Mercury pollution threatens the environment and human health across the globe. This neurotoxic substance is encountered in artisanal gold mining, coal combustion, oil and gas refining, waste incineration, chloralkali plant operation, metallurgy, and areas of agriculture in which mercury‐rich fungicides are used. Thousands of tonnes of mercury are emitted annually through these activities. With the Minamata Convention on Mercury entering force this year, increasing regulation of mercury pollution is imminent. It is therefore critical to provide inexpensive and scalable mercury sorbents. The research herein addresses this need by introducing low‐cost mercury sorbents made solely from sulfur and unsaturated cooking oils. A porous version of the polymer was prepared by simply synthesising the polymer in the presence of a sodium chloride porogen. The resulting material is a rubber that captures liquid mercury metal, mercury vapour, inorganic mercury bound to organic matter, and highly toxic alkylmercury compounds. Mercury removal from air, water and soil was demonstrated. Because sulfur is a by‐product of petroleum refining and spent cooking oils from the food industry are suitable starting materials, these mercury‐capturing polymers can be synthesised entirely from waste and supplied on multi‐kilogram scales. This study is therefore an advance in waste valorisation and environmental chemistry.

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In the present work, nanowire morphologies of α-MnO, cobalt monodoped α-MnO, Cu and Co bidoped α-MnO, and Ni and Co bidoped α-MnO samples were prepared by a facile hydrothermal synthesis. The structural, morphological, surface, and redox properties of all the as-prepared samples were investigated by various characterization techniques, namely, scanning electron microscopy (SEM), transmission and high resolution electron microscopy (TEM and HR-TEM), powder X-ray diffraction (XRD), N sorption surface area measurements, X-ray photoelectron spectroscopy (XPS), hydrogen-temperature-programmed reduction (H-TPR), and oxygen-temperature-programmed desorption (O-TPD). The soot oxidation performance was found to be significantly improved via metal mono- and bidoping. In particular, Cu and Co bidoped α-MnO nanowires showed a remarkable improvement in soot oxidation performance, with its T (50% soot conversion) values of 279 and 431 °C under tight and loose contact conditions, respectively. The soot combustion activation energy for the Cu and Co bidoped MnO nanowires is 121 kJ/mol. The increased oxygen vacancies, greater number of active sites, facile redox behavior, and strong synergistic interaction were the key factors for the excellent catalytic activity. The longevity of Cu and Co bidoped α-MnO nanowires was analyzed, and it was found that the Cu/Co bidoped α-MnO nanowires were highly stable after five successive cycles and showed an insignificant decrease in soot oxidation activity. Furthermore, the HR-TEM analysis of a spent catalyst after five cycles indicated that the (310) crystal plane of α-MnO interacts with the soot particles; therefore, we can assume that more-reactive exposed surfaces positively affect the reaction of soot oxidation. Thus, the Cu and Co bidoped α-MnO nanowires provide promise as a highly effective alternative to precious metal based automotive catalysts.

Spectrally–selective monitoring of ultraviolet radiations (UVR) is of paramount importance across diverse fields, including effective monitoring of excessive solar exposure. Current UV sensors cannot differentiate between UVA, B, and C, each of which has a remarkably different impact on human health. Here we show spectrally selective colorimetric monitoring of UVR by developing a photoelectrochromic ink that consists of a multi-redox polyoxometalate and an e− donor. We combine this ink with simple components such as filter paper and transparency sheets to fabricate low-cost sensors that provide naked-eye monitoring of UVR, even at low doses typically encountered during solar exposure. Importantly, the diverse UV tolerance of different skin colors demands personalized sensors. In this spirit, we demonstrate the customized design of robust real-time solar UV dosimeters to meet the specific need of different skin phototypes. These spectrally–selective UV sensors offer remarkable potential in managing the impact of UVR in our day-to-day life.

Surface defects of Fe-doped CeO2 nanorods were found to be active sites for increasing peroxidase mimetic activity.

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Oxygen vacancies in inorganic semiconductors play an important role in reducing electron-hole recombination, which may have important implications in photocatalysis. Cuprous oxide (Cu2O), a visible light active p-type semiconductor, is a promising photocatalyst. However, the synthesis of photostable Cu2O enriched with oxygen defects remains a challenge. We report a simple method for the gram-scale synthesis of highly photostable Cu2O nanoparticles by the hydrolysis of a Cu(i)-triethylamine [Cu(i)-TEA] complex at low temperature. The oxygen vacancies in these Cu2O nanoparticles led to a significant increase in the lifetimes of photogenerated charge carriers upon excitation with visible light. This, in combination with a suitable energy band structure, allowed Cu2O nanoparticles to exhibit outstanding photoactivity in visible light through the generation of electron-mediated hydroxyl (OH˙) radicals. This study highlights the significance of oxygen defects in enhancing the photocatalytic performance of promising semiconductor photocatalysts.

The catalytic behavior of various CeO 2 -based solid solutions, namely, Ce 12x TM x O 22d (TM = Mn, Fe, or Zr) and Ce 12x RE x O 22d (RE = Pr, La, or Sm) was studied for the removal of elemental mercury (Hg 0 ) from coalderived flue gas by catalytic oxidation (Hg 0 A Hg 2+ ). The investigated catalysts were synthesized by a coprecipitation method and characterized by various techniques, namely, X-ray diffraction (XRD), Raman spectroscopy (RS), high-resolution electron microscopy (HREM), Brunauer-Emmett-Teller (BET) surface area, X-ray photoelectron spectroscopy (XPS), temperature programmed reduction (TPR), and diffuse reflectance spectroscopy (UV-DRS). The XRD results confirmed the incorporation of Mn, Fe, Zr, La, Pr, and Sm cations into the CeO 2 lattice and the formation of nanocrystalline solid solutions. The TEM measurements established the nanocrystalline nature of the solid solutions. The RS measurements suggested that the substitution process promotes the formation of oxygen vacancies, which hastens the diffusion rate of oxygen and improves the Hg oxidation. UV-vis DRS studies demonstrated the presence of the charge transfer transitions O 22 A Ce 3+ and O 22 A Ce 4+ . The XPS and H 2 -TPR results suggested that the reduction of Ce 4+ A Ce 3+ is the foremost reason for the increase in oxygen vacancies, which are beneficial for Hg 0 removal. The order of mercury oxidation activity over various doped catalysts is as follows: CM . CL . CZ . CF . CS . C . CP.