A novel geo-photocatalyst, an iron-containing layered clay mineral, for photocatalytic H2 evolution from water.

An iron-containing phyllosilicate clay mineral is presented as the first example of a naturally occurring photocatalyst for hydrogen evolution from water. Sodium-proton ion exchange and immobilization of Pt nanoparticles were examined to boost photocatalytic hydrogen evolution. Clay and the clay based photocatalysts exhibited high stability upon photocatalytic recycling tests.

Organophilic Clay with Useful Whiteness.

An organophilic clay was obtained by the intercalation of dioctadecyldimethylammonium ions into the interlayer space of a purified bentonite. The organophilic clay was characterized by its excellent whiteness, which originated from the used purified bentonite with a low content of colored impurities, suitable for its practical application in paints, cosmetics, polymer additives, etc. The dioctadecyldimethylammonium-bentonite clay was applied as a support to accommodate polyaromatic molecules to afford luminescent hybrids with high luminescence efficiency, showing its usefulness as a component of photofunctional hybrid materials.

Effective Se reduction by lactate-stimulated indigenous microbial communities in excavated waste rocks.

Waste rocks generated from tunnel excavation contain the metalloid selenium (Se) and its concentration sometimes exceeds the environmental standards. The possibility and effectiveness of dissolved Se removal by the indigenous microorganisms are unknown. Chemical analyses and high-throughput 16S rRNA gene sequencing were implemented to investigate the functional and structural responses of the rock microbial communities to the Se and lactate amendment. During anaerobic incubation of the amended rock slurries from two distinct sites, dissolved Se concentrations decreased significantly, which coincided with lactate degradation to acetate and/or propionate. Sequencing indicated that relative abundances of Desulfosporosinus burensis increased drastically from 0.025 % and 0.022% to 67.584% and 63.716 %, respectively, in the sites. In addition, various Desulfosporosinus spp., Symbiobacterium-related species and Brevibacillus ginsengisoli, as well as the Se(VI)-reducing Desulfitobacterium hafniense, proliferated remarkably. They are capable of incomplete lactate oxidation to acetate as only organic metabolite, strongly suggesting their involvement in dissimilatory Se reduction. Furthermore, predominance of Pelosinus fermentans that ferments lactate to propionate and acetate implied that Se served as the electron sink for its fermentative lactate degradation. These results demonstrated that the indigenous microorganisms played vital roles in the lactate-stimulated Se reduction, leading to the biological Se immobilization treatment of waste rocks.

Novel Flexible Supramolecular Assembly of Dioleyldimethylammonium Ion in a Two-Dimensional Nanospace Studied by Neutron Scattering.

Dioleyldimethylammonium ion was used to construct two-dimensional hybrid structures with clay and the hybrid was shown to possess higher flexibility than that of the hybrid of dioctadecyldimethylammonium and the clay. The important difference between the two surfactant systems was studied by quasi-elastic neutron scattering, confirming the useful characteristics of the presently designed dioleyldimethylammonium-clay over the well-known dioctadecyldimethylammonium-clay for various materials applications.