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.

A mixed-valency bimetallic Ce/Zr MOF with Ce 3+ / Ce 4+ ions incorporated and an oxygen vacancy-rich singlecomponent photocatalyst have been designed through the onestep solvothermal route to harness photons from the visible-light spectrum for green energy (H 2 ) generation and ciprofloxacin (CIP) degradation. The one-pot-engineered bimetallic Ce/Zr MOF shows visible-light-active characteristics accompanied by a narrower band gap, along with enhanced exciton separation and superior ligand-to-metal charge transfer (LMCT), due to the presence of an interconvertible Ce 3+ /Ce 4+ ions pair in comparison to its pristine MOF counterpart. The Ce ion insertion led to increase in electron density around the Zr 4+ ion, along with generation of some oxygen vacancies (OV), which cumulatively led to the rise in the photo-reaction output. The synthesized UNH (Ce/Zr 1:1) MOF displayed a boosted photocatalytic H 2 production rate of 468.30 μmol h −1 (ACE = 3.51%), which is around fourfolds higher than that of pristine MOFs. Moreover, for CIP photodegradation, the UNH (Ce/Zr 1:1) shows an enhanced efficiency of 90.8% and follows pseudo-first-order kinetics with a rate constant of 0.0363. Typically, the active species involved in the photo-redox reaction of the CIP photodegradation follows the order hydroxyl radical (OH • ) < superoxide radical (O 2•− ), as confirmed by the TA and NBT tests. Consequently, the bimetallic Ce/Zr MOF can be readily employed as a robust photocatalyst with enhanced tendencies towards CIP degradation and H 2 evolution.

The current study on Au/Pd@UiO-66-NH2 explores a novel approach towards photocatalytic SMC coupling reaction. This investigation highlights a well studied mechanistic pathway towards the formation of biphenyl as the target product.

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This review focuses on the possible synthesis route, characterization techniques, and mechanistic pathways involved in the photocatalytic applications of MO@MOFs.