Microwave‐Assisted Rapid Substitution of Ti for Zr to Produce Bimetallic (Zr/Ti)UiO‐66‐NH₂ with Congenetic “Shell–Core” Structure for Enhancing Photocatalytic Removal of Nitric Oxide

Abstract

Efficient nitric oxide (NO) removal without nitrogen dioxide (NO2) emission is desired for the control of air pollution. Herein, a series of (Zr/Ti)UiO‐66‐NH2 with congenetic shell–core structure, denoted as Ti‐UION, are rapidly synthesized by microwave‐assisted post‐synthetic modification for NO removal. The optimal Ti‐UION (i.e., 2.5Ti‐UION) exhibits the highest activity of 80.74% without NO2 emission with moisture, which is 21.65% greater than that of the UiO‐66‐NH2. The NO removal efficiency of 2.5Ti‐UION further increases to 95.92% without photocatalyst deactivation under an anhydrous condition. This is because selectively produced NO2 in photocatalysis is completely adsorbed into micropores, refreshing active sites for subsequent reaction. In addition, the enhanced photocatalytic activity after Ti substitution is due to the presence of Ti electron acceptor, the potential difference between the shell and core of Ti‐UION crystal, and the high conductivity of TiO units. Additionally, the improved adsorption of gas molecules not only favors NO oxidation, but also avoids the emission of NO2. This work provides a feasible strategy for rapid metal substitution in metal‐organic frameworks and insights into enhanced NO photodegradation.

A novel numerical method coupling CFD with PSO vs. a mathematical approach in the modeling of photocatalytic degradation of NO

“…5(b), which is determined by the Kubelka-Munk method. 7 This finding is consistent with that in the previous study, 20 and indicates that the prepared UiO-66-NH 2 can respond to low-energy visible light. The existence of photogenerated carriers is confirmed by the photocurrent response plot of the UiO-66-NH 2 sample shown in Fig.…”

“…The mass transfer rate at the catalyst surface, j(x) (mol m −2 s −1 ), is calculated using eqn (7). 11,31…”

“…Highly efficient photocatalysts like metal–organic frameworks (MOFs) have been reported for NO degradation. 7 However, reactor design attracts less attention. To design highly efficient reactors and fill the gap between lab-scale reactors and commercialized reactors, developing models for accurate estimation of kinetic parameters is urgently needed.…”

Bimetallic MOF‐Derived Solar‐Triggered Monolithic Adsorbent for Enhanced Atmospheric Water Harvesting

“…[28,29] Benefiting from the synergistic effects between different components, the charge density and active adsorption sites of the resultant BMOFs will be refreshed. [30,31] MOFs harvest and store water molecules relying on their active adsorption sites and pores, [4,32] so the construction of BMOF offers a novel idea for the design of efficient moisture adsorbents. However, no prior studies have reported the waterharvesting adsorbents based on BMOF and its functionalized forms yet, to the best of our knowledge.…”

Improvement of water adsorption performance of UiO-66 by post-synthetic modification

“…After that, PSM has been increasingly widely used in MOFs. 28–31 Compared to direct solvothermal synthesis, PSM has the advantages of mild reaction conditions, easy control, and can be assembled in multiple steps. For example, Chen et al successfully prepared UiO-66-PDC with the pyridine-2,5-dicarboxylic acid (PDC) ligand by PSM.…”