Yijie Liu,Xianzhe Meng,Chao Li,Yifan Gong,Juan Wang,Jiang Bo
Non-biodegradable pharmaceuticals are a group of emerging contaminants that have gained much attention because of their potential risk of inducing adverse ecological and health effects. An efficient Ti/SnO2-Sb2O5-IrO2-RuO2 electrode was prepared by Pechini method and employed as the anode for electrochemical degradation of selected pharmaceuticals (i.e., ibuprofen, atenolol, and carbamazepine). Compared its counterparts, Ti/SnO2-Sb2O5-IrO2-RuO2 exhibited higher oxygen evolution potential, lower chlorine evolution potential, larger active area, and higher stability. Unlike the negligible effect of solution pH from 4.0 to 10.0, increasing current density favored the target pollutants and COD removal. The removal of IBU was mainly attributed to the reaction with •OH, the contribution of which to IBU removal was enhanced with increasing current density. In contrast to IBU, the removal of ATEN and CBZ was mainly ascribed to the reaction with selective radical chlorine species (RCS) mainly in the form of Cl•, which was produced from direct oxidation of Cl− or indirect oxidation by •OH. It was found that the removal of ATEN and CBZ was less affected by dissolved organic matter (DOM) than that of IBU in municipal effluent. This study demonstrates that Ti/SnO2-Sb-RuO2-IrO2 is an attractive electrode for the destruction of pharmaceutical contaminants.
A novel electrochemical filter has been prepared for the effective adsorption and electrochemical oxidation of aqueous organic pollutants. The adsorptive electrode utilized in the electrochemical filter was a porous Graphite-RuO 2 electrode decorated with multi-walled carbon nanotubes (MWCNTs) adsorption layer, which was prepared by sol–gel coating, thermal decomposition, and vacuum filtration synthesis. The morphology and composition of adsorptive electrode characterized by field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) revealed a uniform distribution of RuO 2 active coating and MWCNTs adsorption layer. Electrochemical measurements indicated that the adsorptive electrode possessed a favorable oxygen evolution potential (OEP) of 1.42 V and inner voltammetric charge 170.05 mC·cm −2 , which were higher than that of non-MWCNTs electrode. Furthermore, the mass transfer of adsorptive electrode was enhanced as high as 4.6-fold in the electrochemical filter. The optimal operation parameters obtained was 3 mA·cm −2 and 7 g·L −1 Na 2 SO 4 . Under this condition, the electrochemical filter can remove > 97% of pyrrole and >75% of total organic carbon. The pyrrole oxidation mechanism of electrochemical filter was also investigated, revealed three dominant reaction stages: adsorption (≤0.3 V), direct oxidation (0.3–1.2 V) and indirect oxidation (>1.2 V). In general, the high electrochemical performance of Graphite-RuO 2 -MWCNTs filter on pyrrole removal resulted from the enhanced mass transfer, which attributed to the synergistic effect of adsorption from MWCNTs, electrochemical oxidation and convection by filtration.
Modulating the hetero-structures with abundant interfaces in catalyst is a feasible but challenging strategy to improve the catalytic performance. In this work, a highly efficient catalyst ( R -CoMoO x /Ni (Co)) was prepared with plentiful interfacial structures to accelerate the hydrogen evolution reaction (HER), which contained both reduced CoO and MoO 2 as a R -CoMoO x substrate and metallic Ni (Co) particles as the catalytic center. The combination of CoO and MoO 2 with a Co-O-Mo local structure in R -CoMoO x led to an electron-enriched Co center to catch the dissociated H + , while the abundant interfacial interaction between R -CoMoO x and Ni (Co) could accelerate the charge transfer and then facilitate the production of H 2 through a fast Volmer-Tafel pathway. As a result, the integrated R -CoMoO x /Ni (Co) catalyst could drive alkaline HER with ultra-low overpotentials of 16 mV for 10 mA cm −2 (25 °C) and 186 mV for 1000 mA cm −2 (60 °C), respectively, with a good stability over 100 h. Moreover, by coupling with RuO 2 electrode in an anion exchange membrane system, it could achieve 1000 mA cm −2 at 1.78 V for overall water splitting with a high energy conversion efficiency of 70.4 %. The H 2 production cost at 1000 mA cm −2 was merely $ 0.952 per gasoline gallon equivalent, much less than the target cost of the US Department of Energy.
危险品化学品经营许可证（带存储）