H2 Production Activity Research Articles

Metal Ni nanoparticles in-situ anchored on CdS nanowires as effective cocatalyst for boosting the photocatalytic H2 production and degradation activity

Rapid recombination of photoinduced charge carriers and photoinstability greatly hinder the large-scale application of CdS photocatalysis. Herein, non-noble metal Ni nanoparticles (NPs) as highly efficient co-catalysts are evenly anchored onto the surface of CdS nanowires (NWs) via a facile freeze calcination method. As a result, the H2 production performance of the optimal Ni/CdS NWs under the filter (λ ≥ 420 nm) is about 80 times that of the bare CdS NWs, reaching 13,267.2 μmol h−1 g−1 and the apparent quantum efficiency (AQE) is 9.3%. Furthermore, Ni/CdS NWs photocatalysts have a surprising performance in the degradation of reactive red (RR2) and tetracycline hydrochloride (TCH), and the optimal photodegradation properties are 0.125 and 0.069 min−1, respectively. According to the experimental characterization and theoretical calculation analysis, the deposition of Ni NPs not only increases the active sites of the reaction but also restrains the recombination of photoinduced charge carriers, so ameliorating the photocatalytic performance of CdS photocatalysts. This work provides a novel standpoint for designing non-noble metal co-catalyst/semiconductor photocatalysts for efficient solar energy conversion.

Dye-sensitized NH2-UiO-66 anchored with copper ions for tandem visible-light-driven hydrogen evolution

Metal-organic frameworks (MOFs) have attracted exciting application prospects in photocatalytic hydrogen (H2) evolution due to the diversity of organic ligands and metal ions. However, the inappropriate conduction band position of pristine MOFs and corresponding large overpotential for H2 evolution restrict the H2 production under visible light. Herein, a dye-sensitized NH2-UiO-66 anchored with copper ions (EY-6Cu-NU-66) was synthesized by in-situ Cu anchoring followed by Eosin Y sensitization. The H2 production activity showed that EY-6Cu-NU-66 reached 3579.82 μmol·g−1·h−1 under visible light, which was four times higher than that of dye-sensitized pristine NU-66 (EY-NU-66) and 99-fold higher than that of 6Cu-NU-66 free of dye sensitization. A series of characterizations and theoretical computations indicated that photo-generated electrons first transfer from the excited Eosin Y to the lowest unoccupied molecular orbital (LUMO) of the NU-66, then further transfer to the transition CuII/CuI metal center that is formed by Cu anchored on -NH2. This tandem mechanism not only improves the visible-light absorption ability of NU-66 but also promotes its separation efficiency of photo-generated carriers, thus greatly reducing the overpotential for H2 evolution. This work provides a new strategy for visible-light-driven H2 production by dye-sensitized MOF-based materials without noble metal loading.

Upgrading of plastic waste-derived wax through air gasification using promoted Ni/Al2O3 catalysts for H2 generation

Catalytic air gasification of plastic waste-derived wax (PW) was performed using Ni/X-Al2O3 (X = Ti, Sr, or La) catalysts to produce H2-rich gas for the first time. For this purpose, X-Al2O3 supports were primarily synthesized by doping different promoters into the Al2O3 structure, followed by the loading of Ni. The catalytic performances of prepared catalysts were compared with that of 10Ni/Al, prepared by impregnation of Ni into commercial γ-Al2O3. Compared with using 10Ni/Al, the use of Ni/X-Al2O3 catalysts resulted in higher activity and selectivity, wherein the highest gas yield (74.78 wt%) and H2 selectivity (25.30 vol%) were achieved using 10Ni/5Ti-Al. Also, the coke yield effectively decreased when using Ni/X-Al2O3 catalysts, particularly 10Ni/5Ti-Al, compared with using 10Ni/Al. These findings are ascribed to the versatile effects of well-dispersed metallic Ni active sites, increased density of Lewis acidic sites at the expense of Brønsted acid sites, and enhanced oxygen transfer capacity of the catalyst owing to Ti addition. Moreover, increasing the concentrations of Ni (up to 10 %) and Ti (up to 5 %) enhanced the catalytic activity and selectivity for H2 production. Increasing the temperature (up to 750 °C) showed a positive effect on the production of H2-rich gas. Furthermore, varying the catalyst-to-feedstock ratio affected the gas yield and H2 selectivity.

3D/2D photocatalyst fabricated from Pt loading TiO2 nanoparticles and converter slag-derived Fe-doped hydroxyapatite for efficient H2 evolution

H2 generation for partially substituting coke by the photocatalysts fabricated from steel slag presents a desirable approach to on-site carbon footprint reduction in the iron and steel-making industry, both environmentally and economically. However, achieving high photocatalytic H2 production activity is primarily limited by the scarcity of active sites due to a small specific surface area, inefficient charge transfer, and partly restricted by slow kinetics of the H2 generation reaction. In this study, 1 wt% Pt clusters are photo-reduced onto sub-15 nm TiO2 nanoparticles (TiO2-Pt) in 20 vol% methanol. Subsequently, the electrostatic assembling method has been employed to combine steel-making converter slag-derived Fe-doped hydroxyapatite (FeHAp) with TiO2-Pt, forming a type II 3D/2D TiO2-Pt/FeHAp heterojunction. Excellent connectivity between these two phases contributes to efficient charge separation, forming a built-in electric field that drives the photo-generated electrons to flow from FeHAp to the Pt cocatalyst on TiO2 nanoparticles through the type-II path. By the synergistic effects, including the large specific surface of sub-15 nm TiO2, Pt cocatalyst-offered rapid H2 generation kinetics,. and the heterostructure-provided enhancement of interfacial charge migration and separation, 60 mg TiO2-Pt/5FeHAp presents an enhanced H2 production activity in 120 mL of 10 vol% triethanolamine (TEOA), enabling the H2 generation rate (3026 μmol·g−1·h−1) to reach 1.85 and 75.78 times greater than that of pristine TiO2-Pt (1638 μmol·g−1·h−1) and FeHAp-Pt (40 μmol·g−1·h−1), respectively, under UV–visible light irradiation for 3 h at 8 °C and obtaining an apparent quantum yield of 4.72 % at 370 nm. This study provides a promising strategy for green hydrogen-based steel-making in the sustainable development of the steel industry.

Hydrogen Evolution of a Unique DNAzyme Composed of Cobalt-Protoporphyrin IX and G-Quadruplex DNA.

Molecular hydrogen (H2 ) is a clean and renewable fuel that has garnered significant interest in the search for alternatives to fossil fuels. Here, we constructed an artificial DNAzyme composed of cobalt-protoporphyrin IX (CoPP) and G-quadruplex DNA, possessing a unique H2 Oint ligand between the CoPP and G-quartet planes. We show for the first time that CoPP-DNAzyme catalyzes photo-induced H2 production under anaerobic conditions with a turnover number (TON) of 1229 ± 51 over 12 h at pH 6.05 and 10 °C. Compared with free-CoPP, complexation with G-quadruplex DNA resulted in a 4.7-fold increase in H2 production activity. The TON of the CoPP-DNAzyme revealed an optimal acid-base equilibrium with a pKa value of 7.60 ± 0.05, apparently originating from the equilibrium between Co(III)-H- and Co(I) states. Our results demonstrate that the H2 Oint ligand can augment and modulate the intrinsic catalytic activity of H2 production catalysts. These systems pave the way to using DNAzymes for H2 evolution in the direct conversion of solar energy to H2 from water.

Sulfur and carbon co-doped g-C3N4 microtubes with enhanced photocatalytic H2 production activity

Sulfur and carbon co-doped g-C3N4 microtubes with enhanced photocatalytic H2 production activity

Conductive Polymer-Inorganic Polythiophene/Cd0.5Zn0.5S Heterojunction with Apace Charge Separation and Strong Light Absorption for Boosting Photocatalytic Activity.

In order to utilize the synergistic effect between a conductive polymer and an inorganic semiconductor to efficaciously enhance charge transfer and solve the problem of unsatisfactory performance of a single photocatalyst, thiophene (Th) was polymerized on the Cd0.5Zn0.5S nanoparticle surface to prepare a conductive polymer-inorganic polythiophene/Cd0.5Zn0.5S (PTh/CZS) heterostructrue through a simple in situ oxidation polymerization for the first time. The as-prepared PTh/CZS heterostructures significantly improved photocatalytic TCH degradation and hydrogen production activities. Especially, the 15PTh/CZS sample exhibited the optimal hydrogen production rate (18.45 mmol g-1 h-1), which was 2.51 times higher than pure Cd0.5Zn0.5S nanoparticles. In addition, 15PTh/CZS also showed very fast and efficient photodegradation ability for degrading 88% of TCH in 25 min. Moreover, the degradation rate (0.06229 min-1) was five times more than that of Cd0.5Zn0.5S. The π-π* transition characteristics, high optical absorption coefficient, wide absorption wavelength of PTh, the tight contact interface, and synergistic effect of PTh and Cd0.5Zn0.5S efficiently boosted charge transfer rate and increased the light absorption of PTh/CZS photocatalysts, which greatly enhanced the photocatalytic abilities. Besides, the mechanism of improved photocatalytic activities for TCH degradation and H2 production was also carefully proposed. Undoubtedly, this work would provide new insights into coupling conductive polymers to inorganic photocatalysts for achieving multifunctional applications in the field of photocatalysis.

Photoredox Cascade Catalyst for Efficient Hydrogen Production with Biomass Photoreforming.

Biomass photoreforming is a promising method to provide both a clean energy resource in the form of hydrogen (H2 ) and valuable chemicals as the results of water reduction and biomass oxidation. To overcome the poor contact between heterogeneous photocatalysts and biomass substrates, we fabricated a new photoredox cascade catalyst by combining a homogeneous catalyst, 2,2,6,6-tetramethylpiperidine 1-oxyl (TEMPO), and a heterogeneous dual-dye sensitized photocatalyst (DDSP) composed of two Ru(II)-polypyridine photosensitizers (RuP6 and RuCP6 ) and Pt-loaded TiO2 nanoparticles. During blue-light irradiation (λ=460±15 nm; 80 mW), the DDSP photocatalytically reduced aqueous protons to form H2 and simultaneously oxidized TEMPO• radicals to generate catalytically active TEMPO+ . It oxidized biomass substrates (water-soluble glycerol and insoluble cellulose) to regenerate TEMPO• . In the presence of N-methyl imidazole as a proton transfer mediator, the photocatalytic H2 production activities for glycerol and cellulose reforming reached 2670 and 1590 μmol H2 (gTiO2 )-1 h-1 , respectively, which were comparable to those of state-of-the-art heterogeneous photocatalysts.

Photoredox Cascade Catalyst for Efficient Hydrogen Production with Biomass Photoreforming

AbstractBiomass photoreforming is a promising method to provide both a clean energy resource in the form of hydrogen (H2) and valuable chemicals as the results of water reduction and biomass oxidation. To overcome the poor contact between heterogeneous photocatalysts and biomass substrates, we fabricated a new photoredox cascade catalyst by combining a homogeneous catalyst, 2,2,6,6‐tetramethylpiperidine 1‐oxyl (TEMPO), and a heterogeneous dual‐dye sensitized photocatalyst (DDSP) composed of two Ru(II)‐polypyridine photosensitizers (RuP6 and RuCP6) and Pt‐loaded TiO2 nanoparticles. During blue‐light irradiation (λ=460±15 nm; 80 mW), the DDSP photocatalytically reduced aqueous protons to form H2 and simultaneously oxidized TEMPO• radicals to generate catalytically active TEMPO+. It oxidized biomass substrates (water‐soluble glycerol and insoluble cellulose) to regenerate TEMPO•. In the presence of N‐methyl imidazole as a proton transfer mediator, the photocatalytic H2 production activities for glycerol and cellulose reforming reached 2670 and 1590 μmol H2 (gTiO2)−1 h−1, respectively, which were comparable to those of state‐of‐the‐art heterogeneous photocatalysts.

Construction of S-scheme heterojunction catalytic nanoreactor for boosted photothermal-assisted photocatalytic H2 production

Reasonable design of heterojunction band structure and strengthening of the photothermal effect is an important method to promote the photothermal-assisted photocatalytic H2 production activity of photocatalysts. Herein, a composite material named as Co3O4/CNNVs S-scheme heterojunction nanoreactor was constructed by loading Co3O4 nanoparticles on the surface of g-C3N4 nanovesicles (CNNVs) through a simple hydrothermal method and used to achieve efficient photothermal-assisted photocatalytic H2 production. In the absence of Pt as a cocatalyst, Co3O4/CNNVs-22.5 exhibited a photocatalytic H2 production rate up to 772.9 μmol g-1h−1 under irradiation with a 300 W Xenon lamp, which is much higher than that of pure CNNVs (15.5 μmol g-1h−1). In the Co3O4/CNNVs photothermal-assisted photocatalytic system, the synergistic effect of the strong photothermal effect of Co3O4 nanoparticles and the thermal insulation effect of hollow CNNVs nanoreactor was shown to be the main reasons for promoting the surface temperature increase of the heterojunction photocatalyst, which effectively facilitates the separation and transfer of photo-generated carriers, thus increasing the photocatalytic H2 production. In addition, the S-scheme heterojunction formed between Co3O4 and CNNVs optimize the charge transfer path. This work presents a reasonable design of highly efficient photocatalyst with a S-scheme heterojunction nanoreactor for the photothermal-assisted photocatalysis.

Au-Deposited Ce0.5Zr0.5O2 Nanostructures for Photocatalytic H2 Production under Visible Light

Pure Ce0.5Zr0.5O2 and Au (0.1–1.0 wt.%)-deposited Ce0.5Zr0.5O2 nanomaterials were synthesized via hydrothermal and non-aqueous precipitation methods using gold acetate as a chloride-free Au precursor. The synthesized nanostructures exhibited enhanced photocatalytic activity for hydrogen production via aqueous bioethanol photoreforming under visible light. Different characterization tools such as powder XRD, HRTEM, FT-IR, DR UV-vis, XPS and N2 gas adsorption were used to analyze the physicochemical properties of the synthesized photocatalysts. The band gap value was lowered from 3.25 eV to 2.86 eV after Au nanoparticles were deposited on the surface of Ce0.5Zr0.5O2. The 1.0 wt.% Au-deposited Ce0.5Zr0.5O2 sample exhibited the highest photocatalytic activity for H2 production (3210 μmol g−1) due to its low band gap, the presence of more oxygen vacancies and its porous character. The EIS results reveal that the deposition of 1.0 wt.% Au nanoparticles is responsible for the highest charge separation efficiency with an increased lifetime of photogenerated e−/h+ species compared to the other samples. In addition, the presence of plasmonic Au is responsible for the effectiveness of the electron trap in improving the rate of H2 formation.

Converting low-polymerized fragments into melem assemblies as charge transport bridges to activate polymeric carbon nitride

The weak hydrogen bonds between melon chains in polymeric carbon nitride (CN) are naturally difficult for carrier transfer and the produced low-polymerized CN fragments further aggravate charge transport. Here, through the controllable depolymerized intervention of CN with molten KSCN, the unstable low-polymerized fragments are concurrently depolymerized and assembled into melem-based nanorods. These massively bonded assemblies in the established composite, as charge transfer bridges, closely connect with melon structures, providing pathways and facilitating charge transfer carriers on chains to nanorods and adjacent chains. Therefore, the proposed “waste into treasure” strategy eliminates the low-polymerized fragments and converts them into charge transport bridges, eventually boosting charge transport and achieving a 16-fold increase in H2 production activity.

Hydrophilic calix[4]arene dye-sensitized Co/g-C3N4 composites with Co single atoms for enhanced visible-light-driven photocatalysis

Single-atom hybrid photocatalysts (Co/g-C3N4/C4EOP) composed of hydrophilic calixarene dyes (C4EOP) and graphite-phase carbon nitrite with monodispersed Co atoms (Co/g-C3N4) are prepared by a facile solution impregnation method, and their photocatalytic performances are evaluated in visible light-driven H2 evolution from water and CO2 conversion. The optimized Co/g-C3N4/C4EOP (1.0 wt%) catalyst exhibits moderate H2 production activity (511 μmol g−1 h−1) and good durability within 60 h (TONC4EOP value of 2255) under visible light. In contrast, the Co/g-C3N4/C4BTP (1.0 wt%) and Co/g-C3N4/M-EOP (1.0 wt%) show much lower activities than Co/g-C3N4/C4EOP (1.0 wt%) under the same conditions. This could be attributed to the higher molar extinction coefficient and better hydrophilicity of C4EOP compared to C4BTP with hydrophobic alkane groups and M-EOP with single D-π-A chain. In addition, Co/g-C3N4/C4EOP (1.0 wt%) catalyst displays highly selective photocatalytic activity for CO2 reduction to CO. This work provides a promising example for the development of efficient dye-sensitized photocatalytic system based on g-C3N4 with non-noble metal for the chemical utilization of solar energy.

Synthesis of Copper/Sulfur Co-Doped TiO2-Carbon Nanofibers as Catalysts for H2 Production via NaBH4 Hydrolysis

Copper/sulfur co-doped titanium dioxide-carbon nanofibers (Cu,S-codoped TiO2 NPs, decorated-CNFs) catalysts were synthesized using the electrospinning process to produce composite nanofibers (NFs). These composite NFs were utilized for the hydrolysis of sodium borohydride (SBH) to generate hydrogen gas (H2), taking advantage of their catalytic properties. The experimental results demonstrated that using 100 mg of composite NFs yielded the highest catalytic activity for H2 production, generating 79 mL of H2 gas within 6 min at 25 °C and 1000 revolutions per minute (rpm) using 1 mmol of SBH. As the catalyst dosage was reduced from 100 mg to 75, 50, and 25 mg, the reaction time increased by 9, 13, and 18 min, respectively. Kinetic studies revealed that the reaction rate followed a first-order reaction, indicating a direct proportionality between the rate of reaction and the catalyst amount. Additionally, it was observed that the concentration of SBH had no influence on the reaction rate, suggesting a zero-order reaction. Increasing the reaction temperature resulted in a reduced reaction time. The activation energy was determined to be 26.16 kJ mol−1. The composite NFs maintained their superior performance over five iterations. These findings suggest that composite nanofibers have the potential to serve as a cost-effective alternative to expensive catalysts in hydrogen production.

Efficient hydrogen production from formic acid over Ag@AgPd nanotriangulars at room temperature

Hydrogen with advantages of high energy density, zero pollution and zero carbon dioxide emissions is regarded as a carrier of clean energy for replacing fossil fuels. Therefore, the development of a high activity, selectivity and stability catalyst for H2 production remains a great challenge. Herein, we report a new Ag@AgPdx nanotriangulars catalysts via immobilizing Pd atoms onto the surface of Ag nanotriangulars, for H2 production from formic acid (FA) at room temperature, with superior catalytic activity and stability over commercial Pd/C and Pt/C. The in-situ DRIFT results shown the FA dehydrogenation process over Ag@AgPd0.8 nanotriangulars, first the HCOOH* was rapidly converted to HCOO*, and finally to CO2*, which explained the fact that Ag@AgPd0.8 nanotriangulars have high activity and selectivity for FA dehydrogenation. This strategy opens up a new way to design effective catalysts for efficient H2 production from FA dehydrogenation to meet the requirement and applications of fuel cell.

Surface Modification with Metal Hexacyanoferrates for Expanding the Choice of H2‐Evolving Photocatalysts for Both Fe3+/Fe2+ Redox‐Mediated and Interparticle Z‐Scheme Water‐Splitting Systems

The construction of Z‐scheme water splitting systems is an effective approach toward harvesting a wide portion of the solar light spectrum; however, the success has often depended on the property of photocatalyst surfaces. This drawback is typified by the limited choice of efficient H2 evolution photocatalysts (HEPs) (e.g., Rh‐doped SrTiO3) for Z‐scheme water splitting using Fe3+/Fe2+ redox couple. The majority of visible light‐responsive materials shows low activity for H2 production with Fe2+ electron donors despite having suitable band levels, probably due to the absence of an effective surface site for oxidizing Fe2+. The choice of HEPs for interparticle Z‐scheme systems has also been limited. Herein, an effective strategy for overcoming these limitations is reported: activation of originally inactive materials via surface modification with metal hexacyanoferrate nanoparticles. Photocatalytic H2 evolution over TaON in aqueous Fe2+ solution is drastically enhanced by comodification with indium hexacyanoferrate (InHCF) and Rh–Cr mixed oxide. InHCF promotes Fe2+ oxidation to Fe3+ utilizing the holes photogenerated in TaON via FeIII/FeII redox cycles, enabling Z‐scheme water splitting with the Fe3+/Fe2+ redox mediator coupled with an O2 evolution photocatalyst under visible light. It is also disclosed that InHCF nanoparticles function as effective solid electron mediators for achieving interparticle Z‐scheme water splitting.

Enhanced photocatalytic H2 production of flower-like MoS2@Ag2S photocatalysts with matched band structures

The flower-like MoS2@Ag2S (MS@AS) photocatalyst was synthesized by the hydrothermal and ion exchange reactions. Results of SEM, TEM, elemental line scan profiles, and XPS analysis revealed that Ag2S nanoparticles were attached to flower-like MoS2. Raman spectra confirm that MoS2 (MS) and MoS2@Ag2S (MS@AS) photocatalysts are hybrid phases of 1 T-MoS2 and 2H-MoS2. Compared with pristine MoS2, the shifts of XPS Mo3d and S2s peaks of MS@AS photocatalyst indicate the interaction between MoS2 and Ag2S (or Ag). The band structure of the photocatalyst is proposed based on the UPS spectrum and Tauc plot of MoS2 and Ag2S. The H2 production efficiency of MoS2@Ag2S photocatalyst reaches 3516 μmol·g−1·h−1, better than that of MoS2. The MoS2@Ag2S photocatalyst exhibits a S-scheme band structure, which can facilitate electron-hole separation and improves photocatalytic H2 production activity.

Growth of tunable Au-BaO@TiO2/CdS heterostructures: Acceleration of hydrogen evolution from water splitting

The need for efficient and sustainable catalysts to generate clean energy through water splitting is a requirement of the current era. In this study, TiO2/CdS heterostructures were synthesized using hydrothermal reaction. To enhance the photocatalytic performances of TiO2/CdS, BaO and Au were in-situ deposited via chemical reduction and hydrothermal treatment at 165 °C for 6 h. Finally Au-BaO@TiO2/CdS catalysts were synthesized for photocatalytic hydrogen generation from water splitting. The optical and structural properties of catalysts were examined with FT-IR, XRD, Raman and UV–Vis-DRS techniques. The morphology and chemical properties of catalysts were obtained using EDX, AFM, XPS and SEM techniques. Photoreaction and H2 production activities were monitored at Pyrex reactor (150 mL) and GC-TCD (Shimadzu-2014). The tunable fabrication approach provides a novel strategy for tailoring the properties of TiO2/CdS heterostructures, allowing for optimization of their photocatalytic performance. The enhanced surface plasmon impact achieved through Au-NPs incorporation opens up new possibilities for improving the efficiency. The results demonstrate that Au-BaO@TiO2/CdS catalysts exhibit significantly higher H2 generation activity (13.54 mmol g−1h−1). This H2 evolution activity was found higher than other catalysts i.e. TiO2/CdS, BaO@TiO2/CdS and Au@TiO2/CdS. Higher catalytic activity in case of Au-BaO@TiO2/CdS was attributed to the co-existence of BaO and Au-NPs. The Au-NPs provide hot electrons (via SPR effect) that increase the electron pool over the surfaces of TiO2/CdS heterostructures. During photoreaction, BaO assists the transfer of photoexcited electrons from TiO2/CdS system to the active centers (i.e. Au cocatalysts). In addition, various factors that affect the H2 production rates (i.e. pH, temperature, catalyst dose and effect of light intensity) were evaluated and discussed.

Robust one-pot solvothermal incorporation of InVO4 with polymeric-C3N4 nanosheets with improved charge carrier separation and transfer: A highly efficient and stable photocatalyst for solar fuel (H2) generation

Polymeric-C3N4 is a photocatalyst with desirable properties for efficient solar fuel (H2) generation. However, p- C3N4 exhibits a low H2 evolution rate. Herein, InVO4 is successfully incorporated on the surface of p- C3N4 nanosheets via a one-pot solvothermal method to generate solar fuel (H2) effectively. The optical gap energy of p- C3N4 was red-shifted to 2.23 eV after incorporating InVO4. A small arc radius of the Nyquist plot and substantial quenching of PL was observed when InVO4 was added to p- C3N4. The optimized catalyst loading (15 wt%) shows a maximum H2 production activity of 8980 µmol/g/h. This outstanding performance is a nearly 56-fold enhancement in comparison with bare p-C3N4. Furthermore, the STH conversion efficiency of 1.87% is achieved with the optimized photocatalysts, which is higher than many g- C3N4 - based photocatalysts. Moreover, the H2 generation activity achieved in the present work is higher than the reported one using the same InVO4-g- C3N4 photocatalysts.

One-step synthesis of multiple electron migration channels TiO2/Fe2O3@Ti3C2 MXene heterojunction composite for high efficiency photo-catalytic hydrogen production

Photo-catalytic hydrogen (H2) production provides a promising technology to tackle the non-renewable energy shortage and environmental pollution problem. However, the rapid recombination of the electron-hole pairs and poorer electric conduction characteristic restrict photo-catalytic H2 production. In this work, a multiple electron migration channels TiO2/Fe2O3@Ti3C2 composite hetero-structure was synthesized by one-step hydrothermal with Ti3C2 in situ autoxidation for Photo-catalytic H2 production. The morphology structures, crystallization properties electrochemical properties were characterized Systematically. Photo-catalytic experiments reveal that the TiO2/Fe2O3@Ti3C2 photo-catalyst displays enhanced response to visible light, increased transient photo-current and excellent photo-catalytic H2 production activity. The hydrogen production rate reached 1634.64 μmol/g/h, which was 9.7 and 16 times that of Ti3C2/TiO2 and single Fe2O3, respectively. The remarkably photo-catalytic H2 production performance of TCTF photo-catalyst was attributed to multiple electron-transfer channels, abundant interface contact sites and excellent light absorption. This research indicates that the hetero-structure photo-catalyst will provide significance insights into the rational design of low-cost, environmentally friendly and high-performance photo-catalysts for photo-catalytic H2 production and other solar-to-fuels conversion and applications.