Metal-Free Synthesis of Boron-Doped Graphene Glass by Hot-Filament Chemical Vapor Deposition for Wave Energy Harvesting

Advances in the synthesis of heteroatom-doped graphene-based materials and their application in sensors, adsorbents and catalysis

In recent years, as a new type of carbon material, graphene has attracted much attention owing to its high conductivity, large specific surface area and excellent chemical stability. After introducing heteroatoms into graphene, the physical, chemical and biological properties of doped graphene are significantly enhanced. This review focuses on synthesis methods for N, B, P and S co-doped graphene and graphene-based composites and comprehensively discusses their recent applications in the fields of sensors, adsorbents and catalysis. The challenges and application prospects of heteroatom doped graphene materials are also proposed. This study provides a reference and guidance for the development and application of new doped graphene materials.

Energy Harvesting of Deionized Water Droplet Flow over an Epitaxial Graphene Film on a SiC Substrate

This study investigates energy harvesting by a deionized (DI) water droplet flow on an epitaxial graphene film on a SiC substrate. We obtain an epitaxial single-crystal graphene film by annealing a 4H-SiC substrate. Energy harvesting of the solution droplet flow on the graphene surface has been investigated by using NaCl or HCl solutions. This study validates the voltage generated from the DI water flow on the epitaxial graphene film. The maximum generated voltage was as high as 100 mV, which was a quite large value compared with the previous reports. Furthermore, we measure the dependence of flow direction on electrode configuration. The generated voltages are independent of the electrode configuration, indicating that the DI water flow direction is not influenced by the voltage generation for the single-crystal epitaxial graphene film. Based on these results, the origin of the voltage generation on the epitaxial graphene film is not only an outcome of the fluctuation of the electrical-double layer, resulting in the breaking of the uniform balance of the surface charges, but also other factors such as the charges in the DI water or frictional electrification. In addition, the buffer layer has no effect on the epitaxial graphene film on the SiC substrate.

Ocean wave energy generator based on graphene/TiO2 nanoparticle composite films

Harvesting ocean wave energy through carbon-based materials, particularly graphene, is receiving increasing attention. However, the complicated fabrication process and the low output power of the present monolayer graphene-based wave energy generators limit their further application. Here, we demonstrate the facile fabrication of a new type of wave energy generator based on graphene/TiO₂ nanoparticle composite films using the doctor-blading method. The developed wave energy harvesting device exhibits a high open-circuit voltage of up to 75 millivolts and a high output power up to 1.8 microwatts. A systematic study was conducted to explore the optimal conditions for the energy harvesting performance.

Tuning the properties of boron-doped reduced graphene oxide by altering the boron content

Boron-doping enhanced the occurrence of the energy bandgap, the pore structure and interfacial charge transfer characteristics.