The recent advancement of water stable metal–organic frameworks (MOFs) expands the application of this unique porous material. This review article aims at studying their applications in terms of five major areas: adsorption, membrane separation, sensing, catalysis, and proton conduction. These applications are either conducted in a water-containing environment or directly targeted on water treatment processes. The representative and significant studies in each area were comprehensively reviewed and discussed for perspectives, to serve as a reference for researchers working in related areas. At the end, a summary and future outlook on the applications of water stable MOFs are suggested as concluding remarks.

Applications of water stable metal–organic frameworks

A review of functionalized carbon nanotubes and graphene for heavy metal adsorption from water: Preparation, application, and mechanism.

Spinel ferrite magnetic adsorbents: Alternative future materials for water purification?

This mini-review presented photocatalytic reduction of Cr(VI) into Cr(III) in some MOFs or their derivatives/composites. The reported examples are collected and analyzed; and the reaction mechanism, the influence of various factors on the photocatalytic performance, the involved challenges, and the outlooks of MOFs as photocatalyst to carry out Cr(VI) reduction are discussed. It can be found that the optical properties of MOFs can be flexible modulated via incorporation into NH 2 group, conductor photocatalysts like ZnO and metal sulfides nanoparticles, noble metal nanoparticles and graphene oxide (GO). It is clear that MOFs have a bright prospective in the fields of photocatalytic reduction of Cr(VI), or even dual functional photcatalysts to carry out Cr(VI) reduction and organic pollutants degradation under visible light irradiation.

Photocatalytic Cr(VI) reduction in metal-organic frameworks: A mini-review

Environmental effects of the Deepwater Horizon oil spill: A review.

Adsorption is widely popular for removal of heavy metals due to its low cost, efficiency, and simplicity. The focus of this review will be the use of inorganic adsorbents engineered at the nanoscale. The applicability of iron oxide (hematite, magnetite and maghemite), carbon nanotubes (CNT), and metal oxide based (Ti, Zn) and polymeric nanoadsorbents are examined. The advantages and limitations of the type of nanoadsorbent and its functionality are evaluated. Current developments and next generation adsorbents are also reviewed. Finally, scopes and limitations of these adsorbents will be addressed while investigating the types of metal ions that are harmful.

https://pubs.rsc.org/en/content/articlepdf/2015/ra/c5ra02714d

Inorganic nano-adsorbents for the removal of heavy metals and arsenic: a review

Photolytic and photocatalytic degradation of surface oil from the Deepwater Horizon spill.

Sunlight creates oxygenated species in water-soluble fractions of Deepwater Horizon oil.

Petroleum films exposed to sunlight produce hydroxyl radical

Photochemical production of singlet oxygen from thin oil films over seawater and pure water was measured with furfuryl alcohol as a selective chemical probe. Oil was collected from the surface of the Gulf of Mexico following the deepwater horizon spill and from other sources. The loss of furfuryl alcohol and the formation of 6-hydroxy(2H)pyran-3(6H)-one were monitored. Total singlet oxygen formation was studied using high furfuryl alcohol concentrations and varying exposure time. The total amount of singlet oxygen produced in 1 h irradiations of thin oil films (100 mg, 60 microns thick) over Gulf of Mexico water and pure water were 1.9 ± 0.4 × 10−5 and 1.6 ± 0.3 × 10−5 mol, respectively. After initial tests were performed, titanium dioxide (TiO2) nanomaterials were added to the system in two different concentrations to study the effects of singlet oxygen formation in the presence of a photocatalyst. The addition of TiO2 nanoparticles did not significantly change the observed formation rate of singlet oxygen. Steady state concentrations of photoproduced singlet oxygen were also determined and found to be near 1 × 10−12 M in water under thin films of oil, which is considerably greater than values previously observed for pure seawater. This study illustrates that oil is a source of singlet oxygen when exposed to sunlight. The fate of oil and other dissolved species will be heavily dependent on the formation and reaction of singlet oxygen in thin oil films on water.

Phoebe Z. Ray

Papers

Inorganic nano-adsorbents for the removal of heavy metals and arsenic: a review

Photolytic and photocatalytic degradation of surface oil from the Deepwater Horizon spill.

Sunlight creates oxygenated species in water-soluble fractions of Deepwater Horizon oil.

Petroleum films exposed to sunlight produce hydroxyl radical

Solar production of singlet oxygen from crude oil films on water