UiO-66-NH₂ Metal–Organic Frameworks with Embedded MoS₂ Nanoflakes for Visible-Light-Mediated H₂ and O₂ Evolution

Abstract

Hydrogen evolution from water splitting by means of a photocatalytic approach is an ideal future energy source and free of fossil reserves, in contrary photocatalytic O 2 evolution remains a bottleneck due to high over potential and low efficiency. For reasonable use of solar light, photocatalysts must be sufficiently stable and efficient toward harvesting of sunlight from both theoretical and practical viewpoints. In this regard, here we have prepared MoS 2 -modified UiO-66-NH 2 MOF through a facile hydrothermal technique and evaluated its efficiency toward photocatalytic H 2 and O 2 evolution by water splitting in the presence of sacrificial agents. A couple of similar type of analyses have been studied previously; however, this analysis represents a diverse scientific approach on the basis of interfacial contact toward reveal the actual potential of nanoflakes MoS 2 as well as UiO-66-NH 2 . In this regard the as-synthesized photocatalyst was wellcharacterized by XRD, FTIR, UV−vis diffuse reflectance spectra, FESEM, HRTEM, XPS, and BET analysis techniques, which provide sufficient evidence toward successful synthesis of the pristine materials and efficacious anchorage of MoS 2 on the active surface of UiO-66-NH 2 by the ionic interaction between Zr−O and S/Mo. Among the synthesized photocatalysts (3 wt %) MoS 2 / UiO-66-NH 2 shows the optimum outcome toward H 2 and O 2 evolution, i.e., 512.9 μmol/h (4.37 times greater than bare UiO-66-NH 2 ) and 263.6 μmol/h (4.25 and 11.32 times greater than bare UiO-66-NH 2 and MoS 2 , respectively). The superior performance obtained by the composite is due to the synergistic effect of pristine UiO-66-NH 2 and MoS 2 which proceeds through a type-II interband alignment for the facile channelization of excitons. This investigation will bestow a beneficial blue-print to construct challenging photocatalysts and to find out the paramount performance toward photocatalytic water redox reaction.

Metal oxide integrated metal organic frameworks (MO@MOF): rational design, fabrication strategy, characterization and emerging photocatalytic applications

“…the hard/soft acid/base principle. 21 In addition to this, visible active MOFs are very essential for which functionalised linkers should be used by either an in situ method or the PSM method. Basically MOFs drew the interest of the research community in 1990 and then various research groups including Yaghi et al paved the way for future MOFs.…”

“…Basically properties such as high reactivity, surface area-volume ratio, good size distribution, high density, limited size of metal oxides (MOs) and internal features, such as magnetic, electrical, optical, mechanical and catalytic properties etc., have enhanced their importance in various fields of applications such as solar cells, batteries, supercapacitors, chemical sensors, anti-corrosion coatings, catalysts etc. [19][20][21][22][23][24][25][26] In this regard, a series of metal oxides has been reported, including TiO 2 , MoO 3 , MnO 2 , Bi 2 O 3 , BiVO 4 , Fe 2 O 3 , NiO, CuO, ZnO, WO 3 , Zn 2 GeO 4 , NiFe 2 O 4 etc. [27][28][29][30][31][32][33][34][35][36][37][38] As a MOF is an incomparable photocatalyst in terms of its surface area, pore volume and flexibility, it can provide an active surface as a host material for the homogeneous dispersion of MOs and so their coordination with the MOF can provide an effective synergistic effect as a photocatalyst.…”

Heterostructured MOFs photocatalysts for water splitting to produce hydrogen

“…3c-e). Besides, the electrostatic interaction between Zr and Mo-S and the ''bottle-aro und-the-ship" method have been recently developed to anchor nanoflake MoS 2 onto the exposed surface of NH 2 -UiO-66 for the formation of type-II heterostructure [47], which were found to well facilitate the charge carriers' migration as well as the photocatalytic activity.…”

Interface enriched highly interlaced layered MoS2/NiS2 nanocomposites for the photocatalytic degradation of rhodamine B dye

“…It conrms the uniform distribution of molybdenum, sulfur and nickel in the nanocomposite matrix. 30,32 Based on the above results, growth mechanism has been proposed in Fig. 6.…”