Synergistic adsorption and photocatalytic degradation of persist synthetic dyes by capsule-like porphyrin-based MOFs

Abstract

The synergistic effects involving surface adsorption and photocatalytic degradation commonly play significant roles in the removal of persistent synthetic organics from wastewater in the case of porous semiconductors. Inspired by the visible-light harvesting advantages of porphyrinbased MOFs, a capsule-like bimetallic porphyrin-based MOF (PCN-222(Ni/Hf)) has been successfully constructed through a facile hydrothermal method. In which, the Hf (IV) ions were exactly bonded to the carboxyl groups substituted on the porphyrin rings, meanwhile the Ni (II) ions were finely bonded to the −N inside the porphyrin rings. The adsorption/photocatalytic performances were assessed by using four persistent dyes including rhodamine B (RhB), basic violet 14 (BV14), crystal violet, and acid black 210 (AB210) as the target substances, and enhanced total removal efficiency was obtained by the bimetallic PCN-222(Ni/Hf) in comparison with that of single . The electrochemical analyses and the sacrificial agent capture experiments were carried out to elucidate the photocatalytic mechanism, and the adsorption/photocatalytic stability of PCN-222(Ni/Hf) is also investigated. The work has broadened the applications of porphyrin-based MOFs in the removal of organics by combining their excellent surface adsorption capacity and photocatalytic activities.

Co-adsorption and Fenton-like oxidation in the efficient removal of methylene blue by MIL-88B@UiO-66 nanoflowers

“…These types of interactions have been reported in the adsorption of aromatic organics by MOFs-based adsorbents. 6,55–58…”

“…These types of interactions have been reported in the adsorption of aromatic organics by MOFs-based adsorbents. 6,[55][56][57][58] To further understand the Fenton-like oxidation behaviour of MIL-88B@UiO-66, equations for reaction kinetic were applied to fit the oxidation kinetics in the presence of H 2 O 2 :…”

Porphyrin-based MOFs for photocatalysis in water: advancements in solar fuels generation and pollutants degradation

“…A related study described the synthesis of a capsule-like bimetallic Hf-PCN-222(Ni) where Hf 4+ is part of the inorganic SBU, while Ni 2+ ions are bonded to the N inside the porphyrin rings, and the free-base counterpart Hf-PCN-222. 131 Authors described the simultaneous removal of four dyes using Hf-PCN-222 where the porphyrin is in its free base form, using visible light (Xe lamp 300 W) in only 2 h, reaching degradation percentages of 99.7% for RhB (40% adsorption/desorption equilibrium, 2 h), 98.6% for basic violet 14 (BV14, 87%), 55.5% for crystal violet (CV, 30%), and 67.9% for acid black 210 (AB210, 27%). The removal efficiencies increased for the metalated form of the MOF, Hf-PCN-222(Ni) reaching degradation percentages of 100% for RhB (99% adsorption/desorption equilibrium, 2 h) and BV14 (87%), 70% for CV (60%) and 83% for AB210 (47%).…”

Porphyrin-containing materials for photodegradation of organic pollutants in wastewaters: a review

“…B. Zhang, X. Zhang and co-workers 83 prepared a bimetallic porphyrin MOF of PCN-222(Ni/Hf) by inserting Ni( ii ) in the inner core of H 2 22 and coordinating Hf( iv ) with the carboxyl groups of the porphyrin. The authors assessed the photocatalytic activity of the MOF for the degradation of four pollutants: RhB, basic violet 14, crystal violet and acid black 210 (AB) – Table 4.…”