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N-doped carbon materials are considered as one of the most promising alternatives for oxygen reduction reaction (ORR). However, they are usually limited due to their low porosity and low active N content. Here, we use adenine as a nitrogen-doped carbon (NC) precursor and the NaCl and ZnCl2 mixed molten salt as a template, and show that the pore structure of carbon materials can be controlled by adjusting the pyrolysis temperature, facilitating the exposure of active sites and improving the graphite-N content. Experiments showed that SZ-NC-900 (where S represents sodium chloride, Z represents zinc chloride) had a hierarchical porous structure (specific surface area was 2710.58 m2 g−1) and high N-doping content (8.93%). Therefore, it exhibited comparable ORR activity in alkaline medium (half wave potential was 0.856 V versus reversible hydrogen electrode). After 5000 cycles, the half-wave potential of SZ-NC-900 shifted only 1.4 mV compared with Pt/C (53 mV). In addition, the zinc–air battery (ZAB) prepared with SZ-NC-900 as the catalyst was superior to the Pt/C-based ZAB, further proving its application value. [ABSTRACT FROM AUTHOR]

Nitrogen-doped graphene (N-G) is considered as a promising catalyst for the oxygen reduction reaction (ORR). However, the contributions of pyridinic N, pyrrolic N and graphitic N in N-G for the ORR catalytic activity are controversial. In this work, the contents of pyridinic N, pyrrolic N and graphitic N in N-G were transformed by annealing at different temperatures. It is found that the total N content in N-G is not the critical factor to determine the ORR activity. An increase in the annealing temperature can enhance the content of graphitic N in N-G, causing an improved catalytic ORR activity, which confirms that graphitic N is the active component. Moreover, the enriched graphitic N in the N-G-1000 catalyst shows a half-wave potential (E1/2) of 0.862 V, 29 mV higher than that of the commercial Pt/C catalyst (0.833 V), which is one of the best reported for ORR metal-free catalysts. [ABSTRACT FROM AUTHOR]

It is well known that surface nanocrystallization and passivation treatment are effective ways of improving corrosion resistance properties of the electrogalvanized steel, but their synergistic effects have rarely been studied. In this study, the effect of surface nanocrystallization on the chromium-free passivation film of electrodeposited zinc coating is investigated. Meanwhile, the formation mechanism of the chromium-free passivation film on electrodeposited zinc coating changing with the reduction of grain sizes from micro to nano-meters is analyzed and a model for the formation mechanism is proposed. The chromium-free passivation film of nanocrystalline zinc coating combines the advantages of passive films and nano-materials, and has better corrosion protection performance than the chromium-free passivation film of coarse-grained zinc coating and nanocrystalline zinc coating as well as a mirror decorative effect with light blue color. The corrosion resistance properties of coarse-grained zinc coating are heightened almost five times due to the synergistic effects of passivation treatment and nano-electrodeposition technologies. [ABSTRACT FROM AUTHOR]

A novel approach for synthesizing a CuInxGa1−xSe (CIGS) thin film is reported. The film is prepared by a one-step electrodeposition from 1-butyl-3-methylimidazolium tetra-fluoroborate (BMImBF4) mixed with ethanol followed by post-annealing. This is a two-electrode preparation process without additives. The film is of high crystalline quality p-type semiconductor with a band gap of 1.41 eV. [ABSTRACT FROM AUTHOR]

An effective composite additive used for an investigated cyanide-free silver plating bath was introduced. Mirror bright silver deposits with an excellent leveling capability as well as a smooth and compact morphology could be obtained from the investigated cyanide-free bath in the presence of the introduced composite additive. [ABSTRACT FROM AUTHOR]