Porphyrin Modified UiO-66-NH2 for Highly Efficient Photoreduction of Cr(VI) under Visible Light

Abstract

Cr(VI) is a common heavy metal pollutants present in the aquatic environment, which possess toxic and carcinogenic properties. In this study, a solvothermal reaction was used to prepare porphyrin (TCPP)-modified UiO-66-NH2 (UNT). The UNT integrated adsorption and photocatalytics in the application for dealing with Cr(VI). The photocatalytic reduction activities of UNT for Cr(VI) were investigated under visible light illumination. We found that the TCPP doping amount of 15 mg UNT (15-UNT) had a 10 times higher reduction rate of Cr(VI) than pristine UiO-66-NH2. The optimal 15-UNT photocatalyst demonstrated the highest photocatalytic activity, and Cr(VI) was completely removed within 80 min. In addition, the introduction of porphyrin not only enhanced the absorption of light but also enabled the transport of photogenerated electrons from porphyrin to UiO-66-NH2, which promoted the separation of charge carriers. Furthermore, the effects of factors such as porphyrin content, pH and light source on the photocatalytic reduction performances of UNT were also explored. Overall, this work presented a possible relationship between the crystal structures and the performance of UNT.

Enhanced photoreduction efficiency of Cr(vi) driven by visible light in a new Zr-based metal–organic framework modified by hydroxyl groups

“…Meanwhile, the peaks with the higher area percentage at 576.7 eV (Cr 2p 3/2 ) and 586.4 eV (Cr 2p 1/2 ) corresponded to the Cr( iii ) product from the photoreduction process. 73,74 These findings affirm the undoubted product was Cr( iii ) after the Cr( vi ) photocatalytic reduction.…”

Interfacial Heterojunction Electronic Modulation on RuSe2@NiFeLDH Heterostructures for Water Splitting

“…It was demonstrated that selenium’s weaker electronegativity than oxygens would increase the hydroxyl ions’ preferred attachment to catalytically active metal sites, hence promoting the latter stages of the oxygen evolution reaction (OER) process. The formation of the heterojunction in photocatalyst applications is well-known in photocatalytic water splitting, − but the formation of interfacial heterojunction and the synergistic effect in electrochemical applications is still a less explored field in hydrogen evolution reaction (HER) and OER processes. Creating heterojunctions of LDHs and RuSe 2 helps in the interfacial synergistic effect between them; heterostructures act as efficient electrocatalysts for electrochemical water splitting.…”

Unlocking photocatalytic NO removal potential in an S‐type UiO‐66‐NH2/ZnS(en)0.5 heterostructure

“…[13] Among various MOF materials, aminofunctionalized Zr-UiO-type MOF (UiO-66-NH 2 ), which consists of octahedrally coordinated Zr atoms (Zr 6 O 4 (OH) 4 ) and 12 2-aminoterephthalic acid (H 2 BDC-NH 2 ) linkers per node, demonstrates exceptional performance in the removal of NO x under solar light conditions. [12,[14][15][16][17] The NH 2 functional groups play a pivotal role in narrowing the bandgap and inducing a positive shift in the valence band (VB). However, this modification results in an energy reduction in the VB edge, leading to a diminished oxidation capability of holes for deep oxidation of NO molecules.…”