Nail Polishes: A Review on Composition, Presence of Toxic Components, and Inadequate Labeling Aislana Cole de Paula, Fabrício Uliana, Eloi Alves da Silva Filho, Priscilla Paiva Luz Dermatology Research and Practice, 2025 Nail polishes were developed in 1920, and since 1940, it has been known that these cosmetics contain toxic and sensitizing components. Over the years, nail polishes have undergone several changes in their formulation to avoid this problem, but new components have also been considered toxic and allergenic. The growing demand for gel nails has also been highlighted in cases of allergy to (meth)acrylates, and the biggest concern that was previously related to the presence of toluene sulfonamide‐formaldehyde resin (TSFR) in traditional nail polish formulations is now also part of (meth)acrylate‐based cosmetics. The beautification caused by nail polish is the main factor behind its constant use throughout the world, but studies have demonstrated its use for other purposes, such as treating fungal diseases, sun protection factor in cancer patients, and as a possible ally in forensic area. This review brings the beginning of the discovery of nail polish and its trajectory to the present day, including its effects on health and its inadequate labeling. Therefore, it is extremely important that legislation monitors the composition of nail cosmetics and that new formulations are studied to make them safe for health and the environment.
PdAg/C Electrocatalysts Synthesized by Thermal Decomposition of Polymeric Precursors Improve Catalytic Activity for Ethanol Oxidation Reaction Yonis Fornazier Filho, Ana Caroliny Carvalho da Cruz, Rolando Pedicini, José Ricardo Cezar Salgado, Rodrigo Vieira Rodrigues, et al. Catalysts, 2022 An efficient ethanol oxidation reaction (EOR) is required to enhance energy production in alcohol-based fuel cells. The use of bimetallic catalysts promises decreasing reliance on platinum group metal (PGM) electrocatalysts by minimizing the use of these expensive materials in the overall electrocatalyst composition. In this article, an alternative method of bimetallic electrocatalyst synthesis based on the use of polymeric precursors is explored. PdAg/C electrocatalysts were synthesized by thermal decomposition of polymeric precursors and used as the anode electrocatalyst for EOR. Different compositions, including pristine Pd/C and Ag/C, as well as bimetallic Pd80Ag20/C, and Pd60Ag40/C electrocatalysts, were evaluated. Synthesized catalysts were characterized, and electrochemical activity evaluated. X-ray diffraction showed a notable change at diffraction peak values for Pd80Ag20/C and Pd60Ag40/C electrocatalysts, suggesting alloying (solid solution) and smaller crystallite sizes for Pd60Ag40/C. In a thermogravimetric analysis, the electrocatalyst Pd60Ag40/C presented changes in the profile of the curves compared to the other electrocatalysts. In the cyclic voltammetry results for EOR in alkaline medium, Pd60Ag40/C presented a more negative onset potential, a higher current density at the oxidation peak, and a larger electrically active area. Chronoamperometry tests indicated a lower poisoning rate for Pd60Ag40/C, a fact also observed in the CO-stripping voltammetry analysis due to its low onset potential. As the best performing electrocatalyst, Pd60Ag40/C has a lower mass of Pd (a noble and expensive metal) in its composition. It can be inferred that this bimetallic composition can contribute to decreasing the amount of Pd required while increasing the fuel cell performance and expected life. PdAg-type electrocatalysts can provide an economically feasible alternative to pure PGM-electrocatalysts for use as the anode in EOR in fuel cells.
Development of palladium catalysts modified by ruthenium and molybdenum as anode in direct ethanol fuel cell Yonis Fornazier Filho, Ana Caroliny Carvalho da Cruz, Rolando Pedicini, José Ricardo Cezar Salgado, Priscilla Paiva Luz, et al. Materials for Renewable and Sustainable Energy, 2021 Physical and electrochemical properties of Pd catalysts combined with Ru and Mo on carbon support were investigated. To this end, Pd, Pd1.3Ru1.0, Pd3.2Ru1.3Mo1.0 and Pd1.5Ru0.8Mo1.0 were synthesized on Carbon Vulcan XC72 support by the method of thermal decomposition of polymeric precursors and then physically and electrochemically characterized. The highest reaction yields are obtained for Pd3.2Ru1.3Mo1.0/C and Pd1.5Ru0.8Mo1.0/C and, as demonstrated by thermal analysis, they also show the smallest metal/carbon ratio compared the other catalysts. XRD (X-ray Diffraction) and Raman analyses show the presence of PdO and RuO2 for the Pd/C and the Pd1.3Ru1.0/C catalysts, respectively, a fact not observed for the Pd3.2Ru1.3 Mo1.0 /C and the Pd1.5Ru0.8Mo1.0/C catalysts. The catalytic activities were tested for the ethanol oxidation in alkaline medium. Cyclic voltammetry (CV) shows Pd1.3Ru1.0/C exhibiting the highest peak of current density, followed by Pd3.2Ru1.3Mo1.0/C, Pd1.5Ru0.8Mo1.0/C and Pd/C. From, chronoamperometry (CA), it is possible to observe the lowest rate of poisoning for the Pd1.3Ru1.0/C, followed by Pd3.2Ru1.3Mo1.0/C, Pd1.5Ru0.8Mo1.0/C and Pd/C. These results suggested that catalytic activity of the binary and the ternary catalysts are improved in comparison with Pd/C. The presence of RuO2 activated the bifunctional mechanism and improved the catalytic activity in the Pd1.3Ru1.0/C catalyst. The addition of Mo in the catalysts enhanced the catalytic activity by the intrinsic mechanism, suggesting a synergistic effect between metals. In summary, we suggest that it is possible to synthesize ternary PdRuMo catalysts supported on Carbon Vulcan XC72, resulting in materials with lower poisoning rates and lower costs than Pd/C. Graphic abstract
Physicochemical and electrochemical characterization of Ce/carbonaceous matrices-based composites Patrícia F. Santos, Josimar Ribeiro, Priscilla P. Luz Solid State Sciences, 2020 Ce/carbonaceous matrices-based composites with potential application in electrochemical processes were successfully produced. Ce-based MOF-76 (Metal Organic-Framework-76 family, formed by lanthanide ions coordinated to 1,3,5-benzenetricarboxylic acid ligand - H3BTC or simply BTC) was prepared with different percentages of graphene oxide (GO) in situ (named Ce-BTC-GOX%), then calcined to CeO2-rGOX%. All obtained materials were characterized by physicochemical techniques. The presence of carbonaceous matrices in the composites improves their thermal stability, alters particles shape, and decreases their size. All materials underwent Cyclic Voltammetry tests and selected composites were evaluated by Electrochemical Impedance Spectroscopy, Hydrogen Evolution Reaction and Oxygen Evolution Reaction. The electron transfer between Ce3+/Ce4+ redox pairs is observed around 1.3 and 1.2 V vs. Ag/AgCl(sat.KCl) for oxidation and reduction, respectively. Among all produced materials, the Ce-BTC-GO30% presented the best electrochemical response, reaching 0.506 mA g-1 of anodic current and 19.92 mC g-1 of charge density. Its capacitance reaches 3340.8 μF cm-2, while its resistance to charge transfer decreases (2.4 Ω cm2) and Tafel equation slopes are 84.3 mV dec-1 for HER and 60.5/127.9 mV dec-1 for OER.
