Hydrogen Production Performance Research Articles

Joint Electrons and Photons Transfer from Dual‐Functional WO3:Yb,Er to Zn0.5Cd0.5S for Efficient H2 Evolution

AbstractUtilization of the near‐infrared (NIR) light in the solar spectrum is critical for efficiency improvement of photocatalytic H2 evolution. However, common semiconductors have low response to the NIR light and narrow bandgap semiconductors have inappropriate redox potentials. Here, the study presents a new dual‐functional up‐conversion strategy in one sensitizer for promoting photocatalytic hydrogen production reactions by converting NIR light to visible light and high‐energy electrons simultaneously, via photon‐photon conversion and photo‐electronic process, respectively. Using WO3:Yb,Er as the sensitizer and Zn0.5Cd0.5S as the hydrogen evolution reaction catalyst, a photocatalytic hydrogen release rate of 24.3 mmol g−1 h−1 under simulated solar‐light has been achieved without using any co‐catalyst. After loading Ni2P as a co‐catalyst, the photocatalytic hydrogen production performance can be further improved to 41.3 mmol g−1 h−1 at 10 °C and 93.3 mmol g−1 h−1 under non‐temperature‐controlled conditions, exceeding most photocatalysts. This work offers a new strategy to improve the NIR light utilization of the solar‐light for promoting photocatalytic hydrogen generation through synergistic photo‐optical, photo‐electronic, and photo‐thermal effects.

Experimental investigation on the electrical and hydrogen-production performance of a novel PEM electrolyzer driven by CdTe PV with a tracking system

Addressing the challenges of intermittent and variable energy supply, solar hydrogen production via electrolysis has garnered significant attention due to its unique advantages, emerging as a hot topic in the scientific research domain. However, the application of this technology is currently mainly related to the non-tracking system, which undergoes a rapid change in solar irradiation during the day. To expand the matching relationship of solar irradiation, PV characteristics, and electrolyzer, this paper proposes the development of a Proton Exchange Membrane (PEM) electrolyzer driven by Cadmium Telluride (CdTe) photovoltaic (PV) modules with a tracking system for hydrogen production. An experimental platform was set up in Chengdu and the performance tests were carried out for different operating modes during summer. The experimental results demonstrate that the average electrical and hydrogen production efficiencies of the system are 13.11% and 7.88%, respectively, on a sunny day, with a total of 566.7 L of hydrogen produced within 7 h of operation. Furthermore, the solar irradiation received by the tracking surface of the system is significantly enhanced by 10.29% in comparison to the horizontal surface. On a cloudy day with an electrolyzer inlet water temperature of 45 °C, the system has the potential to achieve a hydrogen production efficiency of 11.15 %. At a constant current density of 1.0 A/cm2, the efficiency of the electrolysis process increased by 2.07% and 1.25% for each 10 °C increase in the temperature of the electrolyzer, having an inlet temperature of 35 °C. This study offers a novel approach for a PV-PEM system with a higher hydrogen production efficiency while also establishing a robust foundation for technology optimization and broader implementation.

Carboxyl-Group-Bearing Metal Corroles of Cobalt, Manganese and Copper for Electrocatalytic Hydrogen Evolution.

5,15-bis(perfluorophenyl)-10-(4-carboxyphenyl) corrole and its Co(III), Mn(III), and Cu(III) corrole complexes were synthesized. The electrocatalytic hydrogen evolution reaction (HER) of these metal corrole complexes was investigated using different proton sources (AcOH, trifluoroacetic acid, and TsOH) in an organic dimethylformamide solvent. The electrocatalytic HER may proceed through EECC, EECEC, or EEECEC pathways (where E represents electron transfer and C represents proton binding) depending on the acidity and concentration of the proton source used. The Co corrole complex exhibits remarkable hydrogen production performance, achieving a turnover frequency of 201 s-1 and a catalytic efficiency of 1.00. The examined metal corrole complexes also exhibit good HER activity in aqueous solution, with their catalytic activity following an order of 1-Co > 1-Cu > 1-Mn in both organic and aqueous phases.

Development and performance evaluation of a novel solar mid-and-low temperature receiver/reactor with packed metal foam

Solar-driven hydrogen production from methanol decomposition (MD) is an important method of storing solar energy as clean fuels and improving the solar energy utilization efficiency. Catalyst preparation is one of the key steps, but conventional Cu-ZnO-Al2O3 particle catalysts lead to uneven reactor temperature, reducing the efficient conversion of solar energy into fuels. To alleviate this challenge, a monolithic catalyst utilizing packed foamy copper as a carrier is developed with exceptional thermal and mass transfer properties. The experimental results validate its excellent performance in hydrogen production using MD. The absolute conversion increases by an average of 12.11 % at 250 °C and further by 14.43 % at 270 °C compared to the particle catalyst. Based on these findings, a novel solar reactor is proposed, and a multi-field coupling model is built. The comparative results verify the performance advantage of the developed solar thermochemical receiver/reactor with packed metal foam-based catalyst. It maintains high conversion rates and solar-to-fuel energy efficiency, while alleviating overheating problems caused by traditional particle catalysts. Under the design conditions, the new reactor significantly improves the absolute conversion of methanol and the energy efficiency of solar-to-fuel conversion by 4.57 % and 3.00 %, respectively, resulting in 92.64 % and 67.56 %. This study provides a theoretical basis and technical solution for more stable and efficient use of mid-and-low temperature solar energy.

Synthesis and Design Strategies of MXene Used as Catalysts

AbstractMXene have found extensive applications in various fields, including catalysis. Two predominant roles of MXene in catalysis are as catalyst carriers or as catalysts themselves. The former has received significant attention and is addressed in other publications. This review assesses MXene and its derivatives as direct catalysts, which is particularly intriguing due to its potential to reduce the design cost of catalysts. Moreover, an in‐depth discussion of this aspect aids in understanding the true role of MXene in catalysis, beyond its role as a catalyst carrier. For instance, MXene and its derivatives have been extensively employed as photocatalysts, with their catalytic activity significantly influenced by their structural characteristics. Furthermore, due to MXene's remarkable light absorption capacity, it is crucial to explore the contributions of photothermal generation or photocatalytic‐thermocatalytic synergistic effects. Additionally, MXene has demonstrated remarkable electrocatalytic performance in hydrogen production. Moreover, MXene exhibits promising applications in thermal catalysis, such as dehydrogenation and oxidation. A deeper understanding of these aspects can help researchers further design MXene‐based nanomaterials, or alleviate their oxidation. Finally, we offer insights into the future research directions of MXene from our perspective. This review could provide guidance for the design of novel MXene catalysts for industrial applications.

Performance evaluation and energy management strategy of drone methanol reforming fuel cell hybrid power system: A case study

The performance of hydrogen production by methanol steam reforming and high temperature proton exchange membrane fuel cells on drone lacks the comparison of experimental data, resulting in the overall performance improvement of the system is difficult to evaluate. Therefore, the energy management strategy of methanol reforming high temperature proton exchange membrane fuel cell hybrid power system and state machine is designed and optimized. The performance of this system is analyzed and compared with the flight experiment data of a proton exchange membrane fuel cell hybrid UAV. The results show that the SOC of the system can be stabilized between 70 and 80 during the long cruise phase. The test results show that the maximum hydrogen storage mass density of the hydrogen supply system is increased by 67.6%. The flight time of the system under economic cruise flight of the drone is improved by 29.1%–44.9% with different quality of fuel. Under the maximum flight speed of a certain wind speed, the system can meet the flight requirements and increase the flight time by 31.9% and 17.6% respectively under the wind speed of 1.5 m/s and 4 m/s. Its flight time has been greatly improved, and it has great potential as a drone system.

Enhanced photo-fermentative hydrogen production by constructing Rhodobacter capsulatus-ZnO/ZnS hybrid system

This study incorporated ZnO/ZnS nanoparticles with Rhodobacter capsulatus SB1003, forming a hybrid system to promote photo-fermentative hydrogen production. The results indicate that the material’s photocatalytic activity and concentration significantly affected hydrogen yield. The addition of ZnO/ZnS exhibited a more significant auxiliary effect than ZnO and achieved an approximately 30% increase in hydrogen production compared to the control group. ZnO/ZnS enhanced the production of extracellular polymers, thereby strengthening the synergy between the nanomaterials and the bacteria. The photogenerated electrons from ZnO/ZnS were utilized by the photosynthetic bacteria. Furthermore, the activity of nitrogenase was enhanced, resulting in improved hydrogen production performance. This study provides insights into hydrogen production by photosynthetic bacteria with the assistance of inorganic semiconductor nanomaterials.

Z-Scheme LaFeO3/Cd0.7Zn0.3S heterojunction based on 3DOM LaFeO3 perovskite for enhanced photocatalytic hydrogen activity

The narrow band gap semiconductor LaFeO3 with ABO3 perovskite structure has been deeply studied in the field of photocatalysis due to its good thermal stability, chemical stability, photoelectric properties and suitable band position. The inverse opal structure gives the material a large specific surface area and increases the adsorption area and active site of the catalyst. In this work, it is reported for the first time that perovskite LaFeO3 inverse opal was applied to photocatalytic hydrogen production. The Cd0.7Zn0.3S QDs were deposited on the skeleton wall of LaFeO3 inverse opal to construct LaFeO3/Cd0.7Zn0.3S binary heterojunction catalyst. The LaFeO3 3DOM can effectively increase the contact area with Cd0.7Zn0.3S QDs with an increase in specific surface area, and the multiple scattering effect improves the efficiency of light utilization. The introduction of Zn2+ ions regulate the band gap position of Cd0.7Zn0.3S QDs and increases the thermodynamic reduction ability of photo generated electrons. The Z-type heterojunction effect formed by LaFeO3 inverse opal and Cd0.7Zn0.3S QDs facilitates the separation and transmission of photo generated charges. The LaFeO3/Cd0.7Zn0.3S heterojunction catalysts achieved a hydrogen production performance of 277.48 μmol/g/h due to the large specific surface area of 3DOM, good light capture ability, band gap regulation of element doping, and efficient charge separation synergistic effect of heterojunction. This work provides new insights into the design and manufacture of perovskite-type 3DOM heterojunction photocatalysts.

Photoelectron marginalization effect in ZnO/WO3/graphene-like composites: Study of alternating strong-low photocatalytic hydrogen production performance and mechanism

ZnO/WO3/graphene-like composite photocatalysts are prepared by in-situ deposition and successfully utilized for alternating strong-low light catalytic decomposition of water to produce hydrogen. Additionally, the study details the microscopic morphology and optoelectronic properties of the ZnO/WO3/graphene-like composite. The results indicate that an internal electric field is generated between the ZnO/WO3 heterostructure and the graphene-like material. This induced electric field leads to a large amount of ordered electron transfer from ZnO/WO3 to the graphene-like material, resulting in the electron marginalization effect, which ensures the prerequisite for alternating strong-low photocatalytic splitting of water into hydrogen. When the mass fraction of the graphene-like material in the WO3/ZnO/graphene-like composite photocatalyst is 30 %, the photocatalytic hydrogen production rate reaches the maximum value of 820 times that of intrinsic ZnO. Therefore, this work provides a new perspective for alternating strong-low light catalytic water splitting to produce hydrogen.

Electronically Inverted Perovskite‐Type Co‐catalyst as a Universal Platform for Enhanced Photocatalysis

AbstractCo‐catalysts are commonly employed as catalytic centers to activate reactants and intermediates for driving redox reactions with photogenerated carriers during photocatalysis. Herein, a group of electronically inverted perovskite‐type nitrides CuxIn1−xNNi3 (0 ≤ x ≤ 1) are reported as novel and versatile co‐catalysts for the significantly enhanced photocatalytic hydrogen production performance on various photocatalysts, such as metal sulfides (CdS, ZnIn2S4), carbon nitride (g‐C3N4), and metal oxide (TiO2), respectively. The hybrid photocatalyst Cu0.5In0.5NNi3/CdS exhibits an optimal activity up to 6945 µmol g−1 h−1 and a remarkable enhancement factor of 6146% compared with that of pristine CdS. Besides, a high reaction stability with repetitive photocatalytic cycles is achieved. The obvious improvement of activity can be ascribed to the promoted charge separation of energetic carriers due to the metallic properties of CuxIn1−xNNi3 and abundant Ni active sites. A near‐zero Gibbs free energy of adsorbed atomic hydrogen on the Ni‐site is thermodynamically favorable for hydrogen evolution, which can be regulated by electronic states of A‐sites (Cu/In). This work not only demonstrates the great potential of perovskite‐structured nitrides as a universal platform for enhanced photocatalysis but also addresses the importance of exploring new catalytic applications for unique perovskite‐derivatives with cations/anions exchanged in coordinated sites of polyhedral.

Controlled synthesis of the M doped (M = Fe, Cu, Zn, Mn)-Co4S3/Ni3S2 catalyst with high electrocatalytic performance for hydrogen evolution reaction in seawater and urea

Electrolysis of seawater is a promising method for producing hydrogen, but sluggish reaction kinetics and electrolyte containing corrosive ions limit its development. In this work, a series of M doped (M = Fe, Cu, Zn, Mn)-Co4S3/Ni3S2 catalyst has been prepared on Ni foam by hydrothermal method with excellent seawater and urea splitting performance. The unique 3D porous structure provides a large number of active sites for the catalyst, which has strong catalytic activity. Fe-Co4S3/Ni3S2 electrode showed excellent hydrogen evolution reaction (HER) catalytic activity in 1 M KOH + seawater and 1 M KOH + 0.5 M urea, driving a current density of 10 mA cm−2 at a low overpotential of 81 and 66 mV. In addition, Fe-Co4S3/Ni3S2 electrode also shows strong stability in 15 h stability test. The results show that although the impurity ions in seawater affect the activity of catalyst, the corrosion resistance of catalyst also improves the catalytic activity and stability. Density functional theory calculations show that this Fe-Co4S material exhibits the optimal Gibbs free energy of hydrogen, the introduction of this Ni3S2 material enhances the electrical conductivity of the material, and the synergistic catalysis of the two materials promotes the optimal hydrogen production performance of the Fe-Co4S3/Ni3S2 material. This work provides a novel understanding for the research of catalysts used in the electrolysis of seawater and urea.

SnIn4S8/FeNi2P Z-scheme heterojunction hollow nanorods for photocatalytic hydrogen production

Climate change and natural disasters have stimulated the exploration of renewable energy, photocatalytic hydrogen production utilizing solar energy is considered an effective way. In this study, hollow FeNi2-MIL-88 nanorods were synthesized by the hydrothermal method, and then FeNi2P was obtained by gas phase phosphorization. Finally, SnIn4S8 was utilized to coat the surface of FeNi2P through an in-situ growth method to obtain rod-like SnIn4S8/FeNi2P. The results showed that the hydrogen production of SnIn4S8/FeNi2P reached 18083.93 μmol/g within 3 h. And SnIn4S8/FeNi2P showed good stability. The photocurrent response spectra and electrochemical impedance spectra confirmed that SnIn4S8/FeNi2P had good carrier conductivity and effectively inhibited the reorganization of photogenerated carriers. The modification of SnIn4S8 enabled the construction of a Z-scheme heterojunction between SnIn4S8 and FeNi2P. It provided more active sites and promoted the separation of photogenerated carriers, ultimately improving the hydrogen production performance of the SnIn4S8/FeNi2P photocatalyst. It would offer essential insights into the design and development of efficient MOFs-derived photocatalysts.

Nickel doped enhanced LaFeO3 catalytic cracking of tar for hydrogen production

The transformation of biomass into green energy was pivotal for sustainable development, yet the efficient conversion of biomass-derived tar into hydrogen-rich syngas remained a significant challenge. This study addressed the catalytic demand for hydrogen production from tar, focusing on the development of LaNixFe1-xO3 perovskites as catalysts. A series of LaNixFe1-xO3 perovskites with varying nickel doping levels (x=0, 0.25, 0.5, 0.75, 1) were synthesized to evaluate their catalytic performance in converting toluene, a representative tar component, into hydrogen. The LaNi0.5Fe0.5O3 catalyst demonstrated the highest hydrogen yield (14.5L/6h) and volume percentage (82.9V/V%), highlighting the optimal nickel doping level for enhancing hydrogen production. The hydrogen production performance of LaNixFe1-xO3 was significantly affected by nickel doping. In particular, a small amount of nickel doping can significantly enhance the hydrogen production capacity of LaFeO3 and maintain good reaction stability. The enhanced performance was attributed to the high oxygen storage capacity of perovskite, which facilitated the removal of surface carbon and promotes the methanation reaction. Notably, the total content of defect oxygen and surface adsorbed oxygen/hydroxyl groups significantly impacted the hydrogen production efficiency. These findings indicated that LaNi0.5Fe0.5O3 was an effective catalyst for converting biomass-derived tar into hydrogen-rich syngas, offering a promising solution to the catalytic demand in the hydrogen production system.

Trinuclear iron-oxo cocatalyst regulating new electron transfer pathway in Pt loaded bismuth oxychloride for efficient photocatalytic hydrogen production

BiOCl, a traditional p-type semiconductor, finds extensive application in photocatalytic oxidation and degradation, whereas it is less common in photocatalytic water splitting and hydrogen production. Here, the photocatalytic hydrogen production performance of black BiOCl has been examined by the introduction of noble metal platinum and cocatalyst trinuclear iron-oxo cluster. During the 5-h photocatalytic process, the established system significantly augments the hydrogen production efficiency of black BiOCl by an estimated factor of 8.53. Under illumination, trinuclear iron-oxo clusters provide electron recombination with holes in the valence band of the catalyst, thereby increasing the utilization of photogenerated electrons. Additionally, since the specific energy level structure has a significant impact on the cocatalyst function, trinuclear iron-oxo clusters can be suitable in a variety of photocatalytic systems. This new endeavor might present creative design approaches and low-cost cocatalyst alternatives for the photocatalytic hydrogen evolution from the water splitting of conventional p-type semiconductor materials.

Reaction kinetics of Ni-Fe oxygen carriers with high performance for chemical looping hydrogen production

The chemical looping hydrogen production (CLHP) process utilizing iron-based oxygen carriers holds promise for practical hydrogen generation applications. However, challenges persist in developing iron-based carriers that are easy to prepare and demonstrate effective reactivity. Our research focuses on evaluating the CLHP reaction performance using bimetallic Ni-Fe oxygen carrier particles, synthesized by a scalable mechanical mixing method. This study unravels the role of Ni in bimetallic Ni-Fe oxygen carriers and investigates the influence of varying nickel-doping ratios on enhancing the reduction reactivity of iron-based oxygen carriers. Compared to the undoped sample, the 20 wt% nickel-doped Fe2O3/Al2O3 (20NiFe) particles enabled a reduction in the reaction temperature by at least 50 K. With the dopant, the methane conversion rate at 923 K is 500% higher than that of carriers without the dopant. Heterogeneous kinetic analysis demonstrates that the global reduction reaction data for the Ni-Fe oxygen carriers fit with the nucleation-nuclei growth model. Through redox reactivity tests and reduction kinetic analysis, 20NiFe shows the lowest apparent activation energy at 53.93 kJ/mol. Furthermore, the kinetic study and quasi in-situ XRD analysis aid in proposing the evolution process of methane reduction reaction for nickel-doped iron-based oxygen carriers, clarifying the role of doping in improving chemical looping reactivity from a kinetic perspective. This work provides valuable guidance for the design and optimization of oxygen carriers, thus accelerating the readiness for industrial deployment of hydrogen production via chemical looping process.

Effect mechanism of Cd on band structure and photocatalytic hydrogen production performance of ZnS

ZnS is widely used in the photocatalytic decomposition of water to produce hydrogen due to its fast electron-hole pair generation and high negative potential. However, its absorption in the visible region is poor due to its wide band gap, and it has serious photogenerated carrier recombination problems. Herein, a shallow impurity energy level was introduced by doping the ZnS lattice with Cd. Due to its presence, electrons trying to return to the valence band are trapped and excited twice, suppressing the recombination of photogenerated carriers and greatly improving electron utilization. The Cd1.5-ZnS possesses a hydrogen production rate as high as 85722.20 μmol/g, which is 17 times higher than pure ZnS. Meanwhile, Cd1.5-ZnS has a narrower forbidden band and superior visible light absorption, and the serious photocorrosion problem of ZnS has been suppressed. This study provides a viable approach for the synthesis of photocatalysts with adjustable band gaps and enhanced hydrogen precipitation efficiency.

Boosting photoelectrochemical hydrogen production performance by in-situ transformation of self-assembled Cd(OH)2 nanowire on CdS nanorod

In this work, solvothermal methods were used to create CdS nanorods (NRs) on Cd foil. Furthermore, a second hydrothermal procedure was performed in water to improve the photoelectrochemical (PEC) properties of the base material at different time variations (3, 6, and 12 h at 160 °C). After the second hydrothermal process, self-assembled Cd(OH)2 NWs were grown on CdS NR. The optimized Cd(OH)2 NW/CdS NR-6 h photoanode exhibited a higher photocurrent density of 5.7 mA/cm−2 at 0 V vs. Ag/AgCl under one sun illumination. Also, the optimum Cd(OH)2 NW/CdS NR-6 h photoanode showed a hydrogen evolution rate of 216 μmol cm−2 for 3 h. The enhanced PEC performance is mainly attributed to the removal of organic moieties, the partial transformation of self-assembled Cd(OH)2 NWs to CdS NR during PCE measurement, and provided effective charge separation and delayed the recombination. We believe that the findings of this study will provide guidelines for designing and fabricating sunlight-driven photoanodes for the PEC hydrogen production system.

Rapid and complete hydrazine borane decomposition for hydrogen production catalyzed by CoPt/CNTs at room temperature

Recently, hydrazine borane (HB, N2H4BH3) is recognized as an ideal chemical hydrogen storage material due to its high efficiency in storing hydrogen and excellent stability. However, finding an efficient, stable, and low-cost catalyst is still a challenge. In this study, CoPt nanoparticles (NPs) supported on carbon nanotubes (CNTs) are prepared at room temperature. The Co0.4Pt0.6/CNTs catalyst exhibits optimal catalytic performance for hydrogen production from HB at ambient conditions, achieving a total turnover frequency (TOF) value of 1525.4 h−1 and 100% H2 selectivity. The well-dispersed CoPt NPs on CNTs and the synergistic effect between Co and Pt further enhance the decomposition efficiency of HB. This high-performance catalyst has significant implications for the advancement of hydrogen storage materials, particularly in relation to HB.

Size-modulated Pt nanoparticles for low-temperature plasmon-enhanced hydrogen production from aqueous phase reforming of methanol

Al2O3 supported Pt nanoparticles photocatalyst enables efficient hydrogen production (115.2 μmol min−1 gcat−1) through aqueous phase reforming of methanol (APRM) reaction under light irradiation at low temperatures of 150 °C, which is 6 times higher than that of APRM reaction conducted in the dark. We demonstrate that the particle size of Pt nanoparticles greatly affected the light absorption ability, which is of great importance for light utilization of the photocatalyst. The medium particle size of Pt nanoparticles enables the lower electron density states, which is benefit for the dehydrogenation of methanol and the sequential water–gas shift (WGS) reaction and eventually promoted the photocatalytic performance for hydrogen production.

Oxygen vacancies promoted hydrogen production from methanol aqueous phase reforming over MgAl−LDHs supported plasmonic Ru nanoparticles catalyst

Catalytic aqueous phase reforming of methanol is a promising process for the sustainable hydrogen production. The search for highly efficient heterogeneous catalyst is a topic of interest. Herein, we report oxygen vacancies enriched MgAl−LDHs supported plasmonic Ru nanoparticles catalyst exhibit excellent photocatalytic performance for efficient hydrogen production at 150 ºC under light irradiation. Characterizations demonstrate abundant oxygen vacancies are introduced into MgAl−LDHs via “memory effect”. The local electron transfer from oxygen vacancies of the MgAl−LDHs to the Ru nanoparticles leading the formation of electron-rich Ru species, which promote the dehydrogenation of methanol under light irradiation. In situ DRIFTS demonstrated a redox mechanism of water-gas shift reaction due to the existence of oxygen vacancies, which resulted a faster hydrogen production rate. This work displays a facile strategy for synthesis of oxygen vacancies rich LDH supported metal nanoparticles catalysts and deep understanding into the pathway and mechanism toward the effective hydrogen production.