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Ambient-pressure-dried (APD) crack-free Sb-SnO2 xerogel has been developed through a facile sol-gel approach. Propylene oxide was added into the tin and antimony precursors to cause rapid formation of the wet gel, which was then modified with silica and dried under ambient pressure. A silica modification carried out by soaking the wet gel in TEOS/ethanol solution, in combination with solvent exchange, allowed to avoid the risky and costly supercritical drying (SCD) process. The silica possessed dual-functional effects during the synthesis process as surface silylation agent and underlying silica structure. FT-IR, SAXS, TEM, and nitrogen physisorption analysis revealed a favorable silica dispersion, outstanding specific surface area (254 m2 g−1), pore volume (0.52 cm3 g−1), and ideal pore size (8.75 nm) for the products. The key properties of the APD crack-free Sb-SnO2 xerogel were compared with that of SCD aerogel at the same synthesis conditions. Finally, the electrochemical behaviors of 3D electrochemical system filled with the as-synthesized materials as particle electrodes were investigated, which with regard to voltammetric charge and polarization impedance. Padding of the crack-free Sb-SnO2 xerogels yielded a voltammetric charge 2.99 times as large as that of conventional electrochemical system, and decreased the charge transfer resistance from 46.19 to 6.39 Ω, which realize intrinsically enhanced electrochemical performance for 3D electrochemical system. [ABSTRACT FROM AUTHOR]

Diffusion in electrochemistry is a critical issue for water purification. Electrocatalytic reactor system in improving water quality is a useful way to induce convection to enhance diffusion. This study focuses on the preparation and the characterization of Ti/SnO 2 –Sb tubular porous electrode for degrading pyridine wastewater. The electrode as an anode in reactor system is prepared by coating SnO 2 –Sb as an electro-catalyst via Pechini method on the tubular porous Ti. Scanning Electron Microscopy, Energy Dispersive Spectrum, X-ray Diffraction and Pore Distribution are employed to evaluate the structure and morphology of the electrodes coatings, and Linear Sweep Voltammetry and Cyclic Voltammetry are used to illustrate the electrochemical properties of the electrodes coatings. Furthermore, the electrochemical oxidation performance of Ti/SnO 2 –Sb tubular porous electrode is characterized by degrading pyridine wastewater. The effects of flow and static pattern, initial pyridine concentration, supporting electrolyte concentration, current density and pH on the performance of the reactor were investigated in the electrocatalytic reactor system. The results indicated that the removal ratio of pyridine reaches maximum which is 98% under the optimal operation conditions, that are 100 mg L −1 initial pyridine concentration, 10 g L −1 supporting electrolyte concentration, 30 mA cm −2 current density and pH 3. Transition state calculation based on the density function theory was combined with High Performance Liquid Chromatography, Gas Chromatography and Ionic Chromatography results to describe the pathway of pyridine degradation. [ABSTRACT FROM AUTHOR]