In the monolayer limit, transition metal dichalcogenides become direct-bandgap, light-emitting semiconductors. The quantum yield of light emission is low and extremely sensitive to the substrate used, while the underlying physics remains elusive. In this work, we report over 100 times modulation of light emission efficiency of these two-dimensional semiconductors by physical adsorption of O2 an...

The state of vanadium ions in VxOy/SBA-15 (2.7 wt % V) was studied with FTIR spectroscopy using CO and NO as probe molecules. Neither CO (at 85 K) nor NO (at RT) adsorb on the oxidized sample because of the coordinative saturation of V5+ ions and the covalent character of the V5+=O bond. After treatment of the sample in 50 kPa H2 at 673 K, the V5+ ions are reduced to two different types of V3+ ...

The species formed by exposure of a Pd/ceria catalyst to SO2 under various conditions have been studied using temperature-programmed desorption (TPD) and FTIR. For adsorption of SO2 between 298 and 473 K, a molecular SO2 species adsorbs on the surface, possibly as a surface sulfite; and this species converts to a sulfate above 473 K. Exposure of Pd/ceria to SO2 at temperatures above 473 K in th...

Transitional metal nanoparticles or atoms deposited on appropriate substrates can lead to highly economical, efficient, and selective catalysis. One of the greatest challenges is to control the electronic metal-support interactions (EMSI) between the supported metal atoms and the substrate so as to optimize their catalytic performance. Here, from first-principles calculations, we show that an o...

The adsorption and desorption of thiophene and the reactions of thiophene-derived adsorbed species in He, H2, and O2 were examined on H-ZSM5, H-Beta, and H-Y with varying Si/Al ratios. Thiophene adsorption uptakes (per Al) were independent of Al content, but were above unity and influenced by zeolite structure (1.7, 2.2, and 2.9 on H-ZSM5, H-Beta, and H-Y). These data indicate that thiophene ol...

Cooking oil, triglycerides that is liquid at room temperature, one of important foodstuffs. Repeated use cooking oil might decrease the quality and leads to negative impacts on health. An alternative method treat used adsorption with cacao shell. This present study aims find out influences adsorbent size variation peels as reduction free fatty acid, peroxide numbers water content in oil. The te...

Significant research interest has been directed towards the deployment of direct air capture (DAC) as a net-negative CO2 emissions technology to help limit global temperature rise below 2 °C. The scope this review is outline advancement adsorption-based DAC technologies, well highlight still-existing data gaps, for both materials’ development and process design in period 2016 – 2021. On materia...