R. Mekersi , S. Boumaza , A. Bahdaouia , S. Benallal , A. Boudjemaa , M. Trari
{"title":"KNb0.99Eu0.01O3 的合成、表征以及 Ag/La2NiO4/ KNb0.99Eu0.01O3 异质结的光催化 H2 产率改进","authors":"R. Mekersi , S. Boumaza , A. Bahdaouia , S. Benallal , A. Boudjemaa , M. Trari","doi":"10.1016/j.jphotochem.2024.116094","DOIUrl":null,"url":null,"abstract":"<div><div>The perovskite KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> prepared by nitrate combustion is applied as a hydrogen photocathode in heterojunction with La<sub>2</sub>NiO<sub>4</sub> under visible light. The XRD pattern confirms the formation of KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> structure with orthorhombic single phase. The SEM images present grains between 0.2 and 0.4 µm while the optical band gap (3.14 eV) is calculated from the diffuse reflectance. Under illumination, the cyclic voltammetry (CV) and the capacitance measurements in Na<sub>2</sub>SO<sub>4</sub> electrolyte show an increased current below ∼ -0.7 V vs. Ag/AgCl and <em>p</em>-type behavior with a conduction band (CB = −1.95 V) cathodically positioned with respect to H<sub>2</sub> level, thus leading to H<sub>2</sub> photo-production. The hetero-system La<sub>2</sub>NiO<sub>4</sub>/KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> shows a much higher activity than KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> where efficient H<sub>2</sub>-photoevolution occurs with concomitant oxidation of S<sub>2</sub>O<sub>3</sub><sup>2−</sup>, as reducing agent. So, the co-junction of La<sub>2</sub>NiO<sub>4</sub> with KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> facilitates the charge transfer and increases the reaction efficiency. At neutral pH, the H<sub>2</sub> evolution rate for the photocatalysts KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> and La<sub>2</sub>NiO<sub>4</sub>/ KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> are 11.15 and 57 µmol g<sup>−1</sup> min<sup>−1</sup>; respectively. Further enhancement is observed with Ag-loaded La<sub>2</sub>NiO<sub>4</sub>/KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub>, reaching a maximum hydrogen production rate of 67 µmol g<sup>−1</sup> min<sup>−1</sup>, attributed to the lower overpotential introduced by Ag. These findings highlight the potential of the ternary system Ag/La<sub>2</sub>NiO /KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> as an efficient photocathode for H<sub>2</sub> generation.</div></div>","PeriodicalId":16782,"journal":{"name":"Journal of Photochemistry and Photobiology A-chemistry","volume":null,"pages":null},"PeriodicalIF":4.1000,"publicationDate":"2024-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":"{\"title\":\"Synthesis, Characterization of KNb0.99Eu0.01O3 and improved Photo-catalytic H2-Production on Ag/La2NiO4/ KNb0.99Eu0.01O3 hetero-junction\",\"authors\":\"R. Mekersi , S. Boumaza , A. Bahdaouia , S. Benallal , A. Boudjemaa , M. Trari\",\"doi\":\"10.1016/j.jphotochem.2024.116094\",\"DOIUrl\":null,\"url\":null,\"abstract\":\"<div><div>The perovskite KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> prepared by nitrate combustion is applied as a hydrogen photocathode in heterojunction with La<sub>2</sub>NiO<sub>4</sub> under visible light. The XRD pattern confirms the formation of KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> structure with orthorhombic single phase. The SEM images present grains between 0.2 and 0.4 µm while the optical band gap (3.14 eV) is calculated from the diffuse reflectance. Under illumination, the cyclic voltammetry (CV) and the capacitance measurements in Na<sub>2</sub>SO<sub>4</sub> electrolyte show an increased current below ∼ -0.7 V vs. Ag/AgCl and <em>p</em>-type behavior with a conduction band (CB = −1.95 V) cathodically positioned with respect to H<sub>2</sub> level, thus leading to H<sub>2</sub> photo-production. The hetero-system La<sub>2</sub>NiO<sub>4</sub>/KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> shows a much higher activity than KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> where efficient H<sub>2</sub>-photoevolution occurs with concomitant oxidation of S<sub>2</sub>O<sub>3</sub><sup>2−</sup>, as reducing agent. So, the co-junction of La<sub>2</sub>NiO<sub>4</sub> with KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> facilitates the charge transfer and increases the reaction efficiency. At neutral pH, the H<sub>2</sub> evolution rate for the photocatalysts KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> and La<sub>2</sub>NiO<sub>4</sub>/ KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> are 11.15 and 57 µmol g<sup>−1</sup> min<sup>−1</sup>; respectively. Further enhancement is observed with Ag-loaded La<sub>2</sub>NiO<sub>4</sub>/KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub>, reaching a maximum hydrogen production rate of 67 µmol g<sup>−1</sup> min<sup>−1</sup>, attributed to the lower overpotential introduced by Ag. These findings highlight the potential of the ternary system Ag/La<sub>2</sub>NiO /KNb<sub>0.99</sub>Eu<sub>0.01</sub>O<sub>3</sub> as an efficient photocathode for H<sub>2</sub> generation.</div></div>\",\"PeriodicalId\":16782,\"journal\":{\"name\":\"Journal of Photochemistry and Photobiology A-chemistry\",\"volume\":null,\"pages\":null},\"PeriodicalIF\":4.1000,\"publicationDate\":\"2024-10-15\",\"publicationTypes\":\"Journal Article\",\"fieldsOfStudy\":null,\"isOpenAccess\":false,\"openAccessPdf\":\"\",\"citationCount\":\"0\",\"resultStr\":null,\"platform\":\"Semanticscholar\",\"paperid\":null,\"PeriodicalName\":\"Journal of Photochemistry and Photobiology A-chemistry\",\"FirstCategoryId\":\"92\",\"ListUrlMain\":\"https://www.sciencedirect.com/science/article/pii/S1010603024006385\",\"RegionNum\":3,\"RegionCategory\":\"化学\",\"ArticlePicture\":[],\"TitleCN\":null,\"AbstractTextCN\":null,\"PMCID\":null,\"EPubDate\":\"\",\"PubModel\":\"\",\"JCR\":\"Q2\",\"JCRName\":\"CHEMISTRY, PHYSICAL\",\"Score\":null,\"Total\":0}","platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Photochemistry and Photobiology A-chemistry","FirstCategoryId":"92","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S1010603024006385","RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, PHYSICAL","Score":null,"Total":0}
Synthesis, Characterization of KNb0.99Eu0.01O3 and improved Photo-catalytic H2-Production on Ag/La2NiO4/ KNb0.99Eu0.01O3 hetero-junction
The perovskite KNb0.99Eu0.01O3 prepared by nitrate combustion is applied as a hydrogen photocathode in heterojunction with La2NiO4 under visible light. The XRD pattern confirms the formation of KNb0.99Eu0.01O3 structure with orthorhombic single phase. The SEM images present grains between 0.2 and 0.4 µm while the optical band gap (3.14 eV) is calculated from the diffuse reflectance. Under illumination, the cyclic voltammetry (CV) and the capacitance measurements in Na2SO4 electrolyte show an increased current below ∼ -0.7 V vs. Ag/AgCl and p-type behavior with a conduction band (CB = −1.95 V) cathodically positioned with respect to H2 level, thus leading to H2 photo-production. The hetero-system La2NiO4/KNb0.99Eu0.01O3 shows a much higher activity than KNb0.99Eu0.01O3 where efficient H2-photoevolution occurs with concomitant oxidation of S2O32−, as reducing agent. So, the co-junction of La2NiO4 with KNb0.99Eu0.01O3 facilitates the charge transfer and increases the reaction efficiency. At neutral pH, the H2 evolution rate for the photocatalysts KNb0.99Eu0.01O3 and La2NiO4/ KNb0.99Eu0.01O3 are 11.15 and 57 µmol g−1 min−1; respectively. Further enhancement is observed with Ag-loaded La2NiO4/KNb0.99Eu0.01O3, reaching a maximum hydrogen production rate of 67 µmol g−1 min−1, attributed to the lower overpotential introduced by Ag. These findings highlight the potential of the ternary system Ag/La2NiO /KNb0.99Eu0.01O3 as an efficient photocathode for H2 generation.
期刊介绍:
JPPA publishes the results of fundamental studies on all aspects of chemical phenomena induced by interactions between light and molecules/matter of all kinds.
All systems capable of being described at the molecular or integrated multimolecular level are appropriate for the journal. This includes all molecular chemical species as well as biomolecular, supramolecular, polymer and other macromolecular systems, as well as solid state photochemistry. In addition, the journal publishes studies of semiconductor and other photoactive organic and inorganic materials, photocatalysis (organic, inorganic, supramolecular and superconductor).
The scope includes condensed and gas phase photochemistry, as well as synchrotron radiation chemistry. A broad range of processes and techniques in photochemistry are covered such as light induced energy, electron and proton transfer; nonlinear photochemical behavior; mechanistic investigation of photochemical reactions and identification of the products of photochemical reactions; quantum yield determinations and measurements of rate constants for primary and secondary photochemical processes; steady-state and time-resolved emission, ultrafast spectroscopic methods, single molecule spectroscopy, time resolved X-ray diffraction, luminescence microscopy, and scattering spectroscopy applied to photochemistry. Papers in emerging and applied areas such as luminescent sensors, electroluminescence, solar energy conversion, atmospheric photochemistry, environmental remediation, and related photocatalytic chemistry are also welcome.