查看更多>>摘要：The photocatalytic peroxymonosulfate (PMS) activation process offers great potential for organic wastewater treatment. In this study, enol-incorporated carbon nitride (ECN) catalysts were used for PMS activation to degrade organic pollutants under visible-light irradiation. Our experimental and theoretical results revealed that the incorporation of enol into the poly-heptazine-based carbon nitride framework effectively tuned the electronic structure. The obtained ECN showed promoted PMS activation capability, along with increased visible-light harvesting ability and improved photogenerated charge separation. As a result, an excellent performance with a bisphenol A removal rate of 100% within 20 min and a total organic carbon (TOC) removal rate of 86% in 30 min was achieved in the Vis-PMS/ECN process. This was because ECN functioned as an efficient photocatalyst as well as PMS activator, which enabled the PMS activation process to proceed smoothly for center dot SO4- production under visible-light irradiation. These findings could offer some guidelines for the development of efficient metal-free photocatalysts in the persulfate-based advanced oxidation process for environmental remediation.
查看更多>>摘要：Precious metal-free Fe-N-C catalysts efficiently electrocatalyze the oxygen reduction reaction both in acid and alkaline electrolyte. Their stability is however limited in acidic medium, but generally accepted to be much higher in alkaline electrolyte. Herein, by combining advanced electron and X-ray based techniques, we provide comprehensive evidence of a Fe dissolution/reprecipitation mechanism, which partially transforms single Fe atoms into Fe oxide nanoparticles and Fe carbide nanoparticles into Fe carbide core@Fe oxide shell nano particles, and is independent on the gas atmosphere used during the accelerated stress tests. Our work shows that Fe-N-C materials based on zero-valent Fe nanoparticles should be designed so that all Fe nanoparticles are protected by a defect-free graphite shell, for improved durability. For single atom Fe-N-C catalysts, the present study raises the question of a possible synergy between minute amount of Fe oxide nanoparticles and Fe-NxCy single-atom sites, leading to the higher apparent durability of this catalyst.
McMichael, S.Tolosana-Moranchel, A.Cortes, M. A. L. R. M.Hamilton, J. W. J....
13页
查看更多>>摘要：In photoelectrocatalysis (PEC) a considerable amount of research has been focused on improving the photoelectrode; however, cathodic reactions are essential to PEC disinfection. In this work, a TiO2 nanotube (TiNT) array was used as the photoanode with various cathode electrodes materials, including gas diffusion electrodes (GDE) modified with different Pt nanoparticle loadings. The highest rate of E.coli inactivation was achieved with the non-modified GDE (2.51 log) compared to Pt mesh paddle (0.79 log reduction). This was explained by the examining reactive oxygen species generated at the counter electrode, where the non-modified GDE had the highest Faradaic efficiency of 15.5% for the formation of H2O2. Modification with Pt inhibited the formation of H2O2 to below the detection limit. The TiNT photoanode was shown to generate hydroxyl radicals, but importantly, there was reduction of molecular oxygen to superoxide radical at the anode. A thin cell reactor was then constructed using the identified optimal materials and a 5.0 log reduction in E.coli was in 20 min under UVA irradiation.
查看更多>>摘要：The hollow core-shell Co9S8 @ZnIn2S4/CdS nanoreactors are fabricated by growing ZnIn2S4 nanosheets and CdS quantum dots on hollow Co9S8 nanocages for photocatalytic CO2 reduction and H-2 generation. Because of unique structural and compositional advantages, Co9S8 @ZnIn2S4/CdS exhibits a significant photocatalytic BPA degradation of 90.62%, CO production of 82.10 mu mol g(-1) h(-1), and H-2 evolution rate up to 1419.14 mu mol g(-1) h(-1). Excellent photocatalytic performances are attributed to unique core-shell architecture, which can improve the scattering and refraction efficiency of incident light, and the separation and migration of photoinduced carriers. Furthermore, Co9S8 @ZnIn2S4/CdS possesses a broad absorption spectrum facilitating outstanding photothermal performance. The photocatalytic mechanism for the nanoreactor has been discussed in detail.
NSTL
Elsevier