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The paper reports on the preparation of reduced graphene oxide/silver nanoparticles (rGO/AgNPs) nanocomposite through the reduction of graphene oxide (GO) and silver nitrate (AgNO3) using environmentally friendly L-arginine (Arg). The chemical composition of the resulting nanocomposite has been analyzed using transmission infrared (FTIR) spectroscopy, Raman spectroscopy and X-ray photoelectron spectroscopy (XPS). The results indicated that Arg was incorporated in the rGO matrix. The morphology of the rGO/Arg/AgNPs composite has been characterized by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Ag NPs with an average diameter of 20 nm are homogeneously distributed on crumpled graphene nanosheets. The electrocatalytic activity of the rGO/Arg/AgNPs hybrid nanomaterial has been investigated for the nonenzymatic detection of hydrogen peroxide (H2O2) in PBS solution. The sensor displayed a detection limit of ≈50 μM over a wide linear range from 0.2 to 2.5 mM with a sensitivity of 1.34 mA mM−1 cm−2. In addition, the sensor also showed good selectivity for H2O2 detection and long-term stability.

A magnetically separable hybrid material consisting of Co3O4 nanoparticles supported on reduced graphene oxide (Co3O4/rGO) was synthesized through a simple co-reduction process of graphene oxide (GO) and cobalt chloride (CoCl2) using sodium borohydride (NaBH4). The Co3O4/rGO heterogeneous catalyst exhibited a high-performance for the oxidative esterification of aldehydes to the corresponding methyl esters using tert-butylhydroperoxide (TBHP) as an oxidant. Owing to the synergistic effect of rGO support, the hybrid catalyst exhibited superior catalytic activity than the corresponding cobalt oxide catalyst. Importantly, the synthesized hybrid possesses good magnetic properties, which provide the facile recovery of the catalyst by using external magnet.

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Zinc oxide nanorods (ZnO NRs), synthesized by a low temperature chemical method, were postannealed at 260 °C in air and under high pressure water vapor (HWA) at 1.3–3.9 MPa. We found that the UV luminescence intensity increased by a factor of 2–3 after HWA annealing compared to that observed after annealing in air. Structural analysis of the nanorods in relation with their optical properties by means of Raman and XPS spectroscopies, transmission and scanning electron microscopies allow to conclude that the origin of the UV luminescence enhancement is due to the transformation of the Zn­(OH)2 surface–layer into ZnO, but also to the growth of a new thin ZnO layer at the surface of the rods. This layer is 1–2 nm thick and its presence leads to surface reconstruction of the nanorods. In addition, we show that the size and the density of the nanopores within the ZnO NRs are reduced upon HWA annealing with respect to air annealing.

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Strain sensors have spread at present times, and their electrical resistance has been interpreted. In reality, the use of strain sensors has broadened the reach of technology and allowed us to track changes in the environment in various ways. In recent years, due to their distinctive properties, films based on advanced carbon nanomaterials have started applying sophistication sensing. The strength of the tailored material has been obtained in addition to the various functions applied to these nanomaterials due to the particular structure of the nanomaterials. A prime catalyst for developing nanoscale sensors was this excellent feature. Carbon nanomaterials-based films have been increasing widely due to the excellent properties of nanocomposite-based films for sensing applications (piezoelectric application). There is also an instinctive structure of nanomaterials so that the material is high. Carbon nanomaterials such as graphene are now an excellent alternative for the production of sensors for thermal, electric and mechanical reading.