Oxidation behavior and electrical conductivity of MAXs phase (Ti,Nb)3SiC2 as a novel intermediate-temperature solid oxide fuel cell interconnect material in anode environment

(Ti,Nb)₃SiC₂ possesses high oxidation resistance and electrical conductivity in cathode side, endowing it potential application as intermediate-temperature solid oxide fuel cell (IT-SOFC) interconnects. However, the performances of (Ti,Nb)₃SiC₂ in anode side must be well understood before the application comes true. In this paper, the oxidation resistance and electrical conductivity of (Ti,Nb)₃SiC₂ in simulated anode reducing atmosphere are systematically investigated. The oxidation kinetics follows parabolic law with a k_P value of 7.57 × 10^?14 g² cm^?4 s^?1. The formed single oxide layer is composed of uniformly distributed Nb-doped rutile TiO₂ and amorphous SiO₂, without carbon deposition. High partial pressure of H₂ and CO in simulated anode reducing atmosphere inhibit the oxidation by H₂O and CO₂. Nb doping with strengthen the Ti–O bond can also slow down the oxidation rate. ASR of (Ti,Nb)₃SiC₂ after 605 h cyclic oxidation is 1.6 and 3.7 mΩ cm² at 800 °C and 500 °C, respectively. The low ASR comes from the induced extra electrons by Nb doping and the dissolution of H₂O and H₂ in oxide, and the integrated TiO₂ conductive network in the scale. (Ti,Nb)₃SiC₂ exhibits superior performances in simulated anode reducing atmosphere, making it an promising candidate for SOFC interconnect.     

Hydrogen production over the hetero-junction MnO2/SiO2

The motivation of this work is the hydrogen production as a non-polluting renewable energy under visible light. For this purpose, the hetero-junction 2%MnO₂/SiO₂ was synthetized by the impregnation method and characterized by X-ray diffraction, scanning electron microcopy (MEB), FTIR spectroscopy, diffuse reflectance and electrical conductivity. The X-ray analysis shows the amorphous silica substrate and the rutile phase MnO₂. The optical curve (αhν)² as a function of hν shows a direct transition of 1.83 eV for MnO₂. The capacitance measurement of the rutile indicates a flat band potential of ?0.027 V_SCE, more negative than the hydrogen evolution in SO₃^2? aqueous solution. As application, hydrogen was successfully evolved over the hetero-junction MnO₂/SiO₂. A good H₂ production was obtained after 30 min of irradiation corresponding to 5.1 mmol h^?1 g^?1 under visible light (29 mWcm^?2). The improved photocatalytic performance is due to the sensitizer MnO₂ homogeneously supported on porous SiO₂ substrate acting as templating agent.     

Hydrogen production from sulphide wastewater using Ce3+–TiO2 photocatalysis

Cerium (Ce³⁺) doped TiO₂ powder was synthesized by a sol-gel method and characterized by Transmission Electron Microscope (TEM), X-ray Diffraction (XRD), UV–Vis Diffuse Reflectance Spectroscopy (UV-DRS), Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray photoelectron spectroscopy (XPS). The Ce³⁺ doping strongly reduced the band gap of the TiO₂ from 3.2 eV (UV) to 2.7 eV (visible region). The photocatalytic activity of Ce³⁺ doped TiO₂ catalysts was evaluated by hydrogen production from sulphide wastewater under visible light illumination. The photocatalytic production of H₂ was studied in a batch recycle tubular photocatalytic reactor. The results show that 0.4% Ce³⁺–TiO₂ suspended in 500 mL of simulated sulphide wastewater irradiated at 150 W visible lamp produced maximum H₂ of 6789 μmol h^?1. It was noticed that the Ce³⁺ doped TiO₂ performs well than Nano TiO₂ and P25 TiO₂ photocatalysts.     

Facile synthesis of Ti3+ doped Ag/AgITiO2 nanoparticles with efficient visible-light photocatalytic activity

We successfully synthesized novel Ti³⁺ doped TiO₂ and Ti³⁺ doped Ag/AgITiO₂ nanoparticles with efficient visible-light photocatalytic activity for hydrogen production by facile one-step solvothermal method. The as-prepared Ti³⁺ doped TiO₂ nanoparticles displayed excellent visible-light absorption and visible-light driven hydrogen production activity (115.3 μmol g^?1 h^?1), while the commercial TiO₂ had no visible-light response. Moreover, the as-prepared Ti³⁺ doped Ag/AgITiO₂ nanoparticles in this experiment showed highly enhanced visible-light absorption and efficient visible-light driven activity for hydrogen (571.0 μmol g^?1 h^?1), which was 4.95 times as high as that of the as-prepared TiO₂ nanoparticles. And the surface areas of the as-prepared TiO₂ and Ti³⁺ doped Ag/AgITiO₂ catalysts were up to 138.829 m² g^?1 and 102.988 m² g^?1, much higher than that of the commercial TiO₂ (55.516 m² g^?1). Finally, the visible-light photocatalytic mechanism of the Ti³⁺ doped Ag/AgITiO₂ nanoparticles for hydrogen generation was also proposed in detail.     

Construction of ternary hybrid layered reduced graphene oxide supported g-C3N4-TiO2 nanocomposite and its photocatalytic hydrogen production activity

Reduced graphene oxide (rGO) supported g-C₃N₄-TiO₂ ternary hybrid layered photocatalyst was prepared via ultrasound assisted simple wet impregnation method with different mass ratios of g-C₃N₄ to TiO₂. The synthesized composite was investigated by various characterization techniques, such as XRD, FTIR, Raman Spectra, FE-SEM, HR-TEM, UV vis DRS Spectra, XPS Spectra and PL Spectra. The optical band gap of g-C₃N₄-TiO₂/rGO nanocomposite was found to be red shifted to 2.56 eV from 2.70 eV for bare g-C₃N₄. It was found that g-C₃N₄ and TiO₂ in a mass ratio of 70:30 in the g-C₃N₄-TiO₂/rGO nanocomposite, exhibits the highest hydrogen production activity of 23,143 μmol g^?1h^?1 through photocatalytic water splitting. The observed hydrogen production rate from glycerol-water mixture using g-C₃N₄-TiO₂/rGO was found to be 78 and 2.5 times higher than g-C₃N₄ (296 μmol g^?1 h^?1) and TiO₂ (11,954 μmol g^?1 h^?1), respectively. A direct contact between TiO₂ and rGO in the g-C₃N₄-TiO₂/rGO nanocomposite produces an additional 10,500 μmol g^?1h^?1 of hydrogen in 4 h of photocatalytic reaction than the direct contact between g-C₃N₄ and rGO. The enhanced photocatalytic hydrogen production activity of the resultant nanocomposite can be ascribed to the increased visible light absorption and an effective separation of photogenerated electron-hole pairs at the interface of g-C₃N₄-TiO₂/rGO nanocomposite. The effective separation and transportation of photogenerated charge carriers in the presence of rGO sheet was further confirmed by a significant quenching of photoluminescence intensity of the g-C₃N₄-TiO₂/rGO nanocomposite. The photocatalytic hydrogen production rate reported in this work is significantly higher than the previously reported work on g-C₃N₄ and TiO₂ based photocatalysts.     

Catalytic properties of dispersed iron oxides Fe2O3/MO2 (M = Zr,Ce, Ti and Si) for sulfuric acid decomposition reaction: Role of support

Supported iron oxides have been established as an important class of catalyst for high temperature sulfuric acid decomposition. With an objective to elucidate the role of support in modifying the overall catalytic properties of dispersed iron oxide catalysts, a series of supported iron oxide based catalysts, Fe₂O₃ (15 wt%)/MO₂ (M = Zr, Ce, Ti and Si), synthesized by adsorption-equilibrium method, is investigated for sulfuric acid decomposition reaction. The structure of dispersed iron oxide phases largely depended on the nature of the support oxide as revealed by the XRD and Mössbauer studies. α-Fe₂O₃ is found to be present as a major phase on ZrO₂ and CeO₂ support while ε-Fe₂O₃ was the major phase on silica supported iron oxide. On the other hand, presence of mixed oxide Fe₂TiO₅ was revealed over TiO₂ support. Strong dispersed metal oxide-support interactions inhibited the total reduction of the dispersed phase on SiO₂ and TiO₂ as compared to complete reduction of dispersed iron oxide on CeO₂ and ZrO₂ supports during temperature programmed reduction upto 1000 °C. The order of catalytic activity at a temperature of ～750 °C is observed as Fe₂O₃/SiO₂ > Fe₂TiO₅/TiO₂ > Fe₂O₃/ZrO₂ > Fe₂O₃/CeO₂, while at higher temperatures of ～900 °C the SO₂ yield is found to be comparable for all catalysts. A relationship between the rate of sulfate decomposition and catalytic activity is established through detailed TG-DTA investigations of sulfated catalyst and support. Considerable influence of the support oxide on the composition, structure, redox properties, morphology and catalytic activities of the active iron oxide dispersed phase has been observed. Thus, the support oxides operate as a critical component in the complex supported metal oxide catalysts and these findings might influence the design and development of future high temperature sulfuric acid decomposition catalysts.     

High-temperature oxidation process analysis of MnCo2O4 coating on Fe-21Cr alloy

Even though the operation temperature of solid oxide fuel cells (SOFCs) stacks has been reduced (∼750 °C), stainless steel interconnect within the stacks still requires protection by high conductive coatings to delay the growth of oxide scales and reduce chromium evaporation. Manganese cobaltite spinel protective coating with a nominal composition of MnCo₂O₄ was produced on Fe-21Cr stainless steel. Electrical, microstructural and compositional analysis were performed to investigate the interfacial reaction of MnCo₂O₄ protective coating with the stainless steel substrate during 750 °C oxidation process. The spinel coating not only acts as a barrier to Cr outward transport, but also improves the electrical conductivity of the alloy interconnect during long-term oxidation. The coated alloy demonstrates good electrical conductivity with an area specific resistance (ASR) of about 5 mOhm cm² after oxidation for 1000 h at 750 °C, which is about 1/4 of the ASR of bare Fe-21Cr alloy. The reduction of ASR might be caused by the fact that Cr migrated from the steel substrate interact with MnCo₂O₄ coating and generated Mn-Co-Cr spinel phase, which has higher electrical conductivity than that of Cr₂O₃.     

The composite electrolyte with an insulation Sm2O3 and semiconductor NiO for advanced fuel cells

Novel Sm₂O₃?NiO composite was prepared as the functional electrolyte for the first time. The total electrical conductivity of Sm₂O₃?NiO is 0.38 S cm^?1 in H₂/air condition at 550 °C. High performance, e.g. 718 mW cm^?2, was achieved using Sm₂O₃?NiO composite as an electrolyte of solid oxide fuel cells operated at 550 °C. The electrical properties and electrochemical performance are strongly depended on Sm₂O₃ and NiO constituent phase of the compositions. Notably, surprisingly high ionic conductivity and fuel cell performance are achieved using the composite system constituting with insulating Sm₂O₃ and intrinsic p-type conductive NiO with a low conductivity of 4 × 10^?3 S cm^?1. The interfacial ionic conduction between two phases is a dominating factor giving rise to significantly enhanced proton conduction. Fuel cell performance and further ionic conduction mechanisms are under investigation.     

Micro and nano-architectures of Co3O4 on Ni foam for electro-oxidation of methanol

Spinel Co₃O₄ material with different morphologies is directly grown on Ni foam by simple hydrothermal method and subsequent calcination processes. The direct growth of binder free active phase of Co₃O₄ on Ni foam is an effective approach to enhance the electrocatalytic activity of the material. The morphologies of Co₃O₄ strongly depend on the anion of the precursor salt used. Microflowers, microspheres and nanograss morphologies of Co₃O₄ are obtained using chloride, sulfate and acetate salts of cobalt, respectively. The BET surface areas of these cobalt oxide materials are found to increase in the order of microflower-Co₃O₄ (53 m² g^?1) < nanograss-Co₃O₄ (65 m² g^?1) < microsphere-Co₃O₄ (100 m² g^?1). The electrocatalytic activity of these Co₃O₄ materials has been tested for methanol oxidation by cyclic voltammetry and chronoamperometry. All three samples show low onset potentials (0.32–0.34 V) for methanol oxidation. The vanodic peak current of methanol oxidation is found to increase in the order of microflower-Co₃O₄ (28 A g^?1) < nanograss-Co₃O₄ (34.9 A g^?1) < microsphere-Co₃O₄ (36.2 A g^?1) at 0.6 V. This study highlights the significance of the morphology of cobalt oxide in the development of oxide based non-precious electrocatalysts for methanol oxidation.     

rGO supported PdNi-CeO2 nanocomposite as an efficient catalyst for hydrogen evolution from the hydrolysis of NH3BH3

The hydrogen economy is a proposed system that utilizes hydrogen to deliver energy. For the realization of this concept, how to safely, controllably and reversibly store and release hydrogen are critical problems which must be resolved. Metal alloys combined with suitable support materials are widely applied to various catalytic reactions. Here palladium nickel bimetallic nanoparticles doped with cerium oxide on a reduced graphene oxide (rGO) support were prepared by combining metal ion precursors and graphene oxide in a one-pot co-reduction approach. The as-received catalysts were characterized by XRD, TEM, SEM, XPS and ICP-OES, and the results revealed that PdNi-CeO₂ nanoparticles were uniform dispersal on rGO. The as-synthesized PdNi-CeO₂/rGO had been adopted as a heterogeneous catalyst for the hydrogen evolution from the hydrolysis of ammonia borane (NH₃BH₃, AB) at room temperature. Kinetically, the hydrogen-release rate was first-order with the increased concentration of catalysts. The optimized catalyst of Pd_0.8Ni_0.2-CeO₂/rGO with the CeO₂ content of 13.9 mol% exhibited an excellent activity with a turnover frequency value of 30.5 mol H₂ (mol catalyst)^?1 min^?1 at 298 K, and a low apparent activation energy (E_a) of 37.78 kJ mol^?1. The robust catalytic performance of the Pd_0.8Ni_0.2-CeO₂/rGO is attributed to the uniform controlled nanoparticle size, the synergic effect between the nanoparticles bimetallic properties, and the effective charge transfer interactions between the metal and support.     

Surface modification of aligned TiO2 nanotubes by Cu2O nanoparticles and their enhanced photo electrochemical properties and hydrogen generation application

In this work, we report the synthesis of cuprous oxide (Cu₂O) nanoparticles modified vertically oriented aligned titanium dioxide (TiO₂) nanotube arrays through wet chemical treatment of TiO₂ nanotubes and their multi-functional application as enhanced photo electrochemical and hydrogen generation. The synthesized samples were characterized by X-ray diffraction, SEM, TEM, and UV–Vis spectroscopy. The structural characterization revealed that the admixed Cu₂O nanoparticles on the TiO₂ surface did not alter its crystalline structure of vertically oriented aligned TiO₂ nanotube. The photocatalytic performance and hydrogen generation of as synthesized Cu₂O nanoparticles modified aligned TiO₂ nanotube was found to highly depend on the Cu₂O content. The optical characterizations reveal that the presence of Cu₂O nanoparticles extends its absorption into the visible region which improves the photocurrent density in comparison to pristine aligned TiO₂ nanotubes electrodes due to enhanced photoactivity and better charge separation. The optimum photocurrent density and hydrogen generation rate has been found to be 3.4 mA cm^?2 and 127.5 μmole cm^?2 h^?1 in 1 M Na₂SO₄ electrolyte solution under 1.5 AM solar irradiance of white light with illumination intensity of 100 mW cm^?2.     

Fabrication of IrO2 decorated vertical aligned self-doped TiO2 nanotube arrays for oxygen evolution in water electrolysis

To fabricate effective and stable OER electrode in water electrolysis, self-doped TiO₂ nanotube arrays which has a higher electrical conductivity than pristine TiO₂ nanotube arrays was used as the support for loading IrO₂. The self-doped TNTA was fabricated by a simple electrochemical reduction of TNTA in neutral electrolyte solution, and then IrO₂ nano particles were deposited by pulse electro-deposition method. The cyclic voltammetric behavior, electrical conductivity and micro structure of self-doped TNTA prepared at different reduction potential were characterized to obtain an optimal performance, and self-doped TNTA prepared under ?1.9 V (vs. Ag/AgCl) shows the best electrochemical performance. After depositing IrO₂, the OER activity and stability of new electrodes were also determined. Due to the enhanced electrical conductivity of support, the mass activity of IrO₂/self-doped TNTA are 50 times higher than IrO₂/TNTA. The OER stability of new electrode was evaluated under constant current of 5 mA/cm², IrO₂/TNTA and IrO₂/Ti were also tested for comparison. A higher stability of IrO₂/self-doped TNTA electrode is observed than the other two electrodes, and XPS studies indicate a lower oxidation state of Ir in IrO₂/self-doped TNTA, this shows a possible interactions between IrO₂ and the new support.     

Electrodeposited Ni/CeO2 mulriple coating on SUS 430 steel interconnect

Ni/CeO₂ mulriple coating has been fabricated on SUS 430 steel via electrodepositing approach. 100-h initial and 3-week long-term thermal exposing to air at 800 °C has enunciated that the oxide scale grown on the Ni/CeO₂ coated steel contains an external oxide layer of NiFe₂O₄ spinel, a middle oxide layer of NiO and an internal oxide layer of Cr₂O₃. Simultaneously, dispersive CeO₂ particles embed in the oxide scale. Compared to the Ni coated steel on which the same tri-layer oxide structure without discrete CeO₂ particles grows in the same exposing environment, growth rate of the internal Cr₂O₃ layer on the Ni/CeO₂ coated steel has been profoundly suppressed, which subsequently lowers the oxide scale area specific resistance (ASR). Enhancement of the oxidation resistance and reduction of the oxide scale ASR are attributed to the presence of CeO₂.     

Significantly improve photoelectrochemical performance of Ti:Fe2O3 with CdSe modification and surface oxidation

Significant interest has been arisen to explore photoanodes for full optical absorption spectrums and good stability in photoelectrochemistry. Herein CdSe is used to modify Ti:Fe₂O₃ photoanode forming Ti:Fe₂O₃/CdSe heterojunction. Combining with an air annealing treatment, Ti:Fe₂O₃/CdSe exhibits a 6.5 times higher photocurrent density that of the pristine Ti:Fe₂O₃ to achieve 3.25 mA cm^?2 at 1.2 V vs. RHE. The photoelectrochemical (PEC) stability of Ti:Fe₂O₃/CdSe annealed in air shows great improvement comparable to both unannealed and annealed ones in Ar. The enhancement mechanisms for both heterojunction and annealing are explored for fundamental insights, which reveal that the surface oxide layer can significantly increase the PEC stability of Ti:Fe₂O₃/CdSe photoanode. X-ray photoelectron spectra and transmission electron microscope results further confirms the surface oxidation on CdSe layer after annealing in air.     

Mo incorporated W18O49 nanofibers as robust electrocatalysts for high-efficiency hydrogen evolution

Creation of robust and stable electrocatalysts is a persistent objective for high-efficiency hydrogen evolution by water splitting. We present here the experimental realization of one-dimensional Mo incorporated W₁₈O₄₉ nanofibers (NFs) by a template-free solvothermal method. When utilized as electrocatalysts for hydrogen evolution through water splitting, the preliminary results demonstrate that the optimized catalytic electrode from 1 at% Mo doped W₁₈O₄₉ NFs yields an onset overpotential of 89 mV and Tafel slope of 49 mV dec^?1 as well as maximal exchange current density up to 1.60 × 10^?2 mA cm^?2. An overpotential as low as 462 mV is required to attain current density of 50 mA cm^?2 in comparison with 587 mV for pristine W₁₈O₄₉ NFs. Moreover, the Mo doped W₁₈O₄₉ NFs display relative stability by applying a potential of 503 mV and a current density of 80 mA cm^?2 over 24 h in 0.5 M H₂SO₄ aqueous solution, making them promising in practical applications.     

Yttrium dependent space charge effect on modulating the conductivity of barium zirconate electrolyte for solid oxide fuel cell

Development of high proton conducting, chemically stable electrolyte for solid oxide fuel cell application still remains as a major challenge. In this work, yttrium (0, 5, 10, 15 and 20 mol%) doped barium zirconate synthesised by hydrothermal assisted coprecipitation exhibited highly crystalline cubic perovskite. The results demonstrate that the proton conductivity is higher than oxygen ion conductivity measured in the temperature range of 200–600 °C. The 20 mol% Y doped BaZrO₃ exhibited higher protonic conductivity (6.1 mScm^?1) with an activation energy 0.64 eV under the reducing atmosphere. The Mott–Schottky analysis carried out in hydrogen atmosphere at 200 °C revealed that the barrier height of doped BaZrO₃ reduced from 0.6 to 0.2 V. The Schottky depletion layer width also decreased from 4 to 2 nm with the increase in yttrium concentration and the boiling water test showed good phase stability. Our study highlights the critical role of space charge in the grain boundary and its suppression with the increase in dopant concentration. The results demonstrate that Y doped BaZrO₃ sintered at low temperature is a promising candidate as the electrolyte material for the intermediate temperature proton conducting solid oxide fuel cells.     

Improved photocatalytic H2 production assisted by aqueous glucose biomass by oxidized g-C3N4

Chemically modified g-C₃N₄ for the photocatalytic H₂ evolution from water was explored. Bulk g-C₃N₄ was treated in hot HNO₃ aqueous solution to obtain the oxidized material (o-g-C₃N₄), tested in water containing glucose as model water-soluble sacrificial biomass, using Pt as co-catalyst, under simulated solar light. The behaviour of o-g-C₃N₄ was studied in relation with catalyst amount, Pt loading, glucose concentration. Results showed that H₂ production is favoured by increasing glucose concentration up to 0.1 M and Pt loading up to 3 wt%, and it resulted strongly enhanced using small amount of o-g-C₃N₄ (0.25 g L^?1). o-g-C₃N₄ possesses superior photocatalytic activity (～26-fold higher) compared to pristine g-C₃N₄, with H₂ evolution further improved by ultrasound-assisted exfoliation and evolution rates up to ca. 1370 μmol h^?1 per gram of catalyst, with excellent reproducibility (RSD < 6%, n = 3). Significant production was observed also in river water and seawater, with results far better (up to ca. 2500 μmol g^?1 h^?1) compared to commercial AEROXIDE^® P25 TiO₂ under natural solar light.     

Co3O4 nanosheet arrays treated by defect engineering for enhanced electrocatalytic water oxidation

Due to its poor electrical conductivity and finite exposed active sites, the development of high activity Co₃O₄ oxygen evolution reaction (OER) electrocatalysts remains a major challenge. Oxygen vacancies can enhance the electrical conductivity of electrocatalysts and reduce the adsorption energy of H₂O molecules on surfaces, thereby significantly enhancing their electrocatalytic activity. Taking inspiration from this, we demonstrate a green and facile reduction strategy to prepare reduced Co₃O₄ nanosheet arrays (R-Co₃O₄ NSA) with large electrochemical surface area and rich in surface oxygen vacancies. Compared to pristine Co₃O₄ nanosheet arrays (P-Co₃O₄ NSA), R-Co₃O₄ NSA exhibits better OER performance, with a lower overpotential of 330 mV at a current density of 20 mA cm^?2 and a smaller Tafel slope of 72 mV dec^?1. Impressively, the excellent properties of R-Co₃O₄ NSA can rival to the state-of-the-art noble metal oxide electrocatalyst (IrO₂). This strategy of defect-engineering offers a briefness and cost-effective means for the development of highly efficient OER systems.     

Dy doped SrTiO3: A promising anodic material in solid oxide fuel cells

The perovskite-type oxides, having a general formula ABO₃, are promising candidates for anode materials in solid oxide fuel cells. In particular, doped SrTiO₃ based perovskites are potential mixed ionic-electronic conductors and they are known to have excellent thermal and chemical stability along with carbon and sulfur tolerance. In this work, Dy_xSr_1-xTiO_3-δ system with x = 0.03, 0.05, 0.08 and 0.10 is studied to understand the influence of Dy content on its structural and electrical behavior. Electrochemical properties are measured, both in air and hydrogen atmosphere, and structural characterizations are performed before and after electrochemical tests and compared each other to study the stability. Results show that Dy_xSr_1-xTiO_3-δ powders with x ≤ 0.05, are single phase, while for x ≥ 0.08 a small amount of secondary phases is formed. In air, the conductivity is predominantly mixed ionic-electronic type for x ≤ 0.05, becoming ionic for x ≥ 0.08. It is observed that conductivity, for each composition, increases passing from air to hydrogen and activation energy decreases. Dy_0.05Sr_0.95TiO_3-δ shows the highest conductivity in air whereas Dy_0.08Sr_0.92TiO_3-δ in H₂ atmosphere. Degradation observed by XRD is negligible for x ≤ 0.05 but increases with higher Dy content.     

Ionothermal synthesis of TiO2 nanoparticles for enhanced photocatalytic H2 generation

Photocatalytic hydrogen generation is one of the most promising solutions to convert light energy into green chemical energy. In the present work, methoxy ethyl methyl imidazolium methyl sulphonate ionic liquid is used for the synthesis of i-TiO₂ nanoparticles via ionothermal method at 120 °C. The obtained products were characterized by various spectroscopic techniques like XRD, FTIR, Raman, UV–visible, DRS, TEM and TG-DSC analysis. XRD pattern confirmed the anatase phase with minor rutile phase having average crystallite size of 5 nm. From the FTIR spectrum, the band appeared at ～547 cm^?1 confirmed the Ti–O–Ti stretching and also few bands of ionic liquid. UV–vis spectrum clearly reveals the blue shift due to size effect of TiO₂. The spherical surface structure and particle size (15–30 nm) have been studied in detail using TEM images. Finally, the practical applicability of the as synthesized i-TiO₂ nanoparticles is shown by using it as a photocatalyst towards the generation of H₂ through water splitting reaction and it is found to be 462 μmol h^?1g^?1.