Cascade N2 Reduction Process with DBD Plasma Oxidation and Electrocatalytic Reduction for Continuous Ammonia Synthesis.

Due to the extremely high bond energy of N≡N (∼941 kJ/mol), the traditional Haber-Bosch process of ammonia synthesis is known as an energy-intensive and high CO2-emission industry. In this paper, a cascade N2 reduction process with dielectric barrier discharge (DBD) plasma oxidation and electrocatalytic reduction as an alternative route is first proposed. N2 is oxidized to be reactive nitrogen species (RNS) by nonthermal plasma, which would then be absorbed by KOH solution and electroreduced to NH4+. It is found that the production of NOx is a function of discharge length, discharge power, and gas flow rate. Afterward, the cobalt catalyst is used in the process of electrocatalytic reduction of ammonia, which shows high selectivity (Faradic efficiency (FE) above 90%) and high yield of ammonia (45.45 mg/h). Finally, the cascade plasma oxidation and electrocatalytic reduction for ammonia synthesis is performed. Also, the performance of the reaction system is evaluated. It is worth mentioning that a stable and sustainable ammonia production efficiency of 16.21 mg/h is achieved, and 22.16% of NOx obtained by air activation is converted into NH4+. This work provides a demonstration for further industrial application of ammonia production with DBD plasma oxidation and electrocatalytic reduction techniques.

[Fabrication of silver ordered nanoarrays SERS-active substrates and their applications in bladder cancer cells detection].

Highly ordered silver nanopore and nanocap arrays, which were used as surface-enhanced Raman scattering active (SERS-active) substrates, were fabricated by electron-beam evaporating silver on the surface of porous layer and barrier layer of porous anodic alumina (PAA) membranes, respectively. The SERS characteristics of the SERS-active substrates were tested with bladder cancer cells as molecular probe. The results indicated that both the SERS-active substrates displayed a strong SERS enhancement effect. The silver nanocap ordered arrays SERS-active substrate displayed not only higher SERS and fluorescence quenching effect, but also no interferential spectrum related with oxalate impurity remaining in PAA membranes, and therefore can result in the high quality Raman spectroscopy of bladder cancer cells.