Remarkably Enhanced Photodegradation of Organic Pollutants by NH2-UiO-66/ ZnO Composite under Visible-Light Irradiation

Abstract

Semiconductor photocatalysis is a novel highly efficient and low-cost method for removing organic pollutants from wastewater. However, the photoreduction performance of semiconductors on organic pollutants is limited due to the weak absorption of visible light caused by its wide band gap and low carrier utilization rate resulting from severe electron-holes recombination. In the present study, flower-like NH 2 -UiO-66 (NU66)/ZnO nanocomposites were prepared using a facile method and exhibited high efficiency under visible light driven photocatalysts. The X-ray diffractometer (XRD), scanning electron microscope (SEM), transmitor electron microscope (TEM), and X-ray photoelectron spectroscopy (XPS) were used to characterize the prepared samples, indicating that NU66/ZnO was successfully synthesized. The photocatalytic activity of the prepared NU66/ZnO nanocomposites was determined by measuring the photodegradation of methylene blue (MB) and malachite green (MG) under visible-light irradiation. The optimal nanocomposite loading of 5% wt NU66 to NU66/ZnO demonstrated the highest photocatalytic activity for the degradation of MB. The photocatalytic activity of a 5% NU66/ZnO composite was approximately 95-fold and 19-fold higher than that of NU66 and ZnO samples, respectively. The enhanced activity of the 5% wt NU66/ZnO nanocomposite was further confirmed through photoelectrochemical analysis. The formation of type II heterojunctions between the counterparts significantly suppressed recombination of the photogenerated charge carriers. Photocatalytic degradation experiments with different quenchers indicated that the effect of superoxide anion radicals (•O 2 − ) had a greater effect than the other scavengers.Additionally, the improved photocatalytic mechanism underlying the activity of NU66/ZnO nanocomposites was also explored. These findings establish a basis for development of MOF based heterojunction for photocatalytic organic pollution remediation.

Customized Microenvironments Spontaneously Facilitate Coupled Engineering of Real‐Life Large‐Scale Clean Water Capture and Pollution Remediation

“…Traditional thermal distillation desalination methods fail to address the issue of seawater contamination caused by medical and industrial wastes, due to their high cost and potential secondary environmental pollution. [26,27] To tackle this problem, the CCMsx devices offer a promising solution for parallel pollutant removal by employing parallel systems in series, resulting in efficient photothermal/photocatalytic performance (Figure 4a). In experiments, simulated wastewater configurations of MB/TH (0.1 g L −1 , 20 mL) and NaCl solution (3.5 wt%, 80 mL) were utilized.…”

C3N5-based nanomaterials and their applications in heterogeneous catalysts, energy harvesting, and environmental remediation

“…Consequently, to overcome the obstacles hindering efficient energy conversion and environmental protection, extensive efforts have been devoted to exploring novel breakthroughs and frontiers in the fields of materials science and engineering. 3 Semiconductors, such as titanium dioxide (TiO 2 ), 4,5 zinc oxide (ZnO), [6][7][8] cadmium sulphide (CdS), [9][10][11][12] bismuth tungstate, [13][14][15] bismuth vanadate, 16,17 and tantalum pentoxide, 18,19 exhibit exceptional properties across a wide range of photoelectrocatalytic and energy conversion applications. 20 While semiconductor materials have displayed remarkable performance, their synthesis is demanding and difficult to expand on a large scale.…”

One‐Pot MOFs‐Encapsulation Derived In‐Doped ZnO@In2O3Hybrid Photocatalyst for Enhanced Visible‐Light‐Driven Photocatalytic Hydrogen Evolution

“…[8][9][10] Unfortunately, the photocatalytic performance of ZnO is restricted by poor light absorption because of its wide band gap of ≈3.2 eV and it only has light absorption in the UV region that constitutes only 5% of the solar spectrum. [11][12][13] Therefore, many strategies have been reported to trigger ZnO to harvest visible light. Particularly, doping with metal elements is a common strategy to tailor the electronic band structure and reduce the band gap of ZnO and thereby extending the photoabsorption of ZnO to the visible region.…”