Mesoporous TiO2 has gained increasing interest because of its outstanding properties and promising applications in a wide range of fields. Herein, we report the facile synthesis of ordered mesoporous black TiO2 (OMBT) materials, which exhibit excellent photocatalytic hydrogen evolution performances. In this case, the employment of a thermally stable and high-surface-area mesoporous TiO2 as the hydrogenation precursor is the key for fabricating the OMBT materials, which not only facilitate H2 gas diffusion into TiO2 and interaction with their structures but also maintain the ordered mesoporous structures as well as inhibit the phase transformation (from anatase to rutile) and crystal growth during hydrogenation at 500 °C. The resultant OMBT materials possess a relatively high surface area of ∼124 m(2) g(-1) and a large pore size and pore volume of ∼9.6 nm and 0.24 cm(3) g(-1), respectively. More importantly, the OMBT materials can extend the photoresponse from ultraviolet to visible and infrared light regions and exhibit a high solar-driven hydrogen production rate (136.2 μmol h(-1)), which is almost two times as high as that of pristine mesoporous TiO2 (76.6 μmol h(-1)).

No abstract

No abstract

No abstract

This work reports an experimental investigation on the morphology and kinetics of CO2 hydrate formation in the presence of sodium dodecyl sulfate (SDS). The experiments were conducted at 277.15 K and 3.5 MPa, and the quantity of SDS varies from 0 to 3000 ppm. The “wall climbing” phenomenon of CO2 hydrate formation in the presence of SDS was observed, and the growth of CO2 hydrate above the gas–liquid interface was found to become stronger as the SDS concentration was increased from 300 to 3000 ppm. This indicates that the promoting effect of SDS on CO2 hydrate formation was enhanced with the increase of SDS concentration. The largest gas consumption for CO2 hydrate formation in SDS solutions was obtained at 1500 ppm of SDS among the four SDS concentrations tested in this work, which increased by 85% compared to that obtained in pure water under the same temperature and pressure conditions. When CO2 hydrate formation was conducted for a considerably long period, two rapid jumps in the gas consumption could be observed as the SDS concentration increased above 300 ppm, and the plateau between the two jumps was shortened with the increase of SDS concentration. As a result, a high efficiency for CO2 hydrate formation was obtained at 1500 and 3000 ppm of SDS. This will provide an implication to the improvement of the hydrate-based CO2 capture technology in the future.