A First-Principles Thermodynamic Model for the Ba-Zr-S System in Equilibrium with Sulfur Vapor.

The chalcogenide perovskite BaZrS has strong visible light absorption and high chemical stability, is nontoxic, and is made from earth-abundant elements. As such, it is a promising candidate material for application in optoelectronic technologies. However, the synthesis of BaZrS thin-films for characterization and device integration remains a challenge.

Extreme Concentrations of Nitric Oxide Control Daytime Oxidation and Quench Nocturnal Oxidation Chemistry in Delhi during Highly Polluted Episodes.

Delhi, India, suffers from periods of very poor air quality, but little is known about the chemical production of secondary pollutants in this highly polluted environment. During the postmonsoon period in 2018, extremely high nighttime concentrations of NO (NO and NO) and volatile organic compounds (VOCs) were observed, with median NO mixing ratios of ∼200 ppbV (maximum of ∼700 ppbV). A detailed chemical box model constrained to a comprehensive suite of speciated VOC and NO measurements revealed very low nighttime concentrations of oxidants, NO, O, and OH, driven by high nighttime NO concentrations.

Validating HONO as an Intermediate Tracer of the External Cycling of Reactive Nitrogen in the Background Atmosphere.

In the urban atmosphere, nitrogen oxide (NO═NO + NO)-related reactions dominate the formation of nitrous acid (HONO). Here, we validated an external cycling route of HONO and NO, i.e.