Highly porous diamond foam as a thin-film micro-supercapacitor material

Combining nanostructuration with boron doping to alter sub band gap acceptor states in diamond materials

“…Boron-doped diamond foam was prepared as described previously. 32 Briey, silica spheres of 0.5 mm diameter were spin-coated onto a 4 mm thick polycrystalline boron-doped diamond layer on a silicon wafer and seeded by dip-coating in a H-terminated ND solution. Aer overgrowth, this process was repeated twice to obtain diamond foams with 3 layers.…”

“…The resulting diamond lm had a boron concentration of 5 Â 10 20 atoms cm À3 (ca. 2835 ppm) as determined by Raman scattering 32 and comprised of grains with average size of 10 nm. 32 Finally, the silica spheres were removed in hydrouoric acid.…”

“…To this aim, boron doping has been investigated as boron is a trivalent atom with a smaller atomic radius which enables its easy incorporation in the diamond lattice. 25,26 Over the last 30 years, 27 boron doped diamond has been synthesized in different forms such as single crystal (SCD), polycrystalline (PCD) or nanocrystalline lm electrode, [28][29][30] diamond foam (Dfoam) electrodes, 31,32 and nanodiamonds (ND) 33 using primarily CVD [34][35][36] and HPHT 26,37,38 methods. X-ray absorption spectroscopy (XAS) allows the investigation of the unoccupied states in a material.…”

“…According to the pDOS calculations, it is quite clear that the boron atoms at the Pandey-chain reconstructed surfaces contribute to the surface states closer to the valence band edge. As B:PCD-H and B:Dfoam-O contain numerous grain boundaries, 32 based on the theoretical calculations it is therefore reasonable to assert that presence of B atoms near the grain boundaries induce defects at these non-terminated surfaces resulting in the high intensity peaks attributed to surface excitonic states. However, in case of B:Dfoam-H the defect states that are predominantly present at the surface of the crystallites are completely saturated upon hydrogenation [62][63][64] resulting in the absence of states A and B at the H-terminated surfaces as validated by theory calculations.…”

Battery‐like Supercapacitors from Vertically Aligned Carbon Nanofiber Coated Diamond: Design and Demonstrator

“…Such a process is automatically controlled by a single-board microcontroller which is also possible to be connected with a USB connector to a computer ( Figure 6a). [2] , diamond network (network) [3] , diamond/silicon nanowires (SiNW) [4] , diamond foam (Foam) [5] , honeycomb diamond (Honeycomb) [6] , porous diamond (Porous) [7] , BDD/Nanotube (Nanotube) [8] , BDD/carbon fiber (CF) [9] , BDD/'black silicon' (bSi) [10] , nitrogen included ultrananocrystalline diamond (N-UNCD) [11] , diamond paper (Paper) [12] , CNFs/BDD (CNF, this [14] , MnO 2 /BDD (MnO 2 ) [2] , Ni(OH) 2 /Diamond Nanowire (Ni(OH) 2 ) [15] , poly(3,4-(ethylenedioxy)thiophene)-coated diamond@silicon nanowires (PEDOT) [16] ; BDD based PC using redox electrolyte (Dia) [3a] , diamond network PC using redox electrolyte (Network) [3a] , CNFs/BDD PC using redox electrolyte (CNF, this work). [18] Cross-linked N-doped CNF network 1.0M H 2 SO 4 5.9 10.0 [19] Mesoporous CNF 6.0 M KOH 5.1 16.0 [20] CNF paper 6.0 M KOH 7.1 9.0 [21] Porous CNF composites 6.0 M KOH 17.0 20.0 [22] Porous CNF 1.0 M H 2 SO 4 ~6.0 20.0 [23] CNFs/BDD [24] ZnO/porous activated CNF 6.0 M KOH 22.7 4.0 [25] MnO 2 /CNF // CNF 0.5 M Na 2 SO 4 36 4.4 [26] CNFs/BDD …”