cardiovascular disease, and reproductive disorders. Moreover, it poses a signifincant threat to organisms and aquatic ecosystems, leading to water pollution concerns. Therefore, the removal of CaF from wastewater is crucial for mitigating water pollution and minimizing its detrimental impacts on both humans and the environment. In this study, a solar-driven Cu-doped graphitic carbon nitride (Cu/CN) photocatalyst was synthesized and evaluated for its effectiveness in oxidizing CaF in wastewater. The Cu/CN photocatalyst, with a low band gap energy of 2.58eV, exhibited superior performance in degrading CaF compared to pure graphitic carbon nitride (CN). Under solar light irradiation, CuCN achieved a remarkable CaF degradation efficiency of 98.7% CaF, surpassing CN's efficiency of 74.5% by 24.2%. The synthesized Cu/CN photocatalyst demonstrated excellent removal capability, achieving a removal rate of over 88% for CaF in wastewater. Moreover, the reusability test showed that Cu/CN could be successfully reused up to five cycles maintaining a high removal efficiency of 74% for CaF in the fifth cycle. Additionally, the study elucidated the oxidation mechanism of CaF using solar-driven Cu/CN photocatalyst and highlighted the environmental implications of the process.

Recent advances in application of graphitic carbon nitride-based catalysts for degrading organic contaminants in water through advanced oxidation processes beyond photocatalysis: A critical review

Advanced oxidation processes (AOPs) have attracted much interest in the field of water treatment owing to their high removal efficiency for refractory organic contaminants. Graphitic carbon nitride (g-C₃N₄)-based catalysts with high performance and cost effectiveness are promising heterogeneous catalysts for AOPs. Most research on g-C₃N₄-based catalysts focuses on photocatalytic oxidation, but increasingly researchers are paying attention to the application of g-C₃N₄-based catalysts in other AOPs beyond photocatalysis. This review aims to concisely highlight recent state-of-the-art progress of g-C₃N₄-based catalysts in AOPs beyond photocatalysis. Emphasis is made on the application of g-C₃N₄-based catalysts in three classical AOPs including Fenton-based processes, catalytic ozonation and persulfates activation. The catalytic performance and involved mechanism of g-C₃N₄-based catalysts in these AOPs are discussed in detail. Meanwhile, the effect of water chemistry including pH, water temperature, natural organic matter, inorganic anions and dissolved oxygen on the catalytic performance of g-C₃N₄-based catalysts are summarized. Moreover, the reusability, stability and toxicity of g-C₃N₄-based catalysts in water treatment are also mentioned. Lastly, perspectives on the major challenges and opportunities of g-C₃N₄-based catalysts in these AOPs are proposed for better developments in the future research.

Activation of persulfate by stability-enhanced magnetic graphene oxide for the removal of 2,4-dichlorophenol

A stability-enhanced magnetic catalyst, composed of α-Fe₂O₃@Fe₃O₄ shell-core magnetic nanoparticles and graphene oxide (MGO), was prepared and characterized by scanning electron micrope (SEM), X-ray diffraction (XRD), vibrating sample magnetometer (VSM), and Brunauer-Emmett-Teller (BET). Catalyst synthesis was used to efficiently activate persulfate for the removal of 2,4-dichlorophenol (2,4-DCP). A magnetic nanoparticle:GO mass ratio of 5 (MGO-5) exhibited a better catalytic efficiency and could be effectively reused four times. The influences of the pollutant, catalyst, and oxidant concentrations were investigated, and the intrinsic relationships among these factors and the degradation kinetic constant were evaluated by a fitting method. It was found that the catalytic degradation process in the MGO-5-persulfate-2,4-DCP system was most likely dominated by an interfacial catalytic reaction, with an activation energy of 13.88 kJ/mol. Radical quenching experiments and electron paramagnetic resonance (EPR) analysis indicated that both sulfate radicals (SO₄^-) and hydroxyl radicals (OH) were responsible for 2,4-DCP removal, but surface-bounded SO₄^- played a greater role. Chloride ions at a concentration of 0-60 mg/L had no effect on 2,4-DCP removal. The proposed advanced oxidation technology has potential applications for the practical removal of aqueous organic pollutants.