Growth Mechanisms of Nano-to Micro-Sized Lead Sulfate Particles.

PbSO4 is a key component in the charging and discharging of lead acid batteries-such as the cycling of automotive batteries. PbSO4 is a poor conductor that forms on the positive and negative electrodes during discharging and dissolves during charging of a lead acid battery. Over time, buildup of PbSO4 occurs on the electrodes, ultimately reducing the efficiency of the battery. This study aims to determine the nucleation and growth mechanisms of PbSO4 nanoparticles in various solutions to potentially reduce or control the buildup of PbSO4 on battery electrodes over time. The time dependency of particle morphology was observed using various reaction conditions. PbSO4 particles were created using premixed solutions at various times of reaction. H2O, acetone, methanol, ethanol, and isopropanol were used to stop the reaction and development of the PbSO4 particles. The structure of the nanoparticles was characterized via transmission electron microscopy, high-angle annular dark field scanning transmission electron microscopy, and selected area electron diffraction. This study provides insight into the mechanism by which PbSO4 nanoparticles form in various solutions and reveals that the degree of complexity of the solution plays a large role in the nucleation and growth of the PbSO4 nanoparticles. This insight can provide avenues to reduce unwanted buildup of PbSO4 on battery electrodes over time, which can extend battery life and performance.

Molecular sensing and discrimination by a luminescent terbium-phosphine oxide coordination material.

PCM-15 is a robust and recyclable sensor for the effective discrimination of a wide range of small molecules. Sensing is achieved by direct attenuation of the luminescence intensity of Tb(III) ions within the material. A competition study involving trace amounts of NH3 in H2 gas shows that PCM-15 can be used to quantitatively detect trace analytes.

Gas sorption and luminescence properties of a terbium(III)-phosphine oxide coordination material with two-dimensional pore topology.

The structure, stability, gas sorption properties and luminescence behaviour of a new lanthanide-phosphine oxide coordination material are reported. The polymer PCM-15 is based on Tb(III) and tris(p-carboxylated) triphenylphosphine oxide and has a 5,5-connected net topology. It exhibits an infinite three-dimensional structure that incorporates an open, two-dimensional pore structure. The material is thermally robust and remains crystalline under high vacuum at 150 °C. When desolvated, the solid has a CO(2) BET surface area of 1187 m(2) g(-1) and shows the highest reported uptake of both O(2) and H(2) at 77 K and 1 bar for a lanthanide-based coordination polymer. Isolated Tb(III) centres in the as-synthesized polymer exhibit moderate photoluminescence. However, upon removal of coordinated OH(2) ligands, the luminescence intensity was found to approximately double; this process was reversible. Thus, the Tb(III) centre was used as a probe to detect directly the desolvation and resolvation of the polymer.