Hydrogen Incorporation Research Articles

Incorporation of water-derived hydrogen into methane during artificial maturation of source rock under hydrothermal conditions

To investigate the origin of CH bonds in thermogenic methane (CH4), a solvent-extracted sample of organic-rich Eagle Ford shale was reacted with heavy water (D2O) under hydrothermal conditions (350 bar) in a flexible Au-TiO2 cell hydrothermal apparatus at a water-to-rock ratio of approximately 5:1. Temperature was increased from 200 to 350 °C over the course of one month and the concentrations of aqueous species and methane isotopologues were quantified as a function of time. In general, production of hydrogen, CO2, alkanes, and alkenes increased with time and temperature. Methane formed during the early stages of the experiment at 200 °C was primarily C1H4 with some CH3D. With progressively higher temperatures, increasing proportions of deuterated isotopologues were produced. Near the end of the experiment, the concentration of CD4 exceeded that of all other isotopologues combined. These results suggest that competition between rates of kerogen-water isotopic exchange and natural gas generation may govern the D/H ratio of thermogenic gases. Furthermore, hydrogenation of kerogen by water may be responsible for hydrocarbon yields in excess of those predicted by conventional models of source rock maturation in which hydrocarbon generation is limited by the amount of organically bonded hydrogen.

Effects of Hydrogen Incorporation on Mg Diffusion in GaN‐Doped with Mg Ions via Ultra‐High‐Pressure Annealing

Magnesium (Mg) diffusion in gallium nitride (GaN) is assessed using various Mg dosages and annealing durations at 1300 °C under nitrogen at 500 MPa. Low Mg dosages of 3 × 1013 cm−2 result in diffusion based on Fick's law and a diffusion coefficient of 1.36 × 10−14 cm2 s−1. Ambient hydrogen atoms are also introduced into the specimens during annealing. Hydrogen has a larger diffusion coefficient than Mg but the hydrogen concentration is limited by the surface Mg concentration. After hydrogen atoms reach the Mg diffusion front, they enhance Mg diffusion by forming the Mg–hydrogen complexes. The more rapid Mg diffusion at higher Mg dosages above 1014 cm−2 can be explained by diffusive species involving vacancies and hydrogen.

Melting of the Fe‐C‐H System and Earth's Deep Carbon‐Hydrogen Cycle

AbstractThe occurrences and cycling of slab‐originated carbon and hydrogen are considered to be controlled by their reactions with metallic iron from mantle disproportionation and slab serpentinization, to form Fe alloys containing carbon and hydrogen. Here we show experimental results on the phase relations and melting of the Fe‐C‐H system using laser‐heated diamond anvil cell and X‐ray diffraction techniques up to 72 GPa. The incorporation of hydrogen was found to lower the eutectic melting temperatures of Fe‐C alloy by ∼50–178 K at 20–70 GPa, facilitating the formation of metallic liquids in the deep mantle and thus enhancing the mobility and deep cycling of subducted carbon and hydrogen. Hydrogen also substitutes with carbon in Fe‐C metal to form hydride and diamond at relatively high‐temperature conditions (e.g., 42.6 GPa, >1885 K and 71.8 GPa, >1798 K). The hydrogen‐carbon‐enriched metallic liquids provide the necessary fluid environment for superdeep diamond growth.

Incorporation of hydrogen into the packaging atmosphere protects the nutritional, textural and sensorial freshness notes of strawberries and extends shelf life.

Strawberries are known for their high perishability and short shelf life. The effects of incorporating hydrogen gas into sealed packaging on the quality and shelf life of strawberries were evaluated. Fruits were packaged under reducing atmosphere [RAP1 (5% , 4% , 91% ) and RAP2 (10% , 4% , 86% )], modified atmosphere [MAP1 (5% , 95% ) and MAP2 (10% , 90% )], and control, followed by 12weeks storage at 4°C. At the end of storage, RAPs exhibited higher total soluble solids (TSS), firmness, L* and a*, phenolic and anthocyanin contents, and antioxidant activity followed by MAPs when compared with control. RAP2 was more potent in protecting the freshness indices than RAP1, and MAP2 outperformed MAP1, with the best protection characteristic attributed to RAP2. RAP technique extended the shelf life by 3-5 times the control, and 1.5-3.0 times the MAP. RAP should be recommended as a green and healthy preservation technique for the long storage of fresh fruits. The online version contains supplementary material available at 10.1007/s13197-022-05427-y.

Device feasibility and performance improvement methodologies for thin film transistors using In-Ga-Sn-O channels prepared by atomic-layer deposition

Thin film transistors (TFTs) using In-Ga-Sn-O (IGTO) active channel layers, which were prepared by atomic-layer deposition (ALD) techniques, were fabricated and characterized with exploring the optimum IGTO channel compositions and the process conditions for the formation of gate-stack structures. The introduction of an O3 oxidant was confirmed to secure a wider process window, which was explained by hydrogen incorporation from the protection layer/gate insulator stacked layers into the IGTO active channel. The cationic compositions of the IGTO thin films were controlled by subcyclic ratio design of each precursor. When the number of In-Ga precursor subcycles increased from 4 to 6, the Ga/Sn ratio increased from 3.5 to 4.0, leading to marked improvements in the VON characteristics of the fabricated IGTO TFTs. It was found from a comparative analysis on the device characteristics that the Ga/Sn ratio in the IGTO channel had a more dominant effect on the VON characteristics rather than the In/Ga ratio. The device using the channel with a cationic composition of 5.8:4.0:1.0 (In:Ga:Sn) exhibited the field-effect mobility of 19.1 cm2/V s, the subthreshold swing of 0.22 V/dec, and the threshold voltage (VTH) of 0.22 V, which corresponded to the best device characteristics among the fabricated devices. Furthermore, the VTH shifts were examined to be +0.4 and −0.4 V in positive and negative bias stress conditions, respectively, demonstrating excellent gate-bias stress stabilities. The obtained results suggest the device feasibility and fabrication process validity for the TFT applications using IGTO active channel layers prepared by ALD techniques.

The effects of hydrogen incorporation in modified atmosphere packaging on the formation of biogenic amines in cold stored rainbow trout and horse mackerel

The formation of biogenic amines (BAs) in fish products during storage forms a serious challenge to producers and is generally related to the growth of decarboxylase-producing microorganisms. Controlling the formation of BAs is a serious challenge for the fishery industry. This study evaluates the impact of incorporating molecular hydrogen (H2) in a modified atmosphere packaging on the formation of BAs in both freshwater and seawater fish, i.e., rainbow trout and horse mackerel, respectively, stored at + 4 °C for 15 days. Fish samples were packaged in modified atmosphere packaging [MAP1 (50% CO2/50% N2) and MAP2 (60% CO2/40% N2)], reducing atmosphere packaging [RAP1 (50% CO2/46% N2/4% H2) and RAP2 (60% CO2/36% N2/4% H2)], and under air (control). The amount of BAs, except spermidine and spermine, significantly increased during storage in all treated samples. Both MAPs and RAPs showed significant restrictive effects on the formation of heterocyclic, aromatic, and aliphatic di-amines (histamine, tyramine, putrescine, cadaverine) in both fish species, with a more potent effect seen in RAP rather than MAP. Reduction rates of BAs ‎were about two folds higher in RAPs than that of MAPs. This shows the advantage of hydrogen incorporation in the package atmosphere on the inhibition of biogenic amine formation, especially in the presence of a high level of CO2. Therefore, RAP may be proposed as a promising technology for limiting the BA formation in fishery products.

Effect of Ar and H2 mixture gas on SnS thin films deposited by radio frequency (RF) magnetron sputtering

The effect of hydrogen on the deposition of SnS films was investigated using conventional radio frequency (RF) magnetron sputtering. The structure of the deposited SnS films was transformed from amorphous to polycrystalline by increasing the partial pressure of H2 gas. Simultaneously, the H2 supply suppressed the formation of an extra S-rich phase and enabled the Sn/S composition to be controlled by exploiting the reaction between hydrogen and sulfur atoms. By increasing the H2 supply, the Sn/S atomic ratio changed from 0.85 (S-rich) to 1.25 (Sn-rich). As the composition changes as a result of hydrogen supplementation, the carrier concentration of the SnS films decreases with increasing H2 gas supply, which may be due to the increase in the enthalpy of formation of tin vacancies. The incorporation of hydrogen in the films was observed using secondary ion mass spectrometry measurements. The amount of incorporated hydrogen did not strongly depend on the amount of H2 supplied. This suggests that hydrogen may not act as a carrier, but simply serves to modify the Sn/S ratio of SnS films using RF magnetron sputtering.

Volumes and spin states of FeHx: Implication for the density and temperature of the Earth’s core

AbstractHydrogen is the most abundant element in the solar system and has been considered one of the main light elements in the Earth’s core. The hydrogen content in the Earth’s core is determined normally by matching the volume expansion caused by the incorporation of hydrogen into FeHx to the Earth’s core density deficit. The magnitude of this volume expansion at the pressure (P) and temperature (T) conditions of the Earth’s core is still unknown, and the effect of spin transition in FeHx at high pressure is usually ignored. In this study, we simulate the Fe spin transition, equation of state, and hydrogen-induced volume expansion in Fe-H binaries at high P-T conditions using density functional theory (DFT) calculations. Our results indicate that hydrogen could stabilize the magnetic properties of fcc Fe from ~10 to ~40 GPa. A volume expansion induced by hydrogen is linear with pressure except at the Fe spin transition pressure, where it collapses significantly (~30%). The fcc FeH lattice is predicted to expand at an average rate of ~1.38 and 1.07 Å3 per hydrogen atom under the Earth’s outer and inner core P-T conditions, where the hydrogen content is estimated to be ~0.54–1.10 wt% and ~0.10–0.22 wt%, respectively. These results suggest that the Earth’s core may be a potentially large reservoir of water, with up to ~98 times as much as oceans of water being brought to the Earth’s interior during its formation. Based on our predicted hydrogen content in the Earth’s core, we propose that the presence of hydrogen would induce a relatively lower core temperature, ~300–500 K colder than it has been previously speculated.

Modification of the synthesis of layered titanium chloride nitride

Layered titanium nitride chloride (TiNCl) exhibits a relatively high superconducting transition of ∼16 K, and it is a candidate for the unconventional superconductor. To better understand the superconductivity, we modified the synthesis process for TiNCl. Highly crystalline TiNCl was prepared by chemical vapor transport at different transport temperatures and intercalated with sodium (Na) metal. Although the crystallographic parameters obtained through Rietveld refinement are similar, the superconducting properties strongly depend on the treatment temperature of pristine TiNCl. Optical and photoemission spectroscopy revealed an in-gap state below the Fermi level, indicating hydrogen incorporation, similar to the case of β−ZrNCl. Hydrogen temperature-programmed desorption revealed hydrogen emission against the heat treatment of the obtained pristine TiNCl. The in-gap state of hydrogen inhibits the introduction of electron carriers from the intercalated Na metal.

Interpretation of hydrogen incorporation into radio frequency sputtered amorphous silicon based on Berg modelling

Incorporated hydrogen and its bonding configuration have an effect on the electrical and structural properties of hydrogenated amorphous silicon (a-Si) thin films. On one hand hydrogenization is known to be very efficient in reducing the density of dangling bonds responsible for deep levels in the bandgap; the technological process that carries out the incorporation of hydrogen improves the device parameters. On the other hand, the H–Si–H bonding configuration may negatively affect the microstructure of the amorphous lattice and promote the creation of voids.In this work the incorporation of hydrogen into radio frequency sputtered amorphous silicon thin films is interpreted by means of Berg-model handling the hydrogen incorporation as a reactive sputtering process involving ionization of molecular hydrogen followed by reactions between elemental target atoms to compound molecules. This approach is suitable for the interpretation of hydrogen incorporation into a-Si films based on the fact that the amount of incorporated hydrogen is proportional to the current. The imaginary and the real part of the dielectric function deduced from spectroscopic ellipsometry are investigated as a function of hydrogen flow. Using the results of spectroscopic ellipsometry and elastic recoil detection analysis presented earlier, as well as the equations of Berg model, the metal and compound sputtering rate and the sticking coefficient between silicon and hydrogen atoms are calculated.

Spatial ALD of Al2O3 and ZnO using heavy water

Al2O3 and ZnO thin films were deposited from trimethylaluminium (TMA) and diethylzinc (DEZ) in combination with water using cylindrical rotating substrate spatial atomic layer deposition (SALD). The depositions were done between 67 and 140 °C. The growth per cycle for Al2O3 varied between 0.75 and 2.0 × 1015 at./cm2 per cycle and for ZnO between 0.52 and 1.07 × 1015 at./cm2 per cycle. The hydrogen incorporation was studied by varying the deposition temperature and substrate rotation speed. The rotation speed affects the precursor exposure time (46–458 ms) and inert gas purging time (111–1120 ms). The results show that Al2O3 films can contain up to 25 at.% of hydrogen when the deposition temperature is 67 °C or the deposition exposure/purging times are short. The deposition of ZnO in similar conditions produces films with hydrogen concentrations up to 15 at.%. The source of impurity hydrogen was investigated by using heavy water, 2H2O, as an oxygen source. The main hydrogen isotope in the Al2O3 films at low temperatures and fast deposition speed was found to be 1H, while at higher temperatures and lower deposition speeds 2H isotope was dominant. For ZnO, 1H was the majority hydrogen isotope in the films in all the studied deposition conditions except at the lowest rotation speed.

Minimizing and Controlling Hydrogen for Highly Efficient Formamidinium Lead Triiodide Solar Cells.

Formamidinium lead triiodide (FAPbI3) currently holds the record conversion efficiency in the single-junction perovskite solar cell. Iodine management is known to be essential to suppress defect-induced nonradiative losses in FAPbI3 active layers. However, the origin of nonradiative losses and the underlying mechanism of suppressing such losses by iodine-concentration management remain unknown. Here, through first-principles simulation, we demonstrate that native point defects are not responsible for the nonradiative losses in FAPbI3. Instead, hydrogen ions, which can be abundant under both iodine-rich and iodine-poor conditions in FAPbI3, act as efficient nonradiative recombination centers and are proposed to be responsible for the suppressed power conversion efficiency. Moreover, iodine-moderate synthesis conditions can favor the formation of electrically inactive molecular hydrogen, which can dramatically suppress the detrimental hydrogen ions. This work identifies the dominant nonradiative recombination centers in the widely used FAPbI3 layers and rationalizes how the prevailing iodine management reduces the nonradiative losses. Minimizing the unintentional hydrogen incorporation in the perovskite is critical for achieving high device performance.

Investigation of Hydrogen Incorporations in Bulk Infinite-Layer Nickelates

Infinite-layer (IL) nickelates are an emerging class of superconductors, where the Ni1+ valence state in a square planar NiO2 coordination can only be reached via topotactic reduction of the perovskite phase. However, this topotactic soft chemistry with hydrogenous reagents is still at a stage of rapid development, and there are a number of open issues, especially considering the possibility of hydrogen incorporation. Here, we study the time dependence of the topotactic transformation of LaNiO3 to LaNiO2 for powder samples with x-ray diffraction and gas extraction techniques. While the hydrogen content of the powder increases with time, neutron diffraction shows no negative scattering of hydrogen in the LaNiO2 crystal lattice. The extra hydrogen appears to be confined to grain boundaries or secondary-phase precipitates. The average crystal structure, and possibly also the physical properties, of the primary LaNiO2 phase are, therefore, not noticeably affected by hydrogen residues created by the topotactic transformation.

Hydrogen incorporation into amorphous indium gallium zinc oxide thin-film transistors

An experimental study is conducted in which the subgap trap density of states (DoS) is measured by ultrabroadband photoconduction (UBPC) to examine hydrogen incorporation into the channel layer of top-gate amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs). UBPC reveals that hydrogen incorporation leads to the creation of a spectrally broad (∼0.3 eV FWHM) distribution of electronic states in the bandgap centered at 0.4 eV above the valence band mobility edge and to an increase in valence band tail state density. Concomitantly, drain current–gate voltage transfer curves demonstrate that hydrogen incorporation results in a negative shift in the turn-on voltage. Quantitatively, electronic state densities estimated by UBPC and the turn-on voltage shift are identical. These experimental findings imply that hydrogen acts as a donor in a-IGZO, but that its donor ionization energy is extraordinarily large, i.e., ∼2.8 eV, inconsistent with that of a normal donor. It is proposed that this anomalous donor behavior is a consequence of the negative-U property of hydrogen in a-IGZO in which hydrogen ionization precedes its incorporation into the lattice network.

Preparation of Li-Excess and Li-Deficient Antiperovskite Structured Li2+xOH1-xBr and Their Effects on Total Ionic Conductivity.

This paper describes about the effect of Li-H exchange amount on total lithium-ion (Li+) conductivity of Li2+xOH1-xBr (x = -0.5 to +0.4). These samples are systematically prepared at room temperature by a dry ball-milling process using LiOH, LiOH·H2O, Li2O, and LiBr as starting materials. Synchrotron X-ray diffraction analysis reveals that single-phase Li2+xOH1-xBr samples are formed within x = -0.5 to +0.35. For improving total Li+ conductivity (σt), a larger x value increases both the Li carrier density and lattice constant as positive factors, while that decreases both the crystallite size and OH rotational unit possibly assisting Li+ conduction as negative factors. This trade-off provides an optimized σt of 3.6 × 10-6 S cm-1 at the Li-excess Li2.2OH0.8Br composition, which is ca. 3 times higher than pristine Li2OHBr (1.1 × 10-6 S cm-1). The hydrogen incorporation into the lattice is confirmed by neutron diffraction analysis, and the refined composition is almost consistent with the prepared composition.

A Facile Strategy to Realize Rapid and Heavily Hydrogen-Doped VO2 and Study of Hydrogen Ion Diffusion Behavior

Heavily hydrogen-doped VO2 has drawn broad interest due to the modulation of versatile electronic phase transition and structural transition, while it is still challenging for highly efficient and fast hydrogen incorporation in VO2. Herein, we provide a facile approach to achieving rapid and high-concentration hydrogen-doped VO2 preparation. The as-prepared VO2 film instantaneously converted to a partially metallic phase once it was immersed into NaBH4 solution due to the introduction of a light hydrogen dopant. Strikingly, high-concentration hydrogen incorporation into VO2 was achieved as the solution temperature increased over the phase transition temperature. Based on the first-principles calculation, we investigated the diffusion behaviors of hydrogen in M-VO2 and R-VO2 that migrated from the surface to the subsurface and in bulk. The detailed formation energy calculation suggested that the presence of R-VO2 was beneficial to realize heavily H-doped VO2, while the thermodynamic property accelerated the reaction process. The current findings not only supplied a novel strategy to realize fast and high-concentration hydrogen incorporation in VO2, shedding light on hydrogenated metal oxide materials, but also brought insight into a comprehensive understanding of hydrogen diffusion behavior in VO2.

Reversible control of the metal-insulator transition in V2O3 thin films through plasma hydrogenation

We investigate the effect of hydrogen plasma treatment on the metal-insulator transition (MIT) of epitaxial V2O3 films grown on c-Al2O3. The films were exposed to plasma at constant power for varying intervals. With increasing hydrogenation the films display a suppression of the MIT magnitude and temperature due to neutralization of structural defects and passivation of unpaired bonds by incorporation of atomic hydrogen as supported by relaxation in strain by XRD and Raman spectroscopy analysis, while stabilizing the metallic phase due to reduction in Peierls dimerization of V-V bonds. Heating to 350-400 °C the electrical characteristics of the film in the as-grown state are regained showing the possibility of reversibly controlling the MIT characteristics.

Energetic characteristics of hydrogenated amorphous silicon nanoparticles

• Plasma-synthesized amorphous Si NPs ( a -nSi) incorporate abundant hydrogen. • The reactivity of a -nSi/KClO 4 increases by a factor of six compared with nAl. • The energetic performance of nSi is correlated with its hydrogen content. • In situ release of hydrogen from hydrides enhances the reactivity. In this work, we utilize a low-temperature non-equilibrium plasma to nucleate and grow sub-10 nm Si particles with varying degrees of crystallinity by tuning the level of power coupled into plasma discharge. Temperature-programmed desorption spectroscopy shows that as-prepared amorphous Si nanoparticles ( a -nSi) incorporate more hydrogen than crystalline Si nanoparticles ( c -nSi). Further, hydrogen is incorporated in the material in the form of higher silicon hydrides with a lower desorption temperature. Combustion cell measurements show that when formulated with KClO 4 , a -nSi outperforms its crystalline counterpart with respect to pressure output. The pressurization rate of a -nSi/KClO 4 composite increases by a factor of six compared with nAl to 0.66 MPa·μs −1 . Evidence of hydrogen release (∼730 K) from Temperature-jump time-of-flight mass spectrometry (T-Jump TOFMS) of a -nSi/KClO 4 suggests the creation of Si dangling bonds prior to ignition (∼820 K), which then react exothermically with oxygen liberated from KClO 4 , leading to ignition. Explosive reaction of H 2 /O 2 mixture likely contributes to the rapid pressure rise. The enhanced energetic performance of hydrogenated a -nSi compared to its crystalline counterpart suggests that incorporation of hydrogen is a promising strategy for improving the performance of nanoenergetic materials.

The role of H-H interactions and impurities on the structure and energetics of H/Pd(111).

Understanding hydrogen incorporation into palladium requires detailed knowledge of surface and subsurface structure and atomic interactions as surface hydrogen is being embedded. Using density functional theory (DFT), we examine the energies of hydrogen layers of varying coverage adsorbed on Pd(111). We find that H-H and H-Pd interactions promote the formation of the well-known 3×3 phases but also favor an unreported (3 × 3) phase at high H coverages for which we present experimental evidence. We relate the stability of isolated H vacancies of the (3 × 3) phase to the need of H2 molecules to access bare Pd before they can dissociate. Following higher hydrogen dosage, we observe initial steps of hydride formation, starting with small clusters of subsurface hydrogen. The interaction between H and Pd is complicated by the persistent presence of carbon at the surface. X-ray photoelectron spectroscopy experiments show that trace amounts of carbon, emerging from the Pd bulk despite many surface cleaning cycles, become mobile enough to repopulate the C-depleted surface at temperatures above 200K. When exposed to hydrogen, these surface carbon atoms react to form benzene, as evidenced by scanning tunneling microscopy observations interpreted with DFT.

Ion energy-induced nanoclustering structure in a-C:H film for achieving robust superlubricity in vacuum

Hydrogenated amorphous carbon (a-C:H) films are capable of providing excellent superlubricating properties, which have great potential serving as self-lubricating protective layer for mechanical systems in extreme working conditions. However, it is still a huge challenge to develop a-C:H films capable of achieving robust superlubricity state in vacuum. The main obstacle derives from the lack of knowledge on the influencing mechanism of deposition parameters on the films bonding structure and its relation to their self-lubrication performance. Aiming at finding the optimized deposition energy and revealing its influencing mechanism on superlubricity, a series of highly-hydrogenated a-C:H films were synthesized with appropriate ion energy, and systematic tribological experiments and structural characterization were conducted. The results highlight the pivotal role of ion energy on film composition, nanoclustering structure, and bonding state, which determine mechanical properties of highly-hydrogenated a-C:H films and surface passivation ability and hence their superlubricity performance in vacuum. The optimized superlubricity performance with the lowest friction coefficient of 0.006 coupled with the lowest wear rate emerges when the carbon ion energy is just beyond the penetration threshold of subplantation. The combined growth process of surface chemisorption and subsurface implantation is the key for a-C:H films to acquire stiff nanoclustering network and high volume of hydrogen incorporation, which enables a robust near-frictionless sliding surface. These findings can provide a guidance towards a more effective manipulation of self-lubricating a-C:H films for space application.