In-situ reduction by Joule heating and measurement of electrical conductivity of graphene oxide in a transmission electron microscope

Abstract

Graphene oxide (GO) is reduced by Joule heating using in-situ transmission electron microscopy (TEM). The approach allows the simultaneous study of GO conductivity by electrical measurements and of its composition and structural properties throughout the reduction process by TEM, electron diffraction and electron energy-loss spectroscopy. The small changes of GO properties observed at low applied electric currents are attributed to the promotion of diffusion processes. The actual reduction process starts from an applied power density of about 2 × 1014 Wm−3 and occurs in a highly uniform and localized manner. The conductivity increases more than 4 orders of magnitude reaching a value of 3 × 103 Sm−1 with a final O content of less than 1%. We discuss differences between the reduction by thermal annealing and Joule heating.

A solution-processed MoS2/graphene heterostructure mediated by a bifunctional block copolymer as a non-noble metal platform for hydrogen evolution

“…27 Regarding the analysis of the C 1s spectrum, the peaks at $284.5, $286 and $289 eV correspond to C-C, C]O, and COOH, respectively, as it can be observed in GO samples. 28 Next, the electrocatalytic behavior of the heterostructure was evaluated for the HER via LSV assessments aqueous 0.5 M H 2 SO 4 . We screened the optimum mass ratio of the ce-MoS 2 and GO + counterparts within the heterostructure with that of ce-MoS 2 and GO + counterparts with the 10 : 1 mass ratio being the best-performing and used for further evaluation of the electrocatalytic HER activity.…”

“…27 Regarding the analysis of the C 1s spectrum, the peaks at ∼284.5, ∼286 and ∼289 eV correspond to C–C, CO, and COOH, respectively, as it can be observed in GO samples. 28…”

Novel spatially distributed heating carbon fabric and decoupling of interfacial electricity

“…1,2 Resistance heating (Joule heating) is the process by which an electric current pass through a conductor to produce heat, which requires an electrically conductive material. [3][4][5] However, traditional fabric heating elements mostly coated by various conductive particles, nanofiber or nanotubes on non-conductive fibers or fabric in order to render the needed conductivity. [6][7][8][9] The method involving coatings is versatile in terms of the choice of fibers for the fabric, but it suffers from the limited durability and complex technological process of the coating.…”

Heterostructured Mo‐Doped CoP on MXene Supports Enhanced the Alkaline Hydrogen Evolution Activity

“…[25][26] After etching, the bond between MXene and the A-layer is replaced by terminals (-F, -OH, or -O), resulting in many active anchor points on the MXene surface. [27][28][29] Moreover, compared to the conductivity of 2D graphene materials (3400 S ⋅ m À 1 ), [30] that of MXene is as high as 9880 S ⋅ m À 1 , making it more suitable for conductive substrates. [31] Besides, it has been reviewed that the combination of MXene with active materials including MoS 2 , [32][33][34] LDH, [35][36][37] CoP, [38][39] and Mo 2 C, [40][41][42] exhibited excellent HER activity.…”