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Graphene shows great promise as a high-efficiency electrothermal film for flexible transparent defoggers/defrosters. However, it remains a great challenge to achieve a good balance between the production cost and the properties of graphene films. Here, we proposed a cost-effective self-assembly method to fabricate high-performance, large-area graphene oxide/electrochemically exfoliated graphene hybrid films for heater applications. The self-assembled graphene hybrid films with the area of 20 × 20 cm 2 could be transferred onto arbitrary substrates with nonplanar surfaces and simply patterned with the hard mask. After reduction by hydrogen iodide vapor followed by 800 °C thermal treatment, the hybrid films with the transmittance of 76.2% exhibit good heating characteristics and defogging performance, which reach a saturation temperature of up to 127.5 °C when 40 V was applied for 60 s. [ABSTRACT FROM AUTHOR]

The technical advance of plasma enhanced chemical vapor deposition (PECVD) exhibits the potential to grow large-area high-quality graphene films at relatively low growth temperature, which is beneficial to the fabrication of graphene-based electronic devices/sensors and transparent electrode. However, it remains a challenge to overcome the degradation of graphene quality during growth by PECVD, due to the continuous bombardment of plasma ions on the catalyst surface. Herein, the combined techniques of PECVD and the growth of graphene underneath the catalyst layer were proposed. As a result, transfer-free single-layer graphene films with 2.5 inch in diameter on quartz substrate can be obtained with the growth temperature of 700 °C, which is 250 °C lower than that for graphene synthesis using thermal CVD. The graphene films prepared by our method show the ability to form on the rough surfaces with millimeter-scale grooves and have minimal surface contamination, compared to that of conventionally transferred CVD graphene. [ABSTRACT FROM AUTHOR]

Graphene is widely recognized as a promising nanomaterial for the construction of high-performance electrochemical biosensors. However, the lack of strong interfacial forces between graphene and conductive substrates is a bottleneck in the fabrication of highly stable graphene electrodes. In this work, few-layer graphene was directly formed on a high pressure high temperature (HPHT) diamond substrate via sp 3 -to-sp 2 conversion by catalytic thermal treatment and using diamond itself as the carbon source. The hybrid electrode prototype was also highly conductive and had a linear electrochemical response to dopamine in the concentration range of 5 μM – 2 mM, with a low detection limit of 200 nM. After prolonged and repeated exposure to dopamine, electrode fouling was observed which led to sensitivity degradation. Based on the strong interfacial bonding between graphene and HPHT diamond, regeneration of the fouled electrode and full performance recovery would be easily achieved by ultrasonic cleaning. The hybrid electrode is highly robust, and shows potential in its application to the detection of biofouling molecules, food processing and wastewater treatment. [ABSTRACT FROM AUTHOR]

Graphene/carbon nanofilament (G/CNF) hybrids were synthesized by an electrochemical post-treatment of as-prepared CNFs. After the mild electrochemical exfoliation, the surface of CNFs was partially exfoliated and converted into graphene nanosheets. Field emission measurements for G/CNF hybrids show a low turn-on voltage of 1.34 V/μm and a high field enhancement factor ( β ) of 4930. The extraordinary β is attributed to the strong edge emitter effect of graphene nanosheets based on their high aspect ratio and high surface area. [ABSTRACT FROM AUTHOR]