Metal-organic frameworks-derived CoFeN-NC materials with the enhanced catalytic activity and selectivity for the degradation of organic dyes via adsorption and heterogeneous photo-Fenton

• Published in: Applied surface science Vol. 601; p. 154028
• Main Authors: Miao, Shihao, Xia, Hongyu, Gao, Hongcheng, Mao, Xiaoxia, Shi, Mengqin, Zhang, Yuanguang
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2022
• Subjects: Adsorption; Bimetallic; Photo-Fenton; Selectivity; Synergistic effect; Photo-Fenton; Selectivity; Synergistic effect; Adsorption; Bimetallic
• ISSN: 0169-4332; 1873-5584
• DOI: 10.1016/j.apsusc.2022.154028

Possible schematic illustration of photocatalytic degradation of organic dyes under visible light. [Display omitted] •MOFs derived cobalt iron bimetallic catalysts (CoxFe1-xN-NCs) were fabricated via self-assembly and annealing treatment.•Co0.8Fe0.2N-NC exhibited excellent adsorption and photo-Fenton synergistic effect in the degradation of organic dyes.•Co0.8Fe0.2N-NC had obvious selective degradation toward non-azo dyes.•Co0.8Fe0.2N-NC displayed favorable stability characteristics.•The active species were determined and a possible photo-Fenton degradation mechanism was proposed. Nanoscale iron-based materials are widely used as photocatalytic materials for catalytic oxidative degradation of organic dyes in water. Here, a series of MOFs derived nitrogen doped cobalt iron bimetallic carbon composite nanomaterials (CoxFe1-xN-NCs) were prepared by self-assembly and annealing treatment, and their application in the removal of organic dyes in water was investigated by the synergistic effect of adsorption and photo-Fenton. The study found that the Co0.8Fe0.2N-NC exhibit superior catalytic performance for different types of organic dyes. For example, when the concentration of MB was 40 mg L-1, the degradation rate constant was 3.88 × 10-2 min−1, which were 2.9 and 25.2 times the corresponding values of the Fenton-like and photocatalytic system, respectively. Meanwhile, compared with azo dyes Methyl Orange and Congo Red (MO and CR), Co0.8Fe0.2N-NC has obvious selective catalysis for non-azo dyes Methylene Blue, Malachite Green, Rhodamine B and Neutral Red (MB, MG, RhB and NR). Moreover, the reaction of cobalt iron active centers with hydrogen peroxide (H2O2) further promotes the generation of active substances (·OH, ·O2– and h+), speeding up the degradation of organic dyes. These results suggest that the synergistic effect of adsorption and photo-Fenton may provide new clues for the treatment of organic pollutants in wastewater.