BACKGROUND Arsenic in drinking water poses serious potential health risks in more than 30 countries with total affected population of around 100 million people. The present study is devoted to the development of innovative sorbents based on zeolite materials for As(V) sorption by modifying raw materials with iron oxyhydroxide and manganese oxychloride. Natural clinoptilolite and synthetic zeolite A were modified in order to obtain improved sorption of As(V). Sorption properties of newly developed sorbents were studied. Zeolites containing natural clinoptilolite are chosen due to relatively low cost and their broad use in industrial production as well as characteristic large surface area. RESULTS Results obtained indicate that modification of zeolites with FeOOH and Mn8O10Cl3 significantly improves the As(V) sorption capacity of newly developed materials. As(V) sorption on FeOOH‐modified aluminosilicates follows the Langmuir model, while on unmodified aluminosilicates it is described by the Freundlich model. As(V) sorption kinetics on both modified and unmodified materials most precisely can be described by Lagergren's pseudo‐second‐order kinetic model. Elevated As(V) concentration on the surface of Mn8O10Cl3 crystals and amorphous FeOOH indicates these compounds as responsible for sorption increase. CONCLUSION Developed sorbents show improved performance in comparison with their unmodified counterparts, with a dramatic increase in As(V) sorption capacity up to 99.3 times in the case of FeOOH‐modified calcium zeolite A. These materials have great potential for As(V) removal in aqueous medium. © 2017 Society of Chemical Industry

In this study, we investigate triboelectrification in polymer-based nanocomposites using identical polymer matrixes containing different concentrations of nanoparticles (NPs). The triboelectric surface charge density on polymer layers increased as the...

Understanding photochromicity is essential for developing new means of modulating the optical properties and optical response of materials. Here, we report on the synthesis and exciting new photochromic behavior of Nb5+ doped TiO2 nanoparticle colloids (NCs). We find that, in hole scavenging media, Nb5+ doping significantly improves the photochromic response time of TiO2 nanoparticles. In the infrared regime, Nb-doped TiO2 NCs exhibit 1 order of magnitude faster photoresponse kinetics than the pristine TiO2. Enhanced photochromic response is observed in the visible light regime as well. The transmittance of Nb-doped TiO2 NCs drops to 10% in less than 2 min when irradiated by UV-light in the 500 nm range. The photochromic reaction is fully reversible. The physical origin of the high reaction rate is the high Nb5+ concentration. As a donor dopant, Nb5+ builds up a significant positive charge in the material, which leads to highly efficient electron accumulation during the UV irradiation and results in a rapid photoresponse. EPR experiments identify a new defect type from Nb5+ doping, which alters the physical mechanisms available for transmittance modulation. Our new NCs are economic to synthesize and highly suitable for switchable photochromic applications, e.g., smart windows for modulating visible light and infrared transmittance in built-environments.