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The ordered monolayer graphene oxide (GO)-shielded Ag nanowire (AgNW) film was used as a large-area uniform and long-term stable surface-enhanced Raman scattering (SERS) substrate, while the Ag nanoparticles (AgNPs) decorated on the outside surface of GO layers can increase the roughness of the film for providing more SERS active sites. What's more, as a subnanometer spacer, GO created a uniform nanogap between AgNPs and AgNWs that can form more hot spots in the nanocomposite film. By virtue of these advantages, the AgNWs@GO-AgNPs composite film exhibits a highly sensitive SERS measure with a detection limit of rhodamine 6G (R6G) as low as 10 −13 M. Besides, we also investigated the catalytic activity of the AgNWs@GO-AgNPs composite film for the reduction of 4-nitrophenol (4-NP) as a probe reaction.

In this paper, a facile and efficient method combined sol–gel method with hydrothermal process was employed for preparing titanium dioxide (TiO[Formula: see text]/reduced graphene oxide (rGO) nanocomposites without using any reductants or surfactants. This approach leads to the reduction of graphene oxide (GO) and the growth of TiO2 nanorods simultaneously. The results reveal that the TiO2 short nanorods with average size of 15[Formula: see text]nm in length and 10[Formula: see text]nm in diameter were uniformly grown on the rGO sheets with high dispersion. Compared with the pure TiO2 nanoparticles, the TiO2/rGO composites exhibit strong absorption in the visible light range. The photocurrent density of nanocomposites reached 0.826[Formula: see text]mA/cm2 under the simulated sunlight illumination, which is 3.5 times than that of pure TiO2. An enhancement of photocatalytic hydrogen formation rate for the water splitting was observed over the TiO2/rGO composite photocatalysts, the fastest formation rate can reach 889.28[Formula: see text][Formula: see text]mol[Formula: see text]g[Formula: see text]h[Formula: see text] when TiO2 coupling with 1wt.% rGO. Also the hydrogen production rate is about 3.27 times larger than pure TiO2 and 2.23 times than P25 due to the excellent electron trapping and transportation properties of rGO and the synergistic effect between TiO2 and rGO.

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In this study, a novel one‐dimensional iron‐based nitrogen‐doped carbon nanotube (N‐CNT) nanocomposite (Fe/Fe2.5C/Fe3N/N‐CNT) was successfully synthesized in situ by using a facile and low‐cost method. In alkaline media, the typical product (Fe/Fe2.5C/Fe3N/N‐CNT‐30) showed an good onset potential (Eonset=0.93 V vs RHE), half‐wave potential (E1/2=0.79 V vs RHE), and current density (J=6.62 mA cm−2 at 0.2 V vs RHE), especially compared to the commercial 20 % Pt/C catalyst (0.95 V, 0.82 V, 5.61 mA cm−2, respectively). In acidic medium, it also exhibits a good oxygen reduction reaction (ORR) activity. Moreover, Fe/Fe2.5C/Fe3N/N‐CNT‐30 exhibited superior long‐term durability and methanol tolerance compared to Pt/C in both alkaline and acidic media. The excellent electrocatalytic performance of this material is attributed to the abundant carbon defects in the carbon structure, the high content doping of pyridinic N and graphitic N into the CNTs, the multi‐model Fe species as active sites, and the fact that most Fe species within the CNTs avoid corrosion from electrolyte. This study paves a new way for highly active ORR electrocatalysts and promotes the rapid development of CNTs in some frontier fields.