Hydrogen Separation Membranes Research Articles

First-principles evaluation of Pd–Pt–Ag and Pd–Pt–Au ternary alloys as high performance membranes for hydrogen separation

Membrane technologies are considered as a promising candidate for high purity hydrogen separation. Ternary alloys membranes show high permeance, high purity quality and good stability for separation of hydrogen, while the relational separation mechanism at atomic scale is still unclear for the most of ternary alloys. In current work, molecular dynamics (MD) and first-principles simulation are applied to predict H2 separations performances of Pd–Pt–Au and Pd–Pt–Ag membranes from CH4, CO, N2, CO2, H2S and H2O mixed gases. The separation properties of the alloys are evaluated by permeability and selectivity of various gases, and the performance of Pd–Pt–Ag and Pd–Pt–Au three-phase membranes are compared to those of Pd–Pt alloy. Our calculations indicate that Pd–Pt–Au alloy present superior selectivities of 3.6 × 1047, 1.1 × 1028, 3.7 × 1011, 4.9 × 1018, 2.2 × 1010, 1.1 × 106 for H2/CO, H2/CO2, H2/CH4, H2/N2, H2/H2S, H2/H2O, respectively, and a permeability of 1.24 × 10−1mols−1m−2pa−1 toward separation of hydrogen from the gases mixture, which is accorded to experimental conclusions. H2 permeance of the alloys exceeds industrial production limit from 100 to 600 K, while other impurity gases do not reach the permeability limits of industrial production even at high temperatures of 600 K.

Insights into micro-structure and separation mechanism of benzimidazole-linked polymer membrane for H2/CO2 separation

Separation of hydrogen from carbon dioxide for sustainable H2 production and CO2 capture still faces great challenges due to the smaller size of H2 and higher condensability of CO2. Herein, a high-performance benzimidazole-linked polymer (BILP) membrane for hydrogen separation was directly prepared on α-Al2O3 substrate through a facile interfacial polymerization approach at room temperature. The separation performance of the BILP membrane were regulated by controlling the reaction time and the microstructure was systematically characterized. Molecular simulations were performed to deep understand the separation mechanism in the BILP membrane. The best performance membrane displays an extraordinary mixed gas selectivity of 40 for H2/CO2 together with outstanding H2 permeance of 250 gas permeation units (GPU) at 473 K, far exceeding the Robeson’s upper bound. Besides, the membrane can withstand high temperature and pressure, and also shows good H2/N2 and H2/CH4 selectivity. The excellent separation performance, coupled with high temperature and pressure resistance and easy preparation, render BILP membranes great potential for economic H2 purification, H2 recovery, and natural gas treatment.

Hydride ion diffusion along grain boundaries in titanium nitride

Density functional theory (DFT) simulations are utilized to study the absorption and diffusion of hydride ions along four types of titanium nitride grain boundaries: open and compact structures of Σ5 (210)[001] and Σ5 (310)[001]. The absorption energy into bulk vacancies ranges from approx. −0.7 eV in TiN0.7 to −0.38 eV for a single vacancy in TiN, and shows a minor dependence on the hydrogen content in the structure. The absorption energy for vacancy sites at the grain boundaries ranges from −0.44 eV to −0.66 eV. Hydrogen absorption into interstitial sites at the grain boundaries is less favourable, in part due to a positive and fairly large zero-point energy contribution, with absorption enthalpies between −0.09 eV and 0.06 eV. The interstitial diffusion barriers are 1.34 eV and 0.83 eV in the open Σ5 (310) and Σ5 (210) grain boundaries, respectively. In the compact grain boundaries, the migrating hydrogen species changed oxidation state from a hydride ion (H0.5−) to a proton (H0.3+) at the transition state as it formed bonds to nitrogen along the diffusion path. The diffusion barriers are larger than in the corresponding open structures: 1.75 eV and 1.02 eV in the compact Σ5 (310) and Σ5 (210) structures, respectively. The considered grain boundaries and diffusion pathways cannot explain the fast interfacial hydride ion transport reported for hydrogen separation membranes based on TiNx thin films with columnar microstructure.

Electrochemical properties of Sr-doped La2-xSrxCe2O7-δ hydrogen separation membrane

The prominence of hydrogen energy has brought membrane separation technology to forefront attention. La2Ce2O7, possessing a fluorite structure, exhibits notable stability in both H2O and CO2, rendering it a prospective material for membrane separation. The impact of Sr doping on the electrochemical characteristics of La2Ce2O7 was systematically investigated. The findings indicate that a minor addition of Sr2+ through doping enhances the electrical conductivity, with the most significant improvement observed in La2-xSrxCe2O7-δ (x = 0, 0.05, 0.15, 0.30) when doped by 0.05. Elevated temperature and increased hydrogen partial pressure on the feed side enhance hydrogen permeability. Hydrogen permeation is predominantly governed by bulk diffusion when the membrane thickness exceeds 0.59 mm, while for thicknesses below 0.49 mm, the process is influenced by both surface and bulk diffusion. Moreover, the doped La2Ce2O7 exhibit commendable stability in H2O and CO2 environments. Consequently, La2Ce2O7 emerges as a promising candidate for ceramic hydrogen separation membranes.

Improved High-Temperature Stability and Hydrogen Penetration through a Pd/Ta Composite Membrane with a TaTiNbZr Intermediate Layer

In the hydrogen separation membrane, a dense TaTiNbZr amorphous layer was prepared between Pd and Ta to form a Pd/TaTiNbZr/Ta membrane system to prevent the reaction between Pd and Ta at high temperatures. The structural and chemical stability of the Pd/TaTiNbZr/Ta film system at high temperatures were investigated by annealing at 600 °C for 24 h. The high-temperature hydrogen permeation properties of the Pd/TaTiNbZr/Ta film systems were investigated by hydrogen permeation experiments at 600 °C after heat treatment for 6 h. The TaTiNbZr layer was significantly hydrogen-permeable. With the increase in the thickness of the barrier layer, the hydrogen permeability of Pd/TaTiNbZr/Ta decreased, but its hydrogen permeation flux was smaller than that of the highest value of Pd/Ta when it reached the steady state. The presence of the TaTiNbZr layer effectively blocks the interdiffusion between Pd and Ta to form TaPd3, improving the sustained working ability of the Pd/TaTiNbZr/Ta membrane system. The results show that TaTiNbZr is a candidate material for the intermediate layer to improve the high-temperature stability of metal-composite hydrogen separation membranes.

Electrochemical hydrogen pump based on proton exchange membrane for rapid separation of hydrogen and helium

The separation and purification of hydrogen play an essential role in the field of new energy. In addition, it has great significance and economic value in recovering hydrogen isotope gas from plasma ash discharge gas faced by nuclear fusion reactors. Here, we studied the rapid separation of hydrogen and helium by electrochemical hydrogen pump (EHP), a new hydrogen separation and purification method. In the experiment of the hydrogen-helium separation, the recovery rate of hydrogen can reach 97.4%, and the proportion of hydrogen can reach 99.99%. Furthermore, the effects of catalyst layer structure, membrane materials and working conditions for its performance were analyzed. This experiment found that proton conduction in the catalyst layer and proton exchange membrane became the speed-control step of the process. Moreover, efficient catalyst layer design and membrane materials with high proton conductivity are beneficial to improve EHP's performance further. This study could guide further enhancing the hydrogen-helium separation rate in EHP. It aims to promote the development of hydrogen separation and purification of EHP, making it an efficient method of hydrogen-helium separation instead of palladium membrane.

Production of Hydrogen and Solid Carbon by Methane Decomposition under Pressurized Conditions Using a Rotary Reactor and Purification of Yielded Hydrogen by Hydrogen Separation Membrane

Production of Hydrogen and Solid Carbon by Methane Decomposition under Pressurized Conditions Using a Rotary Reactor and Purification of Yielded Hydrogen by Hydrogen Separation Membrane

Integration of biomass gasification and O2/H2 separation membranes for H2 production/separation with inherent CO2 capture: Techno-economic evaluation and artificial neural network based multi-objective optimization

This study delves into the thermodynamic and techno-economic intricacies of a cutting-edge hydrogen production system driven by biomass gasification. The quest for zero emissions propels our innovative integration of an oxygen transport membrane and a hydrogen separation membrane, strategically optimized through artificial intelligence. By situating the oxygen transport membrane near the gasifier, efficient heat transfer and oxygen production synergistically enhance the molar fraction of hydrogen in the syngas. Subsequent utilization of the hydrogen separation membrane, coupled with water gas shift reactors, not only facilitates hydrogen separation and purification but also achieves inherent carbon dioxide capture and storage. This novel membrane-based approach obviates the need for a conventional carbon capture system. Before optimization, our system exhibited a generation rate of approximately 10.29 tons of H2 per day. The levelized cost of production stands at $2.78 per kilogram of hydrogen, with power consumption estimated at 2.99 kWh/kg-H2. The calculated payback period is 9.96 years, considering a sales cost of $3.50 per kg-H2. Multi objective optimization reveals promising prospects, with a potential 26% reduction in power consumption in one scenario. An alternative scenario indicates a remarkable 20% decrease in the system's payback period, accompanied by an 8% dip in the levelized cost of H2. These findings underscore the economic and energy benefits of our membrane-integrated hydrogen production system.

Preparation of a zeolite-palladium composite membrane for hydrogen separation: Influence of zeolite film on membrane stability

With the development of hydrogen energy, palladium-based membranes have been widely used in hydrogen separation and purification. However, the poor chemical stability of palladium composite membranes limits their commercial applications. In this study, a zeolite-palladium composite membrane with sandwich-like structure was obtained by using a TS-1 zeolite film grown on the surface of palladium membrane. The membrane microstructure was characterized by SEM and EDX. The effects of the the TS-1 film on the hydrogen permeability and stability of palladium composite membrane were investigated in details. Benefited from the protection of the TS-1 zeolite film, the stability of palladium composite membrane was enhanced. The results indicate that the TS-1-Pd composite membrane was stable after 8 cycles of the temperature exchanging cycles between 773 K and 623 K. Especially, the loss of hydrogen permeance for TS-1-Pd composite membrane was much smaller than that of the pure palladium membrane when the membrane was tested in the presence of C3H6 atmosphere. It indicated that the TS-1-Pd composite membrane had better chemical stability in comparison with pure palladium membrane, owing to its sandwich-like structure. This work provides an efficient way for the deposition of zeolite film on palladium membrane to enhance the membrane stability.

Ni-doped NbC films for remarkably enhancing hydrogen permeation performance of NbC/V composite membranes

Niobium carbide (NbC) membranes have been shown to be an effective catalytic membrane for hydrogen dissociation and desorption. Here, magnetron sputtering method was applied to dope Ni in NbC films to improve the catalytic properties. It is found that the Ni doping largely affects the surface microstructure and electronic structure of the NbC films, which in turn affects the hydrogen permeation performance of the NbC/V composite membranes. By density functional theory (DFT) calculations, it is known that the doping of Ni can modulate the internal electronic structure of NbC, such as d-band center and bader charge, thus improving the catalytic properties of the NbC films. Typically, under the optimal preparation conditions, the hydrogen permeability of the Ni-doped NbC/V composite membranes was 2.59 × 10−8 mol H2 m−1 s−1 Pa−0.5，at 500 °C, which is higher than that of pure Pd under the same conditions. These findings open up a new way towards the improvement of the catalytic properties for the hydrogen separation membrane materials.

Design of cost-effective and highly efficient systems for protonic ceramic fuel cells based on techno-economic analysis

Theoretically, protonic ceramic fuel cells (PCFCs) are considered to achieve higher energy conversion efficiencies than conventional solid oxide fuel cells. However, doped barium-based perovskite oxide, a typical electrolyte material, has a significant leakage current derived from hole conduction. Therefore, it is still unclear whether the actual performance of whole PCFC systems can reach the expected high efficiency. In this study, two strategies to suppress the leakage current, namely, low-temperature operation and a bilayer electrolyte cell using a high-ion and low-hole conductor, were discussed. The effects of these approaches on production costs and system efficiency were investigated from an economic perspective for social implementation. Moreover, the following technological options were discussed to comprehensively investigate the effects of cell, manufacturing process, and system designs on the system efficiencies and system costs; (1) cell design: examining a high-performance electrode; (2) module production process design: examining the annual production rate, co-sintering of electrode and electrolyte layers, and fabrication of an electrolyte layer with vapor-phase deposition; and (3) system design: examining a methane-fueled system, a multi-stage PCFC operation, a membrane for hydrogen separation, and lower oxygen utilization. Here, we focused on a residential 5 kW alternating current (AC) class system. Consequently, system efficiency and module production cost were calculated as 57 % based on the lower heating value (LHV) in a direct current (DC) and 4,650 USD/system adopting a monolayer electrolyte cell using BaZr0.8Y0.2O3-δ (BZY20) at 600 °C, assuming hydrogen as fuel under the annual production rate of 50 k/year. However, it was suggested that the system efficiency could be improved to 63 % in case of a lower temperature operation at 550 °C and 69 % adopting a bilayer electrolyte cell at 600 °C. Furthermore, technological options resulted in a system efficiency of 71 % and a production cost of 4,480 USD/system in the case of the bilayer cell, assuming a high-performance cathode when fabricated using the co-sintering method. Finally, the electricity cost was calculated to investigate the system lifetime and fuel cost requirements to achieve the present baseload electricity cost. From an economic and performance perspectives, this study could contribute to the widespread use of PCFC devices by exploring new technological options.

A high selective and permeable C7N6 monolayer membrane for H2 purification: First-principles and molecular dynamics simulations

Designing efficient membranes for hydrogen purification and separation is highly desired because of the development of the hydrogen economy. Using the combination methods of density functional theory (DFT) calculations and molecular dynamics (MD) simulations, we theoretically investigated the performance of the C7N6 monolayer for H2 purification and separation. Our DFT calculations indicate that H2 molecules would permeate through the C7N6 monolayer with a relatively low energy barrier (0.689 eV), and the C7N6 monolayer has an ultra-high selectivity of 7.47 × 106, 5.71 × 109, 1.19 × 1011, and 1.08 × 1012 for H2/O2, H2/CO2, H2/CO, and H2/N2 at even high temperature of 500 K, respectively. The MD simulations confirmed that the high selectivity and permeability of the H2 gas above 500 K. Even at higher temperatures of 800 to 1000 K, almost all of H2 gas can be separated by the C7N6 membrane without any other foreign gases passing through the membrane, indicating that the C7N6 monolayer can be used as an ultra-high performance H2 purification and separation membrane on the practical conditions as the C7N6 monolayers are dynamically, thermodynamically, and mechanically stable.

Recent Advancements in Metal-Organic Framework-Based Membranes for Hydrogen Separation: A Review.

Metal-organic frameworks (MOFs) are promising porous materials that have huge potential for gas separation when put in the membrane configuration. MOFs have huge potential of the MOFs such as excellent pore size, ease of tuning the pore chemistry, higher surface area, and chemical and thermal stabilities, MOFs have been explored for various gas separation and storage applications. This review discusses various approaches for fabricating MOFs-based membranes for the separation of H2 gas from a variety of feeds having various gases CO2, CO, N2, and CH4 as impurities. The emphasis has been put on three types of membranes for H2 separation which include MOFs-based hollow fibrous/tubular/disk membranes, MOFs-based mixed matrix membranes (MMMs), and MOFs-based stand-alone membranes. In addition, various challenges such as reducing inhomogeneity between MOFs and polymeric matrices have also been discussed. Similarly, the approaches to successfully decorating MOFs on different supports in different configurations have been explained. The possible ways of improving the MOFs-based membranes for H2 have also been discussed.

H2 permeance and surface characterization of a thin (2 μm) Pd-Ni composite membrane prepared by electroless plating

The high cost of palladium membranes limits their widespread use in industrial applications. We report a novel strategy for the preparation of economic hydrogen separation membranes. In this study, a Pd88-Ni12 composite membrane was prepared with a considerable nickel content (>10 wt%) for the first time using the organic–inorganic activation method in the ELP approach. The H2 permeance of the Pd88-Ni12 composite membrane was 4.34 × 10-7 mol m−2 s−1 Pa−1 at 500 °C with infinite selectivity (H2/N2). The membrane exhibited suitable performance when exposed to binary mixtures under various operating conditions. At 500 °C and 100 kPa, with the same concentration of impurity gases, the H2 permeance of the Pd88-Ni12 composite membrane was 3.33 × 10 -7 mol m−2 s−1 Pa−1 for the H2-Ar mixture, 3.12 × 10 -7 mol m−2 s−1 Pa−1 for the H2-N2 mixture, 2.56 × 10 -7 mol m−2 s−1 Pa−1 for the H2-CO2 mixture, and 2.54 × 10 -7 mol m−2 s−1 Pa−1 for the H2-CO mixture. The effect of operating parameters and the amount of impurity concentration in the gas feed on the stage cut in binary gas mixtures was investigated. Increasing operating temperature and pressure enhanced the stage cut for all mixtures while increasing the impurity concentration in the gas feed led to a decrease in the stage cut, independent of operating conditions. The Pd88-Ni12 composite membrane indicated suitable long-time permeance stability for 150 h at a transmembrane pressure range of 100–300 kPa and 500 °C under an H2/N2 gas atmosphere. Finally, the cost investigation demonstrated that the Pd88-Ni12 composite membrane had a 38 % lower specific cost than the pure palladium composite membrane.

Atomic-level prediction of V–Ni–Al, V–Ni–Co and V–Ni–Fe ternary alloys as highly selective hydrogen separation membranes

VB-group-based ternary alloys membranes for hydrogen separation have attracted great attention because of their superiorities on selectivity and permeability of hydrogen. However, atomic-scale hydrogen separation properties of the ternary alloys are still not studied, further related study is critical for developing high-performance V–Ni-based alloys membranes. In this work, molecular dynamics (MD) and first-principles calculation are incorporated to predict performances of V–Ni–Al, V–Ni–Fe and V–Ni–Co ternary alloys for separation of H2 from N2, CO2, CO, CH4, H2O and H2S mixed gases. Based on calculations of adsorption properties, diffusion energy barrier, selectivity and charge density difference, it reveals that the alloys membranes show excellent permeance and selectivity for separation of hydrogen gas. In particular, V–Ni–Al membrane presents superior diffusion and permeability properties for hydrogen gas. Our calculations provide an insight into atomic-level mechanism of V–Ni–Al, V–Ni–Fe and V–Ni–Co alloys as high-performance hydrogen separation membranes.

Ammonia-assisted ZnO support-induced conversion approach to prepare oriented Zn2(bIm)4 membrane for hydrogen separation

The construction of oriented two-dimensional MOF membrane is highly desirable for gas separation. At present, the most commonly used method is top-down exfoliation-deposition, but this method is complex, time-consuming, arduous, and difficult to prepare on a large-scale. The relatively simple and scalable direct growth approach is more attractive but still a major challenge. In this contribution, an ammonia-assisted ZnO support-induced strategy was developed to prepare highly oriented Zn2(bIm)4 membranes via in-situ solvothermal growth just in one cycle. This proposed approach is on the basis of the self-conversion of ZnO-support in ligand solutions containing ammonia modulators. The effects of ZnO-support calcination temperature, ammonia concentration, growth time and temperature on the formation of Zn2(bIm)4 membrane and gas separation performance were studied in detail. The prepared Zn2(bIm)4 membrane exhibited good stability in the mixed-gas test with H2/CO2 selectivity of 15.3 and hydrogen permeance of 1.25 × 10−8 mol· m−2·s−1·Pa−1, which is better than the upper-bound in 2008. The excellent membrane stability was due to the fact that ZnO support as the nucleation and anchoring sites to make the Zn2(bIm)4 membrane and support integrate. The preparation of Zn2(bIm)4 membrane by support-induced technology has the advantages of relatively simple preparation process, outstanding membrane stability and high gas separation property, which provides a very promising H2/CO2 separation membrane material. This method also provides a new way for the scaling-up 2D MOF membranes and their industrial applications.

Effect of temperature, air exposure and gas mixture on Pd82–Ag15–Y3 membrane for hydrogen separation

Material characterization, hydrogen permeation, and separation properties of a novel ternary Pd82Ag15Y3 membrane were evaluated by feeding single gases and several mixtures at temperature and pressure ranges of 300–600 °C and 1.0–3.0 bar (abs), respectively. The Pd82–Ag15–Y3 membrane was prepared by cold rolling and was characterized by ∼38 μm of thickness. When exposed to air at different temperature and constant pressure of 1 bar, the membrane showed good thermal and chemical stability. In particular, its surface area increased from 615 μm2 at 25 °C to 685 μm2 at 500 °C indicating a potential improvement of hydrogen permeation. However, several agglomerates consisting of metal oxides were formed on the surface at the highest temperature. The temperature was -then- kept constant at 400 °C and the pressure was varied to analyze the effects of singles gases and several mixtures on the hydrogen permeation characteristics. When exposed to pure gases, such as H2 and N2, the membrane showed an H2 permeability of 9.1 × 10−11 mol m−1 s−1.Pa−0.9 and “n” value of 0.9 due to the presence of Y, while no N2 was detected in the permeate stream, respectively. So, the membrane was considered to be completely selective towards H2 permeation. When mixtures were used, the hydrogen permeation decreased by its original value due to the presence of other gases, such as N2, CH4, CO2 and CO. The presence of CO particularly affected the H2 permeating flux due to the competitive adsorption of both gases on the Pd-alloy surface. Finally, the Scanning Electron Microscope (SEM), Energy Dispersive X-Ray Spectroscopy (EDS), Atomic Force Microscope (AFM) and X-ray diffraction (XRD) analysis were performed to observe any changes in the surface and structure of pristine and used membrane.

Hydrogen Exchange and Diffusion Kinetics at Elevated Temperatures in Proton-Conducting Solid Oxide Materials

Storage of purified hydrogen is one of the central challenges in addressing climate change and reducing our reliance on fossil fuels for energy conversion and storage, and therefore there is a global surge in research and development concerning hydrogen purification and storage. In this regard, we are studying proton conduction in solid oxide materials at elevated temperatures for applications in hydrogen separation and compression membranes. Hydrogen compression is the most recommended method to store hydrogen for automotive applications as it allows an increase in the hydrogen volumetric energy density.Traditionally the protonic conductivity in these materials is measured by indirect methods. For example, conductivity measurements in mixed gas atmospheres, comparing for example dry N2 with humidified N2, thereby allowing the contribution of protons to be evaluated. In this study, we for the first time report the evaluation of protonic conductivity in BaZr1-xCexY0.2O3−δ, BaZr0.1Ce0.7Y0.2–xYbxO3–δ and Ba7Nb4MoO20 by direct measurements afforded by the Isotope Exchange Depth Profiling technique with deuterium labelling. We also report the kinetics of H/D transport through the bulk materials and across metal-ceramic interfaces with a particular interest in the behaviour of the interface between the key Pd/Pd alloy catalyst component and the hydrogen-transporting oxide ceramic material. The transport and interface behaviour information will be of significance in designing hydrogen separation and compression membranes. Figure 1

Monolayer Fullerene Membranes for Hydrogen Separation.

Hydrogen separation membranes are a critical component in the emerging hydrogen economy, offering an energy-efficient solution for the purification and production of hydrogen gas. Inspired by the recent discovery of monolayer covalent fullerene networks, here we show from concentration-gradient-driven molecular dynamics that quasi-square-latticed monolayer fullerene membranes provide the best pore size match, a unique funnel-shaped pore, and entropic selectivity. The integration of these attributes renders these membranes promising for separating H2 from larger gases such as CO2 and O2. The ultrathin membranes exhibit excellent hydrogen permeance as well as high selectivity for H2/CO2 and H2/O2 separations, surpassing the 2008 Robeson upper bounds by a large margin. The present work points toward a promising direction of using monolayer fullerene networks as membranes for high-permeance, selective hydrogen separation for processes such as water splitting.

Enhancement of S-scheme heterojunction hematite and titanium dioxide nanocomposite by plasma treatment in the photocatalytic membrane for hydrogen separation

This work evaluated the performance of the photocatalytic membrane reactor (PMR) for hydrogen and oxygen separation. The PMR was conducted in a 500-ml reactor under solar light simulated by a mercury arc lamp (250 W). Hematite (α-Fe2O3) was deposited on titanium dioxide (TiO2) by sol-gel method on the Ti foil while palladium (Pd) was deposited on the other side. The sample surface was modified by argon (Ar) gas plasma treatment at 50 W for 10 min. The S-scheme heterojunction photocatalyst was characterized by X-ray diffraction, scanning electron microscope, transmission electron microscopy, and UV–vis spectroscopy. The charge carrier transport of photocatalysts was also analyzed. The photocatalytic activity was significantly improved by plasma treatment. The band gap energy decreased from 1.88 eV to 1.77 eV, and the average crystalline was reduced from 21.62 ± 4.79 nm to 21.34 ± 5.63 nm. The photocatalytic activity of fabricated materials for hydrogen production was evaluated in multi-cycle experiments. The highest hydrogen production rate of 1346.19 µmol h−1 was observed for the Ar plasma-treated heterojunction α-Fe2O3 and TiO2 nanocomposite sample (α-Fe2O3 @TiO2-P). After 5 cycles, the photocatalyst reaction of α-Fe2O3 @TiO2-P under solar light irradiation showed high stability for H2 production of 85.24 % compared to the first cycle. The S-scheme was photogenerated of charge transferred of type S-scheme mechanism between α-Fe2O3 and TiO2 under solar light. This work provides insight to enhance hydrogen production through the modification of the S-scheme photocatalyst membrane. The improved photocatalytic performance of the fabricated material suggests the effectiveness of the proposed Ar plasma treatment strategy to enhance the photoactivity for H2 production via water splitting.