Three-dimensional (3D) graphene materials, which are integrated using graphene structural units, show great promise for energy-related applications because of the high specific surface area, fast electron transport, and low density. Beyond solution-phase assembly of graphene sheets, chemical vapour deposition (CVD) has been recently introduced as a scalable, high-yield, and facile strategy for preparing 3D graphene materials with relatively high crystallinity and controllable layer numbers. Such 3D graphene structures have served as ideal platforms for constructing next-generation energy storage and conversion devices such as supercapacitors, batteries, and fuel cells. In this tutorial review, we focus on recent progress in the scalable CVD growth of 3D graphene materials (e.g., foams, shells, and hierarchical structures) as well as their applications in energy-related fields. First, we emphasize the role of substrate shape and composition (metal or non-metal) in the CVD growth of diverse 3D graphene materials. The related growth mechanisms of these 3D graphene materials are also analysed and discussed. Second, we demonstrate the applications of the CVD-derived 3D graphene materials in various energy-related devices. Finally, we conclude this review with our insights into the challenges and future opportunities for CVD synthesis as well as the application of such intriguing 3D graphene materials.

26 expanded the application regimes of optical fibre 1-12 . The emergence of graphene excites new 27 opportunities by combining with PCF, allowing for electrical tunability, broadband optical 28 response and all-fibre integration ability 13-18 . However, the previous demonstrations are typically 29 limited to the sample level of micron size, far behind the requirement of real applications for the 30 metre-scale material level. Here, we demonstrate a new hybrid material of graphene photonic 31 crystal fibre (Gr-PCF) with length up to half a metre by chemical vapour deposition method. The 32 Gr-PCF shows strong light-matter interaction with ~8 dB⋅cm -1 attenuation. In addition, the 33 Gr-PCF-based electro-optic modulator demonstrates broadband response (1150 -1600 nm) and 34 large modulation depth (~20 dB⋅cm -1 at 1550 nm) under low gate voltage of ~2 volts. Our results 35 could enable industrial-level graphene applications based on the Gr-PCF, and suggest an infusive 36 platform of two-dimensional material-PCF. 37Graphene is a promising material in photonic and optoelectronic applications due to its superior 38 properties of high carrier mobility, broadband optical response and facile electrical tunability originating 39 from its unique linear dispersion of massless Dirac fermions [19][20][21][22][23][24][25][26][27][28] . Although the light-matter interaction in 40 graphene normalized by its atomic thickness (0.34 nm) is quite strong, the measurable interaction is in 41 fact quite weak (only ~2.3% light absorption) 29 . To greatly enhance light-graphene interaction, many 42 efforts have been devoted to combine graphene flakes with well-designed optical structures, such as 43 gratings, waveguides and microcavities 30-34 , however, all those hybrid structures have still stayed at 44 sample level of micron size, rather than material level of metre size, which limits their massive 45 applications. Therefore, there exists great demand to develop new methods for massive production on 46 graphene-based optical structures for material-level applications. 47Optical fibre provides the highest-quality optical waveguide for information communication and 48 photon manipulation, and it has been massively manufactured at kilometre length scale. PCF represents 49 the most important advance of optical fibre in the last twenty years and possesses extremely rich 50 functions beyond traditional optical fibre in the exciting applications of endlessly single-mode fibres, 51 supercontinuum lasers, frequency combs, optical soliton propagation, high-power pulse delivery and so 52 on 1-7 . Especially, PCF with ingenious porous structure opens up the hard-won opportunity of filling 53 various materials, ranging from gases, liquids, solids to liquid crystals, to expand its great new 54 3 / 14 functionalities in mode-locked fibre lasers, laser frequency conversion, surface plasmon generation, 55 stimulated Raman scattering and in-fibre thermal-or electro-optic devices 8-15 . The rise of 56 two-dimensional (2D) graphene naturally excites the ...

Mass production of high-quality graphene flakes is important for commercial applications. Graphene microsheets have been produced on an industrial scale by chemical and liquid-phase exfoliation of graphite. However, strong-interaction-induced interlayer aggregation usually leads to the degradation of their intrinsic properties. Moreover, the crystallinity or layer-thickness controllability is not so perfect to fulfill the requirement for advanced technologies. Herein, we report a quartz-powder-derived chemical vapor deposition growth of three-dimensional (3D) high-quality graphene flakes and demonstrate the fabrication and application of graphene/g-C3N4 composites. The graphene flakes obtained after the removal of growth substrates exhibit the 3D curved microstructure, controllable layer thickness, good crystallinity, as well as weak interlayer interactions suitable for preventing the interlayer stacking. Benefiting from this, we achieved the direct synthesis of g-C3N4 on purified graphene flakes to form the uniform graphene/g-C3N4 composite, which provides efficient electron transfer interfaces to boost its catalytic oxidation activity of cycloalkane with relatively high yield, good selectivity, and reliable stability.