NMR Investigations of Hydrogen Intercalates in GaSe Layered Crystals

Wear Resistance of Spark Ignition Engine Piston Rings in Hydrogen-Containing Environments

“…The hydrogen forms a "nanoband," limited by the linear size of the crystallite and capable of reversible absorbing-releasing hydrogen cycles. Under the mentioned conditions, the absolute value of the change in the parameter c trends according to the thermal expansion mechanisms from room temperature to 373 K [28,29,31]. During hydrogen intercalation, the crystal lattice parameter a is also altered (from 0.375 to 0.377 nm).…”

“…where σ 0 is the depth of the potential well; P H is the pressure of the counterbody per unit area of the body, MPa; S is Sutherland's constant (S H2 = 72); and K, gradT, and gradP are the gradients of temperature and pressure on the body surface. The characteristic cross-sectional size L for bodies can be determined from the parameters of the crystal lattice, taking into account the fact that the piston rings are made of high-strength nodular cast iron (Figure 1) with inclusions of graphite (which belong together with molybdenum disulfides and diselenides, and gallium and indium monoselenides) to the family of 2D layered materials with their unique properties [24][25][26][27][28][29][30][31][32]. On the lattice scale, the distance between graphite layers intercalated by hydrogen (up to 75 ppm and possibly by short-length hydrocarbons) [33] is equal to 0.335 nm, can be taken as the characteristic size of the section, and is the ideal gap (due to low van der Waals interaction between the layers) for the hydrogen intercalation process and the formation of the hydrogen nanocontainer [16].…”

“…In combination with transparent conductive graphene, these structures can be used for 2D electronics and optoelectronics. Record figures of merit for the layered materials have been observed in carriers' mobility, optical sensitivity, catalytic hydrogen generation, and reversible hydrogen storage [24][25][26][27][28][29]. It has been established that ultrathin InSe layered materials possess several unique properties that qualitatively distinguish them from other graphene-like two-dimensional crystals.…”

“…As its concentration increases (x > 2), Н2 molecules dissociate and enter the matrix layers of the crystal in the form of ions [26,28,29]. Proton saturation describes the following reaction [30]: Ga(In)Se + x H + + x e − = HxGa(In)Se (4) With the change in hydrogen concentration (in the х = 0 ÷ 2.5 range), the interlayer cell parameter c increases nonlinearly according to c(x) ~ th(x) dependence.…”

“…As its concentration increases (x > 2), H 2 molecules dissociate and enter the matrix layers of the crystal in the form of ions [26,28,29]. Proton saturation describes the following reaction [30]: Ga(In)Se + x H + + x e − = H x Ga(In)Se ( 4)…”